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. That was true in early versions of LEED (and is still the case in the prerequisite, EAp3).
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 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 is more comprehensive than EAp3: Fundamental Refrigerant Management, which only concerns the use of ozone-depleting CFCs in equipment.
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 gross ARI-rated ton). 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.
Because requirements are based on the average refrigerant impact per ton of capacity, a low-performing system can be offset by high-performing systems, or a building with a large amount of heat pumps can still comply if the cooling capacity of the heat pumps is high enough.
That said, there are some project types where meeting these requirements will be more difficult. Supermarkets and restaurants with high volumes of commercial refrigerators need to carefully plan how to design HVAC&R systems to earn the credit.
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.
For new construction projects, the short answer is that you don’t have to worry about it: only the default leakage rate of 2% is accepted in the credit calculations.
All HVAC&R equipment that will serve the project building should be included in the calculations.
Any permanently installed piece of equipment containing greater than 0.5 lbs. of refrigerant and included in the project scope should be included in calculations.
The system capacity should be based on the outdoor units, while all parts of the system including outdoor, indoor units, branch selectors and piping should be counted for the total refrigerant charge.
The system capacity should be based on the outdoor units. If you have multiple interior devices connected to one outdoor unit, the cooling capacity should be for the outdoor unit, but the refrigerant charge must include all interior devices.
While a phase-out is allowed in the prerequisite, EAc4 is like other credits where the credit should be achieved as part of the LEED scope of work. The work should be completed during construction.
The project team must use equipment life values from the 2007 ASHRAE Applications Handbook as listed in the LEED Reference Guide. For equipment not listed in the ASHRAE Applications Handbook, the equipment life must be assumed to be 15 years—no estimates are allowed. An alternative equipment life may only be used if a manufacturer’s guarantee and equivalent long-term service contract can be provided.
Portable fire extinguishers are not required to be included in EAp3 or EAc4.
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 credit form 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.
Even one piece of equipment can tip your calculations to compliance or noncompliance. Use the calculator in the LEED Online credit form 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 credit form. It is the relationship between how much refrigerant is needed (in pounds) and the cooling capacity (in gross ARI-rated 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 2009 for New Construction and Major Renovations
To reduce ozone depletion and support early compliance with the Montreal Protocol while minimizing direct contributions to climate change1. Climate change refers to any significant change in measures of climate (such as temperature, precipitation, or wind) lasting for an extended period (decades or longer). (U.S. Environmental Protection Agency, 2008)
2.The increase in global average temperatures being caused by a buildup of CO2 and other greenhouse gases in the atmosphere. This temperature change is leading to changes in circulation patterns in the air and in the oceans, which are affecting climates differently in different places. Among the predicted effects are a significant cooling in Western Europe due to changes in the jet stream, and rising sea levels due to the melting of polar ice and glaciers..
Do not use refrigerants.
Select refrigerants and heating, ventilating, air conditioning and refrigeration (HVAC&R) that minimize or eliminate the emission of compounds that contribute to ozone depletion and global climate change1. Climate change refers to any significant change in measures of climate (such as temperature, precipitation, or wind) lasting for an extended period (decades or longer). (U.S. Environmental Protection Agency, 2008)
2.The increase in global average temperatures being caused by a buildup of CO2 and other greenhouse gases in the atmosphere. This temperature change is leading to changes in circulation patterns in the air and in the oceans, which are affecting climates differently in different places. Among the predicted effects are a significant cooling in Western Europe due to changes in the jet stream, and rising sea levels due to the melting of polar ice and glaciers.. 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 must comply with the following formula, which sets a maximum threshold for the combined contributions to ozone depletion and global warming potential:
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 HVAC&R equipment must be calculated using the following formula:
Small HVAC units (defined as containing less than 0.5 pounds 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 pounds of refrigerant, are not considered part of the base building system and are not subject to the requirements of this credit.
