Refrigerants & Environmental Impacts: A Best Practice Guide [Elementa Consulting] by Introba

Refrigerants & Environmental Impacts

A BEST PRACTICE GUIDE

R12

R290 R410a R1234 ze

R404a R513a

R11

R32

R718 R1234 yf

R113 R1233 R407c R744 zd

R22

R134a R114

R717

Main Authors Louise Hamot – Global Lead of Life Cycle Research at Integral Group (Lille) Hugh Dugdale – Associate Principal at Elementa Consulting (London) Olivier Boennec – Associate at Elementa Consulting (London) Contact louise.hamot@integralgroup.com

Contributors Bhavin Degadwala – Associate Principal Mechanical at Integral Group (Toronto) Clara Bagenal George – Associate at Elementa Consulting (London) Eben Simmons – Associate Director at Umow Lai (Melbourne) Edward Garrod - Principal at Elementa Consulting (London) Lisa Westerhoff – Sustainability Principal at Integral Group (Vancouver) Mike Godawa - Senior Principal at Integral Group (Toronto) Mudit Srivastava – Mechanical Designer at Integral Group (Toronto) Stuart Hood – British Columbia Regional Director (Vancouver) Disclaimer This document is based on the best knowledge available at the time of publication. However no responsibility of any kind for any injury, death, loss, damage or delay however caused resulting from the use of these recommendations can be accepted by Integral Group, its member companies, the authors or others involved in its publication. In adopting these recommendations for use each adopter by doing so agrees to accept full responsibility for any personal injury, death, loss, damage or delay arising out of or in connection with their use by or on behalf of such adopter irrespective of the cause or reason therefore and agrees to defend, indemnify and hold harmless Integral Group, its member companies, the authors and others involved in their publication from any and all liability arising out of or in connection with such use as aforesaid and irrespective of any negligence on the part of those indemnified. This publication is primarily intended to provide guidance to those responsible for the design, installation, commissioning, operation and maintenance of building services. It is not intended to be prescriptive, exhaustive or definitive and it will be necessary for users of the guidance given to exercise their own professional judgement when deciding whether to abide by or depart from it. Version 1: September 2020 © Integral Group 2020

Contents Executive Summary 4 Introduction 6 Overview 8 Refrigerant Development

Life Cycle

Environmental Impacts

History + Properties of Refrigerants

Best Practice Guidance

4 Steps to Best Practice

Selection Implementation

Further Aspects to Consider

Safety 34 Practical Considerations

Appendices 38 A1 Glossary

A2 Definitions

A3 Refrigerant Information

A4 Refrigerant Leakage

A5 Refrigerant Recovery

A6 References

Executive Summary Over the next 30 years, if we could reduce refrigerant leakage to 0.4% of refrigerant used, it would save 89.7 gigatons of CO2e

By sharing our knowledge of current best practices we can accelerate the transformation of the built environment to meet our climate change obligations.

Louise Hamot Louise is Integral Group's Global Lead for Life Cycle Research, based in Lille, France

This best practice guide is intended to help those responsible for the design, installation, commissioning, operation and maintenance of building services to make well-informed decisions in the design of refrigerant based systems. We particularly encourage its use during initial design stages, whenever these systems are being considered. The guide reviews currently available refrigerants for common system types, with advice on how to reduce refrigerant charge, leakage, and enhance recovery at end of life. It should be considered â&#x20AC;&#x2DC;liveâ&#x20AC;&#x2122; and will be updated periodically to reflect latest industry data. It has been prepared by an international team of Integral Group's mechanical and sustainability engineers led by Louise Hamot, Integral's Global Lead for Life Cycle Research. Refrigerant use continues to grow. Climate change is already increasing the demand for cooling in buildings around the world. At the same time, renewable and low carbon energy sources are displacing fossil fuels from our electricity grids making combustion-free heating and cooling systems that depend on refrigerants ever more attractive. Our ongoing research into whole life carbon emissions has highlighted the serious risk of significant climate change impacts of refrigerant use - from leakage and poor end of life recovery. These impacts could be almost entirely avoided if passive design measures were fully exploited to eliminate or at least reduce demand, and the best performing refrigerant were then specified and properly managed. Engineers can only specify refrigerants that are commercially available, permitted, safe and technically appropriate for the chosen application. Nonetheless they share a collective responsibility to encourage manufacturers to offer improved equipment with ever lower life cycle impacts. Readers are expected to exercise their own professional judgement when deciding whether to follow the recommendations provided in this guide. We hope that by raising awareness of best practices they will have greater confidence both prioritising passive measures and adopting new technology that can dramatically reduce the impact of refrigerants on the environment. Refrigerants & Environmental Impacts

EDUCING REFRIGERANT GWP IMPACT HAS BEEN IDENTIFIED THE NUMBER ONE ACTION WE CAN DO TO MITIGATE CLIMATE CHANGE (Drawdown, Paul Hawken, 2019)

• Use natural/hydrocarbons refrigerants with GWP <5 e.g. Ammonia, CO2, Propane, HFOs • If low GWP refrigerants are not available, do not go over GWP 750 unless it can be proven that the volume is very low and the GWP of the whole system is under 750

DISTRIBUTED SYSTEM: R32 (lowest available) CENTRALISED SYSTEM: Ammonia (large scale), CO2 or HFOs INDIVIDUAL SYSTEM: Propane, CO2

USE LOW GWP REFRIGERANTS

• Minimise refrigerant charge, as it will reduce leakage global warming potential • Consider refrigerant charge when comparing system. e.g. a 500kW chiller with R410a (GWP 2088) can have lower total GWP than when using R134a (GWP 1460) because the refrigerant charge is significantly less • Avoid split systems and favour water-based packaged types

DISTRIBUTED SYSTEM: Hybrid VRF CENTRALISED SYSTEM: Better heat exchangers, water cooled units INDIVIDUAL SYSTEM: N/A • • • •

Leak-free installation by a manufacturer registered installer of the specific product Maintenance by a manufacturer registered contractor of the specific product Avoid constant over pressure Ensure frequent leak test in accordance with local regulations / best practice

DISTRIBUTED SYSTEM: Pressure test, room sensors, hybrid systems CENTRALISED SYSTEM: Leak detection, high quality sensors INDIVIDUAL SYSTEM: Leak detection, high quality sensors • Ensure 100% recovery and reuse of the refrigerant undertaken by a contractor trained by the manufacturer of the specific product

