CS-2009 EAc4: Enhanced Refrigerant Management

  • NC_CS_EAc4_Type3_Refrigerant Diagram

  • Some common misconceptions

    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). 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 (ODP and GWP), 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. 

    Two main requirements

    To earn this credit, you’ll need to:

    • minimize refrigerant environmental impact by avoiding refrigerants entirely or using systems that reduce their harmful impacts; 
    • and not install or retain fire suppression systems with CFCs, HCFCs or halonsHalons are substances, used in fire-suppression systems and fire extinguishers, that deplete the stratospheric ozone layer.. 

    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.

    Why it matters

    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.

    Thinking ahead to earn the credit

    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.

    A centralized plant helps

    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.

    FAQs for EAc4

    Where can refrigerant equipment rates be obtained for equipment?

    Per LEED InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. #1540 issued 9/11/2006 and rescinded on 4/30/2009, NC-v2.2 projects registered after April 30, 2009 must use default values for leakage rates. All NC-2009 projects must use default values for leakage rates.

    In the past the use of non-default leakage rates were acceptable provided that documentation was provided. Has that changed?

    Yes, USGBC is no longer accepting non-default leakage rates.

    Which portions of a VRF/VRV system should be considered for this credit?

    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.

    Should all commercial refrigerant equipment be accounted for, including both upright and under-counter?

    Any piece of equipment containing greater than 0.5 lbs. of refrigerant should be included in calculations.

    For a split system, does the cooling capacity refer to the cooling power of the interior device (evaporator) or of the outdoor unit (condenser)?

    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.

    What is the required timeline for completing a CFC phaseout for EAc4?

    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.

    How can I document a longer equipment life (20 or 30 years) than what is listed in the LEED Reference Guide?

    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, an assumed equipment life of 15 years must be used. An alternative equipment life may only be used if supporting documentation can be provided justifying the value. As stated in the LEED Reference Guide, acceptable supporting documentation includes a manufacturer’s guarantee and equivalent long-term service contract. An estimated equipment life is not allowed.

    Do the requirements apply to portable fire extinguishers or only permanently installed building-wide fire suppression systems?

    Portable fire extinguishers are not required to be included in EAp3 or EAc4.

Legend

  • Best Practices
  • Gotcha
  • Action Steps
  • Cost Tip

Pre-Design

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  • Consider Option 1

  • 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.

  • Option 2 

  • To comply with Option 2, you’ll need to calculate the weighted impact of the following characteristics of all refrigerants used in your project: 

    • environmental impact (through destruction of the ozone layer and the concentration of greenhouse gases in the atmosphere);
    • coolant capacity and refrigerant charge (determined by equipment specs); 
    • rate of refrigerant leakage (determined by equipment life);
    • and end-of-life refrigerant loss (largely determined by equipment specs).

  • 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. 

  • Core and Shell projects include all equipment within the project scope and LEED boundary. For example, this may include AC systems in common areas and heat pumps in tenant spaces.

  • 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. 

Schematic Design

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  • 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. 

Design Development

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  • 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. 

Construction Documents

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  • 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.) 

Construction

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  • 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. 

Operations & Maintenance

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  • 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. 

  • USGBC

    Excerpted from LEED 2009 for Core and Shell Development

    COPYRIGHT © 2009 BY THE U.S. GREEN BUILDING COUNCIL, INC. ALL RIGHTS RESERVED

    EA Credit 4: Enhanced refrigerant management

    2 Points

    Intent

    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..

    Requirements

    Option 1

    Do not use refrigerants.

    OR

    Option 2

    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 building 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:

    LCGWP + LCODP x

    105

    		 ≤ 100




    Calculation definitions for 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 HVAC&R equipment must be calculated using the following formula:

    ∑ ( LCGWP + LCODP x 105 ) x

    Qunit

    		≤ 100
    ——————————————————————————————

    Qtotal




    Calculation definitions for [ ∑ (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 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..