Do not operate or install fire suppression systems that contain ozone-depleting substances such as CFCsChlorofluorocarbons (CFCs) are a compound of carbon, hydrogen, chlorine and fluorine, once commonly used in refrigeration, that depletes the stratospheric ozone layer., hydrochlorofluorocarbons (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&R systems for the refrigeration cycle that minimize direct impact on ozone depletion and global climate change1. Climate change refers to any significant change in measures of climate (such as temperature, precipitation, or wind) lasting for an extended period (decades or longer). (U.S. Environmental Protection Agency, 2008)
2.The increase in global average temperatures being caused by a buildup of CO2 and other greenhouse gases in the atmosphere. This temperature change is leading to changes in circulation patterns in the air and in the oceans, which are affecting climates differently in different places. Among the predicted effects are a significant cooling in Western Europe due to changes in the jet stream, and rising sea levels due to the melting of polar ice and glaciers.. Select HVAC&R equipment with reduced refrigerant charge and increased equipment life. Maintain equipment to prevent leakage of refrigerant to the atmosphere. Use 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.
Sample LEED Online forms for all rating systems and versions are available on the USGBC website.
Documentation for this credit can be part of a Design Phase submittal.
In a project I'm working on , we are using two heat pumps for cooling and heating,such that only one heat pump is going to be used during the summer season(cooling) and both pumps are to be used in winter (heating). My question is do we need to enter the two heat pumps data into the Refrigeration Impact Calculation table or just one ?
We were previously unable to achieve this credit for a project receiving chilled water from a campus central plant employing 4 electric centrifugal chillers and 3 heat recovery chillers. The tonnage for these chillers was originally input as their total capacity, but we would like to reduce that tonnage to just that which is dedicated to our building (the plant serves like 20 buildings). Is it acceptable to take just our building's peak cooling load and distribute this evenly among the chillers for the "Q (tons)" variable? If so, what supporting documentation besides a load calc might be needed? Thanks.
If a university building is tied in to a campus chilled water distribution, does the campus chiller plant have to be included in the building's refrigerant use?
If the building is only to use chilled water coils from this loop, does this satisfy the requirement?
Yes, the campus chiller plant must be included on the calculations, check section 2.6 in the district energy guide http://www.usgbc.org/resources/des-district-energy-systems-guidance-v22-...
To my knowledge you do not need additional chillers or heat pumps in the project building to satisfy the credit.
The reference guide definition of Rc states "0.5 to 5.0 lbs of refrigerant per ton of gross ARI rated cooling capacity". What do you do for equipment that has a charge of above 5.0 lbs/ton?
You should use the actual refrigerant charge in the credit calculations. However, you'll need to have very refrigerant-efficient equipment elsewhere in your project to balance out that charge and meet the credit requirements, depending on the refrigerant type and equipment lifespan.
In our project there are couple of cool rooms/freezers using reciprocating compressors.
Shall we list it as reciprocating compressor or we need to select other and type in refrigeration units?
The problem is if we select other then we need to upload documentation to support the life span,etc.
Thank you :)
I would list as reciprocating
There is no mention of screw chillers either under the credit EA 4 or ASHRAE application.
I can only see absorption, scroll and reciprocating.
Can someone please help me with the life span to consider for screw chillers?
As you know it has to be backed up by a source etc.
If you have specific documentation on the equipment lifespan from the manufacturer, like a guarantee/warranty or service contract, then you should use that lifespan. If you don't have any information, you should use the default "other equipment" lifespan of 15 years.
If I only use HVAC units totally 0.5 lbs of refrigerant on the project, do I qualify for the 2 points in this credit?
If I only use many HVAC units with 0.5 lbs of refrigerant per unit, do I still qualify for the 2 points in this credit?
Yes. If you can avoid refrigerants you would be eligible. Similarly, if all your refrigerants were in equipment with a charge of 0.5 lbs or less, you would be eligible.
we use VRF system for A/c we use value given in LEED guide Rc 2.2 lb/ton
As per the the default calculation we get points but the reviewer tells Rc for VRF is very low it may be "3 - 6" lb/ton
Is it possible to get points for VRF system
awaiting For your Reply
The refrigerant charge (Rc) should be the actual amount of refrigerant being used. The table in the Reference Guide shows you the maximum charge that would still meet the credit - it is not a default.
In the case of VRF (or any split system), you must include all the refrigerant in the distribution piping. This usually makes the credit very difficult for VRF systems to achieve.
