This credit can be fairly difficult to understand at a glance. So let’s start by getting some common misconceptions out of the way.
One common misconception is that this credit specifies or prohibits a certain refrigerant type. This is true of the prerequisite, (EAp3), however for this credit, there are both HCFCsHydrochlorofluorocarbons (HCFCs) are refrigerants that cause significantly less depletion of the stratospheric ozone layer than chlorofluorocarbons. (hydrochlorofluorocarbons) and HFCs (hydrofluorocarbonsHydrofluorocarbons (HFCs) are refrigerants that do not deplete the stratospheric ozone layer but may have high global warming potential. HFCs are not considered environmentally benign.) that may or may not meet the requirements.
Another misconception is that this credit solely concerns refrigerants’ ozone-depleting and global-warming potentials (ODPOzone Depletion Potential (ODP) is a measure of ozone impact a chemical has relative to CFC-11 (trichlorofluoromethane), which has a ODP of 1. and GWPGlobal Warming Potential (GWP) is a measure of substances’ ability to absorb heat and warm the atmosphere relative to carbon dioxide, which has a GWP of 1, over a given time period. ), and that a refrigerant like R-410A automatically complies because it has low ODP and GWP numbers. But the credit requirements also include other variables, such as the ratio of coolant charge to cooling capacity for a given compressor unit, and this credit considers the life of the unit and the refrigerant leakage rateThe speed at which an appliance loses refrigerant, measured between refrigerant charges or over 12 months, whichever is shorter. The leakage rate is expressed in terms of the percentage of the appliance's full charge that would be lost over a 12-month period if the rate stabilized. (EPA Clean Air Act, Title VI, Rule 608).. R-410A, for example, may be compliant in some scenarios but not in others.
To earn this credit, you’ll need to:
The credit is about reducing the environmental impact of refrigerants in HVAC&R equipment, and relates to all space conditioning and large-scale refrigeration systems in project buildings. It deals with two environmental impacts of concern: depletion of the ozone layer, and greenhouse gas emissions. EAc4 goes a step further than EAp3: Fundamental Refrigerant Management, which only sets the thresholds for ozone-depleting compounds.
All permanently installed HVAC&R equipment with more than 0.5 lbs of refrigerant— including chillers; unitary HVAC equipment (split and packaged); room and window air-conditioners; computer, data center, and telecom room cooling units; and commercial refrigeration equipment—is addressed by this credit.
The credit also addresses fire suppression systems that contain ozone-depleting substances, including CFCs, HCFCs, or halons. Halon production was banned in the U.S. in 1994, as it is many times more ozone-depleting than CFCs and HCFCs.
While ozone is an unwanted pollutant at ground level (it’s a key component of smog), in the upper atmosphere a sparse layer of ozone plays a critical role in filtering out harmful ultraviolet rays from sunlight.
The Montreal Protocol on Substances that Deplete the Ozone Layer—the world’s first global environmental protection treaty—prescribed a complete phase-out of CFC-based refrigerants by 1995, and of HCFCs by 2030 in developed countries. As a result, environmentally preferable refrigerants are becoming more widely available for new systems.
From an environmental perspective, the best way to earn this credit is to avoid the use of refrigerants altogether, by using either passive or evaporative cooling strategies, or with absorption chillers (see Related Products in the right column).
If neither of these is an option for your project, earning this credit will be more about the selection of mechanical equipment and associated refrigerants.
The best way to determine credit compliance is to run compliance calculations as soon as an HVAC system is proposed. Not all compressor units have to be in compliance individually; this credit calculation uses a weighted average based on cooling capacity (in tons). Leakage rates and coolant charge are as important as GWP and ODP factors in influencing credit calculations.
If your project already has designed an HVAC system and now wants to change the refrigerant to meet the credit, you will find that it may not be as simple as swapping out the coolant or the compressor unit for a more environmentally benign choice. Rather, your entire HVAC system may have to be resized to accommodate the different capacities and efficiencies of the newer units.
