Pol01 - Impact of refrigerants – Above Green

(4 credits available)

Aim

To reduce the level of greenhouse gas emissions arising from the leakage of refrigerants used to heat or cool the building.

Assessment criteria

This issue is split into two parts:

Buildings that use no refrigerants (including connection to systems off site) (all available credits)
OR
For buildings that use refrigerants:
- Prerequisite
- Ozone depletion potential (1 credit)
- Impact of refrigerant (1 to 2 credits)
- Leak detection (1 credit)

The following is required to demonstrate compliance:

All available credits - No refrigerant use

Where the building does not require the use of refrigerants within its installed plant or systems, or any off-site system it is connected to.

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

Prerequisite

All systems (with electric compressors) must comply with the requirements of EN 378:2008+A2:2012 (parts 2 and 3) or ISO 5149:2014 and where refrigeration systems containing ammonia are installed, the Institute of Refrigeration Ammonia Refrigeration Systems Code of Practice

One credit - Ozone depleting potential (ODP)

The refrigerants used must have an ozone depleting potential of zero.

Two credits - Impact of refrigerant

Where the systems using refrigerants have Direct Effect Life Cycle CO₂ equivalent emissions (DELC CO₂ₑ) of ≤ 100 kg CO₂ₑ/kW cooling or heating capacity. To calculate the DELC CO₂ₑ., please refer to Relevant definitions and Methodology. OR

Where air-conditioning or refrigeration systems are used to heat or cool the building the refrigerants used have a Global Warming Potential (GWP) ≤ 10.

One credit - Impact of refrigerant

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

One credit - Leak detection

Where systems using refrigerants have a permanent automated refrigerant leak detection system installed; OR where an inbuilt automated diagnostic procedure for detecting leakage is installed. In all instances a robust and tested refrigerant leak detection system must be installed and must be capable of continuously monitoring for leaks.

The system must be capable of automatically isolating and containing the remaining refrigerant charge in response to a leak detection incident (see Other information).

Checklists and tables

None.

Compliance notes

Ref	Terms	Description
Shell and core (non-residential and residential institutions only)
CN1	Applicable assessment criteria	Shell only: This issue is not applicable. Shell and core: All criteria relevant to the building type and function apply. Refer to Appendix D – Shell and core project assessments for a more detailed description of the shell and core assessment options.
CN1.1	Avoiding the need for refrigerants	Shell and core: If the building is designed in such a way that it avoids the need for refrigerant containing building services or connection to off-site systems, and therefore no 'refrigerant-using' building services or systems will be specified for the fit-out, then the available credits can be awarded by default.
Residential - Partially fitted & Fully fitted
CN2	Applicable Assessment criteria - Single and multiple dwellings	Both options: All criteria relevant to the building type and function apply. Refer to Appendix E – Applicability of BREEAM New Construction to single and multiple dwellings, partially and fully fitted for a more detailed description of residential assessment options.
General
CN3	Industrial buildings without offices & with untreated operational areas	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.
CN3.1	Country regulations on the use of Ozone Depleting Substances (ODS)	Where legislation within the country of assessment prohibits the use of ozone depleting substances in new refrigeration systems, the credit for using substances with an ozone depletion potential of zero will be filtered out of the assessment. At the time of writing all European countries are known to fall into this category.
CN3.2	Refrigerant charge of less than 6kg	For installations of small multiple hermetic systems only where the refrigerant charge in each unit is less than 6kg, 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. Note: solutions such as this may be less energy efficient and as such may impact on the achievement of credits under .
CN3.3	Specification of multiple systems	Where more than one air-conditioning or refrigeration system is servicing the building, the assessor must source the relevant technical data for each system and enter it into 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.
CN3.4	Leak detection. See criteria 7 and 8 .	The refrigerant leak detection 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 benchmarks. Exceptions to this are systems that use natural and environmentally benign refrigerants, such as air and water (for example lithium bromide or water absorption chillers) and installations of small multiple hermetic systems, where CN3.2 applies. These types of system and refrigerants will achieve the leak detection credit by default.
CN3.5	ODP data not available	Where ODP data for the specified refrigerant are not available, the credit cannot be awarded on a default basis.

Methodology

The number of Pol 01 BREEAM credits achieved is determined by the assessor using the BREEAM Pol 01 calculator.