• Provide strong project briefing to minimise carbon emissions • Adopt best practice maintenance in line with manufacturer’s recommendations • Plan end of life, decommissioning scenarios to ensure 100% refrigerant recovery

REDUCE REFRIGERANT CHARGE

+ MITIGATE REFRIGERANT LEAKAGE

ENHANCE REFRIGERANT RECOVERY

WHAT YOU CAN DO Client

Manufacturer • Focus development on zero or low GWP refrigerant systems and improve global distribution • Design products that use minimal amount of refrigerant at best performance • Design for efficient refrigerant recovery

Consultant • Passive design to avoid/ minimise size of active cooling and heating • Specify products with zero or low GWP • Specify systems with minimal refrigerant charge at best performance • Specify comprehensive leak detection and leak tests

Design Team • Coordinated passive design to avoid/minimise active cooling and heating • Be aware of the potential damage associated with refrigerant use • Consider space requirements for low GWP refrigerant-based systems

Executive Summary |

REDUCE REFRIGERANT NEED

• Explore all passive measures to reduce/eliminate active heating and cooling • Active refrigerant based systems only where the only viable combustion-free option

Introduction

NREL Energy Systems Integration Facility is a 10 MW data center in Golden, Colorado. Its chillerless and refrigerant free design uses evaporative cooling towers with heat exchangers for direct liquid cooling to high density server racks. Image ÂŠ NREL / Dennis Schroeder

Overview To make informed choices, the building industry needs to understand the impacts of the systems they design and products they specify. This guide aims to raise awareness and accelerate adoption of best practices in minimizing the environmental impact of refrigerants.

Context Improving the environmental impacts of the built environment is a priority in a climate crisis. One of the most significant impacts from the building industry is the emission of substances that cause ozone depletion and which contribute to the greenhouse effect and global warming. These emissions need to be understood and drastically reduced. The demand for air conditioning is increasing worldwide due to improvements in socio-economic conditions in many countries, the falling cost of equipment, air pollution and forest fire smoke preventing buildings from being naturally ventilated, and last but not least rising temperatures. At the same time, we are witnessing the decarbonization of electricity grids as renewable energy sources displace coal and natural gas. This shift encourages the application of electric heating systems such as heat pumps (HP) over traditional systems powered by the combustion of fossil fuels. Both factors lead to an increase in demand for systems using vapour compression that contain refrigerant gases, which subject to their properties and life cycle can have damaging environmental effects. In 1987, the Montreal Protocol banned refrigerants with a high Ozone Depletion Potential (ODP) but did not address the Global Warming Potential (GWP) of the gases that would replace them. In 2016, the Kigali accord set an agenda to phase out these high GWP refrigerant gases, but the reality is that such refrigerants are still widely used. Currently, refrigerant through leakage is one of the biggest contributors to climate change within the building industry. Over the next 30 years, if we could reduce refrigerant leakage to 0.4% of refrigerant used, it would save 89.7 gigatons of CO2 equivalent compared to continuing with business as usual (Hawken, 2017). Slowly, alternative refrigerants with lower GWP are appearing on the market, driven by regulation changes. However, it is our belief that the building industry can and should go further, starting now. To fully understand the global warming impact of our buildings we need to go beyond operational carbon and account for embodied carbon as well. The role played by refrigerant use is significant, and once understood and quantified can then be carefully considered and reduced. Studies by Integral Group in figures 1a and 1b (right) help to illustrate the important of GWP associated with refrigerant use at product and building level across different scenarios.

Aim & Scope of this Document This document aims to: • Provide an introduction to the topic of refrigerants, through their history, life cycle stages, types • Improve industry awareness on the significant environmental impacts due to refrigerant leakage • Offer guidance on best practices to limit the environmental impact of HVAC refrigerant based products. This document focuses only on refrigerant associated with HVAC systems within buildings for heating and cooling purposes. It does not consider the food industry related refrigerants. Solid-state refrigeration (magnetic refrigeration and thermoelectric effect) are outside the scope of this document but would deserve a further study.

How to Use the Document The guide is structure into the following sections: • • • •

Section 1 introduces the topic of refrigerant general knowledge within a building services context Section 2 provides guidance on best practices in refrigerant use and selection Section 3 provides guidance on practical and legal aspects linked to the use of refrigerants The appendices go into detail on existing refrigerants, leakage, end of life and feature some examples. Definitions and a Glossary of terms can be found at the beginning of the appendices.

Refrigerants & Environmental Impacts

GWP (Tonne CO2e)

Gas Boiler

Gas CHP

ASHP

Introduction | Overview

2019 GWP<150

Figure 1a Whole Life Carbon of different heat generation equipment for passivhaus type building

VRF

Whole life carbon emissio building (2,0 1,600 1,400

GWP (Tonnes CO2e)

1,200 Primer Elementa Consulting Study for CIBSE Technical Symposium 2019, published in LETI Embodied Carbon

1,000 fired combined

This study investigated whole life carbon (WLC) of four types of heat-generation equipment: gas boiler, gas heat and power (CHP), air source heat pump (ASHP), and variable refrigerant flow systems (VRF). For ASHP and VRF, carbon 800 equivalent emissions from refrigerant leakage make up a large proportion of the CO2e because the global warming potential of refrigerants currently most commonly 600 used is higher than that of CO2. In some situations, refrigerant leakage has a higher impact than operational carbon emissions, and 400 the WLC impact of ASHP can become similar to gas boilers. However, when refrigerants with a global warming potential of 150 are used, ASHP emits approximately 80% less WLC than gas boilers and 85% less WLC than CHP. 200

Whole life carbon emissions over 30 years of a US low energy office building (2,000 sqm) using a VRF system Figure 1b Whole life carbon emissions over 30 years of a US low energy office building (2,000 sqm) using a VRF system 1,600

GWPCO2e) (Tonnes CO2e) GWP (Tonne

Aspirational (but not feasible yet)

13%

20%

MEP Embodied Carbon (medium imp Building Embodied Carbon Operational Carbon

1,000 800 600 400 200 0

Best Prac

Refrigerant Leakage

1,400 1,200

Aspirational Aspirational 1 (but not feasible yet) 1% 99% Refrigerant Leakage

Best Practice Best Practice 677 (R32) 6% 97%

Practice as Usual Practice as Usual 2088 (R410A) 6% 97%

Worst Practice Worst Pratice 2088 (R410A) 10% 90%

GWP Annual Leakage rate End of Life Recovery Rate

MEP Embodied Carbon (medium impact scenario) Integral Group/Elementa Consulting Study published in LETI, 2020 and CIBSE Journal 2019 Building Embodied Carbon The graph shows whole life carbon emissions over 30 years of an low energy US West coast office building. This double story Operational Carbon building uses a VRF system. Depending on the refrigerant used, its leakage rate and recovery at end of life, refrigerant can have a different impact on global warming. Operational carbon emissions were estimated based on the building energy bills and grid carbon factor modelling for the 30 years. The building embodied carbon was estimated in a study by Integral (Total White Paper) and the embodied carbon of MEP - for a medium impact scenario is from a study by Elementa consulting.

