ALAN L. ENGLANDER
AL SUSTAINABILITY DISCLAIMER: I do NOT profit from, endorse or sell any products or services mentioned in these entries.
ALSUSTAINABILITY.NET
Number 6 Fuel Oil On The Way Out In New York City
Earlier this year, New York City has taken steps towards banning the use of Number 6 Fuel Oil. The Mayor's Office of Long Term Planning and Sustainability has introduced a phase-out on the burning of No. 6 plan in 2008 and later has expanded that to include No. 4 fuel oil as well. The plan is to have these fuels banned entirely by 2020. The plan is to require all new installations burn only No. 2 fuel oil, and that burners that cannot be easily repaired to convert over to No. 2 fuel oil, upon failure, between now and 2030, with a full conversion to No. 2 fuel oil by 2030, regardless of the burner condition. The law is to take effect in October, 2012, and will begin by capping the sulfur content of ANY heating oil in New York City to 1,500 parts per million, while requiring a minimum two percent biodiesel content. Buildings that now burn No. 6 would have to convert to No. 4
The reason for this is that they emit high levels of soot and sulfur and nitrogen dioxides and well as carbon dioxide when compared with No. 2 fuel oil or natural gas. These emissions, referred to as PM 2.5, are of concern as they are comprised of very small particles, which upon inhalation, penetrate deep into the lungs. It is felt strongly that this contributes to higher levels of lung cancer, heart disease and asthma. No. 6 fuel oil emits as much as 15 times more soot material than that of No. 2 oil.
In New York City, one percent of the buildings create 87 percent of the oil- heat related soot. The New York City health Department has said that it has measured considerably higher readings of particulate matter as well as sulfur dioxide in areas with high levels of No. 6 and No. 4 fuel oil use. The use of cheaper No. 6 fuel oil is NOT confined to low income areas; in fact, in Manhattan, many of the buildings that burn No. 6 oil are found the wealthiest districts. It is estimated that there about 10,000 buildings in New York City that burn No. 6 or No. 4 fuel oil.
The ban is not without controversy. The main reason is increased cost in converting over for the properties that burn them. No. 6 oil is often 40 percent cheaper than No. 2. In addition, No. 6 has far higher Btu values per gallon than that of No.2 oil. In addition, to comply with the ban, burners and entire systems would need to changed out, which can, according to a number of articles posted on this topic, can cost a property as much as $300,000. (The range has been stated as between $100,000 and $200,000 in most sources that I have read) At this time, the preferred choice would really be for all buildings to convert to natural gas or at least to the newer reformulated ultra-low sulfur No. 2 oil.
Now, a bit of background on No. 6 fuel oil and the other fuel oils. No. 6 fuel oil, often referred to as Bunker C or Bunker oil, is the heaviest and dirtiest of all the oils. It is is classified as a residual product that results from the refining of gasoline and distilled oils. Distillate products, which include No. 2 and No. 4 oils, result from the heating and condensing of the oils during the refining process. Some articles use the term sludge to describe and classify No. 6 fuel oil, as it is a dark-brown-black very thick tar-like substance at cooler temperatures. In fact, it is so viscous that it must be pre-heated by a water bath-like system in order for it to be pumped into a burner. As mentioned above, aside from its dirty and more difficult handling characteristics, it has appealed to building owners and operators due to its economical nature. No. 6 oil has a Btu of up to 155,000 per gallon. By contrast, No. 2 oil has around 139,000 Btu per gallon. No. 4 oil has about 150,000 Btu. per gallon, and is a blend of No. 6 and No. 2 oil. No. 4 oil is mainly used for industrial or larger buildings, where No. 2 oil -- the most common of all oils in use in the U. S., is mostly used by more modern commercial applications. Ultra-low sulfur No. 2 oil is really the equal of the ultra low diesel fuel now being used in greater frequency each year.
The reason why No. 6 fuel oil is so dirty is directly related to its chemical composition. As stated above, it is the residual product of distillation of oil. It contains a broad array of components, of which include 15% paraffin, 45% naphthalene, 25% aromatic, and 15% non-hydrocarbon compounds. It also contains both cracked and non-cracked distillates, which also contain amounts of polycyclic aromatic hydrocarbons (PAHs) It is these compounds that give off much of the toxic pollution in the emitted exhaust fumes. These compounds are the result of the using of both the cracked and un-cracked residuals in the manufacture of No. 6 oil. In addition, most blending stocks have been noted to include five percent or more of the four to six ringed condensed aromatic hydrocarbons. In addition, there is also the presence of benzene, toluene and ethyl benzene toluene (BTEX) are seen to lesser amounts. These compounds are known to be rather toxic, and have been the subject of intense regulation in the public water supply area since the mid 1980's.
In addition, No. 6 fuel oil also contributes to metal contamination in New York City's air. Nickel levels are said to be as much as nine times the national average. The City Herald in a March, 17, 2011 Internet post, stated this, and went on to state that these nickel levels in the air may lead to heart disease and premature death.
There are other intermediate fuel oils -- No. 3 and No. 5, which are a step between No. 2, 4, and No. 6. These oils are essentially just that -- a step higher in Btu and more polluting than the lower numbered No.2 fuel oil. They are not seen in use as often as No. 2, 4 or No. 6.
By contrast, No. 1 fuel oil is used almost exclusively in residential applications such as single family homes. It has a Btu output of around 135,000 per gallon. Natural gas has a Btu content of just over 100,000 per 100 cubic feet -- the standard measure of the fuel, which is used as the basis of comparison to that of fuel oil for efficiency purposes. In summary, as the numbers go up on the fuel oil classes, so does the Btu output and unfortunately, the emitted pollutants.
Adding to the controversy is the fact that while No. 6 oil and for that matter No. 4 often result in higher operating costs than compared with systems that burn No. 2 oil. This is largely due to the same polluting sulfur and nitrogen dioxides that are all the reason for the proposed ban. These products create very corrosive conditions in the burner as well as the stack flue. In fact, the stack temperature must be maintained at or greater than 225 degrees F. in order to avoid corrosive condensation formation. This factor creates an additional issue -- the reality of the incomplete utilization of the potential Btu content available. One might conclude that by not taking more of the heat out of the exhaust flue gasses, we loss a significant amount of Btu. This waste heat is now easily reclaimed with the common 92 percent-plus efficient natural gas burners that can produce waste flue exhaust gasses at temperatures well below 140 degrees, F., often far less. In fact, PVC plastic pipe is commonly used as the flue pipe material.
With regard to natural gas, fuel oil proponents are quick to point out that natural gas emits large amounts of methane, which is a greenhouse gas. My feeling here, is that we have some measure of control in the matter. First, we can choose to install 92 percent efficient or better natural gas burners that will use less gas, resulting in less emissions. In addition, these systems extract so much heat from the gas, that condensate is produced,which in turn, may reduce the emissions even further, as more of the exhaust is reduced to liquid condensate,which is NOT released into the atmosphere. In exchange, we gain more Btu from the gas, which means more "green" in our pockets for the effort. In short by using burners that are 92 percent or greater, will reduce the amount of greenhouse gasses for two reasons -- less gas will need to burned due to more Btu recovery and less exhaust products are released into the atmosphere.
With No. 6 fuel oil, as I said earlier, we also have the need to pre-heat the oil in order to burn it. This is often associated with mandatory additional professional staff to operate and maintain a No. 6 fuel oil system. In addition, there is also the issue of premature tank failure with the heavier fuel oils. Once again one can argue that over time, the added costs of operation may be able to par-laid into converting to cleaner burning fuel, when these added maintenance costs are done away with.
With all this said, it is time to take stock in the fuels that are used, and look at the overall picture, from both an environmental AND and economical point of view. In many cases it will be clear that when a system is in need of replacement or substantial renovations are planned, there will be significant savings to be had with converting to cleaner burning AND at the same time, MORE EFFICIENT HVAC systems. In my opinion, it makes much sense to look beyond the oil burner itself, and take into account the ENTIRE building system -- envelope, mechanical, plumbing lighting and HVAC and aim to REDUCE overall energy use from the start. This will ultimately reduce pollutants emitted as well as carbon footprint perhaps as much as much as the banning of No. 6 fuel oil . Once again, we have the chance to employ integrated building design and gain from the synergies between efforts to achieve an even more higher performing building that is more environmentally responsible. This building will also be far more cost effective in its operation, with superior return on investment.
I do NOT mean to say that No.6 fuel oil must be not phased out; it must be phased out as planned. It is just too dirty to be allowed to be used in perpetuity.
The reason for this is that they emit high levels of soot and sulfur and nitrogen dioxides and well as carbon dioxide when compared with No. 2 fuel oil or natural gas. These emissions, referred to as PM 2.5, are of concern as they are comprised of very small particles, which upon inhalation, penetrate deep into the lungs. It is felt strongly that this contributes to higher levels of lung cancer, heart disease and asthma. No. 6 fuel oil emits as much as 15 times more soot material than that of No. 2 oil.
In New York City, one percent of the buildings create 87 percent of the oil- heat related soot. The New York City health Department has said that it has measured considerably higher readings of particulate matter as well as sulfur dioxide in areas with high levels of No. 6 and No. 4 fuel oil use. The use of cheaper No. 6 fuel oil is NOT confined to low income areas; in fact, in Manhattan, many of the buildings that burn No. 6 oil are found the wealthiest districts. It is estimated that there about 10,000 buildings in New York City that burn No. 6 or No. 4 fuel oil.
The ban is not without controversy. The main reason is increased cost in converting over for the properties that burn them. No. 6 oil is often 40 percent cheaper than No. 2. In addition, No. 6 has far higher Btu values per gallon than that of No.2 oil. In addition, to comply with the ban, burners and entire systems would need to changed out, which can, according to a number of articles posted on this topic, can cost a property as much as $300,000. (The range has been stated as between $100,000 and $200,000 in most sources that I have read) At this time, the preferred choice would really be for all buildings to convert to natural gas or at least to the newer reformulated ultra-low sulfur No. 2 oil.
Now, a bit of background on No. 6 fuel oil and the other fuel oils. No. 6 fuel oil, often referred to as Bunker C or Bunker oil, is the heaviest and dirtiest of all the oils. It is is classified as a residual product that results from the refining of gasoline and distilled oils. Distillate products, which include No. 2 and No. 4 oils, result from the heating and condensing of the oils during the refining process. Some articles use the term sludge to describe and classify No. 6 fuel oil, as it is a dark-brown-black very thick tar-like substance at cooler temperatures. In fact, it is so viscous that it must be pre-heated by a water bath-like system in order for it to be pumped into a burner. As mentioned above, aside from its dirty and more difficult handling characteristics, it has appealed to building owners and operators due to its economical nature. No. 6 oil has a Btu of up to 155,000 per gallon. By contrast, No. 2 oil has around 139,000 Btu per gallon. No. 4 oil has about 150,000 Btu. per gallon, and is a blend of No. 6 and No. 2 oil. No. 4 oil is mainly used for industrial or larger buildings, where No. 2 oil -- the most common of all oils in use in the U. S., is mostly used by more modern commercial applications. Ultra-low sulfur No. 2 oil is really the equal of the ultra low diesel fuel now being used in greater frequency each year.