    Potential Technologies & Strategies

    Design and operate the facility without mechanical cooling and refrigeration equipment. Where mechanical cooling is used, utilize base building HVAC&R systems for the refrigeration cycle that minimize direct impact on ozone depletion and 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..

Organizations

US EPA Significant new alternative policy

Program to evaluate and regulate substitutes for the ozone-depleting chemicals that are being phased out under the Clean Air Act.

Technical Guides

2007 ASHRAE Applications Handbook – HVAC Applications

To determine the service life of a piece of HVAC equipment.

Treatment of Distric or Campus Thermal Energy in LEED v2 and LEED 2009 (Updated August 13, 2010)

Required reference document for DES systems in LEED energy credits.

Web Tools

Atmospheric Life of Refrigerants

The table ranks commonly used refrigerants based on their life in the atmosphere. Longer-lived compounds typically have higher global warming potential (GWP).

Publications

Green Fire suppression technologies

Article describing the movement towards Halon free chemicals with a comparative analysis.

Greenhouse Effect

Greenhouse Effect explained and illustrated.

The Greenhouse Effect

Greenhouse Effect explained and illustrated.

Articles

Good Ozone, Bad Ozone

Article explaining the ozone layer problem.

Refrigerant Management Calculator

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.

LEED Online Forms: CS-2009 EA

The following links take you to the public, informational versions of the dynamic LEED Online forms for each CS-2009 EA credit. You'll need to fill out the live versions of these forms on LEED
Online for each credit you hope to earn.

These links are posted by LEEDuser with USGBC's permission. USGBC has certain usage restrictsions for these forms; for more information, visit LEED Online and click "Sample Forms Download."

The following links take you to the public, informational versions of the dynamic LEED Online forms for each CS-2009 EA credit. You'll need to fill out the live versions of these forms on LEED
Online for each credit you hope to earn.

These links are posted by LEEDuser with USGBC's permission. USGBC has certain usage restrictsions for these forms; for more information, visit LEED Online and click "Sample Forms Download."

Design Submittal

PencilDocumentation for this credit can be part of a Design Phase submittal.

36 Comments

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Adam Targowski Owner ATsec
Jan 22 2013
LEEDuser Member
573 Thumbs Up

EA Cre 4_LEEDonline form

This credit is listed in Appendix 4 under case C so it should include tenant spaces as well. I have a question regarding filling in the LEEDonline form. Is it ok if we fill in the form only with equipment data from C&S scope of work and provide sample tenant lease requiring tenants to comply with LEED requirements for they spaces? We don't have to fill in the table with predicted data for tenant spaces since we don't really know what they will install (and tenant lease will cover that), is that correct?

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Mar 21 2013 LEEDuser Moderator

Sounds to me like this is the right approach.

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Ismael Arroyo Director Energetica Soluciones y Consultoria IAC S.A.
Jun 19 2012
LEEDuser Member
17 Thumbs Up

hi The project we´re working

hi

The project we´re working on will be cooled by coolling towers, so the tenants can have cooled water to install their own HVAC system. We´re no using any type of refrigerant, but a mechanical cooling system. Can we apply to this credit?

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Ante Vulin Sustainability Manager, YR&G Jun 20 2012 LEEDuser Expert 354 Thumbs Up

Ismael, this credit is a "Case C" credit, according to CS Appendix 4 in the BDC Reference Guide, meaning that in cases with a limited scope of work "compliance cannot be documented without including data from anticipated tenant work. . . such data must be supported by tenant sales and/or lease agreements."

It sounds like future tenants will install HVAC systems with refrigerants, and so you can only pursue this credit if these tenants will be required to comply with the credit.

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Yoyo Shek Consultant Allied Environmental Consultants Limited
May 25 2012
LEEDuser Member
32 Thumbs Up

List of Approved non-default leakage rate

I think most of the projects have encouraged similar project when dealing with the 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). (2% by default).
Does anyone know if USGBC has a list for those approved refrigerants/suppliers that we could apply a lower leakage rate? I think it would be more convenient for all project runner.