Refrigerant Development Since their appearance in the 1930s refrigerants have evolved to improve their performance, increase their safety, and limit their impact on the environment.

Definition A refrigerant is a fluid that can easily change state, from a liquid to vapor and then condense back to liquid. These phase transitions are used in heat pumps and refrigeration cycles to create heating and cooling through closed loops called vapor-compression cycles. Refrigerants are classified by ASHRAE - Standard 34 (ASHRAE, 2019) and assigned an ‘R’ number, determined by the molecular structure.

History & Types of Refrigerant in Use Different refrigerants have been used since their introduction in the 1930’s with the first vapor compression systems: •

1830 – 1920’s: Sulphur dioxide and methyl chloride were the main refrigerants used but ended up creating public concern due to their high toxicity and flammability.

•

1920 – 1970’s: Chlorofluorocarbon (CFCs) In the 1920’s, scientists led by Thomas Mindley, came up with a nonflammable and non-toxic refrigerant they named Freon 12 (R-12), the first CFC. From that date onwards, R12 and other CFCs (e.g. R-11, R-113, R-114), became widely used.

•

1970 – 1990’s: Hydrochlorofluorocarbons (HCFCs) In the 1970’s, concern among scientists was raised about CFC ‘s impact on the ozone layer; In 1977, the World Plan of Action on the Ozone Layer by the United Nations Environment Programme (UNEP) was launched and eventually led to a phase out from CFCs to HCFCs with less Ozone Depletion Potential (ODP). R-22 became a popular refrigerant.

•

1990’s – now: Hydrofluorocarbons (HFCs) In 1987, the Montreal Protocol was signed by every UN member nation, banning both CFCs and HCFCs to protect our ozone layer. This international environmental agreement came into effect in 1989 and from 1995 eradicated production. It led to new types of refrigerant coming to market: HFCs. R-134a, R-410a slowly replaced Freon (R-12) and R22. However, substitution of by HFCs did not address the very high Global Warming Potential (GWP) of these gases. In 1997, several countries ratified the Kyoto Protocol to reduce greenhouse gas emissions (GHG), which drew attention to this aspect but did not create a mechanism to address it. HFCs are still widely used in existing systems.

•

2015 – now: Hydrofluoro-olefins (HFOs) and natural/hydrocarbons options. The European Union introduced its F-Gas Regulation in 2015, limiting the volume of HFCs used to reduce GWP of fluorinated gases. More recently in 2016, the Kigali amendment to the Montreal Protocol set a strict time line to phase out HFCs; first in high-income countries and then in low-income countries by 2030. As a result, new refrigerants with lower GWP and without ODP, such a HFOs recommended by the new F-Gas Regulation (e.g. R-1234ze, R-1233zd, R-1234yf) are now appearing in the market, as well as other natural/hydrocarbons options (e.g. ammonia, CO2, water, propane). New and existing technologies that use no refrigerants (solid state) or use low-GWP refrigerants are developing and coming to market maturity. Such systems are often limited by technology, safety risks, regulation or cost to use in smaller systems or niche applications.

More information is provided in Appendix 3.

Refrigerants & Environmental Impacts

Cl + O3

GLOBAL WARMING

Cl-O + O2

Ozone

UV (Ultra Violet)

IR (Infrared Radiation)

LEAKAGE RISK

CFCs HCFCs HFCs

Figure 2 Environmental Impacts of Refrigerants

Introduction | Refrigerant Development

OZONE DEPLETION

Life Cycle The Life Cycle of Refrigerant in HVAC systems can be broken down into distinct phases - production, use and end of life or wherever possible, recovery. Production Stage The production process to generate refrigerants are varied. HFCs and HFOs tend to require multiple steps and inputs, while production of natural or hydrocarbon refrigerants is less complex. The United States, Mexico, China and Japan are the main producers of refrigerants (Booten, et al., 2020). HFCs and HFOs are typically produced by mixing different refrigerants together. For instance, to produce R410a (HFC), R125 and R32 must be mixed in a 50/50 proportion. R32 is produced using hydrogen fluoride and R30 using steam and electric energy (Oekobaudat, 2018). R125, very common in CFC blends, is mainly composed of C2HF5. CO2 is generally a byproduct from industrial processes.

Use Stage Refrigerants used in HVAC systems equate to c.396 kilotons globally (Booten, et al., 2020), a figure which is likely to rise. A refrigerant can be used throughout the life of an HVAC system. However, there is usually a need for top-up due to leakage as the loss of refrigerant affects the systemâ&#x20AC;&#x2122;s performance - 50% leakage is regarded as the breaking point for system performance (Eumonia Research & Consulting Ltd, 2014). The refrigerant can also become degraded which requires filtering. For instance, about 1,200 tonnes of R410A (GWP 2088) are predicted to be in use in heat pumps in the UK in 2020 (Eumonia Research & Consulting Ltd, 2014).

End of Life / Recovery Most refrigerant can be reused in other systems, infinitely and without affecting performance. Factory sealed small volumes can be taken from site and safely discharged, while split systems such as VRF / DX systems need to be drained on site. If this is not possible, destruction should happen in an approved facility, equipped to absorb and neutralise acid gases and other toxic processing products. Best scenarios assume 100% recovery while more pessimistic ones assume 85% recovery for split systems. More information on these estimates is provided in Appendix 5.