Thank you for your support
I am very new to LEED and trying to apply for it for a project we have in hand. There are some issues with table L-2 of eac4.
Table L-2 of eac4 cannot be filled in manually and is to be auto-populated using eap3 table. In this case, eap3 is filled out and is located in the same folder as eac4.
The link between the two files doesn't seem to work.
Can someone please help?
If you are having trouble with the forms you should ask for help through the Help Center on LEED Online.
I am working on a large project for which the cooling is predominantly from central chillers providing chilled water. This complies easily with the requirements of EAc4.
However, there are also split systems provided for standby cooling in the event that there should be some failure in the chilled water system. Do these back-up systems need to be included in the calculations? As they will not be at their working pressure, the leakage should be low and refrigerant pump down systems could be added if required to further reduce the leakage when they are not in use.
Interesting question. The credit language applies only to "base-building systems". Lately reviewers have taken that to mean all the equipment that provides primary cooling whether installed by the owner or a tenant. But back-up systems have not been addressed and I don't find any previous rulings on the topic.
Logically, I would say that the back-up systems should be included, but you might want to submit an interpretation to confirm.
I have a project with a commercial kitchen, so we're gathering info on all of the walk-in coolers, freezers, etc. However, I'm not sure how to document the ice maker cooling capacity since they are specified with an ice harvest rate (lbs/24 hrs) and energy consumption rate (kWhA kilowatt-hour is a unit of work or energy, measured as 1 kilowatt (1,000 watts) of power expended for 1 hour. One kWh is equivalent to 3,412 Btu./100 lbs ice) not a direct cooling capacity. Can I just multiply these values for a 24-hr average kW cooling capacity, then convert to tons?
(FYI, I tried deciphering the Energy Star product criteria for more details but I don't think it helps... http://www.energystar.gov/index.cfm?c=comm_ice_machines.pr_crit_comm_ice...)
I'd start by arguing that an ice maker is not "base-building" equipment. You will likely lose that argument.
The cooling capacity should be a multiple of the input energy, so I think you've got to figure out the total cooling effect. That's the latent heat of fusion for the ice produced + the cooling of the input water from tap temperature to 0˚C/32˚F. If you just use the input kW you'll shortchange yourself.
Too bad you can't just figure out how many tons of ice you are making.
To follow up on my original post, the ice maker supplier was eventually able to provide a "heat load chart" (in BTUA unit of energy consumed by or delivered to a building. A Btu is an acronym for British thermal unit and is defined as the amount of energy required to increase the temperature of 1 pound of water by 1 degree Fahrenheit, at normal atmospheric pressure. Energy consumption is expressed in Btu to allow for consumption comparisons among fuels that are measured in different units./hr) for each product model. I'm using that since it's all I have.
Christopher, I agree with your "base buildingThe base building includes elements such as the structure, envelope, and building-level mechanical systems, such as central HVAC, etc." argument but the Reference Guide as written suggests that anything other than a plug-in beverage cooler must be included. If anyone has more a specific clarification on refrigeration equipment, please share!
I'm hoping to get some feedback on what is actually required to be uploaded in support of table 4-1. Our MEP engineer is claiming that the numbers he provided in table 4.1 were default life value numbers ( as opposed to non-default life value numbers); and the upload requires documentation that support the non-default values only. We are not able to meet compliance without any uploads to the form. Are we missing something here? What is actually required to be submitted for this credit?
People seem to get confused by Table 2 in the Reference Guide, which lists maximum refrigerant charge that will still meet the credit, per refrigerant type. These are not defaults, there are no defaults.
You should fill out the table with the actual refrigerant charge for each piece of equipment. You don't typically need to submit the equipment cut sheets, but you should have them handy in case the reviewer asks for back up info.
For split systems, don't forget to include all the refrigerant used to fill the piping.
Hi Chris! Thanks for giving us some feedback on this credit. I have a follow up question for anyone who can answer. If the refrigerant charge (Rc) number entered into the Refrigerant Impact Calculation (Table EAc4-1) for each piece of equipment listed is more than the amount listed in the reference guide, will we only meet the credit if the life of the equipment is longer than the typical years listed? We are meeting the average refrigerant impact per ton, but our Rc numbers seem several times higher than what's listed in Table 2 from the reference guide. Any feedback on this would be great! Thanks
1) you are going to have a hard time convincing the reviewers your equipment has a longer than normal life.