The reason why No. 6 fuel oil is so dirty is directly related to its chemical composition. As stated above, it is the residual product of distillation of oil. It contains a broad array of components, of which include 15% paraffin, 45% naphthalene, 25% aromatic, and 15% non-hydrocarbon compounds. It also contains both cracked and non-cracked distillates, which also contain amounts of polycyclic aromatic hydrocarbons (PAHs) It is these compounds that give off much of the toxic pollution in the emitted exhaust fumes. These compounds are the result of the using of both the cracked and un-cracked residuals in the manufacture of No. 6 oil. In addition, most blending stocks have been noted to include five percent or more of the four to six ringed condensed aromatic hydrocarbons. In addition, there is also the presence of benzene, toluene and ethyl benzene toluene (BTEX) are seen to lesser amounts. These compounds are known to be rather toxic, and have been the subject of intense regulation in the public water supply area since the mid 1980's.
In addition, No. 6 fuel oil also contributes to metal contamination in New York City's air. Nickel levels are said to be as much as nine times the national average. The City Herald in a March, 17, 2011 Internet post, stated this, and went on to state that these nickel levels in the air may lead to heart disease and premature death.
There are other intermediate fuel oils -- No. 3 and No. 5, which are a step between No. 2, 4, and No. 6. These oils are essentially just that -- a step higher in Btu and more polluting than the lower numbered No.2 fuel oil. They are not seen in use as often as No. 2, 4 or No. 6.
By contrast, No. 1 fuel oil is used almost exclusively in residential applications such as single family homes. It has a Btu output of around 135,000 per gallon. Natural gas has a Btu content of just over 100,000 per 100 cubic feet -- the standard measure of the fuel, which is used as the basis of comparison to that of fuel oil for efficiency purposes. In summary, as the numbers go up on the fuel oil classes, so does the Btu output and unfortunately, the emitted pollutants.
Adding to the controversy is the fact that while No. 6 oil and for that matter No. 4 often result in higher operating costs than compared with systems that burn No. 2 oil. This is largely due to the same polluting sulfur and nitrogen dioxides that are all the reason for the proposed ban. These products create very corrosive conditions in the burner as well as the stack flue. In fact, the stack temperature must be maintained at or greater than 225 degrees F. in order to avoid corrosive condensation formation. This factor creates an additional issue -- the reality of the incomplete utilization of the potential Btu content available. One might conclude that by not taking more of the heat out of the exhaust flue gasses, we loss a significant amount of Btu. This waste heat is now easily reclaimed with the common 92 percent-plus efficient natural gas burners that can produce waste flue exhaust gasses at temperatures well below 140 degrees, F., often far less. In fact, PVC plastic pipe is commonly used as the flue pipe material.
With regard to natural gas, fuel oil proponents are quick to point out that natural gas emits large amounts of methane, which is a greenhouse gas. My feeling here, is that we have some measure of control in the matter. First, we can choose to install 92 percent efficient or better natural gas burners that will use less gas, resulting in less emissions. In addition, these systems extract so much heat from the gas, that condensate is produced,which in turn, may reduce the emissions even further, as more of the exhaust is reduced to liquid condensate,which is NOT released into the atmosphere. In exchange, we gain more Btu from the gas, which means more "green" in our pockets for the effort. In short by using burners that are 92 percent or greater, will reduce the amount of greenhouse gasses for two reasons -- less gas will need to burned due to more Btu recovery and less exhaust products are released into the atmosphere.
With No. 6 fuel oil, as I said earlier, we also have the need to pre-heat the oil in order to burn it. This is often associated with mandatory additional professional staff to operate and maintain a No. 6 fuel oil system. In addition, there is also the issue of premature tank failure with the heavier fuel oils. Once again one can argue that over time, the added costs of operation may be able to par-laid into converting to cleaner burning fuel, when these added maintenance costs are done away with.
With all this said, it is time to take stock in the fuels that are used, and look at the overall picture, from both an environmental AND and economical point of view. In many cases it will be clear that when a system is in need of replacement or substantial renovations are planned, there will be significant savings to be had with converting to cleaner burning AND at the same time, MORE EFFICIENT HVAC systems. In my opinion, it makes much sense to look beyond the oil burner itself, and take into account the ENTIRE building system -- envelope, mechanical, plumbing lighting and HVAC and aim to REDUCE overall energy use from the start. This will ultimately reduce pollutants emitted as well as carbon footprint perhaps as much as much as the banning of No. 6 fuel oil . Once again, we have the chance to employ integrated building design and gain from the synergies between efforts to achieve an even more higher performing building that is more environmentally responsible. This building will also be far more cost effective in its operation, with superior return on investment.
I do NOT mean to say that No.6 fuel oil must be not phased out; it must be phased out as planned. It is just too dirty to be allowed to be used in perpetuity.
New Advances In Glazing Materials -- Phase-Changing Heat-Storing Thermal Mass Capability Is Now Reality
Environmental Building News reported on a revolutionary development in glazing materials in its August 2010 edition. The product, GlassX , is a quadruple (or at least double) glazed system developed in Europe that incorporates a phase-changing material that is capable of storing heat. (NOTE: When accessing the GlassX website, it will NOT initially be in English; click on EN at the top of the page.) In North America, GlassX is distributed through Greenlight Glass Systems in Vancouver.
In its full version, the GlassX system is quadruple glazing unit that has three separate insulating glazing units to create an assembly about three inches thick, with a weight of almost 20 pounds (95 KG/square meter)
The outermost section of the system is filled with a low conductive gas such as Krypton that has a prismatic filter suspended into it. This prismatic filter is designed to reject the higher angle light (greater than 40 degrees -- Summer sunlight) but allow lower angle winter sunlight (less than 35 degrees) to pass through. Thus, we now have passive solar heating with an automatic summer control that serves the duty of a window equipped with automated shades or louvers incorporated into a single glazing unit.
Obviously, this form of the system is best suited for south-facing sections of the building, as we can now maximize the winter solar gain, while sharply curtailing the unwanted summer heat gain. This is aided by an inner facing layer of low-emissivity (low-e) coated cavity to retard heat transfer in a similar manner to that of standard double glazed systems.
The real crowning glory in this system is the innermost layer that faces the interior of the building space. This is an additional cavity filled with polycarbonate channels that contain a salt hydrate phase changing material (PCM). This material will change from a solid to liquid over a short range of temperature. This is known as Phase Change. In this application, GlassX will change from solid (crystal) to liquid from 79 degrees F. to 86 degrees. This property allows for the heat storage and release to take place at the room-temperature range. It is the phase change that allows for the storage and release of heat. The ice to water or water to steam is the best example of this. In order to get the phase change, a considerable amount of energy far and beyond that normally needed is required to get the temperature to raise (or lower) that one degree to the phase change. Once this energy has been applied, the phase will change, and with it, substantial energy storage or release is seen. For example, water can continue to absorb a lot energy while at the boiling point (liquid to steam / gas phase) as well as at the freezing point (ice -- solid phase)
The salt-hydrate phase-change material (PCM) according to the article is capable of storing as much heat as nine inches (240 mm) of concrete when an 18 degree F (10 degree C) difference is applied) What really makes this PCM product useful in sustainable building design is the ability of it to release this stored heat gradually over a 20 hour period at a rate of between 16 and 32 BTU per square foot (50-100 Wh / M).
The thermal insulation performance is also impressive, as when krypton gas is used in the outer facing section, the U-value is as low as 0.07. In addition, as long as sunlight is not blocked by the prismatic layer, the light transmission is a high as 45 percent during the liquid phase of the PCM. When the PCM is crystallized, the light transmission will drop to 28 percent.
Perhaps one of the first questions asked would be how can we tolerate only 28 percent light transmission? The answer can be VERY simple: If the budget allows (more on this later) the designer or architect can design the GlassZ system to be a good part of the exterior wall (envelope) of the building. In doing this, the interior wall can either be light transmitting if desired, or light blocking, covered with heat-transmitting material. Regular clear-glazed low-e krypton (or argon) filled windows (often venting) are then placed at appropriate locations for daylight / view / ventilation. The main idea here is to allow GlassX to form the building envelope and at the same time serve as a thermal mass unit.
Durability is the primary concern in any new technology, and with GlassX, this has been addressed by the inventor, Dietrch Schwartz. Dietrch Schwartz guarantees the PCM to last 100 years based on 50 to 100 phase change cycles per year. In addition, there are no moving parts to wear out.
As mentioned at the outset, the full featured GlassX system is best used on a south (or perhaps west) exposure, several other versions (also at lower cost) are available. These include a quadruple system with PCM but no prismatic filter for non-southern exposures, a triple glazed system with prismatic filter and gas filled insulating glass unit IGU and PCM IGU, as well as a dual-glazed unit containg only the PCM.
At the present, the GlassX unit is available in heights up to 110 inches (280 cm) and a maximum width of 59 inches (150 inches) As of last summer, GlassX was only manufactured at two locations -- one in Austria, and the second in Germany. As of mid-2010 there were no installations in North America, but several were in the works.
PCM technology is NOT for every building. It is VERY important to study the ENTIRE building system. Factors to consider are location, orientation and perhaps most importantly COST. GlassX IS RATHER EXPENSIVE at $60 to $90 per square foot ($560 - $970 per square meter) This said, if the the analysis and first cost budget allows, the superior performance may very well justify its use, as it could translate into a rapid payback on investment.
In short, GlassX is an innovation well worthy of consideration by all design teams desiring to produce a sustainable environmentally friendly cost effective building.
In its full version, the GlassX system is quadruple glazing unit that has three separate insulating glazing units to create an assembly about three inches thick, with a weight of almost 20 pounds (95 KG/square meter)
The outermost section of the system is filled with a low conductive gas such as Krypton that has a prismatic filter suspended into it. This prismatic filter is designed to reject the higher angle light (greater than 40 degrees -- Summer sunlight) but allow lower angle winter sunlight (less than 35 degrees) to pass through. Thus, we now have passive solar heating with an automatic summer control that serves the duty of a window equipped with automated shades or louvers incorporated into a single glazing unit.