Refrigerants & Environmental Impacts

1 Introduction | Life Cycle

TRANSPORT

WHOLESALE

CHARGE/ REFILL

SUPPLY REFRIGERANT IN BOTTLES

HVAC USE

RECOVERY BOTTLE PRODUCTION

TO BE REUSED RECLAIMED BOTTLE TO BE RECYCLED

ODP

GWP

DECHARGE/ RECOVERY

TRANSPORT DESTRUCTION

LEAKAGE RISK

END OF LIFE

Figure 3 Refrigerant Lifecycle and Environmental Impacts

Environmental Impacts The major issue associated with the use of refrigerant is leakage, resulting in release of refrigerant into the atmosphere. Refrigerant leakage can occur during any stage of its life cycle, but the use phase is typically when leakages occur the most. Actual data on leakage rates are hard to find. However, anecdotal reports suggest that leakage rates during the ‘use’ phase could be between 1% and 10% with an average of 3%. During removal at end of life stage, leakage rates range from 1% to 3%. More detailed information is provided in Appendix 4. The impact of leaked refrigerant can be classified in terms of three major impacts: 1. Ozone depletion potential 2. Global warming potential 3. Other environmental impacts.

Ozone Depletion Potential (ODP) The ozone layer of our stratosphere protects the Earth’s surface from the sun’s ultraviolet radiation. Long term exposure to UV radiation leads into “higher incidence of skin cancers and eye cataracts, more-compromised immune systems, and negative effects on watersheds, agricultural lands and forests” (UNEP, n.d.). The CFCs and HCFCs refrigerant are halogenated carbons which both contain chlorine atoms. Once these refrigerants are released into the atmosphere by leakage, they move up to the stratosphere and release chlorine. The chlorine atoms then react with ozone to create oxygen and chlorine oxide, thus participating in ozone depletion (Cl + O3 -> Cl-O + O2). Ozone depletion potential (ODP) is defined as the ratio of global loss of ozone compared to the one due to the refrigerant R-11 (CFC) for the same mass. R-11 has an ODP of 1 and has the worst ODP of all refrigerants used until now. In general, the ranking of refrigerants by ODP follows the order: CFC>>HCFC>>HFC> – HFO – HC/Natural. More information is provided in Figure 2 and Appendix 3. In 2019, NASA announced that the ozone hole had shrunk to its smallest size since it was first observed (Gray & Stein, 2019). However, it should be noted that CFCs and HCFCs have a very long lifetime and are likely to still affect our ozone layer in the years ahead. They continue to be produced illegally notably in some Chinese provinces (Rigby, et al., 2019; University of Bristol, 2020).

Refrigerants & Environmental Impacts

1 Global Warming Potential is an indicator for climate change and accounts for the ability of greenhouse gas (GHG) to trap heat within the atmosphere compared to CO2 over a specific time period (typically 100 years). It is therefore calculated in CO2 equivalent and is typically referred as carbon emissions. The 2019 Emission Gap Report from UNEP states that GHG emissions have risen at a rate of 1.5% per year in the last decade. The latest IPCC publication reports that building emissions must be reduced by 80–90% by 2050 to achieve global warming of no more than 1.5°C above pre-industrial levels. The GWP given for a refrigerant is associated with the leak of 1kg into the air during the use phase, as the production stage impact is much smaller and 100% of the refrigerant is typically assumed to be recycled - whereas in reality a figure of 98% is common (See Appendix 5). Refrigerant GWP varies by type. In this document, it is considered that low GWP is under 10 kgCO2e, medium GWP under 750 and high GWP above 750. In general, the ranking of refrigerants by GWP follows the order: CFC>>HCFC>>HFC>>HFO >HC/Natural. More information is provided in Figure 4 and Appendix 3. For instance, in the case of R410a, the Oekobaudat database gives the following GWP figures: • • • •

Production (modules A1 – A3) : 8.063 kgCO2e Use (module B1): 2088 kgCO2e - which is the GWP figure commonly used End of life (modules C1-C4): 0 as consider 100% recycled Recovery (module D): -7.33 kgCO2e

The GWP figures in this report come from IPCC Report AR4 (2007) and are calculated over a 100 year time-horizon.

Other environmental impacts There can be other environmental impacts associated with the use of refrigerants. For instance, R134a has a high impact on 'Marine Water Aquatic Eco Toxicity' for instance (Eumonia Research & Consulting Ltd, 2014). Recently, the Journal of Geophysical Research shared concerns about the dramatic rise of an ozone replacement called short chain perfluoroalkyl carboxylic acids (sc PFCAs) or “forever chemicals” which can be found in refrigerants, including HFOs (Pickard, et al., 2020). Insufficient data exist today to assess how much this will affect our environment and health, but there are growing concerns.

Introduction | Environmental Impacts

Global Warming Potential (GWP)

History + Properties of Refrigerants

HISTORY

WORLD PLAN OF ACTION ON OZONE LAYER 1977

MONTREAL PROTOCOL 1989

CFC

HCFC

ODP 1 GWP 4000

ODP 0.05-0 GWP>1500

Impact

Pressure

Temp. Â°C Safety

POTEN

TI A L

PROPERTIES

OZON E DEPL ETION

R12

R22

R407c

R410a

R134a

ODP

0.05

GWP

10700

1810

1774

2088

1430

-29.8

-40.8

-48.5

-26.2

-160

-155

-92.5

High Low Boil Freeze Toxic

Flammable

Figure 4 History and Properties of Refrigerants

Refrigerants & Environmental Impacts

HFC

HFO

ODP 0 GWP 600 2000

Natural & HC

ODP 0 GWP<150

ODP 0 GWP<5

GLOB AL WA RMIN G POT

(ODP)

Introduction | History + Properties of Refrigerants

KYOTO PROTOCOL F-GAS REGULATION PROTOCOL KIGALI ACCORD 1997 2015, 2016

NOW?? E NTI A

L (GW

Time

R32

R1234 ze

R1233 zd

R290

R744

R717

677

-51.7

-19

18.32

-42.1

-78.5

-33.34

-136

-185.89

-56.6

-77.73

Maybe

Y ND: Not Determined

Best Practice Guidance

435 Indio Way in Sunnyvale, California is a pioneering speculative Net Zero Energy deep retrofit. Prioritizing passive design features minimised refrigerant charge by reducing peak demands on HVAC systems by 80%. Free cooling is harnessed using exposed thermal mass, ceiling fans and night time flush with operable windows and skylights. The compressors were downsized to ventilation air only. Image ÂŠ Bruce Diamante

4 Steps to Best Practice Current best practice to limit the environmental impacts from refrigerant selection is a combination of refrigerant choice, mitigating refrigerant leakage, and improving refrigerant recovery.