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Hernando Miranda Owner, Soltierra LLC May 25 2012 Guest 2761 Thumbs Up

LEED claims the forced default is 2%, and cannot be changed. This may not be true.

Trane was allowed to use a 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). of 0.5% for new R-123 chillers, which is completely ridiculous. It is ridiculous because leakage rate has a huge impact on the calculations. More than any of the other factors.

Trane seems to claim you can still use their 0.5% rate.

http://www.trane.com/Commercial/EnergyIaqEnvironment/8_2_1_LeedAndGreenB...

Trane's alternative calculation tool: http://www.trane.com/Commercial/Uploads/Xls/2282/EAc4Calculator_LEED-V3_...

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Yoyo Shek Consultant, Allied Environmental Consultants Limited May 28 2012 LEEDuser Member 32 Thumbs Up

I have a project that exactly uses Trane model thus obtain that 2 points.
But I also still think it is not reasonable as the 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). seems to be the only factor to determine the credit compliance.
Moreover, the steps to provide the leakage rate <2% are somewhat impractical for residential A/C unit.
Besides, if we have to keep the leakage rate = 2%, that means we need to limit the refrigerant charge (lbs/ton). However, I can't find any model that could offer such "low" refrigerant charge. Of course, perhaps I miss out some. Otherwise, that just means the credit is not practical to meet.

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Hernando Miranda Owner, Soltierra LLC May 28 2012 Guest 2761 Thumbs Up

The Trane 0.5% leakage could only be used for R-123 chillers. It would not automatically apply to all Trane equipment.

Small sized HVAC units will not comply with the credit regardless of the refrigerant type, assuming you are using standard refrigerants (R-410a). The reason is that the refrigerant charge per ton is always higher with smaller tonnage equipment. For R-410a the charge has to be about 1.98 lbs/ton to drop below 100 for the calculated impact.

Refrigerant HFO-1234yf has ZERO ODP and 4 GWP. This is a replacement for R-134a, a refrigerant used in car A/C systems. While approved for car use, and starting to be used in non-mobile applications in Europe, this is a long way from being used in small scale building A/C systems in the U.S.

The USGBC EAc4 equation did not consider that the method would prevent small scale systems from qualifying and would nearly always allow all large commercial equipment to qualify. In other words, they developed a tool to give a LEED point for large scale projects at the expense of the smaller LEED projects.

The USGBC did not invent the calculation method. They borrowed it. The calculation method was developed in 1993 based on a study of chillers using R22, R123 and R134a.
It was not a study based on any other HVAC equipment type or refrigerants.

Because 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). is the determining factor in the calculations, and lower OPD & GWP refrigerants generally require higher charges per ton you can easily figure out that newer environmentally responsible refrigerants will never be green in LEED, but environmentally less responsible refrigerants will always be considered green in LEED.

Unfortunately, the above is the way it is with LEED and EAc4. The one-size-fits-all equation doesn't make environmental sense.

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Yoyo Shek Consultant, Allied Environmental Consultants Limited May 29 2012 LEEDuser Member 32 Thumbs Up

Hi Hernando!
You point out the key problems clearly!
I see there are other refrigerant options that have lower ODP & GWP. However, I strongly believe that it would have a negative impact in energy efficient because of the lower COP.
Besides, the refrigerant charge may even higher than the prescribed level.
With the view of such, perhaps this credit is un-achievable for small A/C unit.

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Omar Katanani
May 07 2012
LEEDuser Member
5153 Thumbs Up

Additional "reserve" refrigerant box

Dear all,

The project we're working on will be cooled with centrifugal chillers. The Mechanical Engineer is suggesting installing a "Reserve refrigerant box", which is a cylinder containing the same refrigerant as the one of the chillers.
This box is piped to the chillers, and will serve as an "replenishment supply" in case there is any leakage from the chillers.

Our query is:

Do you think we should include this additional "reserve" refrigerants in this credit calculations?

Many Thanks..

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Aug 31 2012 LEEDuser Moderator

Omar, I think it fits with the credit intent to include this refrigerant.