Obviously, this form of the system is best suited for south-facing sections of the building, as we can now maximize the winter solar gain, while sharply curtailing the unwanted summer heat gain. This is aided by an inner facing layer of low-emissivity (low-e) coated cavity to retard heat transfer in a similar manner to that of standard double glazed systems.
The real crowning glory in this system is the innermost layer that faces the interior of the building space. This is an additional cavity filled with polycarbonate channels that contain a salt hydrate phase changing material (PCM). This material will change from a solid to liquid over a short range of temperature. This is known as Phase Change. In this application, GlassX will change from solid (crystal) to liquid from 79 degrees F. to 86 degrees. This property allows for the heat storage and release to take place at the room-temperature range. It is the phase change that allows for the storage and release of heat. The ice to water or water to steam is the best example of this. In order to get the phase change, a considerable amount of energy far and beyond that normally needed is required to get the temperature to raise (or lower) that one degree to the phase change. Once this energy has been applied, the phase will change, and with it, substantial energy storage or release is seen. For example, water can continue to absorb a lot energy while at the boiling point (liquid to steam / gas phase) as well as at the freezing point (ice -- solid phase)
The salt-hydrate phase-change material (PCM) according to the article is capable of storing as much heat as nine inches (240 mm) of concrete when an 18 degree F (10 degree C) difference is applied) What really makes this PCM product useful in sustainable building design is the ability of it to release this stored heat gradually over a 20 hour period at a rate of between 16 and 32 BTU per square foot (50-100 Wh / M).
The thermal insulation performance is also impressive, as when krypton gas is used in the outer facing section, the U-value is as low as 0.07. In addition, as long as sunlight is not blocked by the prismatic layer, the light transmission is a high as 45 percent during the liquid phase of the PCM. When the PCM is crystallized, the light transmission will drop to 28 percent.
Perhaps one of the first questions asked would be how can we tolerate only 28 percent light transmission? The answer can be VERY simple: If the budget allows (more on this later) the designer or architect can design the GlassZ system to be a good part of the exterior wall (envelope) of the building. In doing this, the interior wall can either be light transmitting if desired, or light blocking, covered with heat-transmitting material. Regular clear-glazed low-e krypton (or argon) filled windows (often venting) are then placed at appropriate locations for daylight / view / ventilation. The main idea here is to allow GlassX to form the building envelope and at the same time serve as a thermal mass unit.
Durability is the primary concern in any new technology, and with GlassX, this has been addressed by the inventor, Dietrch Schwartz. Dietrch Schwartz guarantees the PCM to last 100 years based on 50 to 100 phase change cycles per year. In addition, there are no moving parts to wear out.
As mentioned at the outset, the full featured GlassX system is best used on a south (or perhaps west) exposure, several other versions (also at lower cost) are available. These include a quadruple system with PCM but no prismatic filter for non-southern exposures, a triple glazed system with prismatic filter and gas filled insulating glass unit IGU and PCM IGU, as well as a dual-glazed unit containg only the PCM.
At the present, the GlassX unit is available in heights up to 110 inches (280 cm) and a maximum width of 59 inches (150 inches) As of last summer, GlassX was only manufactured at two locations -- one in Austria, and the second in Germany. As of mid-2010 there were no installations in North America, but several were in the works.
PCM technology is NOT for every building. It is VERY important to study the ENTIRE building system. Factors to consider are location, orientation and perhaps most importantly COST. GlassX IS RATHER EXPENSIVE at $60 to $90 per square foot ($560 - $970 per square meter) This said, if the the analysis and first cost budget allows, the superior performance may very well justify its use, as it could translate into a rapid payback on investment.
In short, GlassX is an innovation well worthy of consideration by all design teams desiring to produce a sustainable environmentally friendly cost effective building.
More on Net-Zero Buildings
Earlier in 2009, I wrote on the topic of Net-Zero Energy buildings. During this pas year, there has been much discussion at both the print and online media as well as personal encounters at meetings and seminars regarding this effort. As I discussed last year, the term net zero is used to describe a building in terms of being able to, either through the use of Renewable Energy, or a combination of renewable energy and conservation efforts, use no more energy from the electric grid or any other energy source than it is able to generate on-site. As such, a net energy building WILL almost always purchase energy from outside sources, use it during certain time frames and then regenerate new energy on site to "pay back" what it has purchased.
In most cases, if net-zero energy is achieved, it will almost always be done in the context of a single story building with plenty of roof exposure to the sun. Solar Voltaic Panels are the most common renewable energy source used in this effort, as they are the easiest to incorporate into a building and site plan design. Wind Energy is also possible, but the need for large open spaces as well as land-use and zoning prohibitions and the proximity to other neighboring sites has been a limiting factor in the use of this excellent energy source in many cases. HOWEVER, a U. S. DOE - Pacific Northwest National Lab study in last year, quoted in the August, 2010 issue of Environmental Building News (page11) shows that in five different scenarios when Chicago (a high wind area) and Phoenix ( a high sun area) wind energy actually did better in Phoenix. In addition, achieving net-zero can be VERY costly and is NOT always possible in many buildings due to energy needs per square foot far exceeding the renewable energy generation capability in the space available.
The paragraph above states the major issues working against the goal of net-zero energy buildings in so many cases. The fact that we need such a large roof area to total interior building area makes achieving this goal more and more difficult as the number of stories of the building increase. In fact, an article written in the August, 2010 issue of Environmental Building News quotes a National Renewable Energy Lab (NREL) study done as early as 2007. At that time, it was found that with a one-story building could reasonable achieve net-zero 88% of the time, while at two floors, it dropped to 48%. By the time we get to four floors, it was found that only three percent of the buildings were capable of achieving net zero.
In addition, site issues can also preclude the use of solar energy in areas where the building is shaded by significant trees, or cannot be oriented to face the best exposure to the sun on the given lot dimensions. In the case of trees, it is often far better from an environmental point of view NOT to clear the trees, as to do so, creates the unwanted effects of increased storm water and heat island effect.
This gives reason to suspect that a net zero building can have unwanted environmental side effects, the worst being the contribution of Urban Sprawl. Urban sprawl results when large amounts of land are cleared and built up with buildings often containing just a one or perhaps two stories. In this case, unlike major cities such as New York, the utilization density per square foot of space becomes so small, that the amount of energy saved by the net zero building could be offset by the negative impacts on the loss of open space and the attendant issues of storm water management and traffic. Speaking of traffic, and the need to build more roads and parking facilities, we have another issue -- that of additional energy consumption on the part of single occupancy vehicles needing to commute to a remote site where public transportation is not readily available. While we all realize that it is NOT possible or even advisable to ban all single occupancy vehicle use, its effect on a net zero energy building could offset the energy savings, as well as generate more environmental issues. Version 2 of the Living Building Challenge takes on this issue, by advocating attempting to design to the creation of car-free living. The Living Building Challenge is yet another sustainable building and design rating system, and is more stringent than that of LEED.
Given these concerns, a growing school of thought now encourages designers to take these potential negative side effects into account. One alternative is to take net zero to a broader, and larger level -- Net-Zero Neighborhoods or Communities. In this effort, rather than trying to beat ourselves to death in making each and every building totally net-zero, we will take the entire surrounding area, or neighborhood into account and aim for net-zero energy on an overall basis. This effort has many advantage, but also disadvantages. One of the main advantages is cost savings per building, as each building can pursue the most cost-efficient project in its design as space and orientation permits. The second advantage deals with the ability of being able to pool efforts by having buildings that are more able in terms of orientation to the sun (or perhaps amenable to wind power) build these efforts into the total plan, while other buildings in the community that are not able to do so, would contribute other environmentally sustaining efforts such as storm water as well as waste-water management, and pocket parks.
Another possible energy efficient design tool made available by community based efforts is the use of District Energy Systems. The idea of district energy systems is not new; many colleges, universities and multiple building campuses have employed this design for decades. In this application, a centralized heating and/or cooling plant is used. This plant is then designed to operate in stages as the need of the total campus dictates. In such a manner, during mild periods, only perhaps 30% of the total equipment will be used, allowing the remainder to be taken off-line. This 30% is now operating at peak efficiency, with automatic savings being seen. Short-cycling of compressors is minimized or eliminated, and full AFUE is seen in combustible heating equipment. Another clear advantage can be less initial building costs, as less total capacity is needed, as each building has access to the total capacity of the central plant, eliminating the need for each and every building to design for unusually large and rarely seen load capacity. This means smaller total equipment size for the overall plant. Cornell University in Ithica, New York did this with their cooling plant. I wrote on this in an entry last year.
One main disadvantage of the community or neighborhood based attempt at net-zero is financing. A second issue is that of ownership of the entire set of systems involved. Who will actually pay for the full build-out of the system? Each stake-holder is now sharing a central plant that they do not have true and full ownership of. Also, we see problems when just one building of perhaps several dozen is completed, and ready for occupancy well before the central plant can be brought on line. In this case, a temporary plant may need to be built during this time, creating the effect of consuming more raw materials and thus, not being as green or carbon-footprint friendly as intended.
I do NOT mean to say that we should abandon our quest for net-zero. Rather, we need to focus our design energies into determining what is REALLY best for the individual project that we are involved in. As net-zero can be VERY difficult and often cost-prohibitive to achieve, it may be best to concentrate our efforts in these case on doing more with an inclusive overall design that includes building massing, envelope, lighting, HVAC systems, water efficiency, open space, and storm-water management where applicable for the individual site. In other words, we would be best to do what we can do best for each site, and NOT try to conquer the impossible. It is far better to do something that results in substantial overall savings in one or more areas than not achieve a satisfactory level in the total combined project. That said, net-zero should and must be the initial design goal; this serves to challenge the design team to "put their thinking caps on" and not leave any opportunities available unused.
In most cases, if net-zero energy is achieved, it will almost always be done in the context of a single story building with plenty of roof exposure to the sun. Solar Voltaic Panels are the most common renewable energy source used in this effort, as they are the easiest to incorporate into a building and site plan design. Wind Energy is also possible, but the need for large open spaces as well as land-use and zoning prohibitions and the proximity to other neighboring sites has been a limiting factor in the use of this excellent energy source in many cases. HOWEVER, a U. S. DOE - Pacific Northwest National Lab study in last year, quoted in the August, 2010 issue of Environmental Building News (page11) shows that in five different scenarios when Chicago (a high wind area) and Phoenix ( a high sun area) wind energy actually did better in Phoenix. In addition, achieving net-zero can be VERY costly and is NOT always possible in many buildings due to energy needs per square foot far exceeding the renewable energy generation capability in the space available.