Step 1: System selection and refrigerant choices Refrigerant selection considerations for new systems When considering refrigerant use, consider: 1. Necessity to use refrigerant All passive measures to reduce or eliminate active heating and cooling should be exhausted, and all non-refrigerant and combustion-free systems should be investigated, before it is decided that an active refrigerant-based heating/cooling system is the only viable option. 2. Selection of a refrigerant with the lowest GWP The second key selection criterion to consider is the GWP of the refrigerant to be used in the system, and to select the refrigerant with the lowest possible GWP that is available and meets system requirements. In relation to ODP, the good work of previous protocols has already had the desired impact in many countries and all new refrigerants sold are now rated 0 for ODP. However, in the pursuit of lower GWP, there should be no compromise on a 0 rating for ODP.

REFRIGERANT CHOICE OPTIONS in order of best practice Natural/hydrocarbon substances â&#x20AC;&#x201C; GWP < 5 Ammonia (R717), CO2 (R744), and Propane (R290) are three of the most interesting current options. These natural refrigerants are less likely to have unintended consequences, as they are known substances. Today, their use is aspirational for most sectors since products are not widely available to enable their selection. With pressure from industry, it is hoped that manufacturers will increase the range of applications that can use these refrigerants. HFOs â&#x20AC;&#x201C; GWP < 10 Alternative low GWP refrigerants currently available commercially are HFOs R1234ze, R1234yf, R1233zd. HFCs - GWP < 750 If you cannot use a low (<10) GWP refrigerant, then the next set of commercially available substances have GWP between 450-750. Most major manufacturers will now offer systems in the <750 GWP bracket. Only in limited circumstances in the current market should there be a reason to go above this band. New units with GWPs over 750 should be avoided, unless it can be proven that the volume is measurably less and that the overall warming potential of the whole system is less than a comparable system in the 450-750 band. 3. Refrigerant charge reduction When comparing systems, the GWP of the refrigerant should not be the only consideration, as the refrigerant charge will also have a big impact on the overall effect the system could have, if discharged to atmosphere. For instance, although R410a has GWP 46% higher than R134a, the equivalent 500kW cooling air-cooled chiller has a 62% lower potential impact. Similarly, whilst R513a offers a GWP 70% reduction when compared to R410a, it actually only delivers a 37% saving in this instance.

Refrigerants & Environmental Impacts

2 ESEER*

Refrigerant charge (kg)

Unit area (m2) â&#x20AC;&#x201C; footprint of chiller

Total GWP for the system (tCO2e)

Ammonia (GWP=0)

5.6

18.6

R1234ze (GWP=6)

5.48

290

15.7

1.74

R513a (GWP=631)

5.16

180

11.3

113.6

R134a (GWP=1430)

5.37

330

15.7

471.9

R410a (GWP=2088)

4.19

13.1

181.6

Table 1: Example of varying total GWP for a selection of 500kW chillers * ESEER = European Seasonal Energy Efficiency Rating

The only clear winners are Ammonia and R1234ze, which have such low (or zero) GWP that the volume used does not affect performance. This shouldnâ&#x20AC;&#x2122;t mean to ignore the leakage potential from R1234ze systems as a full discharge would still equate to a 14,000+ mile journey in a new petrol car - assuming 122 gCO2 /mile (UK Department for Transport, 2015). Based on these considerations, the below system recommendations are in order of priority from a volumetric and leakage risk perspective. For each system, the intention is to identify the lowest impact refrigerant based on current UK market availability (this advice may vary for international markets). This is not an exhaustive list of every engineering option, but a summary of the more common systems.

Centralised Chillers and Heat Pumps (new) These systems require factory produced package unit(s), and then use water as the distribution fluid around the building. During construction, these units are pressure tested, fully charged with refrigerant at the factory and hermetically sealed. There is no requirement to handle any refrigerant on site. During the equipment life it may require de-gassing and re-gassing for maintenance activities, but this can be easily controlled local to the unit in a plant location.

REFRIGERANT CHOICE OPTIONS in order of best practice for centralised systems Ammonia (GWP =0) The optimum GWP performance and one of the best energy efficiency solutions is Ammonia, however, this is often more expensive than the alternatives and requires a larger plant area for the equipment. There are toxicity issues with Ammonia which need to be carefully considered, but these considerations vary from region to region, often leading to this being best suited to large scale energy centres. R744 - CO2 (GWP=1) While not as efficient as ammonia or some HFOs, CO2 is starting to be found in some residential centralised systems as it can produce high enough temperature for domestic hot water use. HFOs (GWP < 10) There are now many R1234ze or R1234yf (HFOs) units becoming available on the market. These are slightly larger than some of the traditional higher GWP alternatives, but offer similar or better energy efficiency. When these units first came to market, they were significantly more expensive, however with the progression of the market towards lower GWPs they are becoming more affordable. HFC (GWP < 750) A short-term solution to lower GWP is offered by R454b, R513a and R32. These products are relatively new to the market but are gradually increasing their market share. Again, as these units are often roof mounted, flammability issues can be controlled. HFC (GWP > 750) There are still units available with R410a, R407c and R134a, but these should no longer be specified due to the high associated GWP. Whichever refrigerant is selected, the main components that affect refrigerant volume are the heat exchangers. In recent times, manufacturers have been transitioning towards flooded evaporators and condensers (a shell and tube heat exchanger where the water is in the tube and the refrigerant is the shell surrounding the tubes). Flooded evaporators increase equipment efficiency but also increase refrigerant volumes.

Best Practice Guidance | 4 Steps to Best Practice

Refrigerant

REFRIGERANT CHARGE REDUCTION MEASURES OPTIONS for centralised systems Microchannel air to refrigerant heat exchanger These new type of heat exchangers consists of hollow blades with multiple channels where refrigerant has greater contact to air and replaces the traditional tubes. Micro plate heat exchanger for refrigeration systems below 400 kW The plates that separate the fluids (refrigerant vs. water) comprise dimples rather than channels. These offer even lower refrigerant volumes and have a smaller overall size compared to traditional plate heat exchangers. Water cooled units for centralised systems Refrigerant volume is much lower due to smaller heat exchangers. However, as they tend to be in basement plant rooms, the refrigerant used can be a cause for concern and exceed the legal weight limits of refrigerants in indoor spaces according to ISO817, CSA B-52, ASHRAE 15 and IEC60335, therefore water cooled are not a simple straight forward recommendation. The comparison becomes complex when considering the whole life carbon performance of water cooled vs. air cooled, as there are other factors to consider, e.g. increased material use due to different locations for condenser and heat rejection, increased chemical usage to maintain water quality, and the volume of water used by the evaporative water cooled units.