Post a Reply
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Johannes Gellrich
Mar 30 2012
Guest
94 Thumbs Up

District Cooling - Free Cooling

Dear all,
Our building is supplied with cold water from a DES. The DES consists of scroll compressors, centrifugal chillers and free cooling from a river.

Am I allowed to incldue the free cooling in my EAc4 calculations, so that I fill out the form with HVAC equipment type "other" and refrigerant "none". (since free cooling uses water which has no impact).
- Or am I supposed to do the calculation only for all equipment with refrigerants?

Thank you for your help!

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Aug 31 2012 LEEDuser Moderator

Johannes, please review USGBC's guidance on treatment of DES systems in LEED.

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Magnus Stagnäs Life Cycle Engineer Finnmap Consulting Oy
Mar 30 2012
LEEDuser Member
187 Thumbs Up

EAc4 and district heating

Our project building will we connected to a large-scale city district heating network. In the design review we got the following comment:

"Please see the Treatment of District or Campus Thermal Energy document (http://www.usgbc.org/ShowFile.aspx?DocumentID=7671) and the 2010 LEED Application Guide for Multiple Buildings and On-Campus Building Projects (https://www.usgbc.org/ShowFile.aspx?DocumentID=10486) for more information regarding how to document this credit when utilizing district or campus heating. Please provide additional documentation as necessary to confirm that the district or campus heating system meets the requirements of this credit."

What kind of documentation is the review team seeking for? The only guideline I could find in the above mentioned documents is that all downstream and 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. must meet the credit requirements to earn this credit. How do I demonstrate compliance for the district heating system?

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Maria Porter Environmental Certification Engineer, Skanska Sweden Mar 30 2012 LEEDuser Member 867 Thumbs Up

Hi Magnus
Do you not have district cooling as well? I have district heating and cooling and have this credit together with two of Sweden’s district cooling/heating companies. One of them is reviewed and ok. You have to contact the company serving your building with district cooling and ask them for all information regarding this credit. It is in their interest to have it done too. You have to do it the same way as if it were a smaller cooling machine, just that the numbers will be a lot bigger. But the end result should still be under 100 (impact per ton) to show compliance.
If you have no refrigerants then there is nothing to show.
Does this help at all?

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Magnus Stagnäs Life Cycle Engineer, Finnmap Consulting Oy Mar 30 2012 LEEDuser Member 187 Thumbs Up

Hi Maria, thank you for your answere.

We don't have district cooling, only heating. That is what makes me confused. We have chiller units on the roof of the building and the documentation for these is OK. Now the review team asks us to demonstrate compliance also for the district heating.

I assume the district heating company doesn't use refrigerants, so that shouldn't be a major problem. However, a couple of concerns remain:

First; the table in the LEED Online form is for cooling units only. How do I document the requirements for a district heating plant?

Second; if I enter the capasity of the district plant (huge capasity compared to the buildings own cooling units) into the table, the relative impact of the cooling units will be close to zero. This can't be the purpose of this credit, can it?

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Maria Porter Environmental Certification Engineer, Skanska Sweden Apr 03 2012 LEEDuser Member 867 Thumbs Up

Magnus
You have to ask the district heating company if they have refrigerants. Otherwise you have your review response there: No refrigerants!
If you have refrigerants, it is not a problem to show this in the same table as your other smaller machines. The end result is "Average refrigerant impact PER ton", so it doesn't affect the end result (assuming refrigerants are compliant). Stockholms district energy system supplies several thousand buildings, but it is not a problem in the end. Figures are just larger in the calculation. But it did take me some thinking and googling to figure uot the metrics, how to convert Q (tons) to SI-units.
Good luck!

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Magnus Stagnäs Life Cycle Engineer Finnmap Consulting Oy
Feb 16 2012
LEEDuser Member
187 Thumbs Up

Non-default values for Lr and Mr

According to the reference guide I can use non-default values for Lr and Mr if providing supporting evidence material. Our project will be connected to the a district cooling plant with rigorous quality and maintenance programs, so I think we have good premises for this. However, the LEED Online form (v4) doesn't allow me to change these values.

