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Pol 01 Impact of refrigerants

Number of credits available Minimum standards
3 No

Aim

To reduce the level of greenhouse gas emissions arising from the leakage of refrigerants from building systems.

Assessment Criteria

The following is required to demonstrate compliance for:

Three credits

  1. Where the building does not require the use of refrigerants within its installed plant/systems.

OR alternatively, where the building does require the use of refrigerants, the three credits can be awarded as follows:

Two credits

  1. Where the systems using refrigerants have Direct Effect Life Cycle CO2 equivalent emissions (DELC CO2e) of 100 kgCO2e/kW cooling capacity. To calculate the DELC CO2e the following information is sourced from the design team and entered into the BREEAM Pol 01 calculator:
    1. Global Warming Potential (GWP) of the specified system refrigerant(s)
    2. Total refrigerant charge (kg)
    3. Cooling capacity of the system(s) (kW)
    4. Sectoral release factors:
      1. Annual refrigerant leakage rate (% of refrigerant charge):
      2. Annual purge release factor (% of refrigerant charge):
      3. Annual service release factor (% of refrigerant charge):
      4. Probability factor for catastrophic system failure (%)
      5. Recovery efficiency (% of refrigerant charge):

    For further detail refer to the Relevant definitions and Calculation procedures sections within Additional Information.
    OR

  1. Where air-conditioning or refrigeration systems are installed the refrigerants used have a Global Warming Potential (GWP) 10.

OR

One credit

  1. Where the systems using refrigerants have Direct Effect Life Cycle CO2 equivalent emissions of (DELC CO2e) of 1000 kgCO2e/kW cooling capacity.

One credit

  1. Where systems using refrigerants are contained in a moderately air tight enclosure (or a mechanically ventilated plant room), and an automated permanent refrigerant leak detection system is installed covering high-risk parts of the plant OR where a refrigerant leakage/charge loss detection system is specified, which is not based on the principle of detecting or measuring the concentration of refrigerant in air.
  2. The automatic shutdown and pump down of refrigerant occurs on the detection of refrigerant leakage/charge loss.
  3. Automatic pump-down to either a separate storage tank or into the heat exchanger is acceptable, but only where automatic isolation valves are fitted to contain the refrigerant once fully pumped down.
  4. The alarm threshold that triggers automatic pump down upon detection of refrigerant in the plant room/enclosure is set to a maximum of 2000ppm (0.2%), but lower levels can be set.
  5. Use a robust and tested automated permanent refrigerant leak detection system, normally defined as that included on the Enhanced Capital Allowance (ECA) Energy Technology Product List1www.eca.gov.uk (or an equivalent list).

Compliance Notes

Ref

Terms

Description

CN1 

Scope of this issue

The criteria of this issue apply to air conditioning and refrigeration systems installed in the building for the following uses, regardless of the systems refrigerant charge (kg), including:

  1. Comfort cooling and/or space heating (including assessment of refrigerants in heat pumps).
  2. Cold storage, including commercial food/drink display cabinets but excluding domestic white goods e.g. fridges and freezers
  3. Process based cooling loads e.g. servers/I.T equipment.

For installations of small multiple hermetic systems only: Where the refrigerant charge in each unit is less than 5kg the credit for leak detection and containment can be awarded by default. This is on the basis that the risk of a large refrigerant leak due to system failure is minimised, as individual leaks from each system will be small where leakage occurs, and therefore there is little life cycle benefit of requiring leak detection equipment on each small system.

CN2 

Specification of multiple systems Where a building is installing multiple air conditioning/refrigeration systems the assessor must source the relevant technical data for each system and enter it in to the Pol 01 calculator. The calculator will then determine the weighted average DELC for the multiple installation and the BREEAM credits can be awarded or withheld accordingly.

CN3 

Shell only

If the building is designed to be fully naturally ventilated, and therefore no 'refrigerant using' building services or systems will be specified for the fit out, then the available credits can be awarded.

If the building is not designed to be naturally ventilated and the refrigerant type cannot be confirmed, because its specification is the responsibility of a future tenant as part of their fit out works, then compliance with this BREEAM issue can only be demonstrated via one of the following means in shell only buildings/areas:

  1. Option 1 – Use of a tenancy lease agreement between the developer and tenant/s (full value of available credits)
  2. Option 2 – A Green Building Guide for tenant fit outs (half the value of the available credits)
  3. Option 3 – Developer/Tenant collaboration (full value of available credits)

Refer to Appendix D – BREEAM New Construction and shell and core/speculative assessments of this Scheme Document for further description of the above options.