Distributed systems (new) Distributed systems are based on the premise of refrigerant circulating around the whole building. These can be set up as heating only, cooling only, heating or cooling or both simultaneously. These systems are called Variable Refrigerant Volume (VRVÂŽ) or Variable Refrigerant Flow (VRF) when heat recovery system is provided or multi-split systems for single mode operation.

REFRIGERANT CHOICE OPTIONS in order of best practice for distributed systems There are limited reduced GWP options for this type of system, with the best currently on the market R32 (GWP 675). R32 is an HFC refrigerant that is the least toxic of all Class A (non-toxic) refrigerants listed in ISO817. It is not explosive, and it is also extremely difficult to ignite. Although available in many parts of the world, it must be noted however that R32 is not currently available in the US and not likely to appear on the market before 2025. With distributed systems, the refrigerant charge is generally greater than with centralised water-based systems and comes with the added risk that is it inserted on-site under construction conditions. The best option for reducing the system GWP is to reduce the quantity of refrigerant in the system. Even with this major improvement on the current installations, leakage should still be carefully managed, and the charge still represents a large amount of CO2e should it be lost to atmosphere.

REFRIGERANT CHARGE REDUCTION MEASURES OPTIONS for distributed systems Hybrid VRF: the distributed system uses refrigerant in the primary routes and switches over to a water-based medium for the final run outs and in fan coil units. This has the added benefit of keeping the refrigerant containing elements within common parts where it is easier to manage toxicity and flammability risks. This type of system can reduce the refrigerant content by as much as two thirds when compared to a traditional VRF system. When this is combined with the shift from R410a to R32 this can offer a 90% reduction in the whole system GWP. Moreover, in the case of renovation or tenant fit-out in multi-tenanted buildings, only the water based elements need to be modified - which eliminates the leakage risk associated with works to the refrigerant containing parts of the system.

Refrigerants & Environmental Impacts

2 As the electricity grid in many countries becomes decarbonised, the switch from gas-fired boilers to electric heat pumps on a domestic scale is becoming popular. This is creating a whole new market for refrigerant equipment and applies another market pressure when considering the phase down of refrigerants with this high quantity of small charge systems. The same approach as commercial systems should be adopted for residential systems, first attempting to minimise the GWP refrigerant used, and then to minimise the volume of refrigerant used with a preference for packaged units over split systems.

REFRIGERANT CHOICE OPTIONS in order of best practice for residential scale systems The selection of refrigerants available for residential scale systems is more limited than commercial units, however there are still some good options. R290 Propane (GWP=4) Flammability of this refrigerant is easily managed by the very small quantity involved and since there are products where all the refrigerant containing elements of the system are located externally. It seems to be the best option available for : air source heat pump (heating and hot water), water source heat pump (suitable for ambient loop or ground source system), close coupled to hot water cylinders. In the UK, there are far more residential R290 products available. R744 CO2 (GWP= 1) for air source heat pump (hot water only), it seems to be the best option available. R134a (GWP =1430) for integrated into mechanical ventilation units (also known as exhaust air heat pump) it seems to be the best option available. This list was accurate at the time of writing for the UK market, a search for lower GWP alternatives is always recommended per region. Warning: Just because it is a small refrigerant charge the leakage issue must not be ignored. A residential R410a heat pump may only contain 2kg of refrigerant, however if this is lost to atmosphere it represents 4 tonnes of CO2e. Moreover, at building level, the total charge of individual systems may exceed the charge for a centralised system because of the number of units. Thus, the same recommendation applies, ideally keep the GWP below 10, and if not possible do not exceed 750.

Best Practice Guidance | 4 Steps to Best Practice

Residential Scale Systems (new)

Centralised Systems

Distributed Systems

Individual Systems

Communal Heat Pump

VRF

Split DX Packaged Individual Heat Pump

Chiller

Refrigerant charge

GWP not meeting GWP meeting climate targets climate targets

Best Refrigerant Options: Ammonia CO2 Water Propane R1234ze R1234yf R32 R513a R134a R407c R410a

Refrigerant charge

Best Refrigerant Options: Ammonia CO2 Water Propane R1234ze R1234yf R32 R513a R134a R407c R410a

Refrigerant charge

Best Refrigerant Options: Ammonia CO2 Water Propane R1234ze R1234yf R32 R513a R134a R407c R410a

ASHP, WSHP, closed loop

Exhaust air heat pump

Leakage risk:

Leakage risk - Split:

Sealed units so precharge

Typically high distribution length

Not necessary sealed

Leakage - Packaged: Small charge - sealed and precharge but can add up due to # of units

Charge Reduction:

Heat Interface Unit

Distribution Length

Water cooled Units

Hybrid VRF

Figure 5 Refrigerant Options by System Type

Refrigerants & Environmental Impacts

Charge Reduction: Already minimal but still need make sure to address refrigerant leakage

2 Best Practice Guidance | 4 Steps to Best Practice

Impact of system choices on refrigerant charge by GWP (average kg/kW) Impact of System Choices on Refrigerant volume by capacity and GWP 1.2

Worst Practice

Refrigerant Charge (kg/kW)

0.8

0.6

0.4

Best Practice

0.2

0 0

500

1000

1500

2000

2500

GWP (kgCO2e)

Air chiller

Systems:

Air Recovery Heat Pump

Small Heat Pump Air recovery Heat Pump

HVRF

Small heat pump

VRF

Water Recovery Heat Pump

Water cooled Chiller

Water Recovery Heat Pump

VRF

Water cooled chiller

H - VRF

Air cooled chiller

Best Practice by Product Type There are many different products and many different system set-ups, which leads to a vast array of possibilities. To provide an overarching metric to compare performance this graph measures volume normalised by capacity (kgCO2/kW) against the refrigerant GWP. The graph shows the relative poor performance of VRF compared to best practice with chillers. The entries on this chart are limited by sample of products, however it is recommended to plot in this way to achieve a strong selection comparison tool. This graph is based on 276 data points and only reflects average.

Figure 6 Refrigerant Considerations by Product Type

HFCs refrigerant replacement in existing systems As HFCs have a high GWP and are being phased out, it is essential to find ways to replace them in existing systems. In the implementation of the Montreal Protocol it was possible, for example, to replace R22 (HCFC) with R410a or R12 (CFC) with R134a in the same equipment, with only a small loss of performance. Information differs depending on which manufacturers information you refer to, however there appears to be some similar alternatives in the quest to drive down the GWP. Here are some HFC replacement options for R134a, R407c and R410a. There are potentially other high GWP refrigerants currently in use, these are likely to require a full replacement.