The paragraph above states the major issues working against the goal of net-zero energy buildings in so many cases. The fact that we need such a large roof area to total interior building area makes achieving this goal more and more difficult as the number of stories of the building increase. In fact, an article written in the August, 2010 issue of Environmental Building News quotes a National Renewable Energy Lab (NREL) study done as early as 2007. At that time, it was found that with a one-story building could reasonable achieve net-zero 88% of the time, while at two floors, it dropped to 48%. By the time we get to four floors, it was found that only three percent of the buildings were capable of achieving net zero.
In addition, site issues can also preclude the use of solar energy in areas where the building is shaded by significant trees, or cannot be oriented to face the best exposure to the sun on the given lot dimensions. In the case of trees, it is often far better from an environmental point of view NOT to clear the trees, as to do so, creates the unwanted effects of increased storm water and heat island effect.
This gives reason to suspect that a net zero building can have unwanted environmental side effects, the worst being the contribution of Urban Sprawl. Urban sprawl results when large amounts of land are cleared and built up with buildings often containing just a one or perhaps two stories. In this case, unlike major cities such as New York, the utilization density per square foot of space becomes so small, that the amount of energy saved by the net zero building could be offset by the negative impacts on the loss of open space and the attendant issues of storm water management and traffic. Speaking of traffic, and the need to build more roads and parking facilities, we have another issue -- that of additional energy consumption on the part of single occupancy vehicles needing to commute to a remote site where public transportation is not readily available. While we all realize that it is NOT possible or even advisable to ban all single occupancy vehicle use, its effect on a net zero energy building could offset the energy savings, as well as generate more environmental issues. Version 2 of the Living Building Challenge takes on this issue, by advocating attempting to design to the creation of car-free living. The Living Building Challenge is yet another sustainable building and design rating system, and is more stringent than that of LEED.
Given these concerns, a growing school of thought now encourages designers to take these potential negative side effects into account. One alternative is to take net zero to a broader, and larger level -- Net-Zero Neighborhoods or Communities. In this effort, rather than trying to beat ourselves to death in making each and every building totally net-zero, we will take the entire surrounding area, or neighborhood into account and aim for net-zero energy on an overall basis. This effort has many advantage, but also disadvantages. One of the main advantages is cost savings per building, as each building can pursue the most cost-efficient project in its design as space and orientation permits. The second advantage deals with the ability of being able to pool efforts by having buildings that are more able in terms of orientation to the sun (or perhaps amenable to wind power) build these efforts into the total plan, while other buildings in the community that are not able to do so, would contribute other environmentally sustaining efforts such as storm water as well as waste-water management, and pocket parks.
Another possible energy efficient design tool made available by community based efforts is the use of District Energy Systems. The idea of district energy systems is not new; many colleges, universities and multiple building campuses have employed this design for decades. In this application, a centralized heating and/or cooling plant is used. This plant is then designed to operate in stages as the need of the total campus dictates. In such a manner, during mild periods, only perhaps 30% of the total equipment will be used, allowing the remainder to be taken off-line. This 30% is now operating at peak efficiency, with automatic savings being seen. Short-cycling of compressors is minimized or eliminated, and full AFUE is seen in combustible heating equipment. Another clear advantage can be less initial building costs, as less total capacity is needed, as each building has access to the total capacity of the central plant, eliminating the need for each and every building to design for unusually large and rarely seen load capacity. This means smaller total equipment size for the overall plant. Cornell University in Ithica, New York did this with their cooling plant. I wrote on this in an entry last year.
One main disadvantage of the community or neighborhood based attempt at net-zero is financing. A second issue is that of ownership of the entire set of systems involved. Who will actually pay for the full build-out of the system? Each stake-holder is now sharing a central plant that they do not have true and full ownership of. Also, we see problems when just one building of perhaps several dozen is completed, and ready for occupancy well before the central plant can be brought on line. In this case, a temporary plant may need to be built during this time, creating the effect of consuming more raw materials and thus, not being as green or carbon-footprint friendly as intended.
I do NOT mean to say that we should abandon our quest for net-zero. Rather, we need to focus our design energies into determining what is REALLY best for the individual project that we are involved in. As net-zero can be VERY difficult and often cost-prohibitive to achieve, it may be best to concentrate our efforts in these case on doing more with an inclusive overall design that includes building massing, envelope, lighting, HVAC systems, water efficiency, open space, and storm-water management where applicable for the individual site. In other words, we would be best to do what we can do best for each site, and NOT try to conquer the impossible. It is far better to do something that results in substantial overall savings in one or more areas than not achieve a satisfactory level in the total combined project. That said, net-zero should and must be the initial design goal; this serves to challenge the design team to "put their thinking caps on" and not leave any opportunities available unused.
Light Imprints -- Integrating Sustainability and Community Design
This entry will detail the second of the two webinars that I participated in during mid July. In this webinar, we dealt with the topics raised in Thomas E. Low's new book entitled: "Light Imprint Handbook -- Integrating Sustainability and Community Design". This does NOT mean that we dealt with street or exterior lighting issues, but rather the broad area of community planning to create a more sustainable community via the wise use of planning from the aspects of storm water management, street and park placement, proper use of open space and its preservation, along with other items.
To accomplish these goals we need to change our mindsets about how we go about community planning. For example, we MUST attempt to create a gradual and continual transition from rural to city environment via the use of green ways that weave this together in a coordinated fashion. This avoid the sharp contrast between rural open space and dense urban settings.
One of the first tools used is to deal with storm water management in a more natural and aesthetic manner by NOT using Pipe and Pit methods in which a series of drainage pipes leads to a retention pond or other storage system. Rather we will use a series of vegetative swails or a series of rain gardens to keep the storm water on the original property and have it recharge the aquifer right there. In doing this, we create a natural setting that emulates nature, rather than place a large artificial open retention pond. This is known as Low Impact Best Management Practice.
Open space is further preserved by not cutting down and replacing all the vegetation. Rather, we will aim to keep as much of the tree and plant life on the site and work around them when designing a site or subdivision plan.
The term Smart Code enters into the picture, as we need to further coordinate this effort via the updating of planning and land-use codes to move this effort along. Environmental corporate responsibility is needed as well; all too often, office parks have in the past clear-cut land and over-paved the original open space.
The need to create a walkable and linked community is a MAJOR priority here. We aim to NEVER cut a community into two or more separate unconnected sections by placing a drainage channel or other non-walkable structure between them. Corner cafes and urban interior block parking lots are also used.
The City of Habersham, South Carolina was profiled in their highly successful efforts here. It was shown how low impact parking lots for the management of storm water runoff was used. In this effort, as described above, they used existing trees and landscape elements in the drainage efforts rather than replace them.
Green sprawl v.s Urban Green deals with concept of creating low impact rain gardens for drainage, and weaving in open space with developed space. This contrasts with the traditional approach in which large "McMansion" style homes are built on small lots with very shallow setbacks.
Green ways that function as both parks and transportation are also a valuable tool. Charlotte, North Carolina has used them with great success in their street car system. Intra-modal transportation also plays a role here in that several modes of transportation -- pedestrian, bicycle, rail, bus and car can be accessed in a seamless fashion from a low-impact center.
As said earlier, the need to incorporate nature into the community is paramount. This is best done by gradually transitioning from a dense wooded or open rural landscape into an urban community. This also has the benefit of creating a better sense of community life and well-being.
Cost is a big issue here; in light of the current economic situation facing most municipalities, we need to be aware of this, and be ready to use alternative sustainable designs that are less costly.
A concept known as Light Impact Overlay is used to plan for really sustainable coordinated communities. Here, we will see extensive use of pocket parks and less "pipe to to pit" drainage systems. When properly done, this can actually save 30% per lot in development costs.
In summary, if a well planned transition from rural to urban development is undertaken, we will have a seamless, fully interconnected and highly functional community in which its residents can reside in, work and play with very minimal impact on the environment.
To accomplish these goals we need to change our mindsets about how we go about community planning. For example, we MUST attempt to create a gradual and continual transition from rural to city environment via the use of green ways that weave this together in a coordinated fashion. This avoid the sharp contrast between rural open space and dense urban settings.
One of the first tools used is to deal with storm water management in a more natural and aesthetic manner by NOT using Pipe and Pit methods in which a series of drainage pipes leads to a retention pond or other storage system. Rather we will use a series of vegetative swails or a series of rain gardens to keep the storm water on the original property and have it recharge the aquifer right there. In doing this, we create a natural setting that emulates nature, rather than place a large artificial open retention pond. This is known as Low Impact Best Management Practice.
Open space is further preserved by not cutting down and replacing all the vegetation. Rather, we will aim to keep as much of the tree and plant life on the site and work around them when designing a site or subdivision plan.
The term Smart Code enters into the picture, as we need to further coordinate this effort via the updating of planning and land-use codes to move this effort along. Environmental corporate responsibility is needed as well; all too often, office parks have in the past clear-cut land and over-paved the original open space.
The need to create a walkable and linked community is a MAJOR priority here. We aim to NEVER cut a community into two or more separate unconnected sections by placing a drainage channel or other non-walkable structure between them. Corner cafes and urban interior block parking lots are also used.
The City of Habersham, South Carolina was profiled in their highly successful efforts here. It was shown how low impact parking lots for the management of storm water runoff was used. In this effort, as described above, they used existing trees and landscape elements in the drainage efforts rather than replace them.
Green sprawl v.s Urban Green deals with concept of creating low impact rain gardens for drainage, and weaving in open space with developed space. This contrasts with the traditional approach in which large "McMansion" style homes are built on small lots with very shallow setbacks.
Green ways that function as both parks and transportation are also a valuable tool. Charlotte, North Carolina has used them with great success in their street car system. Intra-modal transportation also plays a role here in that several modes of transportation -- pedestrian, bicycle, rail, bus and car can be accessed in a seamless fashion from a low-impact center.
As said earlier, the need to incorporate nature into the community is paramount. This is best done by gradually transitioning from a dense wooded or open rural landscape into an urban community. This also has the benefit of creating a better sense of community life and well-being.
Cost is a big issue here; in light of the current economic situation facing most municipalities, we need to be aware of this, and be ready to use alternative sustainable designs that are less costly.
A concept known as Light Impact Overlay is used to plan for really sustainable coordinated communities. Here, we will see extensive use of pocket parks and less "pipe to to pit" drainage systems. When properly done, this can actually save 30% per lot in development costs.
In summary, if a well planned transition from rural to urban development is undertaken, we will have a seamless, fully interconnected and highly functional community in which its residents can reside in, work and play with very minimal impact on the environment.