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

Direct effect life cycle and carbon dioxide

Where:

Refrigerant loss operational (RLO) = (Ref_charge x Sys _op-life x (L1 + L2 + S1 + S2))/100

Refrigerant loss system retirement (RLSR) = Ref_charge x (1 - Ref_RecEff/100)

Where:

Ref_charge: Refrigerant charge (kg)
Sys_op-life: System operational lifetime (years)
Ref_RecEff: Refrigerant Recovery Efficiency factor (%)
L1: Annual Leakage Rate (% Refrigerant charge)
L2: Annual Purge Release factor (% Refrigerant charge)
S1: Annual Service Release (% Refrigerant charge)
S2: Probability factor for catastrophic failure (% Refrigerant charge loss/year)
GWP: Global Warming Potential of refrigerant
CC: Cooling or heating capacity (kW).

The following default values must be used, where system specific data are not available:

Sys_op-life: System operational design life (years): see Table 54

Ref_RecEff: Refrigerant recovery efficiency factor (%): 95%

L1: Annual leakage rates (% refrigerant charge): see Table 55

L2: Annual purge release factor (% refrigerant charge): 0.5 (if the system does not require an annual purge, zero should be used)

S1: Annual service release (% refrigerant charge): 0.25 (this applies where the system requires opening up to carry out the annual service. For systems which do not require opening up, there will be no associated annual release of refrigerant, therefore a default of zero should be used)

S2: Probability factor for catastrophic failure (% refrigerant charge loss/year): 1% (based on a failure rate of 1 in 100 systems).

The following information must be sourced from the design team's mechanical and electrical engineer or system manufacturer:

System type
Ref_charge: Refrigerant charge (kg)
GWP: Global Warming Potential of refrigerants
Cooling or heating capacity (kW).

Table 54 Default system operational design life values

System type	Default system operational design life values (years)
Small and medium capacity chillers	15
Large capacity chillers	20
Unitary split	15
Variable Refrigerant Flow (VRF) system	15
All other systems	10
These figures are based on those reported in LOT 6 for air-conditioning units and the British Refrigeration Association's (BRA) Guideline Methods of Calculating TEWI (2006)4. Note: The following should be considered when determining whether the system specified is defined as small or medium or large: Large capacity chiller: centrifugal compressor Medium capacity chiller: scroll or screw compressor Small capacity chiller: scroll compressor.

Table 55Average annual leakage rates

System type	Annual leakage rate (% of charge per annum)
Cold storage and display systems
Integral cabinets	3%
Split or condensing units	18%
Centralised	19%
Air-conditioning systems
Unitary split	15%
Small-scale chillers	10%
Medium or large chillers	5%
Heat pumps	6%
These figures are based on those reported in LOT 6 for air-conditioning units and also 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).

Evidence

Criteria

Interim design stage

Final post-construction stage

All

The following as appropriate:

Confirmation of the absence of refrigerant in the development
A copy of the specification clause or letter from the M&E engineer or system manufacturer confirming relevant refrigeration type and system information
A completed copy of the BREEAM Pol 01 calculator.

As design stage.

Assessor’s building or site inspection or as-built drawings.

Manufacturer’s information.

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: kg CO₂ₑ). The calculation involves estimating the total refrigerant release over the period of operation and subsequent conversion to an equivalent mass of carbon dioxide. Should the system use several different refrigerants, e.g. a primary refrigerant and a secondary coolant, or a cascade system, individual calculations are made for all refrigerants which contribute to the direct effect (see Methodology for a description of how DELC is calculated).

Global warming potential

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.

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).

Ozone depleting substances (ODS)

"Substances known to deplete the stratospheric ozone layer. The ODSs controlled under the Montreal Protocol and its Amendments are chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, methyl bromide (CH₃Br), carbon tetrachloride (CCl₄), methyl chloroform (CH₃CCl₃), hydrobromofluorocarbons (HBFCs) and bromochloromethane (CH₂BrCl).", extracted from IPCC/TEAP report, Special Report on Safeguarding the Ozone Layer and the Global Climate System, Cambridge University, 2006.

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 infrared, semiconductor 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 Environmental Protection Act 1990 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 or reclamation.

Robust and tested refrigerant leak detection system

This is normally defined as that included on the Enhanced Capital Allowance (ECA) Energy Technology Product List (or an equivalent list). Where the system does not fall within the scope of the ECA energy technology product list or an equivalent list, the design team must demonstrate to the assessor that the system specified meets the principles of the scheme as far as is applicable.

Small-scale white goods

These should be defined as domestic-scale white goods and would also include small individual display cabinets, for example drinks cabinets in small retail shops.

Systems using refrigerants

The criteria of this issue apply to air-conditioning and refrigeration systems used to heat or cool the building for the following uses, regardless of the system's refrigerant charge (kg):

Comfort cooling or space heating (including assessment of refrigerants in heat pumps)
Cold storage, including commercial food and drink display cabinets but excluding small scale white goods (see definition above)
Process-based cooling loads, e.g. servers, IT equipment
Off-site facilities such as district heating or cooling systems.