2) If the Rc for each is more than the reference guide table, you are not going to get the credit.
I have a project with an air-source heat pumpA type of heating and/or cooling equipment that draws heat into a building from outside and, during the cooling season, ejects heat from the building to the outside. Heat pumps are vapor-compression refrigeration systems whose indoor/outdoor coils are used reversibly as condensers or evaporators, depending on the need for heating or cooling. In the 2003 CBECS, specific information was collected on whether the heat pump system was a packaged unit, residential-type split system, or individual room heat pump, and whether the heat pump was air source, ground source, or water source. that can either do heating, cooling or simultaneous heating and cooling. The heat pump has two refrigerant circuits. Can I count the heating tonnage against one of the refrigerant circuits and the cooling tonnage against the other?
Is it possible to use the refrigerant R-1234 (HFO) to replace the R-134 in a centrifugal chiller?
It has low 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. (around 4 or 5) and zero ODPOzone Depletion Potential (ODP) is a measure of ozone impact a chemical has relative to CFC-11 (trichlorofluoromethane), which has a ODP of 1. , but it is not in the LEED online form nor in the BD&C guide.
Do we have to do a CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide?
Thanks in advance.
Use the data you have for the refrigerant, and list your source of information. I don't think you need a CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide.
We have a MR V3.0 project that uses district cooling.
First I thought this was great, as no refrigerants are used in the building.
Now the district energy guidelines say, that we have to provide all the data, even for the upstream equipmentUpstream equipment consists of all heating or cooling systems, equipment, and controls that are associated with a district energy system but are not part of the project building's thermal connection or do not interface with the district energy system. It includes the central energy plant and all transmission and distribution equipment associated with transporting the thermal energy to the project building and site., and show that it meets the credits requirements.
Problem is, that the district cooling provider is in no way obliged to lay open his books and give the client somewhat sensitive data about his cooling production. So it is very hard, if not impossible, to get the necessary data for this credit.
I really had to laugh when I read that for Enhanced Commissioning, the upstream equipment has to be commissioned...really? We have absolutely no claim to get access to the production plant.
The district cooling contract just says you buy cold water and give back slightly warmer water in return.
Or am I misinterpreting things?
Unfortunately it's true, and I feel your pain! Having a good relationship with a third-party district plant manager can be tricky, but the benefit is that you have a better chance at improving the performance for your own building through including the upstream equipmentUpstream equipment consists of all heating or cooling systems, equipment, and controls that are associated with a district energy system but are not part of the project building's thermal connection or do not interface with the district energy system. It includes the central energy plant and all transmission and distribution equipment associated with transporting the thermal energy to the project building and site. in the credits listed in the District Energy System Guidelines. For this credit in particular, it's a question of meeting the credit intent--is keeping the refrigerant use for your building outside in a district plant really the same as not having any refrigerants?
If you haven't already, I would recommend posting in the Enhanced Commissioning credit forum for advice on commissioning upstream equipment, as lots of people have shared their experiences with district systems there as well.
The link above for the 2007 ASHRAE Applications Handbook, HVAC Applications seems to be broken.
Does anyone have information on how to determine the service life of a piece of HVAC equipment?
For anyone else who is wondering, I found my answer on pages 310/ 311 of the LEED v2009 Reference Guide.
Was just wondering if someone could shed some light on the Refrigerant Charge and how I go about finding it? I am using R-410A as the refrigerant.
John, this is typically covered in the system specs. Can you clarify what obstacles you're facing in finding it? (If you join LEEDuser as a member, you'll get lots of useful guidance on this above.)
I always have a hard time finding the refrigerant charge and i have looked at specs. What else can you recommend Tristan? Thank you.
My reply is late for the OP but may help others...
In my experience the refrigerant charges are difficult to obtain since they are rarely included in equipment specs / cut sheets / shop drawings. I've always had to request the info from the equipment suppliers. It may be listed in the manual if the equipment is pre-charged at the factory. The real challenge is with systems requiring field-installed refrigerant lines (split DX systems, coolers/freezers with remote condensers, etc) since the refrigerant charge depends on the size and length of installed piping. In that case, I request an estimate from the refrigeration contractor once we've received shop drawings, then request confirmation once the equipment has been installed and charged.