Sustainable Streets
In mid July, I participated in two webinars that dealt with the sustainable design aspects of neighborhoods. Here, I will report on the first of them -- Technologies for Sustainable Streets. This was hosted by Ron Blank and Associates, and featured Landon Boone and Phil Sheldon.
Five areas make up the areas needed to be addressed when one designs for sustainable streets:
When choosing a paving material we need to consider how well the paving product can be recycled when it reaches the end of its useful life. Roads and side walks do NOT last forever. It may appear as a surprise that despite its apparent durability and dense nature, concrete is NOT a good candidate for recycling. Asphalt, on the other hand, is very easily recycled by simply milling it off the road surface and mixing it with new asphalt and bituminous material. In addition, concrete has a far higher carbon foot print than that of asphalt. In fact, asphalt has less than 60% of the carbon footprint of concrete, and is thus considered to be the greener of the two pavement choices.
Heat Island Effect is dramatically evident with pavement surfaces. In Vancouver, a study showed that the temperature of a developed paved area was 5 to 8 degrees hotter than an unpaved area nearby. This is where the concept of Solar Reflective Index (SRI) come in to play. A white surface has a SRI of 100, which means that it reflects 100 percent of the heat energy and absorbs none, while a total black surface is just the opposite. LEED requires that the SRI for paved surfaces be 29 or greater.
Just because dark surfaces are often preferred and even required in the design does not mean that we cannot get an SRI value greater than 29. While fresh asphalt has an SRI of only 5, and will have an average temperature of 123 degrees, and aged asphalt has an SRI of 10 with a temperature of 115 degrees, we can use proteolytic asphalt or coatings to get the SRI value up to 80 with an average temperature of less than 90. This really brings down the Heat Island Effect FAST. Even some of the dark colored asphalts have SRI values of over 30 when made with the proteolytic method. Dark surfaces are easier on the eyes, as they produce less glare. Thus, we can still use dark colors for pavement and see a temperature reduction of 15 degrees.
Volatile Organic Carbon (VOC) emissions also must be considered when specifying the paving material. California, a leader in environmental design, requires this value to be 100 or less. By using Advanced Acrylic coatings, we can get a VOC value of 21.
LEED for Neighborhood Development emphasizes three design areas: Smart location and linkage, Neighborhood Pattern and Design, and Green Construction and Design.
In the area of Smart Location, we take into account just how the location can utilize bicycle storage and network, as well as pedestrian access to all areas. These two items help to significantly reduce Vehicular Miles Traveled. There is also a Green Rating System for Roads that is similar to LEED in concept. Community outreach, tree-lined streets and Regional Priorities are emphasized in this system.
Life and Safety as well as Pedestrian Oriented Streets are a major goal in this effort. It is of interest that speed bumps do NOT work well to reduce traffic speed; people often just speed up after each bump. it has been found that reducing lane width has a far better effect. Also of value are traffic circles.
New York City, another leader in sustainable design and building codes, has done much in this area. They have reclaimed much space from vehicular traffic and provided it for pedestrian use on several of their main thoroughfares. These include Times Square, 57 and 34 Streets, as well as Broadway. In these reclaimed areas, one can now see a mall-like effect, with pedestrian walks as well as seating, which creates a park-like effect, while at the same time improves community linkage and pedestrian safety. In the paved areas, only low VOC pavement was used, and different colors for coatings were employed to make for easy and fast identification of these specific use locations. So far, the efforts have paid off with a 50% reduction in traffic accidents.
In the area of Neighborhood Identity, one can use Inlaid Durable Design Materials to create a means of identity and at the same time, unify a neighborhood. Cross walks can bear a logo or other means of specific community appeal.
Regarding the coatings that I mentioned above, they can last for two to 10 years, depending on traffic load, and road salt does NOT degrade them. (Snow plowing can ruin them, however.) Thus, one needs to take into account the traffic load VERY CAREFULLY when considering this type of pavement specification.
Five areas make up the areas needed to be addressed when one designs for sustainable streets:
- Environmentally Responsible Design
- Visually appealing and sense of community
- Durable and practical over life cycle of the pavement
- Safety
- Provide for Multiple Transport Modes
When choosing a paving material we need to consider how well the paving product can be recycled when it reaches the end of its useful life. Roads and side walks do NOT last forever. It may appear as a surprise that despite its apparent durability and dense nature, concrete is NOT a good candidate for recycling. Asphalt, on the other hand, is very easily recycled by simply milling it off the road surface and mixing it with new asphalt and bituminous material. In addition, concrete has a far higher carbon foot print than that of asphalt. In fact, asphalt has less than 60% of the carbon footprint of concrete, and is thus considered to be the greener of the two pavement choices.
Heat Island Effect is dramatically evident with pavement surfaces. In Vancouver, a study showed that the temperature of a developed paved area was 5 to 8 degrees hotter than an unpaved area nearby. This is where the concept of Solar Reflective Index (SRI) come in to play. A white surface has a SRI of 100, which means that it reflects 100 percent of the heat energy and absorbs none, while a total black surface is just the opposite. LEED requires that the SRI for paved surfaces be 29 or greater.
Just because dark surfaces are often preferred and even required in the design does not mean that we cannot get an SRI value greater than 29. While fresh asphalt has an SRI of only 5, and will have an average temperature of 123 degrees, and aged asphalt has an SRI of 10 with a temperature of 115 degrees, we can use proteolytic asphalt or coatings to get the SRI value up to 80 with an average temperature of less than 90. This really brings down the Heat Island Effect FAST. Even some of the dark colored asphalts have SRI values of over 30 when made with the proteolytic method. Dark surfaces are easier on the eyes, as they produce less glare. Thus, we can still use dark colors for pavement and see a temperature reduction of 15 degrees.
Volatile Organic Carbon (VOC) emissions also must be considered when specifying the paving material. California, a leader in environmental design, requires this value to be 100 or less. By using Advanced Acrylic coatings, we can get a VOC value of 21.
LEED for Neighborhood Development emphasizes three design areas: Smart location and linkage, Neighborhood Pattern and Design, and Green Construction and Design.
In the area of Smart Location, we take into account just how the location can utilize bicycle storage and network, as well as pedestrian access to all areas. These two items help to significantly reduce Vehicular Miles Traveled. There is also a Green Rating System for Roads that is similar to LEED in concept. Community outreach, tree-lined streets and Regional Priorities are emphasized in this system.
Life and Safety as well as Pedestrian Oriented Streets are a major goal in this effort. It is of interest that speed bumps do NOT work well to reduce traffic speed; people often just speed up after each bump. it has been found that reducing lane width has a far better effect. Also of value are traffic circles.
New York City, another leader in sustainable design and building codes, has done much in this area. They have reclaimed much space from vehicular traffic and provided it for pedestrian use on several of their main thoroughfares. These include Times Square, 57 and 34 Streets, as well as Broadway. In these reclaimed areas, one can now see a mall-like effect, with pedestrian walks as well as seating, which creates a park-like effect, while at the same time improves community linkage and pedestrian safety. In the paved areas, only low VOC pavement was used, and different colors for coatings were employed to make for easy and fast identification of these specific use locations. So far, the efforts have paid off with a 50% reduction in traffic accidents.
In the area of Neighborhood Identity, one can use Inlaid Durable Design Materials to create a means of identity and at the same time, unify a neighborhood. Cross walks can bear a logo or other means of specific community appeal.
Regarding the coatings that I mentioned above, they can last for two to 10 years, depending on traffic load, and road salt does NOT degrade them. (Snow plowing can ruin them, however.) Thus, one needs to take into account the traffic load VERY CAREFULLY when considering this type of pavement specification.
New York City Green Codes Session I
On Tuesday, June 28, the Urban Green Council presented its first in a series of five sessions on the status and progress of New York City's effort to create a full Green Building Code. This series is devoted to passing on information gathered by the New York City Green Codes Task Force.
In this first session, it was planned to have City Council Speaker Christine Quinn give a keynote address summarizing the Task Force progress to date. Then, City Council Member Eric Martin Dilan, as well as Dan Nall from WSP Flack + Kurtz join with Urban Green Council Executive Director Russell Unger and Charlotte Matthews of Related Companies were to present a further panel discussion. Unfortunately, due to the ongoing budget crisis, only Russell Unger and Charlotte Matthews were present. However, they were rather successful in bringing us up to date on the Task Force history and its progress to date.
Readers of my blog will remember in January of this year, NYC passed the most sweeping energy code to date in the nation. I attended five separate meetings on this topic, and have blog entries on each. As of July 1, this has become law.
The Green Codes Task force takes this effort much further, in that it will include a re-writing of the entire set of building codes that NYC will ultimately follow. All areas will be included; not just energy. We will see plumbing, water efficiency, materials and resources, ventilation -- indoor environmental quality, as well as other green and sustainable issues being incorporated. This will evolve into what I believe will be the most comprehensive and strict green building code in the nation.
As I have noted, NYC plans by the year 2025 to aim for the requirement that all new and renovated buildings meet Net Zero Energy Building criteria. As I have said in earlier entries, this will mean that the building will need to through both conservation and the use of on-site renewable energy sources be totally neutral in its energy usage needs. By this, we mean that the building can still purchase energy from the grid, BUT it must, at some time during a set period of time generate enough energy through renewable sources, such as solar or wind, to offset this purchase, by sending the same amount back to the Power Grid that it purchased. Of course conservation through both envelope, lighting and HVAC efficient equipment will play a role here in reducing the total energy needed, we will also now see water efficiency through stricter plumbing fixture requirements. Toilets that use less than 1.6 gallons per flush and waterless urinals have been proposed to be part of the new Green Code.
We MUST note that none of these additional items have come without protest from various city agencies and trade unions. One example is the use of fire retardant suppressants, such as foam, and fabric additives. The NYC Fire Department will need to sign off on changing the current requirements, which mandate the use of high content VOC agents that have been found to contribute to respiratory and other health issues. Another example is the use of waterless urinals. The plumbing union has expressed concerns about this. Thus, there are MANY hurdles to overcome in getting a comprehensive green building code on the books in NYC.
As we know, codes exists due to need. It is the thinking behind these needs and the means of implementation that make them happen. The Task Force was a result of the NYC Mayor's Office and the NYC Council working with the Urban Green Council to create such agency. It is now know as the NYC Green Codes Task Force.
The NYC Green Task Force went through several ways to start the process:
All told at this time, 111 recommendations for green building requirements have been placed on the table for consideration, and there have been numerous breakdowns and consolidations of these. One example was to require buildings to make stairwells available for passage at all times. The Department of Health liked this, as it would promote physical fitness, while at the same time, reduce elevator related energy use. The idea was tabled, as it was considered to be too risky if someone were to fall in the stairwell and not immediately be found.