This is a relatively easy credit to obtain if your project has a centralized cooling plant, with a favorable “coolant charge to cooling capacity” ratio. But even for projects with smaller, more dispersed units, this credit should be achievable if you consider the credit requirements early.
Ironically, some of the refrigerants that can help earn this credit are used in systems with poorer energy efficiency, resulting in increased greenhouse gas emissions. (CFCs were super-efficient, they just happened to be toxic and destroyed the ozone layer.) The life cycle of operational efficiency and refrigerant performance is not covered by this credit, but leakage and direct environmental impact are. Any loss of efficiency is a trade-off that has to be accounted for in EAc1.
If your project has no cooling system or uses a system without refrigerants, you can achieve the credit through Option 1 (“do not use refrigerants”). Document your credit compliance path with appropriate supporting documents by completing the submittal template and providing cut sheets or other confirmation of the system type.
Earning EAp2 and drawing up energy efficiency goals can help to determine your project’s cooling strategy as it relates to energy consumption. This exercise may help you prioritize energy performance versus refrigerant selection, when applicable.
If your building uses only natural ventilation, it complies with Option 1 and the credit is automatically earned without your having to submit any calculations.
To comply with Option 2, you’ll need to calculate the weighted impact of the following characteristics of all refrigerants used in your project:
The calculated weighted average for the project should not exceed 100:
(LCGWP + LCODP x 105 ≤ 100). See the credit language and LEED Online for additional detail on the formulas behind that calculation.
All permanently installed HVAC&R equipment with more than 0.5 lbs of refrigerant—including chillers; unitary HVAC equipment (split and packaged); room and window air-conditioners; computer, data center, and telecom room cooling units; and commercial refrigeration equipment—is addressed by this credit.
Any fire suppression systems must contain no halons, CFCs, or HCFCs. This requirement is separate from the refrigerant requirements and is not included in refrigerant compliance calculations.
EPA’s SNAP program (see Resources) lists a range of alternatives to ODP substances. Review these alternatives and confirm the applicability to your system type. Consider using these to help meet the credit requirements.
Identify suitable systems in collaboration with the project owner and facilities management. Common alternatives for fire suppression systems usually are based on carbon dioxide, water, or dry chemicals (ABC or BC type powders).
If your project building is connected to a district chilled-water system, you have to include all the chillers in that system in the calculations, even if they are outside your project’s scope or control. As a rule of thumb, if the system is serving your LEED project it should be included in calculations, whether it is within your project scope of work or not.
Even one piece of equipment can tip your calculations to compliance or noncompliance. Use the calculator in the LEED Online submittal template to run calculations from the beginning of HVAC system selection (note that your project has to be registered through LEED Online to download those forms). This gives a sense of how far from compliance a system may be; teams then get a better idea of how significant a change may be required. Note that annual leakage and end-of-life refrigerant loss rates are set to defaults but can be edited if needed.
Consider incorporating passive cooling strategies in your design to reduce or eliminate the need for mechanical equipment that uses refrigerant.
Your mechanical engineer can investigate alternative mechanical systems that use natural refrigerants such as water, carbon dioxide, or ammonia.
There may be first-cost and operating-cost differentials for alternative refrigerants, so careful research is required.
Operations and maintenance staff need to be on board if you select a system that is unconventional or requires a new maintenance protocol. It is best to have operations and maintenance staff participate in MEP meetings regardless of system type.
Check the table of commonly used refrigerants in the LEED Reference Guide. Identify those that have lower values of ozone-depleting or global-warming potential (ODP or GWP, respectively).
Consult equipment cut sheets for refrigerant name and capacity, leakage rate, and end-of-life loss—or call the manufacturer directly for this information. A higher leakage rate implies a higher environmental impact as well as a higher recharging cost for the project.