What do you suggest, can I submit a manual calculation along with the evidence material to demonstrate credit compliance and to support the non-default values?

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Yetsuh Frank Director, YR&G sustainability consulting, education and analysis Feb 28 2012 LEEDuser Expert 281 Thumbs Up

Magnus,

Unfortunately you are not allowed to change the 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).. While this was permitted at one point, the section of the 2009 Reference Guide that permitted this was removed via addendum, here: https://www.usgbc.org/ShowFile.aspx?DocumentID=8603.

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Hernando Miranda Owner, Soltierra LLC May 21 2012 Guest 2761 Thumbs Up

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). skewed the calculations, significantly.

Changing equipment life and Mr have small effects.

The USGBC Credit Ruling consultants did not catch this when they allowed the Lr to vary via a very old 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. The original USGBC TSAC (Technical Science Advisory Committee) report clearly stated leakage variations were an issue.

Of interest might be the original recommended originally defaults published by the USGBC's TSAC way back in 2004. Just before the conclusions section of the report:

"LEED should provide default values for Lr, Mr, and Life, perhaps at 1%, 3%, and 30 yr. A project or manufacturer must provide convincing evidence to support values other than the defaults. Manufacturers’ assertions of low leakage rates based on testing of joints under laboratory conditions would not be considered convincing, because most of the leakage occurs during servicing, rather than as some gradual diffusion process in every installation."

Oddly, the recommended values were adjusted to higher values by someone other than the TSAC, making it much harder to earn the credit, especially for small HVAC equipment.

Lr is 2% vs. recommended at 1%. MR is 10% vs. recommended at 3%. These two are constant, regardless of equipment type.

Life was changed based on life values for equipment type from ASHRAE. This change makes a bit more sense.

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BH .
Aug 25 2011
LEEDuser Member
601 Thumbs Up

Sample Form Problem

Applying values to "Refrigerant Impact Calculaton" chart, we have final impact per tone equal to 100 for each device. "average refrigerant impact per ton (must be less than or equal to 100)" is 100. Even than we can get 2 points in summary (all other areas are correct and checked).

DId some of you had such a problem? Should we describe it in "special circumstances" of sample form?

Thanks.

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Nov 21 2011 LEEDuser Moderator

BH, I would try upgrading to the most recent v4 form.

Also, are you using the actual LEED Online form for documentation, or the sample form? The sample form is just for informational purposes.

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Maria Porter Environmental Certification Engineer, Skanska Sweden Jan 25 2012 LEEDuser Member 867 Thumbs Up

Hi BH
I just ran in to the same problem I think. Although everything is filled out correctly in the version 4 form and the value is well under 100 the number of credits earned still remains zero. I have done this credit before and I'm confident nothing is missing. So as Tristan says above I am going to try the feedback form online and see if there is a better version of it.
Maria

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Emily Catacchio Sustainability Specialist, Wight and Company Jan 25 2012 LEEDuser Moderator

Make sure that under credit information, you have checked the number of points you're trying to earn (assuming that option is available on this credit.)

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Maria Porter Environmental Certification Engineer, Skanska Sweden Jan 26 2012 LEEDuser Member 867 Thumbs Up

No sorry, it's a 2 or nothing credit. Nothing to check.

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Emily Catacchio Sustainability Specialist, Wight and Company Jan 26 2012 LEEDuser Moderator

Alright, well it was worth a shot. You should submit feedback. In addition I would call GBCI and have them open the form to see if they can reproduce the issue. It's nice to know that it's not just your machine. They will also document the interaction which is helpful when you get a response to your feedback message.

Good luck!

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Yolanda Sanchez Arch. Axioma
Jul 11 2011
Guest
41 Thumbs Up

HVAC System

HVAC for the whole building is in the process of being designed (VRF system). We would like to know if the system can be installed in 2 stages, but we would like to submit the LEED certification after stage 1 is completed. Is this a valid approach for LEED CS 2009? Could this stepped approach in installing the HVAC System compromise the certification?
• The first stage comprises all piping and HVAC preparations for the whole building, but HVAC equipment would be initially installed only in the areas to be occupied by the owner of the project. This would happen before full occupation and appropriate commissioning tests are conducted.
• The second stage of the project is to install HVAC units on the tenants’ spaces as they occupy their rented areas.