CN4 

Industrial buildings without offices & with untreated operational areas See criterion 1 This issue will be filtered from the scope of assessment for industrial units designed without offices and where the operational area will be untreated, i.e. not designed to be air-conditioned or contain a cold storage facility with refrigeration plant.

CN5 

Solid refrigerant See criteria 2, 3 & 4 Systems using solid refrigerants are likely to meet the above requirements by default as no or very little refrigerant will escape to the atmosphere in the event of system failure and leakage. Where this is confirmed by the project’s mechanical and electrical engineer (or refrigeration system manufacturer) via the relevant sectoral release factors, the three available credits can be awarded without the need for a calculation.

CN6 

Leak detection and pump down See criteria 5,6,7,8 & 9 The refrigerant leak detection and pump down criteria are still applicable in instances where any type of non-solid refrigerant is present, i.e. even if the refrigerant meets BREEAM’s DELC CO2e benchmark(s). Exceptions to this are systems that use natural and environmentally benign refrigerants, such as air and water (for example lithium bromide/water absorption chillers) and installations of small multiple hermetic systems, where the refrigerant charge in each unit is less than 5kg (as outlined above).

CN7 

CO2 as a refrigerant See criteria 2, 3 & 4 Where CO2 is used as a refrigerant and the design team confirm the system/installation complies with the requirements of BS EN 378:20082BS EN 378:2008 Refrigerating systems and heat pumps. Safety and environmental requirements, BSI. and the Institute of Refrigeration Carbon Dioxide as a Refrigerant Code of Practice3Carbon Dioxide as a Refrigeration Code of Practice, Institute of Refrigeration, 2009., compliance with the refrigerant recovery system criteria is not required (criteria 6 & 7).

CN8 

Ammonia as a refrigerant See criteria 2, 3 & 4 Where ammonia is used as a refrigerant, the refrigerant recovery system credit/requirements can be awarded/met without the need for a recovery system, provided that the design team confirm the system/installation complies with the requirements of BS EN 378:2008 and the Institute of Refrigeration Ammonia Refrigeration Systems Code of Practice4Ammonia Refrigeration Systems Code of Practice, Institute of Refrigeration, 2009.

CN9 

High-risk parts See criterion 5 High-risk parts of refrigeration plant typically include the pipe work/pipe joints connected and close to the compressor. Evaporator or condenser coils can be omitted from the coverage of the system.

CN10 

Manual refrigerant recovery system The provision of any manual system, including manual storage cylinders on site, does not comply with the criteria.

Schedule of Evidence

Ref Design stage
Post-construction stage
1 Documentary evidence confirming the absence of refrigerant in the development As design stage, plus assessor’s building/site inspection and or as built drawings confirming the presence of compliant refrigeration plant, or absence of plant.
2 - 9

A copy of the specification clause or letter from the M&E engineer/system manufacturer confirming relevant refrigeration type and system information.

A completed copy of the BREEAM Pol 01 Calculator.