R-410A is a common replacement for R-22 as it is more environmentally benign, with similar performance. It can help with compliance, depending on the equipment variables of “coolant charge to cooling capacity” ratio.
Because mechanical conditioning and ventilation represents a large portion of your building’s energy use, equipment—and consequently refrigerant—selection will affect your energy consumption and costs.
System choice is crucial to earning this credit. Centralized systems are likely to be more efficient and to make compliance easier. Equipment for decentralized systems has been slower to convert to more benign refrigerants, so compliance can be more difficult.
Check multiple equipment manufacturers to see what refrigerants they specify for their equipment. There may be a variety of system types that will help meet the credit requirements in a variety of ways.
Packaged terminal air conditioners (PTACs) typically use refrigerants with a high environmental impact. These units may make meeting the credit requirements more challenging, especially for hotels and multifamily residential projects, which tend to use them. The industry has been moving toward upgrading these refrigerants, so check with manufacturers for recent upgrades to their products. Newer refrigerants may help credit calculations.
Common split systems use varying refrigerants, in a range of quantities and leakage rates. These systems can have a hard time meeting the threshold for credit compliance because their leakage rates are high. Check your specifications early in the design stage and investigate these products if you’re thinking of using split systems.
The default leakage rate used in the credit form calculator is 2%, and the end-of-life refrigerant loss value should be 10%. If your project has equipment with different leakage rates, those values can be used instead.
There are trade-offs with all refrigerants. R-410A, for example, has a lower refrigerant charge, defined as the ratio of refrigerant to gross cooling capacity, but it uses more energy which may increase operating energy costs and will have a negative impact on your compliance with EAc1: Optimize Energy Performance, and total energy use reduction for the project.
All refrigerants involve tradeoffs. HFCs, for example, don’t contain chlorine and have zero ozone depletion potential, but they have significant global warming impact. HFCs are also less efficient than conventional, chlorine-based refrigerants, which are the most damaging to the ozone layer. Ammonia is highly efficient and ozone safe, but it can be hazardous to human health if released in large quantities.
Note that this credit requires the weighted average of all refrigerants to be less than 100, even if, individually, some are higher. That’s why it’s important to run the calculations several times until the final equipment is selected for your project.
Complete credit calculations based on the finalized mechanical system design.
The refrigerant charge is typically calculated automatically in the LEED Online submittal template. It is the relationship between how much refrigerant is needed (in pounds) and the cooling capacity (in tons) of the equipment.
Specifying high-quality equipment with a long lifespan can reduce environmental impacts, since most leakage occurs during installation and decommissioning. For information about the service life of different types of HVAC equipment, refer to the 2007 ASHRAE Applications Handbook—HVAC Applications. (See Resources.)
Complete your documentation on LEED Online. Input the product make and model. If not using the defaults provided by LEED Online, input the refrigerant charge, leakage rate, and end-of-life leakage based on the equipment data.
Organize documentation of equipment specs and the maintenance requirements intended to minimize refrigerant leakage and transfer this information to the owner’s facility managers.
Retain the manufacturer’s cut sheets showing the leakage rate of each piece of equipment.
Provide refrigerant leak-detection equipment in the same location as your HVAC&R equipment.
Put in place a program of preventive maintenance for the equipment end-of-life management.
Retain manufacturers’ data and design specifications for your fire suppression system, confirming that it meets the credit requirements.
Refrigerants are not harmful to the atmosphere until they are released into it. Comply with best-practice refrigerant management regulations to minimize leakage rates during operation and when installing or removing new equipment.
Excerpted from LEED for New Construction and Major Renovations Version 2.2
Reduce ozone depletion and support early compliance with the Montreal Protocol while minimizing direct contributions to global warming.
Do not use refrigerants.