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Nov 21 2011 LEEDuser Moderator

Yolanda, your description seems consistent with how a typical CS HVAC system might be installed, and seems consistent with the credit requirements. You do need to require the use of certain systems in your tenant lease agreements to qualify for the credit, however.

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Joaquim Lima
Apr 13 2011
Guest
206 Thumbs Up

Please, How to calculate the

Please,

How to calculate the Refrigerant Charge??

Thanks!

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Apr 22 2011 LEEDuser Moderator

Joaquim, I would consult the manufacturer, and/or check the nameplate on the HVAC unit.

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John Albrecht Director of LEED Services Sieben Energy Assoc.
Mar 28 2011
Guest
1516 Thumbs Up

leakage rate

I was told that "the USGBC changed the way they force manufacturer's to calculate their refrigerant amounts within the last year. The biggest change has been the leakage percentage. Where this manufacturer had used 0.73% in the past based off of their own studies of their equipment, the USGBC now requires every manufacturer to use 2% which obviously increases the refrigerant amount. Combine this with the mandated minimum efficiencies which forces everyone to use larger condenser coils, and no manufacturer meets the USGBC refrigerant requirements."

Is this true and IS the bar for compliance set that high in LEED 2009?

Thanks, John

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Daniel LeBlanc Senior Sustainability Manager, YR&G May 11 2011 LEEDuser Expert 586 Thumbs Up

John,

This is true for v2.2 projects registered after April 30, 2009, but not true for LEED 2009. The default 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). is still 2%, but according to the Reference Guide, "Applicants may use alternative values for refrigerant leakage rate...provided the alternative values are approved by the USGBC."

When using alternative values in the calculations, they ask for documentation of the Manufacturer's test data; leak detection equipment; preventative maintenance program to minimize leakage; and a program to recover/recycle the refrigerant at the end of life.

So if you have the manufacturer leakage rate and the other components in place, you should be able to use an alternative leakage rate as long as it is accepted by the reviewer.

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John Albrecht Director of LEED Services, Sieben Energy Assoc. Jun 02 2011 Guest 1516 Thumbs Up

Daniel thanks. Our preferred RTU manufacturer is asking if there is a set process for pre-approval of alternate leakage rates by the USGBC, or is this 'approval' done on a project by project alternative basis during certification? Or could one project's credit success via an alternative compliance path and leakage rate constitute 'approval' for subsequent projects? Thanks for any guidance. John

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Daniel LeBlanc Senior Sustainability Manager, YR&G Jun 02 2011 LEEDuser Expert 586 Thumbs Up

John,

For 2009, there is no pre-approval process and approvals are on a project by project basis. As you said, you would submit the documentation along with your design or construction submittal as an alternative compliance path.

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Sara Neff Director, Sustainability Programs Kilroy Realty Corporation
Dec 09 2010
Guest
507 Thumbs Up

Average Maximum Refrigerant Charge, or Charge per Unit?

I am having trouble understanding the allowable amount of refrigerant charge if I have multiple chillers and would like to pursue EA Credit 4. According to the reference guide, "Most projects have multiple units of base building NVAC&R equipment, but if each unit is compliant, the project as a whole meets the requirement." What happens if I have two units, only one of which is compliant on its own, but if the two units are averaged together, then they're compliant? Or, more simply, I am I allowed to use the average, or does one chiller with too much refrigerant charge make me ineligible for this credit?

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Scott DeGaro Sustainability Administrator, Barge Waggoner Sumner & Cannon, Inc. Dec 09 2010 Guest 379 Thumbs Up

The calculations are the weighted average refrigerant impact of all pieces of equipment. So if one unit is compliant and one isn't, but their weighted average is compliant than your project is compliant.

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