Refrigerant

There are three main make-ups of refrigerants:

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 the earth's ozone layer.
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 to be 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 installations 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.

Other information

Automatic isolation and containment of refrigerant

Any system that isolates and contains refrigerant within the system so as to minimise leakage to the atmosphere in the event of a systems failure. An example of a system which could meet criterion 8 would be one which initiates an automated shut down and pump down of the refrigerant into a separate storage tank.

Common refrigerants

Table 56List of some common refrigerant types with low GWP

R-Number	Chemical name	GWP 100-year
R-30	Dichloromethane	9
R-170	Ethane	3
R-290	Propane	3
R-600	Butane	3
R-600a	Isobutane	3
R-702	Hydrogen	5.8
R-717	Ammonia	0
R-718	Water	<1
R-729	Air (nitrogen, oxygen, argon)	0
R-744	Carbon dioxide	1
R1150	Ethylene	3
R-1234yf	2,3,3,3-Tetrafluoropropene	>1
R-1270	Propylene	3
Sources: The United Nations Environment Programme (UNEP) '2010 Report of the Refrigeration, Air-conditioning and Heat Pumps Technical Options Committee' (pages 29-30). EN 378-1:2008+A2:2012: Refrigerating systems and heat pumps - Safety and environmental requirements. Part 1: Basic requirements, definitions, classification and selection criteria - Annex E. The Intergovernmental Panel on Climate Change 5th Assessment Report, Chapter 8, 'Anthropogenic and Natural Radiative Forcing', 2013. 'Global environmental impacts of the hydrogen economy', Derwent et al, 2006.

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 EN 378-16 and the British Refrigeration Association's (BRA) Guideline Methods of Calculating TEWI for further details. The BRA publication also includes sectorial release factors for new systems designed to best practice standards.

REAL Zero

REAL Zero was a UK led project to investigate the causes of and solutions to refrigerant leakage, against the background of the EU F Gas Regulation. It brought together expertise across sectors and provided practical guides and training booklets. It was subsequently updated and developed into a European e-learning programme known as REAL Skills.

For further information including guidance notes, calculators, tools and case study information visit: http://www.realskillseurope.eu/

Ozone depleting potential refrigerants

Both CFCs and HCFCs are now tightly controlled or due to be phased out in the foreseeable future in all signatory countries to the Montreal Protocol on Substances That Deplete the Ozone Layer, BREEAM only recognises refrigerants that have an ODP of zero. Table 57 gives current ODP figures for a range of available substances that are capable of acting as refrigerants; assessors should use this to verify the ODP of the specified refrigerant. Substances not on this list should be referred to the BREEAM office so that an appropriate figure can be established.

Note: This table omits substances that are not typically used as refrigerants in buildings.

Table 57Ozone depleting potential of refrigerants

Refrigerant type	Ozone depleting potential
R11 (CFC-11)	1.00
R12 (CFC-12)	1.00
R113 (CFC-113)	0.80
R114 (CFC-114)	1.00
R115 (CFC-115)	0.60
R125 (CFC-125)	0.00
Halon-1211	7.90
Halon-1301	15.90
Halon-2402	6.00
Ammonia	0.00
R22 (HCFC-22)	0.05
R123 (HCFC-123)	0.02
R134a (HFC-134a)	0.00
R124 (HCFC-124)	0.02
R141b (HCFC-141b)	0.11
R142b (HCFC-142b)	0.07
R143a (HFC-143a)	0.00
R32 (HCFC-32)	0.00
R407C (HFC-407)	0.00
R152a (HFC-152a)	0.00
R404A (HFC blend)	0.00
R410A (HFC blend)	0.00
R413A (HFC blend)	0.00
R417A (HFC blend)	0.00
R500 (CFC/HFC)	0.74
R502 (HCFC/CFC)	0.33
R507A (HFC azeotrope)	0.00
R290 (HC290 propane)	0.00
R600 (HC600 butane)	0.00
R600a (HC600a isobutane)	0.00
R290/R170 (HC290/HC170)	0.00
R1270 (HC1270 propene)	0.00
The United Nations Environment Programme (UNEP) '2010 Report of the Refrigeration, Air-conditioning and Heat Pumps Technical Options Committee' (pages 29-30). EN 378-1:2008+A2:2012: Refrigerating systems and heat pumps - Safety and environmental requirements. Part 1: Basic requirements, definitions, classification and selection criteria - Annex E.