Select refrigerants and HVAC&R that minimize or eliminate the emission of compounds that contribute to ozone depletion and global warming. The base buildingThe base building includes elements such as the structure, envelope, and building-level mechanical systems, such as central HVAC, etc. HVAC&R equipment shall comply with the following formula, which sets a maximum threshold for the combined contributions to ozone depletion and global warming potential:
LCGWP + LCODP x 105 ≤ 100
LCODP = [ODPr x (Lr x Life +Mr) x Rc]/Life
LCGWP = [GWPr x (Lr x Life +Mr) x Rc]/Life
LCODP: Lifecycle Ozone Depletion Potential (lbCFC11/Ton-Year)
LCGWP: Lifecycle Direct Global Warming Potential (lbCO2/Ton-Year)
GWPr: Global Warming Potential of Refrigerant (0 to 12,000 lbCO2/lbr)
ODPr: Ozone Depletion Potential of Refrigerant (0 to 0.2 lbCFC11/lbr)
Lr: Refrigerant Leakage RateThe speed at which an appliance loses refrigerant, measured between refrigerant charges or over 12 months, whichever is shorter. The leakage rate is expressed in terms of the percentage of the appliance's full charge that would be lost over a 12-month period if the rate stabilized. (EPA Clean Air Act, Title VI, Rule 608). (0.5% to 2.0%; default of 2% unless otherwise demonstrated)
Mr: End-of-life Refrigerant Loss (2% to 10%; default of 10% unless otherwise demonstrated)
Rc: Refrigerant Charge (0.5 to 5.0 lbs of refrigerant per ton of Gross ARI rated cooling capacity)
Life: Equipment Life (10 years; default based on equipment type, unless otherwise demonstrated)
For multiple types of equipment, a weighted average of all base building level HVAC&R equipment shall be applied using the following formula:
[ ∑ (LCGWP + LCODP x 105) x Qunit ] / Qtotal ≤ 100
Qunit = Gross ARI rated cooling capacity of an individual HVAC or refrigeration unit (Tons)
Qtotal = Total Gross ARI rated cooling capacity of all HVAC or refrigeration
Small HVAC units (defined as containing less than 0.5 lbs of refrigerant), and other equipment such as standard refrigerators, small water coolers, and any other cooling equipmentThe equipment used for cooling room air in a building for human comfort. that contains less than 0.5 lbs of refrigerant, are not considered part of the “base building” system and are not subject to the requirements of this credit.
Do not install fire suppression systems that contain ozone-depleting substances (CFCsChlorofluorocarbons (CFCs) are a compound of carbon, hydrogen, chlorine and fluorine, once commonly used in refrigeration, that depletes the stratospheric ozone layer., HCFCsHydrochlorofluorocarbons (HCFCs) are refrigerants that cause significantly less depletion of the stratospheric ozone layer than chlorofluorocarbons. or HalonsHalons are substances, used in fire-suppression systems and fire extinguishers, that deplete the stratospheric ozone layer.).
Design and operate the facility without mechanical cooling and refrigeration equipment. Where mechanical cooling is used, utilize base buildingThe base building includes elements such as the structure, envelope, and building-level mechanical systems, such as central HVAC, etc. HVAC and refrigeration systems for the refrigeration cycle that minimize direct impact on ozone depletion and global warming. Select HVAC&R equipment with reduced refrigerant charge and increased equipment life. Maintain equipment to prevent leakage of refrigerant to the atmosphere. Utilize fire suppression systems that do not contain HCFCsHydrochlorofluorocarbons (HCFCs) are refrigerants that cause significantly less depletion of the stratospheric ozone layer than chlorofluorocarbons. or HalonsHalons are substances, used in fire-suppression systems and fire extinguishers, that deplete the stratospheric ozone layer..
Program to evaluate and regulate substitutes for the ozone-depleting chemicals that are being phased out under the Clean Air Act.
To determine the service life of a piece of HVAC equipment.
Required reference document for DES systems in LEED energy credits.