At the present, the Task Force is working with the areas of water and lighting efficiency. One major issue has been the lack of clarity on the codes; interpretation has been the major issue now and in the past. In fact, I, Myself raised the question as to just when will the new code actually kick in during a construction project. Is it based on the percentage disturbed of the total square feet, total cost, or just the mere replacement of a plumbing fixture. The answer is, depending on the area of the building code, all of the above. With plumbing, for example, if just one fixture or roughing is changed or moved, this area MUST be brought up to current code. If an area is NOT touched, it will NOT be required to meet the new code in this case.
Another area of concern deals with ventilation. As we aim to make to make building envelopes more airtight, will we now need to address this concern at the residential level, such as apartments. We have dealt with this at the commercial level, but will now need to strongly consider the requirement of make-up air and energy recovery ventilators. I have learned that Canada has required this for a number of years, as their winters are much more severe in regard to heating degree days, that energy tight building envelopes are a must. But. with energy tight building envelopes comes the need for make-up ventilation devices in order to maintain proper indoor environmental quality. Canada has such a requirement for such devices. In fact, in my cousin's Lake Placid, NY town house (built in 2007), which is located in a climate similar to that of Canada, such equipment is already in place. It should be noted that much of Lake Placid, which has perhaps the cheapest electric rates in the nation, (4.87 cents per kilowatt hour during the winter) heats with resistive electric heat. The current New York State Energy Code currently requires increased levels of building envelope insulation and air-tightness above and beyond that of non-electrically heated homes. As such, his town house has a heat recovery ventilation system in place
The main thrust of the effort of the Task Force will be to deal with renovations -- NOT to require existing building that are NOT undergoing changes to meet the new green codes. This is based on the idea that there is CONSTANT CHURNING OF TENANTS AND BUILDING RENOVATIONS TAKING PLACE ON AN ONGOING BASIS.
It is expected that the process of the Task Force will take two years; thus by the summer of 2012, we should see what at the time of this writing, the nation's most stringent Green Building Code.
In this first session, it was planned to have City Council Speaker Christine Quinn give a keynote address summarizing the Task Force progress to date. Then, City Council Member Eric Martin Dilan, as well as Dan Nall from WSP Flack + Kurtz join with Urban Green Council Executive Director Russell Unger and Charlotte Matthews of Related Companies were to present a further panel discussion. Unfortunately, due to the ongoing budget crisis, only Russell Unger and Charlotte Matthews were present. However, they were rather successful in bringing us up to date on the Task Force history and its progress to date.
Readers of my blog will remember in January of this year, NYC passed the most sweeping energy code to date in the nation. I attended five separate meetings on this topic, and have blog entries on each. As of July 1, this has become law.
The Green Codes Task force takes this effort much further, in that it will include a re-writing of the entire set of building codes that NYC will ultimately follow. All areas will be included; not just energy. We will see plumbing, water efficiency, materials and resources, ventilation -- indoor environmental quality, as well as other green and sustainable issues being incorporated. This will evolve into what I believe will be the most comprehensive and strict green building code in the nation.
As I have noted, NYC plans by the year 2025 to aim for the requirement that all new and renovated buildings meet Net Zero Energy Building criteria. As I have said in earlier entries, this will mean that the building will need to through both conservation and the use of on-site renewable energy sources be totally neutral in its energy usage needs. By this, we mean that the building can still purchase energy from the grid, BUT it must, at some time during a set period of time generate enough energy through renewable sources, such as solar or wind, to offset this purchase, by sending the same amount back to the Power Grid that it purchased. Of course conservation through both envelope, lighting and HVAC efficient equipment will play a role here in reducing the total energy needed, we will also now see water efficiency through stricter plumbing fixture requirements. Toilets that use less than 1.6 gallons per flush and waterless urinals have been proposed to be part of the new Green Code.
We MUST note that none of these additional items have come without protest from various city agencies and trade unions. One example is the use of fire retardant suppressants, such as foam, and fabric additives. The NYC Fire Department will need to sign off on changing the current requirements, which mandate the use of high content VOC agents that have been found to contribute to respiratory and other health issues. Another example is the use of waterless urinals. The plumbing union has expressed concerns about this. Thus, there are MANY hurdles to overcome in getting a comprehensive green building code on the books in NYC.
As we know, codes exists due to need. It is the thinking behind these needs and the means of implementation that make them happen. The Task Force was a result of the NYC Mayor's Office and the NYC Council working with the Urban Green Council to create such agency. It is now know as the NYC Green Codes Task Force.
The NYC Green Task Force went through several ways to start the process:
- Mandate LEED
- Adapt ASHRAE Standard 189.1
- Made in NYC: The Green Codes Task Force.
All told at this time, 111 recommendations for green building requirements have been placed on the table for consideration, and there have been numerous breakdowns and consolidations of these. One example was to require buildings to make stairwells available for passage at all times. The Department of Health liked this, as it would promote physical fitness, while at the same time, reduce elevator related energy use. The idea was tabled, as it was considered to be too risky if someone were to fall in the stairwell and not immediately be found.
At the present, the Task Force is working with the areas of water and lighting efficiency. One major issue has been the lack of clarity on the codes; interpretation has been the major issue now and in the past. In fact, I, Myself raised the question as to just when will the new code actually kick in during a construction project. Is it based on the percentage disturbed of the total square feet, total cost, or just the mere replacement of a plumbing fixture. The answer is, depending on the area of the building code, all of the above. With plumbing, for example, if just one fixture or roughing is changed or moved, this area MUST be brought up to current code. If an area is NOT touched, it will NOT be required to meet the new code in this case.
Another area of concern deals with ventilation. As we aim to make to make building envelopes more airtight, will we now need to address this concern at the residential level, such as apartments. We have dealt with this at the commercial level, but will now need to strongly consider the requirement of make-up air and energy recovery ventilators. I have learned that Canada has required this for a number of years, as their winters are much more severe in regard to heating degree days, that energy tight building envelopes are a must. But. with energy tight building envelopes comes the need for make-up ventilation devices in order to maintain proper indoor environmental quality. Canada has such a requirement for such devices. In fact, in my cousin's Lake Placid, NY town house (built in 2007), which is located in a climate similar to that of Canada, such equipment is already in place. It should be noted that much of Lake Placid, which has perhaps the cheapest electric rates in the nation, (4.87 cents per kilowatt hour during the winter) heats with resistive electric heat. The current New York State Energy Code currently requires increased levels of building envelope insulation and air-tightness above and beyond that of non-electrically heated homes. As such, his town house has a heat recovery ventilation system in place
The main thrust of the effort of the Task Force will be to deal with renovations -- NOT to require existing building that are NOT undergoing changes to meet the new green codes. This is based on the idea that there is CONSTANT CHURNING OF TENANTS AND BUILDING RENOVATIONS TAKING PLACE ON AN ONGOING BASIS.
It is expected that the process of the Task Force will take two years; thus by the summer of 2012, we should see what at the time of this writing, the nation's most stringent Green Building Code.
ASHRAE STANDARD 189.1 -- IT'S NOW REALITY!
At the Winter ASHRAE Meeting, held this past January, the first Green Standard for the design of High-Performance Buildings Except Low-Rise Residential Buildings was approved. Readers of my blog may remember that I wrote on this Standard early in 2009, when it was still in the development and review phase.
What sets this apart from rating systems, such as LEED, is that it is a code-intended standard. This means that it can be used as the basis for municipal codes, as it is ANSI sanctioned. Thus, unlike the LEED rating system, which is a voluntary rating system, this can be incorporated into mandatory building codes in the same manner as ASHRAE Standard 90.1 has been with energy codes throughout the USA. This is due to the fact that it includes mandatory and prescriptive performance criteria
ASHRAE Standard 189.1 covers ALL areas of sustainable building design and operations, and in many areas, mirrors the LEED rating system. This is what sets this apart from any other ASHRAE Standard, which up until now have covered only issues related to energy use, heating, cooling, ventilation and refrigeration operations and safety issues. Thus, ASHRAE has now introduced a Standard that covers such areas as sustainable sites (land use) water efficiency, light pollution issues, the building's impact on the atmosphere as well as indoor environmental quality. Thus, a design team will need to take into account the building's source contaminant and emissions.
This Standard was a four year effort that involved not just teams from ASHRAE, but USGBC and Illuminating Engineering Society of North America (IESNA), as well as the public. Three review period were conducted during this effort, and over 2500 comments were received.
One item in which this Standard differs from the past, is that for the first time, future provisions for on-site renewable energy will be required, unless the building is located in a poor incident solar radiation area. Another exemption is granted for a period of up to ten years, if 70 kWh / Square-foot of green power is purchased. The prescriptive requirement here will be 6 kBtu / square-foot. If one chooses to use the performance path, increased energy efficiency can substitute for renewable energy.
Standard 189.1 is NOT intended to replace Standard 90.1; rather it is meant to build on this standard, which is the current basis of all energy codes in use in the USA today.
Standard 189.1 will result in a solid increase in energy savings. These will vary from region to region, but on the average, the savings will be 30% over that of Standard 90.1.
Standard 189.1 is intended to blend with and compliment the LEED rating system and Energy Star; in fact it was these systems that served as the basis for this Standard. As said above, we now have a ANSI model code language that can be incorporated into new green building codes. It is intended to compliment green rating systems, not to compete or eliminate them, but rather to set a new level of mandatory minimum standard that a building must meet in terms of sustainability. At the present, efforts are underway to educate model code organizations, as they are looking for guidance in just how to incorporate green standards into their codes at all levels.
While the emphasis of this entry has focused on mandatory codes, Standard 189.1 can also serve as a reference for jurisdictions seeking to provide a guidance reference for green designations or voluntary programs in place of actual mandatory requirements. Also, a jurisdiction may choose to modify or regionalize the requirements. However, if a jurisdiction wants to adapt a provision that is more stringent than the requirements found in the Federal Register, they must first request a waiver from the U. S. Department of Energy. This issue of Federal Preemption was a contentious issue during the review process. The creation of various paths to compliance dealt with these issues.
As noted above, we now see exterior lighting included in Standard 189.1. The main aim here is to deal with issues of back-lighting, up-lighting and glare. Again, we saw much contention with these provisions.