For consultants, it would be good practice to specify it as a parameter to be included in the supplier's equipment shop drawings and/or as part of the contractor's materials reporting requirements for LEED credits.
Hi! We use a heatpump system, which is used to supply heat as back-up solution. The processes in our building produce waste heat which is utilized for heating the building, but in case extra heating is needed the heat pumps kicks in.
The heatpump uses R407C.
How to determine the cooling capacity then? The system is not made for cooling at all, it has 24 kW of heating capacity.
I would think that the form does not support this kind for system.
Can I ignore the heatpump for this credit?
Many thanks in advance.
This is a really interesting question! Although there's no clear international compliance path for this credit that I know of that could provide clear guidance, it'd be great to hear if anyone's had experience with this on international projects in heating-only climates.
When it comes down to it, the intent of this credit is all about the use efficiency of the refrigerants for space conditioning compared to their environmental impacts. My instinct is that it makes sense to use the heating capacity instead of the cooling capacity in the calculations, because then you're still finding the average refrigerant impact per kW of conditioning capacity. If you do go this route, I would be sure to provide at least an extra narrative explaining that the calculations are based on heating capacity to avoid confusion.
Yes, definitely an interesting question. Please keep us updated if you decide to include heat capacity in your calcs. I agree with Melissa that including heating capacity in calcs is in alignment with the intent of the credit. Taking this one step further then, do you think that both cooling AND heating capacity should be included in calcs for a VRF system that transfers excess heat from one part of the building to another part? If instead of VRF, the spaces were cooled and heated with two separate systems (and the heating system was a heat pumpA type of heating and/or cooling equipment that draws heat into a building from outside and, during the cooling season, ejects heat from the building to the outside. Heat pumps are vapor-compression refrigeration systems whose indoor/outdoor coils are used reversibly as condensers or evaporators, depending on the need for heating or cooling. In the 2003 CBECS, specific information was collected on whether the heat pump system was a packaged unit, residential-type split system, or individual room heat pump, and whether the heat pump was air source, ground source, or water source.), then following the logic of this thread, you would account for refrigerant in both the heating and the cooling systems. So wouldn't it be appropriate then to account for both heating and cooling capacities in a single VRF system?
It sounds like what you're talking about is a heat recovery function in the VRF system. From a holistic perspective, that would be a great strategy compared to the alternative you suggest as far as reducing both refrigerant and potentially energy as well. However, if the excess heat is already in the building and not brought in from the outside through a refrigerant cycle, it seems to me like it starts to go beyond the simple equipment refrigerant use efficiency metric that this credit is based on.
There are also some other special considerations for VRF and VRV systems for this credit which are covered in the Bird's Eye View above.
Does anybody have an example of a long term service contract, or know specifically what needs to be included in the contract in order for it to be accepted by the 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). reviewer? We have a signed document from the equipment manufacturer attesting to the life span of the equipment and commiting to servicing the unit over its life, but it was not accepted by the GBCI reviewers. Are the GBCI reviewer looking for a more detailed scope document that outlines how the unit will be serviced? Any input would be appreciated. Thanks!
Does anyone have any experience earning compliance with this credit in a Dining Hall application?
Laura, any specific questions you have?
Yes, we are working on a dining hall project and would love to earn compliance with this credit but due to the fact there is a lot of refrigeration equipment, it seems nearly impossible to achieve. Does anyone have any experience achieving compliance with this credit for this applicable and if so, any recommendations you could give?
We have some large commercial catering refrigerators and freezers which are standalone and plugged into a normal power socket rather than integral to the building. The refrigerant charges of a couple of these are greater than 0.5lbs therefore I understand that these need to be considered for EAp3 and the EAc4 credit (EAp3 is straight forward). However the calculations for the EAc4 are based on Air Con systems and not refrig units. Has anyone successfully shown that they have a compliant refrigerator if they put it through the EAc4 calculator or is it always the case that the Building's chillers systems need to offset the non compliant refrigeration units.