REFRIGERANT CHOICE OPTIONS to replace R407c (HFC) There is currently no direct replacement for R407c (GWP=2107) To improve these systems modification, or full replacement, will be required to the refrigeration equipment. The recommendation though is to seek a full replacement of R407c utilising the lowest GWP (ideally a natural substance) to have the maximum positive impact. R134a (GWP= 1430) This would potentially require the evaporator to be replaced with a re-sized vessel. It is not ideal to have to modify the system to accommodate a still relatively high GWP refrigerant, although this would still offer over a 30% reduction. This would potentially also open the option for future change to R513a.

REFRIGERANT CHOICE OPTIONS to replace R134a (HFC) Different options exist to replace R134a (GWP=1430): R513a (GWP=631) Potential direct substitute for R134a in some instances with no plant modifications (some manufacturers have already future proofed their current R134a range to accommodate the change), The change from R134a to R513a would come with approximately a 4% reduction in performance. R1234yf (GWP<1) Another alternative with even greater potential to reduce the GWP would be R1234yf, if available this would lower the GWP of the associated system by over 99%. The choice of replacement might be influenced by the acceptable flammability risk for the specific project, as R513a is non-flammable however R1234yf has low flammability (as defined in ISO:817). R514a (GWP <1) Another potential alternative in low pressure heat pumps/chillers but cannot be used for high pressure systems.

REFRIGERANT CHOICE OPTIONS to replace R410a (HFC) There is currently no direct replacement for R410a (GWP = 2088), there are potentially products under development (R466A or R452B) but nothing commercially available at present (this may vary with region). As R410a works at a high pressure, which can lead to these systems having a shorter life span, the time frame for full replacement may not be too long. The priority for these systems if they cannot be replaced is to potentially increase maintenance to protect against leakage as far as practically feasible.

Refrigerants & Environmental Impacts

Refrigerant leakage mitigation is a key step towards improving the environmental impacts associated with refrigerant use. In Drawdown, Paul Hawken calculates that over 30 years, capturing 87% of refrigerants from equipment leaks and at the end of equipment life would avoid emissions equivalent to 89.7 gigatons (89.7 billion tons) of CO2 (Hawken P., 2017) In the UK, operational leakage in 2020 would represent about 70,000 kg of refrigerant lost, representing about 130,000 tonnes of CO2e (Eumonia Research & Consulting Ltd 2014). More information concerning legal aspects and leakage data can be found in Appendix 4.

General Recommendations Similar to the selection of a new system, mitigating actions are based around the priority of dropping the GWP of the refrigerant, then dropping the volume and finally working with factory sealed equipment wherever feasible. Once this process has been completed there are a few other tasks that can be undertaken to help mitigate further the risk of leakage within the system: •

Installation by a registered installer with the manufacturer of the system This could potentially extend to adding a requirement for the manufacturer to attend site and confirm all their requirements have been met. This is the most reasonably practical step that can be taken to ensure the system has the best chance of being leak-free due to installation risk.

•

Maintenance by a registered contractor with the manufacturer of the system Harder to enforce, but it should also be specified within all operating procedures/manuals. For example, some manufacturers have prescriptive procedures for how to recover refrigerants from their systems in order to achieve 100% recovery (or as close to it as possible). If an unregistered contractor is permitted to work on the system, then there is a significantly increased risk of refrigerant leakage during servicing. Correct maintenance should avoid constant over pressure in any part of the system, which can reduce plant life and increase the probability of a leak

•

Leak Test Systems should undergo leak tests in accordance with the local regulator. If no test is required, then it is recommended to follow the F-Gas requirements (see table below). Leak tests can be : •

indirect i.e. looking for signs from operation of a leak – e.g. a loss in suction pressure or low liquid level in liquid receiver direct, e.g. via hand-held leak detector or tracer dyes with UV lamp

• or • fixed (mandatory under F-Gas for systems over 500 tonnes, but available for smaller systems)

System Charge

Leak Test Frequency for Systems with no fixed leak detection

Leak Test Frequency for System with fixed leak detection

5 to <50 tonnes CO2e *

Once per year

Once every two years

50 to 500 tonnes CO2e *

Twice per year

Once per year

>500 tonnes CO2e *

N/A

Twice per year

Table 2 : Leak Test Frequency requirements by F6Gas Regulation * CO 2 equivalent relates to GWP, e.g. 5 tonnes CO 2 equivalent equals 5 tonnes of CO 2e or 2.4kg of R410a.

Best Practice Guidance | 4 Steps to Best Practice

Step 2: Refrigerant Leakage Mitigation

Leakage mitigation recommendations - specific to systems Even though the leakage risk is lower for sealed units during the use phase, the following measures are still recommended:

LEAKAGE MITIGATIONS MEASURES for sealed units Leak detection with a pump down receptacle The type of detection system can vary between devices, a common approach is to locate a refrigerant sensor in the compressor enclosure of the unit, this will then activate the alarm if any refrigerant is detected. High Quality Sensor to enhance leak detection system Sensors are available on the market that can detect refrigerant as low as one part per million (ppm), which gives the system the ability to react at much lower volumes of leakage. For split systems, the risk of leakage is significantly increased due to the requirement for elements of the system to be installed on site - often in challenging conditions. In the event there is a leak detected on a split system, the emergency procedure should be to recover the remaining refrigerant as quickly as possible, then fix and test the system prior to recharging. Fixing a full system increases the risk of further leakage occurring.

LEAKAGE MITIGATIONS MEASURES for split units Pressure tests Consideration should be given to increasing the test pressure for these systems to give greater confidence that they will not leak during normal working pressures. It is recommended that all system pressure testing is witnessed by a third party, which may be an addition to the standard witnessing scope. Room sensors Assists in identifying the location of any potential leak, which could take a considerable time if detection was limited to central system monitoring. Hybrid Systems Significantly reduces the volume of refrigerant, and as such the environmental risk associated with a leak. If a hybrid system is not achievable then consideration should be given to installing multiple smaller systems, in lieu of one large system. This will limit the volume of any one system and reduce the leakage risk should a fault occur.

Step 3: Refrigerant recovery optimisation Most manufacturers have a methodology that best suits the recovery of refrigerant from their system, to minimise leakage. These methods should always be followed, and ideally undertaken by a contractor trained by that specific manufacturer on the process. In the UK, Daikin have launched a scheme called â&#x20AC;&#x2DC;Reclaim with confidenceâ&#x20AC;&#x2122;. This scheme is based on Daikin being paid to recover the refrigerant on your site (be it from a Daikin system or not). Daikin will safely remove the refrigerant from site and provide any necessary paperwork. Other manufacturers may offer similar services. By utilising a service of this type the risk of leakage is being minimised during recovery by employing qualified engineers who spend their whole time focused on this process. More information about legal aspects and recovery data can be found in Appendix 5.