Standard 198.1 will be under continuous review; it will be altered as needs arise at any time. In addition, daylight provisions will be reviewed to ensure that they mesh with Standard 90.1. A user's manual will be published sometime this summer. For further information, refer to: www.ashrae.org/greenstandard
What sets this apart from rating systems, such as LEED, is that it is a code-intended standard. This means that it can be used as the basis for municipal codes, as it is ANSI sanctioned. Thus, unlike the LEED rating system, which is a voluntary rating system, this can be incorporated into mandatory building codes in the same manner as ASHRAE Standard 90.1 has been with energy codes throughout the USA. This is due to the fact that it includes mandatory and prescriptive performance criteria
ASHRAE Standard 189.1 covers ALL areas of sustainable building design and operations, and in many areas, mirrors the LEED rating system. This is what sets this apart from any other ASHRAE Standard, which up until now have covered only issues related to energy use, heating, cooling, ventilation and refrigeration operations and safety issues. Thus, ASHRAE has now introduced a Standard that covers such areas as sustainable sites (land use) water efficiency, light pollution issues, the building's impact on the atmosphere as well as indoor environmental quality. Thus, a design team will need to take into account the building's source contaminant and emissions.
This Standard was a four year effort that involved not just teams from ASHRAE, but USGBC and Illuminating Engineering Society of North America (IESNA), as well as the public. Three review period were conducted during this effort, and over 2500 comments were received.
One item in which this Standard differs from the past, is that for the first time, future provisions for on-site renewable energy will be required, unless the building is located in a poor incident solar radiation area. Another exemption is granted for a period of up to ten years, if 70 kWh / Square-foot of green power is purchased. The prescriptive requirement here will be 6 kBtu / square-foot. If one chooses to use the performance path, increased energy efficiency can substitute for renewable energy.
Standard 189.1 is NOT intended to replace Standard 90.1; rather it is meant to build on this standard, which is the current basis of all energy codes in use in the USA today.
Standard 189.1 will result in a solid increase in energy savings. These will vary from region to region, but on the average, the savings will be 30% over that of Standard 90.1.
Standard 189.1 is intended to blend with and compliment the LEED rating system and Energy Star; in fact it was these systems that served as the basis for this Standard. As said above, we now have a ANSI model code language that can be incorporated into new green building codes. It is intended to compliment green rating systems, not to compete or eliminate them, but rather to set a new level of mandatory minimum standard that a building must meet in terms of sustainability. At the present, efforts are underway to educate model code organizations, as they are looking for guidance in just how to incorporate green standards into their codes at all levels.
While the emphasis of this entry has focused on mandatory codes, Standard 189.1 can also serve as a reference for jurisdictions seeking to provide a guidance reference for green designations or voluntary programs in place of actual mandatory requirements. Also, a jurisdiction may choose to modify or regionalize the requirements. However, if a jurisdiction wants to adapt a provision that is more stringent than the requirements found in the Federal Register, they must first request a waiver from the U. S. Department of Energy. This issue of Federal Preemption was a contentious issue during the review process. The creation of various paths to compliance dealt with these issues.
As noted above, we now see exterior lighting included in Standard 189.1. The main aim here is to deal with issues of back-lighting, up-lighting and glare. Again, we saw much contention with these provisions.
Standard 198.1 will be under continuous review; it will be altered as needs arise at any time. In addition, daylight provisions will be reviewed to ensure that they mesh with Standard 90.1. A user's manual will be published sometime this summer. For further information, refer to: www.ashrae.org/greenstandard
Optimizing Energy Use in Sustainable Corporate Interiors
The New York Urban Green Council held their monthly High Performance Green Building Salon this past Thursday, with topic being optimization of energy use in sustainable corporate interiors.
The presenters were:- Pat Sapinsley, AIA LEED AP, senior Associate, Good Energies,
- Steven South, LEED AP BD+C, Project Designer, Perkins and Will
- Shoshanna Segal, LC, IESNA, IALD, LEED AP, HLB Lighting Design
A major one of their investments has been Sage Electochromatics, on which I have a blog entry in late 2008 or very early 2009. Sage has perfected a superior gazing system that by the use of electronic changes to the glass tinting dramatically reduces solar gain when it not wanted.
The Sage product that was described in ASTM tested, and lets in heat when needed, while providing for a range of transmissible light as high a 62% down to as little as 3%. This has the effect of reducing and controlling glare, a major issue in occupant comfort, as well as a LEED credit factor in the area of Indoor environmental quality. This glazing system can be programmed to respond to the solar patters that effect the particular building it is used in. The glazing system does need some energy to perform its electro chromatic changes, as well as to retain them, when in operation. To initiate the change, .28 watts per square foot (S. F.) are needed; while to retain the change, only .10 watts per S. F. are needed. It is expected that by 2011, Sage will have this glazing system in sizes up to 60 inches by 120 inches. In terms of the ASTM tests, it has performed flawlessly at a range of 30 years with 90 cycles per day FAR MORE than any building would EVER need during its life cycle expectancy. Only one or two changes per day would be needed in reality. The air space is one-half inch with argon gas fill. The only drawback is that in areas that now require anti-ballistic glazing coatings in the post 9/11 era, the system cannot be used at the present.
The second area covered by the team was energy use controls. COFRA / Good Energies has invested in the area of Smart Grid and Meter controls. This application has been used in the residential area to alert homeowners to their energy usage and allow them to make wiser choices, as well a providing for remote control via an i-Pod like device.
A second area of investment has been the Tendril Product Interface. This system allows the utility to, upon customer enrollment, to communicate with the user's energy system main and actually dump loads during critical periods. In exchange, the customer gets a rebate from the utility. This system works via broadband communications, and can use thermostats, computers, outlets, or even mobile devices to execute the load dumping.
Ice Energy is another one of COFRA / Good Energies investments. I also have a blog entry on this dating back to July, 2009. This allows for cooling to be stored in the form of ice at night, during lower outdoor ambient temperatures, and lower periods of electrical demand. This allows a building to use only a fan to cool during the peak usage daytime periods, which in turn, shifts loads away from the critical peak periods. While not really intended to save energy, it does provide some savings, in that the ice creation is done at night, when the ambient temperatures are lower, meaning more BTU"s per kilowatt hour are obtained. This load shifting eases the peak demand, which in turn, has two benefits: less likely brownouts, and less of a need for new power plants to built. Also, it probably reduces smog, as it is during the sunlight hours that most smog is created when power plants are running, especially the dirty coal-fired ones.
COFRA / Good energies has all the above mentioned technologies in their projects, and also emphasizes daylight harvesting, perimeter office layout design, light sensors, re-directing up to 82% of construction waste from landfills, as well as 42% of materials obtained from locally manufactured sources and 98% FSC certified wood.
At this time, COFRA / Good Energies recognizes the value of LED lighting, but does not feel that the efficacy of them is strong enough for wide spread application; thus they have concentrated on the use of linear fluorescent, combined with light colored floors and walls, as well as the use of perimeter office layout with interior glazed partitions for daylight. Their experience has shown that daylight harvesting does NOT always guarantee a LEED daylight and view credit; one of their projects that they showed us, while seemingly very well lit was denied the credit, as it could NOT meet the strict 75% area coverage as prescribed by LEED.
Regarding the use of sensors, the placement at North, South, East, and West in the New York City area is NOT always adequate, as the factor of shadows from adjacent buildings is a major player here.
Lastly, but NOT LEAST was the mention of curtailable Ballasts. These ballasts, which control lighting fixtures, can communicate with the utility to respond to demand reduction needs from the utility. COFRA / Good Energies has invested in LUM Energy that produces such a product. Phillips also has a product on the market.
COFRA's / Good Energies projects come in with a .75 watt per S. F. power consumption, which is 24% BELOW present code. While this is very good, one member of the audience told me after the presentation, that this is now standard practice for sustainable design. In addition, we must also keep in mind ASHRAE Standard 189.1, the high performance building standard that aims for a 30% reduction from that of their Standard 90.1, which is the basis for almost all national and local codes.
Green and Sustainability -- an Olympic Win
The current Olympic Winter Games in Vancouver are officially green by LEED standards. From the Olympic Village that houses the athletes to the various venues, there are MANY green features that were brought into this most wonderful event for the world to see.
For starters, the medals awarded to the athletes are made from recycled electronics (materials and resources credit here)
The athletes themselves made a call to address the issues of global warming, as they can see first hand the, effects of not taking action. The Winter Games depend on snow and ice; global warming drastically effects this. David Suzuki, of the foundation that bears his name, has placed supreme emphasis on this fact, and says that choices that we make today will effect the future of where and how future Winter Games will be held.
A scorecard was put together that details this effort, and can be found on the David Suzuki Foundation web Site http://www.davidsuzuki.org/Climate%20Change/Projects/Olympics/default%20asp
Ten areas were addressed, and overall, the Vancouver Games performed with a Bronze level. The ten areas covered are:
Free public transit is part of the effort, as well.
Even the village site was a former brown field site; meaning that it was reclaimed from a previous use, which will be turned into a mixed use sustainable community that will consist of stores, housing, daycare, and a community center after the Games.
The Richmond Oval, site of the speed skating events is built with a massive wood wave roof that comes from local lumber salvaged after a pine-bee
There are, however, critics that question just how green the Games really are, when on must factor in the vast emissions from trucks just to bring in the needed snow that nature did not provide. (Is this an early effect of global warming here?)
Despite any questions raised, in my opinion, the Vancouver 2010 Winter Olympic Games earn at least a Gold Medal for the sustainable design efforts and success that is clearly seen.
For starters, the medals awarded to the athletes are made from recycled electronics (materials and resources credit here)
The athletes themselves made a call to address the issues of global warming, as they can see first hand the, effects of not taking action. The Winter Games depend on snow and ice; global warming drastically effects this. David Suzuki, of the foundation that bears his name, has placed supreme emphasis on this fact, and says that choices that we make today will effect the future of where and how future Winter Games will be held.
A scorecard was put together that details this effort, and can be found on the David Suzuki Foundation web Site http://www.davidsuzuki.org/Climate%20Change/Projects/Olympics/default%20asp
Ten areas were addressed, and overall, the Vancouver Games performed with a Bronze level. The ten areas covered are:
- Goals: A good effort to achieve renewable energy, as well as energy efficiency was achieved, but other areas were rated vague
- In terms of transparency, the rating was quite good
- Measuring Climatic Impact: A significant improvement was seen by the Vancouver Games in this area, when compared to previous Game Sites.
- Venues: Once again, the Vancouver Games will leave the site with innovative and energy efficient buildings that will serve for many years after the Games.
- Energy Use: The Vancouver Games use mostly clean energy sources, such as electricity from local natural hydroelectric systems, seawater and ground source heat.
- Transportation: Even though reference have been made to the availability of free public transit, green house gas emissions were not dealt with properly.
- Overall Green House Gas Emission Reduction: The reduction was about 15%
- Offsetting Remaining Emissions: Half of the emission were reduced from game-related activities, a rather substantial amount.