The table ranks commonly used refrigerants based on their life in the atmosphere. Longer-lived compounds typically have higher global warming potential (GWPGlobal Warming Potential (GWP) is a measure of substances’ ability to absorb heat and warm the atmosphere relative to carbon dioxide, which has a GWP of 1, over a given time period. ).
Article describing the movement towards Halon free chemicals with a comparative analysis.
Greenhouse Effect explained and illustrated.
Article explaining the ozone layer problem.
If you need to complete a CFC phase-out plan for LEED compliance, here's a sample.
This sample equipment spec sheet highlights the data points and calculations you'll need to use to determine the refrigerant charge (Rc) input required for LEED documentation.
Use this refrigerant management calculator to track and document your compliance with EAp3 and EAc4. You may also use the LEED Online credit form to document compliance, but that form has a finite number of rows, whereas this one can be expanded indefinitely. If you choose to use this calculator, add a narrative in LEED Online about using a supplemental calculator to complete calculations, and upload the document on LEED Online.
This template is the flattened, public version of the dynamic template for this credit that is used within LEED-Online v2 by registered project teams. This and other public versions of LEED credit templates come from the USGBC website, and are posted on LEEDuser with USGBC's permission. You'll need to fill out the live version of this template on LEED Online to document this credit.
Documentation for this credit can be part of a Design Phase submittal.
I downloaded the EAc4 calculator from this website and after I entered a variety (Lieberts, Mr. Slim's, chillers) of equipment into the spreadsheet, in the end the weighted average/ton is 99.9 therefore showing the project is compliant.
But when I fill out the EAc4 template online, the template shows that the project has an average refrigerant per ton of 102 and showing the project as non compliant.
Has anyone else ever been this close, how did you justify it and were you denied this credit by the reviewers?
Is your project v 2.2 or 2009? There are some slight differences between the default assumptions in v2.2 and NC-2009 related to equipment life that can lead to different calculations. But the calculator and both versions of the forms provide identical results if all the inputs are the same.
For compliance, I am not aware of anyone getting the credit by being close.
My project is actually 2009 and after posting I saw it in v2.2. After I saw your response that the calculator and both versions of the template should be the same, I went back to the calculator and saw the mistake. Thanks.
We are working on a multifamily building having 10 AHU1.Air-handling units (AHUs) are mechanical indirect heating, ventilating, or air-conditioning systems in which the air is treated or handled by equipment located outside the rooms served, usually at a central location, and conveyed to and from the rooms by a fan and a system of distributing ducts. (NEEB, 1997 edition)
2.A type of heating and/or cooling distribution equipment that channels warm or cool air to different parts of a building. This process of channeling the conditioned air often involves drawing air over heating or cooling coils and forcing it from a central location through ducts or air-handling units. Air-handling units are hidden in the walls or ceilings, where they use steam or hot water to heat, or chilled water to cool the air inside the ductwork. types, for which 3 of them have the refrigerant charge piping connected to a condensing unit on the roof (fifth floor). When filling out the template do you go by what the cutsheet of the units tell you (7.6 m of interconnecting piping) or do you go by what the contractor decides to install, which is not determined yet because the building is not built and therefore the charge on the long piping is not determined. Thanks.
If the equipment vendor can provide a selection sheet that includes a total required refrigerant charge(including all distribution piping) for this specific installation/project, you should use that number. It sounds like you may already have this information.
My equipment vendor is just providing a fixed number - 6.4 Lbs for a particular unit. What do we have to do to account for refrigerant in piping? I don't find any guidance in the LEED manual or the credit resources. Perhaps I have overlooked something?
Lawrence, you need to include the refrigerant in the piping.
Project is designed with natural ventilation in all habitable areas, except two elevator equipment rooms, which require controlled environment for equipment operation. Is there any way these two units can be considered as operational requirement only and not factor into Refrigerant Calculation?
Ravi, I don't follow your argument for not including those units. There is just one exception, for small equipment, that's noted in the credit language (see above).