The ref guide talks about "all Base BuildingThe base building includes elements such as the structure, envelope, and building-level mechanical systems, such as central HVAC, etc." systems in which case I would rather exclude the standalone catering equipment from the calculations but then again... the wording also suggests that anything over 0.5lbs needs to be accounted for.
1) Does off the shelf plug in catering equipment really need to be included in EAc4
2) Has anyone got any examples of compliant refrigerator or freezer units (EnergyStar listings are not helpful in this regard)?
I'm also wondering what the answers to these questions are?
How does one determine if a piece of equipment "contains greater than 0.5 lbs. of refrigerant"? I've been checking cut sheets and called an equipment vendor but I can't find this information. Is there a general rule of thumb?
In a preliminary design review for our project, the reviewer has asked us to provide supplementary calculations to show the credit compliane. We are currently using the version4 of the form and it doesn't have the provision to upload any additional documents for this particular credit. Can anyone suggest how we can go about this.
Many thanks for the help.
Mridual, check the "additional circumstances" box on the form and you should see a place to enter a short narrative and upload documentation.
Thanks Tristan. Did the same.
Has anyone had any experience combining the approaches in Option 1 and Option 2 to achieve this credit? We plan to use economizerAn economizer is a device used to make building systems more energy efficient. Examples include HVAC enthalpy controls, which are based on humidity and temperature. cooling for most of our cooling needs. Economizer cooling is simply increasing outdoor air flow rates when cooling is needed - in our climate, OA is cooler than indoor spaces subject to internal loads. We do also have a few small split-AC units for communication/server rooms, so we cannot use Option 1. However, we are minimizing the amount of refrigerant used in the building by cooling with outdoor air (which has ODPOzone Depletion Potential (ODP) is a measure of ozone impact a chemical has relative to CFC-11 (trichlorofluoromethane), which has a ODP of 1. =0 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. =0). It seems reasonable to me to claim credit for the refrigerant reduction inherent in economizer cooling.
My approach to documentation is this: Use Option #2, but instead of using the Rc of the AC units and refrigerant lines, I plan to modify the Rc to take into account the cooling provided by economizer cooling. The modified Rc would be equal to the total refrigerant charge of the AC system divided by the total cooling tons provided to the building by BOTH the AC system and the Economizer system. This would result in an accurate "unit of refrigerant per unit of cooling" figure.
A different method that just occurred to me would be to add the economizer cooling system as a separate HVAC equipment, with "Refrigerant Used" being "None" (in EAp3 template). This seems more direct to me.
Has anyone used this approach before? Do you think this is reasonable?
Thanks for your input.
Unfortunately, the credit does not incentivize reduction in refrigerant (unless no refrigerants are used at all). Rather, it is based on refrigerant management which takes into account leakage rates, equipment life, and types of refrigerant used. So, regardless of how often you are using your refrigeration equipment, you need to enter the data from all systems.
As you can imagine, your economizerAn economizer is a device used to make building systems more energy efficient. Examples include HVAC enthalpy controls, which are based on humidity and temperature. strategy is used very often here in Canada. However, it is rare that an owner will agree to zero DX cooling. It seems you might be in the same boat, since you say that economizer mode will be used for "most" of you cooling.
Thank you, David. It still seems to me that using a cooling system that has no refrigerants (i.e. EconomizerAn economizer is a device used to make building systems more energy efficient. Examples include HVAC enthalpy controls, which are based on humidity and temperature. cooling) reduces the ozone and global warming impact related to cooling the building. 92% of the cooling load for the building is handled by a zero-refrigerant system. Over 95% of the floor space of the building is conditioned by a zero-refrigerant system. Isn't this better than using refrigerant-based cooling systems to condition the whole building (meaning more refrigerant leaking, more emissions, etc.)? I don't understand the logic of treating the zero-refrigerant approach as an all-or-nothing proposition.