Additional Information

Relevant definitions

Direct Effect Life Cycle (DELC) Carbon Dioxide Equivalent
A measure of the effect on global warming arising from emissions of refrigerant (in the case of this BREEAM assessment issue) from the equipment to the atmosphere over its lifetime (units: kgCO2eq.). The calculation involves estimating the total refrigerant release over the period of operation and subsequent conversion to an equivalent mass of CO2. Should the system use several different refrigerants, e.g. a primary refrigerant and a secondary coolant, or a cascade system, individual calculations will have to be made for all refrigerants which may contribute to the direct effect (see below for a description of how DELC is calculated)
Moderately airtight enclosure
This can be defined as an enclosure that does not produce a draught or significant fresh air ingress that would dilute any leaked refrigerant gas (dilution may prevent detection).
Ozone Depleting Potential
ODP is the ratio of the relative amount of degradation to the ozone layer caused by a particular substance relative to the calculated depletion for the reference gas CFC 11 (ODP = 1.0). The ODP of the refrigerants is not assessed under this issue and there is no link between GWP and ODP.
Refrigerant leak detection
An automated permanently installed multi-point sensing system, designed to continuously monitor the atmosphere in the vicinity of refrigeration equipment and, in the event of detection, raise an alarm. The system may be aspirated or have multiple sensor heads linked to a central alarm unit or BMS. Various sensor types are available including infra-red, semi-conductor or electro-chemical.
Refrigerant recovery
The process of removing refrigerant from a system and storing it in an airtight container.
Refrigerant pump down
The specification of automatic refrigerant pump down can further limit potential losses and damage to the environment and have subsequent economic benefits to the building owner. Under the United Kingdom 1990 Environmental Protection Act unwanted refrigerant and refrigerating system oil are classified as either controlled or hazardous waste. Not only is it an offence to discharge them to the environment, but there are procedures regarding transport, storage, transfer of ownership and ultimate disposal. Article 16 of EC regulation 2037/2000 specifies that used CFCs and HCFCs must be recovered for destruction or recycling/reclamation.
Global Warming Potential GWP
GWP is defined as the potential for global warming that a chemical has relative to 1 unit of carbon dioxide, the primary greenhouse gas. In determining the GWP of the refrigerant, the Intergovernmental Panel on Climate Change (IPCC) methodology using a 100-year Integrated Time Horizon (or ITH) should be applied.
Refrigerant
There are three main make-ups of refrigerants:
    1. Hydrogenated Fluorocarbon Refrigerants (HFCs) are made up of hydrogen, fluorine, and carbon. Because they do not use a chlorine atom (which is used in most refrigerants) they are known to be one of the least damaging to our ozone.
      Hydrogenated Chlorofluorocarbon Refrigerants (HCFCs) are made up of hydrogen, chlorine, fluorine, and carbon. These refrigerants contain minimal amounts of chlorine; they are not as detrimental to the environment as some other refrigerants.
      Chlorofluorocarbon Refrigerants (CFCs) contain chlorine, fluorine and carbon. These refrigerants carry high amounts of chlorine so they are known for being the most hazardous to the ozone layer.
  • The use of CFCs and HCFCs as refrigerants has been addressed under the Montreal protocol. Phase out programmes have been agreed resulting in these substances no longer being used as refrigerants in all new build and most existing situations. The industry’s favoured replacements are currently HFCs which are often potent global warming contributors. Hydrocarbons and ammonia-based refrigerants have low or zero GWP and are therefore preferred long-term options. These are now widely available and are valid alternatives to HFCs in all buildings, provided health and safety issues are fully addressed.
    The United Nations Environment Programme (UNEP) hosts a HCFC Help Centre which contains information about the management and phase out of HCFCs and alternatives to HCFCs in the refrigeration and air conditioning sector http://www.uneptie.org/ozonaction/topics/hcfc.asp

    Checklists and Tables

    Table 32 List of some common refrigerant types with low GWP

    R-Number Chemical name

    GWP

    100-yr

    R-30 Dichloromethane 8.7
    R-170 Ethane 5.5
    R-290 Propane 3.3
    R-600 Butane 4
    R-600a Isobutane 3
    R-702 Hydrogen 5.8
    R-717 Ammonia 0
    R-718 Water 0.2 ±0.2
    R-729 Air (Nitrogen, oxygen, argon) 1
    R-744 Carbon dioxide 1
    R1216 Ethylene 3.7
    R-1234yf 2,3,3,3-Tetrafluoropropene 4
    R-1270 Propylene 1.8
    Sources: The United Nations Environment Programme (UNEP) ‘2006 Report of the Refrigeration, Air conditioning and Heat Pumps Technical Options Committee’
    Appendix A of the Department of Trade and Industry guidance ‘Refrigerant and Air Conditioning CFC and HCFC Phase Out: Advice on Alternatives and Guidelines for Users’ http://www.berr.gov.uk/files/file29101.pdf

    Calculation procedures

    The Direct Effect Life Cycle CO2e emissions (DELC) per kW of cooling capacity are calculated using the following equation:

     Direct Effect Life Cycle CO2e emissions (DELC) per kW of cooling capacity calculation

    Where:

    Refrigerant loss operational: (Refcharge x Sys op-life x (L1 + L2 + S1 + S2)) /100

    Refrigerant loss system retirement = Refcharge x (1 - Ref RecEff/100)

    Where:

    1. Refcharge: Refrigerant charge
    2. Sysop-life: System operational lifetime (years) - use default value of 10 years
    3. RefRecEff: Refrigerant Recovery Efficiency factor (%)
    4. L1: Annual Leakage Rate (units: % refrigerant charge)
    5. L2: Annual Purge Release factor (% Refrigerant charge)
    6. S1: Annual Service Release (% Refrigerant charge)
    7. S2: Probability factor for catastrophic failure (% refrigerant charge loss/year)
    8. GWP: Global Warming Potential of refrigerant
    9. Cooling capacity (kW)