- Mobilizing Sponsors and Others: The Vancouver Games excelled here.
- Public Engagement: This was rated the lowest of the ten areas, in terms of success on the part of the Vancouver Games.
Free public transit is part of the effort, as well.
Even the village site was a former brown field site; meaning that it was reclaimed from a previous use, which will be turned into a mixed use sustainable community that will consist of stores, housing, daycare, and a community center after the Games.
The Richmond Oval, site of the speed skating events is built with a massive wood wave roof that comes from local lumber salvaged after a pine-bee
There are, however, critics that question just how green the Games really are, when on must factor in the vast emissions from trucks just to bring in the needed snow that nature did not provide. (Is this an early effect of global warming here?)
Despite any questions raised, in my opinion, the Vancouver 2010 Winter Olympic Games earn at least a Gold Medal for the sustainable design efforts and success that is clearly seen.
Permeable Pavement -- A New Approach To Storm Water Control and Water Quality and Supply Issues
I have run across several articles on the topic of permeable pavement systems. As we all know, when land is paved with traditional concrete or asphalt, it becomes an Impervious surface which does not allow water to seep back into the earth below. This creates a major problem with storm water runoff, as well as not allowing for the natural recharge of the aquifer that supplies much of the drinking water in many areas.
Until only several months ago, I never realized that such product even existed. The first mentioning of this idea was at the November 30, 2009 meeting that the Rockland County Municipal Planning Federation held, in which a presenter briefly touched upon the idea.
This system will be of welcome to any designer or land-use planner dealing with a municipality that has a limit on the amount of allowable impervious surface. Obviously, the use of this system will allow for greater coverage for pavement than would be allowed for standard pavement.
After doing some research on my own, I have found that permeable pavement is now available in both concrete as well as asphalt. It has its major value in light traffic areas, such as parking lots, side walks and patios. This is due to the fact that both systems do not possess the strength needed to handle heavy highway or even secondary road traffic at this time.
In general, for both permeable concrete and asphalt, it is possible to achieve a permeability rate of not less than five gallons per square foot per minute. This is far greater than what would fall in a 100 year storm, the general standard by which storm water control must comply with.
In the case of permeable cement, it is the unique manufacturing process that allows for this to happen. First, there is a careful control of the amount of water and cement in the mix, so as to create a paste that forms a thick coating around the aggregate materials. Second, there is little or no sand in the mix. This now creates a highly permeable interconnected set of voids that allows for the fast rate of drainage through the pavement. In fact, the voids account for 15 to 25% of the product.
EcoCreto is an example of a permeable concrete system that now claims to have a hardened strength as high as 5000 pounds within 28 days, and is 100% permeable. In addition, EcoCreto claims to reduce storm water contaminates such as suspended solids by up to 90%. Also claimed, is the reduction of heavy metals by 40 to 90%, as well as the removal of 90% of mineral oils, and 60% of phosphorous. Obviously, this goes a long way in addressing a major issue -- storm water quality control. The LEED rating system deals with this as well as storm water quantity control. By pre treating the water contaminates prior to the water seeping back into the aquifer to this level, we provide for far better aquifer recharge protection in terms of both quality and quantity of the water. As a result of this, this product is recognized by the federal Environmental Protection Agency as a Best Management Practice (BMP) for the control and management of storm water runoff.
In addition to the advantages of the permeable pavement allowing for the water to penetrate into the soil below, the soil and adjacent sub-surface also further purify the water, via microbial activity.
We MUST note that the property in which permeable pavement is considered for use be evaluated for its ability to absorb the water; if the water table is already high, or there is the presence of heavy clay or solid bedrock, the system will have limited effectiveness.
In general, a 12 to 36 inch sub base is prepared under where the pavement will be laid. This will consist of gravel, and sometimes, a piping network to allow for the water to be either drained directly into the ground below, or if needed, re-directed to an alternative location for seepage into the aquifer.
Porous asphalt is created in a similar fashion, and has the same benefits as concrete.
In terms of cold weather performance, especially with snow and ice, I ran across a PDF of an article from Storm Water, (September, 2008) that said that these products can be used in cold climates; in fact, it was claimed up a 75% reduction in the need for salt application for de-icing -- a BIG help to the environment as well as a cost-saver. In addition, increased slip resistance was noted when permeable pavement was used. This is most likely due to two factors: the increased texture created by the voids at the surface, and the lack of sheet water flow, resulting in less ice formation. However, a designer needs to take into account the frequency of freeze-thaw cycles, as this can effect the performance of the permeability if the cycles are too quick. Under most cases, the system allows water to drain away to warmer ground below prior to the pores being clogged with ice.
In spite of the porous voids and stone-like surface, these products have seen no issues with pedestrian traffic, even with high heel shoe use.
When used with proper planning, it is quite possible to significantly reduce or possibly eliminate the need for actual storm water catch basins and piping, thus saving far more than what the initial additional cost of using permeable paving vs. conventional materials. Thus, we see the interconnection of trade-offs and synergies that I have mentioned elsewhere. The final result can be a lower life-cycle cost, especially given the fact that industry expectations for the permeable pavement products to have a longer service life than that of standard pavements.
We also will benefit from the reduction of standing pools of water in parking lots, which in summer, can breed mosquitoes and in winter, turn to slippery ice.
Even higher traffic areas can find a use for this product, as the entire shoulder area can be paved with permeable material, creating a continuous drain to the earth below, while the traffic lane is paved with stronger conventional pavement.
For light duty projects such as patios or side walks, a product known as PermaPave can be used. This has all the properties of the above mentioned products, but comes in pre-formed paver blocks similar to the standard blocks used in driveways that we see in almost all neighborhoods today. PermaPave comes in 12 colors and four different sizes, ranging from 16" x 16" down to 8" x 4". It is installed in a similar way as standard pavers, but one MUST pay attention to the proper preparation of the sub surface below, to allow for drainage into the aquifer.
In summary, we have MANY advantages to using porous pavement products, from the environmental point of view to reduced maintenance.
Until only several months ago, I never realized that such product even existed. The first mentioning of this idea was at the November 30, 2009 meeting that the Rockland County Municipal Planning Federation held, in which a presenter briefly touched upon the idea.
This system will be of welcome to any designer or land-use planner dealing with a municipality that has a limit on the amount of allowable impervious surface. Obviously, the use of this system will allow for greater coverage for pavement than would be allowed for standard pavement.
After doing some research on my own, I have found that permeable pavement is now available in both concrete as well as asphalt. It has its major value in light traffic areas, such as parking lots, side walks and patios. This is due to the fact that both systems do not possess the strength needed to handle heavy highway or even secondary road traffic at this time.
In general, for both permeable concrete and asphalt, it is possible to achieve a permeability rate of not less than five gallons per square foot per minute. This is far greater than what would fall in a 100 year storm, the general standard by which storm water control must comply with.
In the case of permeable cement, it is the unique manufacturing process that allows for this to happen. First, there is a careful control of the amount of water and cement in the mix, so as to create a paste that forms a thick coating around the aggregate materials. Second, there is little or no sand in the mix. This now creates a highly permeable interconnected set of voids that allows for the fast rate of drainage through the pavement. In fact, the voids account for 15 to 25% of the product.
EcoCreto is an example of a permeable concrete system that now claims to have a hardened strength as high as 5000 pounds within 28 days, and is 100% permeable. In addition, EcoCreto claims to reduce storm water contaminates such as suspended solids by up to 90%. Also claimed, is the reduction of heavy metals by 40 to 90%, as well as the removal of 90% of mineral oils, and 60% of phosphorous. Obviously, this goes a long way in addressing a major issue -- storm water quality control. The LEED rating system deals with this as well as storm water quantity control. By pre treating the water contaminates prior to the water seeping back into the aquifer to this level, we provide for far better aquifer recharge protection in terms of both quality and quantity of the water. As a result of this, this product is recognized by the federal Environmental Protection Agency as a Best Management Practice (BMP) for the control and management of storm water runoff.
In addition to the advantages of the permeable pavement allowing for the water to penetrate into the soil below, the soil and adjacent sub-surface also further purify the water, via microbial activity.
We MUST note that the property in which permeable pavement is considered for use be evaluated for its ability to absorb the water; if the water table is already high, or there is the presence of heavy clay or solid bedrock, the system will have limited effectiveness.
In general, a 12 to 36 inch sub base is prepared under where the pavement will be laid. This will consist of gravel, and sometimes, a piping network to allow for the water to be either drained directly into the ground below, or if needed, re-directed to an alternative location for seepage into the aquifer.
Porous asphalt is created in a similar fashion, and has the same benefits as concrete.
In terms of cold weather performance, especially with snow and ice, I ran across a PDF of an article from Storm Water, (September, 2008) that said that these products can be used in cold climates; in fact, it was claimed up a 75% reduction in the need for salt application for de-icing -- a BIG help to the environment as well as a cost-saver. In addition, increased slip resistance was noted when permeable pavement was used. This is most likely due to two factors: the increased texture created by the voids at the surface, and the lack of sheet water flow, resulting in less ice formation. However, a designer needs to take into account the frequency of freeze-thaw cycles, as this can effect the performance of the permeability if the cycles are too quick. Under most cases, the system allows water to drain away to warmer ground below prior to the pores being clogged with ice.
In spite of the porous voids and stone-like surface, these products have seen no issues with pedestrian traffic, even with high heel shoe use.
When used with proper planning, it is quite possible to significantly reduce or possibly eliminate the need for actual storm water catch basins and piping, thus saving far more than what the initial additional cost of using permeable paving vs. conventional materials. Thus, we see the interconnection of trade-offs and synergies that I have mentioned elsewhere. The final result can be a lower life-cycle cost, especially given the fact that industry expectations for the permeable pavement products to have a longer service life than that of standard pavements.
We also will benefit from the reduction of standing pools of water in parking lots, which in summer, can breed mosquitoes and in winter, turn to slippery ice.
Even higher traffic areas can find a use for this product, as the entire shoulder area can be paved with permeable material, creating a continuous drain to the earth below, while the traffic lane is paved with stronger conventional pavement.
For light duty projects such as patios or side walks, a product known as PermaPave can be used. This has all the properties of the above mentioned products, but comes in pre-formed paver blocks similar to the standard blocks used in driveways that we see in almost all neighborhoods today. PermaPave comes in 12 colors and four different sizes, ranging from 16" x 16" down to 8" x 4". It is installed in a similar way as standard pavers, but one MUST pay attention to the proper preparation of the sub surface below, to allow for drainage into the aquifer.
In summary, we have MANY advantages to using porous pavement products, from the environmental point of view to reduced maintenance.