Hi Lyle. I'm with you, I just don't know of a USGBC ruling to support this method (e.g. you may need to make an official query). I searched the CIRs here in Canada, and there is a recent one (February) where the applicant is using evaporative cooling (no refrigerants) for most of the building, and then split systems for servers etc. They wanted to know if/how they could account for the evaporative system. It seems the CaGBC's answer leans your way (I should have checked these first!):
"Projects using evaporative cooling may consider these systems in the EAc4 calculations under Option 2. For simplicity, in order to calculate the Average Refrigerant Atmospheric Impact, the 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. of the evaporative cooling system can be entered as zero in the LEED Letter Template for this system. Furthermore, any number may be entered under the Rc (lb/ton) for this system as this value become irrelevant to the calculation when ODP and GWP are zero. ... Submissions should include a narrative explaining the conditions at which the rated capacity (Qunit) of the evaporative cooling system is determined."
You may want to use this as a basis for your question. Canadian CIRs are not applicable to the USGBC, but should provide an indication.
Thank you, David. That is very helpful. Can you please tell me what CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide# (or LI-Canada#?) you are referring to? I'm not sure if I have access to Canadian CIR database, but it will help me to find it or reference it accurately.
Sorry for the delay, Lyle. I am referring to CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide 1105: "Using evaporative cooling systems under EAc4 Option 2". Hope that helps.
Just curious if anyone has pursued this methodology (and earned compliance) for EAc4 with evap cooling to date?
It worked for me for economizerAn economizer is a device used to make building systems more energy efficient. Examples include HVAC enthalpy controls, which are based on humidity and temperature. cooling. I think the key was a very proactive narrative justifying the approach. I think this should be incorporated into an addenda.
Regarding EAc4 equipment life, the reference guide tries to summarize the equipment life by system from the ASHRAE Applications Handbook 2007, but does not accurately represent heat pumps. Here's my point:
Ref. guide states: "Assume equipment life as follows (from ASHRAE Applications Handbook 2007):
-Window air-conditioning units and heat pumps, 10 years
-Unitary, split, and packaged air-conditioning units and heat pumps, 15 years"
If you look at the equipment life table from ASHRAE Applications Handbook 2007, the first bullet is partially correct as window AC units are listed as 10 years (although the table has no window heat pump).
The issue I have, is with the second bullet, as it basically says that all other heat pumps have 15 year equipment life. The ASHRAE table lists 15 year life for Residential single or split package AC, Commercial through-the-wall AC, Residential air-to-air, and Commercial air-to-air. However, it lists >24 years for Water-cooled package AC and Commercial water-to-air heat pumps.
For a water source AC or heat pump unit, 9 year difference in service life makes a big difference with the refrigerant calculation. Has anyone run into any problem with this by using 24 years for water source heat pumps?
I ran into the same issue with two NC projects where we had WSHP's. You have to be able to justify using 24 years. I attached a PDF copy of both the 2007 and 2011 equipment Median Life Cycle ASHRAE application tables and cited both water cooled package and commercial water to air equipment using Abramson etEvapotranspiration (ET) is the loss of water by evaporation from the soil and by transpiration from plants. It is expressed in millimeters per unit of time. al. 2005 studies.
You could also contact your LEED Review Ceritifcation Body Team for further clarification.
Jesus, Did they accept the ASHRAE 2011 equipment median life you cited?
We have a project where a Walk-in refrigerator and freezer are planned. These rooms will be equiped with dedicated split-system charged with R404.
It seems that the Rc will be above the 5lb/tons, mostly because of the distance between the freezer rooms and the mechanical rooms.
In the LEED-Canada template, there a limit of 5lb/ton. Is this an ARI requirement or could we just propose an alternate calculation to demonstrate compliance.
All the other systems are compliant with the requirements.
Earning this credit is based on the average refrigerant impact per ton, for all HVACR equipment in the project scope. It is possible that you can still comply if one type of equipment exceeds the maximum charge. But if you have entered all your equipment into the credit form and still do not comply, you may be out of luck.
We are using the EAc4 calculator published by Trane for a similar scenario. As it uses the same default values and formulae, we're confident it will be accepted in lieu of the LEED Canada template that doesn't accept an input greater than 5lb/ton.
For refrigeration equipment(Freezers/coolers etc etc) what is the life expectancy that should be put into the EAC4 template? The equipment in question are freezers and coolers that are to be attached to Indoor Water-Cooled Remote condensing units. There is no manufacturing data as the equipment is custom made.
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