    With the exception of system operational life, which is a fixed default for the purpose of the BREEAM assessment, the information above should be sourced from the design team’s mechanical and electrical engineer and/or system manufacturer. The following default values can be used, where system specific data is not available:

    1. Annual service release: 0.25%
    2. Probability factor for catastrophic failure: 1% (based on a failure rate of 1 in 100 systems)
    3. Annual leakage rate: see Table 33

    Table 33 Average annual leakage rates for the UK

    System type

    Annual leakage rate

    (% of charge per annum)

    Cold storage and display systems
    Integral cabinets 3%
    Split/condensing units 18%
    Centralised 19%
    Air conditioning systems
    Unitary split 16%
    Chillers 10%
    Heat pumps 6%
    These figures are based on those reported in Table 2 of the Market Transformation Programmes Briefing Note for Commercial Refrigeration no. 36, ‘Direct Emission of Refrigerant Gases’, (version 1.2). The figures are based on the average of the leakage rates from the four separate studies reported in Table 2 (where a range is reported the higher value was used).

    Other information

    The formula used to calculate the Direct Effect Life Cycle CO2e emissions in BREEAM is based on the Total Equivalent Warming Impact (TEWI) calculation method for new stationary refrigeration and air conditioning systems. TEWI is a measure of the global warming impact of equipment that takes into account both direct emissions (as assessed in this BREEAM issue) and indirect emissions produced through the energy consumed in operating the equipment (which is assessed in the BREEAM energy section).

    Refer to BS EN 378-15BS EN 378-1 Refrigerating systems and heat pumps - Safety and environmental requirements Part 1: Basic requirements, definitions, classification and selection criteria. BSi, 2008 and the British Refrigeration Association’s (BRA) Guideline Methods of Calculating TEWI6Guideline Methods of Calculating TEWI Issue 2, (2006), BRA Specification. for further detail. The BRA publication also includes sectoral release factors for new systems designed to best practice standards.

    REAL Zero

    The refrigeration and air-conditioning sector supported by the Carbon Trust is working across all sectors of business and industry, to help achieve significant reductions in carbon emissions due to refrigerant leakage from installed systems. The Institute of Refrigeration led initiative, Real Zero, is building a clearer understanding of where and why leakage occurs as well as how to prevent it.

    For further information including guidance notes, calculators/tools and case study information visit: www.realzero.org.uk

    Leak detection systems/devices

    1. Handheld detectors (which include semi-conductor and corona discharge types) do not comply with BREEAM criteria.
    2. Corona discharge detectors are not suitable where flammable refrigerants are used, or in potentially explosive atmospheres.
    3. Indicator dyes: these consist of fluorescent or coloured dyes added to the refrigerant to show leakage sites. The use of the dye should be approved by the compressor manufacturer. Some compressor manufacturers do not approve the use of indicator dyes, in which case either an alternative type of equipment should be used, or an alternative type of leak detection specified.
    4. Halide torch detectors: this type of detection is only appropriate for chlorine-based substances such as CFCs and HCFCs, and should not be used in areas where naked flames are prohibited. Compounds which do not contain chlorine, e.g. HFCs, cannot be detected by this method. When awarding this credit in instances where these detectors are in use, the assessor should confirm that the refrigerant is chlorine based.
    5. Electronic leak detectors: these must be designed to detect a certain type of, or multiple types of, refrigerant, i.e. CFC, HFC, HCFC, etc.
    6. Standing hold test: systems based on monitoring pressure drops within the pipe work are not necessarily compliant with the BREEAM criteria. There are natural fluctuations to the pressure of the refrigerant due to changes in volume and temperature of the system, and to the ambient temperature of the surroundings. Low pressure and high pressure switches, which are standard equipment on refrigerant plant, are therefore not sufficient to award the credit. Other methods exist, such as pressurising the system with a high pressure, dry nitrogen gas for a period of time and then identify whether or not the pressure drops during this time. However, this requires systems to be shut down for a period of time (usually overnight or longer).
    7. Systems NOT based on the principle of detecting or measuring the concentration of refrigerant in air: Such systems (for example based on sensing the presence of refrigerant vapour in liquid-carrying pipes) are now commercially available.
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