Tristan, The reason is that the types of HVAC units available are not meeting the ozone depleting calculation requirements. Since these units are strictly for operation of the equipment and we have successfully designed the rest of the habitable building with natural ventilation, I am trying to find some justification to get this credit, maybe I am stretching it.
Ravi, I think you're stretching it—I don't see a justification that fits with the LEED credit requirements.
Tristan, I agree, this may be construed as stretching. Thank you for your quick response and as always, appreciate your help.
My understanding is that only Walk-in Coolers and Freezers would be considered "base buildingThe base building includes elements such as the structure, envelope, and building-level mechanical systems, such as central HVAC, etc." refrigeration equipment, and not "kitchen equipment" such as ice machines, display cases, etc.
Can anyone please confirm this? Thank you in advance!
That was my understanding, but my review came back saying I needed to include it and resubmit.
The credit language offers this guidance "Small HVAC units (defined as containing less than 0.5 lbs of refrigerant), and other equipment such as standard refrigerators, small water coolers, and any other cooling equipmentThe equipment used for cooling room air in a building for human comfort. that contains less than 0.5 lbs of refrigerant, are not considered part of the “base building” system and are not subject to the requirements of this credit."
So, I imagine that if any of your other equipment contains more then 0.5 lbs it would need to be included. Perhaps this was the case with your equipment as well Veronica?
Please also note the equipment must be permanently installed in the building
Yes, all the kitchen equipment on my project contains over 0.5 lbs and had to be included in the calculation. It had very little impact on the total calculation, but it was quite an ordeal to get the information from some manufacturers.
Thanks to everyone for the replies, and I think most, if not all our Kitchen Equipment with refrigerants will qualify as "portable" and *not* "permanently installed in the building". And therefore that equipment is not required to be included in the calculation.
I am sure that others have run into this situation before, so I hope there is a GBCIThe Green Building Certification Institute (GBCI) manages Leadership in Energy and Environmental Design (LEED) building certification and professional accreditation processes. It was established in 2008 with support from the U.S. Green Building Council (USGBC). accepted solution. Is there a way to find refrigerant charge through calculation or in a table, in pounds, when it is not a catalog listing that the manufacturer holds? We have 3 sizes of small split system units (not flooded coil thankfully). The standard verbiage is "pre-charged for 15' of line", however all the way up to the manufacturer's technical engineering department, no one can give us a figure of what that is. Table 2 (page 310) in the LEED reference guide seems like it is only a shorthand version of the calculation in order to simplify equipment selection. Our chillers and large Split-system DX units have both been clearly listed and therefore easy to attain, however we need this final piece of the puzzle to put this credit to rest. Thank you for your input.
Refrigerant charge is literally how much of refrigerant would you need to refill back into the system over time of use. This is something all AC manufacturers have to provide to the customer as a need for operation. Do you think you can find out the total lbs of refriigerant they expect it to be refilling for each unit, then calculate the lbs/ton yourself? The lbs/ton = lbs they expect to be refilling/ size of the AC unit. We got this information for our AC units. What manufacturer is this?
We have a building that uses indirect/direct evaporative coolers in lieu of nearly 60 tons of packaged DX systems. We have one 15 ton DX unit and a few 2 ton split systems for electrical rooms. The one packaged DX unit may be able to guarantee 0.5% leakage and longer life (25 years) and get us close to this credit. However, if we take out the evaporative coolers and add higher efficiency packaged DX units this would help offset the inefficient split systems. It seems counter to the intent that we need to add refrigerant to the project to reach this credit. Hence having only a 2 ton split system on a building that has an equivalent of 60 tons of evaporatively cooled and we lose this credit?
I believe the evaporative coolers don't have refrigerants? The credit accounts for only the equipment using refrigerants like the 15 ton DX unit and the 2 ton split systems. You might have calculated the combined effect of refrigerants to be less than 100.
Please provide more information about the project if we can help further.
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