Step 4: Selection Implementation See next Section.

Refrigerants & Environmental Impacts

Work on design to reduce refrigerant charge

Have you minimised the volume of refrigerant used in your system?

Can you use a natural refrigerant?

Specify refrigerant with lowest GWP

KEY Meeting Climate Targets

Re-design your system and repeat

* perfluoroalkyl carboxylic acids

Can you use a refrigerant with a GWP < 10, that doesn’t contain PFCAs* or “forever chemicals”?

R-717 R-744

Find appropriate manufacturer & conditions to mitigate refrigerant leakage and optimise refrigerant recovery

R-290

Can you select a system where all elements using refrigerants are factory sealed? N

HFO: R-1234ze R1234yf R-1233yf R-513a R-454b

Can you use a refrigerant with GWP < 750? N

HFC: R-32

Check legal & practical aspects linked to the refrigerant/ product selected

Is the whole system charge GWP is smaller than one of the alternative options dismissed above? Y

Can you specify a manufacturer, registered installer and contractor + ensure frequent leak testing? N

HFC: R-134a R-410a

N Start again

R-407a If you still cannot find

Can leak detection be provided? (sensors in sealed systems or room sensors + pressure test in unsealed systems) Y

Can 100% of the refrigerant will be recovered at end of system life in a suitable way?

Try again

You are ready for step 4 - more in the following section

Change product or start again

Figure 7 Selection Process Summary

The refrigerant meets selection criteria. Communicate best practice maintenance requirements

Check for legal and practical aspects linked to the use of this refrigerant of which you should be aware

Best Practice Guidance | 4 Steps to Best Practice

Selection Process Summary

Selection Implementation

Strand Palace Hotel in the heart of London meets comfort expectations of guests using a hybrid VRF system - currently the biggest in Europe. A small quantity of refrigerant is used to transport heating or cooling to a central branch controller, this energy is then transferred to water to be carried to the individual hotel rooms, through old service shafts and existing wall spaces.

Further Aspects to Consider A range of legal and practical aspects should be considered when selecting a refrigerant.

Legal Aspects When considering both systems and refrigerant, a designer must consider the legal implications around health, safety, ownership and maintenance.

Fluorinated Gas Regulation In most countries around the world, fluorinated gas (CFCs, HCFCs, HFCs) are regulated by law. Many F-gases are entirely banned, notably HCFC gases. F-Gas Regulation in Europe In the European Union and the United Kingdom, the Fluorinated Gas regulation controls the installation, servicing, sale, and decommissioning of fluorinated gases (more information in the appendices). This regulation is under the jurisdiction of the European Court of Justice and implemented by environmental agencies. Since 2015-2016, fluorinated gases are subject to a quota system: the goal is to reduce by 79% the use of HFCs by 2030 (European Commission, 2015). Consequently, it is against the law to: • •

work with F gas if you don’t have the correct qualifications trade in F-gas using disposable containers and to import a F-gas outside of the quota system

CARB HFC rulemaking in California In 2016, California Senate Bill 1383 specified a target 40% reduction in state-wide HFC emissions below 2013 levels by 2030. Measures to meet this target were adopted by CARB’s Board with the two HFC rulemakings in 2018, which limit the use of HFCs. However, it only prohibits the use of certain HFC in retail food refrigerant equipment, vending machine, foams and not in typical building systems (California Code of Regulations, 2018).

Ozone-depleting Substances and Halocarbon Alternatives Regulations (ODSHAR) in Canada The ODSHAR replaces Canada’s Ozone depleting Substances Regulations 1998 in 2016 to meets its obligations under the Montreal Protocol. From 2020 onward, import and manufacture of HCFCs will be prohibited, with exception of R123 for the servicing of existing systems. The regulations also implement HFCs phase down through a consumption allowance system, to meet eventually 85% phase out compared to 2019 by 2036 (Government of Canada, 2020).

Ozone Protection and Synthetic Greenhouse Gas Management Regulations in Australia In 2016, the government of Australia decided to phase down HFC to meet obligations of the Kigali Amendment to the Montreal Protocol starting in 2019. It will result in 85% import phase out by 2036 and import bans of specified equipment with high GWP refrigerant (Australian Government, 2020). Warning: In recent years, due to the phase out and phase down of existing refrigerants, and the associated increase in cost, a black market has formed trading in HCFC refrigerants (Environmental Investigation Agency, 2019). Designers should remind clients to only obtain refrigerants from a reputable source and advise that the use of black-market products could lead to prosecution.

Refrigerants & Environmental Impacts

HFC phase out based on average consumption levels

85% HFC phase out in developed countries 80% HFC phase out in developing countries group 1 85% HFC phase out in developing countries group 2

70% HFC phase out in developed countries 10% HFC phase out in developing countries group 1 85% HFC phase out in developed countries 50% HFC phase out in developing countries group 1 30% HFC phase out in developing countries group 2

10% HFC phase out in developed countries 2025 2019

2029

F-GAS EU REGULATION (2015) HFC phase out based on 2009 to 2012 sales

2039

79% HFC sales phase out to compared to sales between 2009 and 2012 Market prohibition on single split AC with less 3 kg of refrigerant with GWP<750 Restrictions on commercial use display units with GWP < 150 Market prohibition on stationary equipment that contains or that relies on HFCs with GWP < 2,500, except for cooling equipment below -50Â°C

Restrictions on commercial use display units with GWP < 2,500

Figure 8 Examples of Flourinated Gas Phase Out Regulation

2049

time

Selection Implementation | Further Aspects to Consider

KIGALI AMENDMENT (2016)

Safety Fire Risk / Flammability The flammability of refrigerant is indicated by ASHRAE 34 (2013) ratings: •

A1 no flame propagation

•

A2L lower burning velocity class “mildly flammable”

•

A2 lower flammability

•

A3 highly flammable

Each category is defined by a burning velocity (BV) and a minimum ignition energy (MIE). However, in some local geography this classification is not recognised. For example, in the UK, the Health and Safety Executive (HSE) does not recognise A2L. This poses a barrier to installation and can lead to liabilities. On the other hand, ASHRAE has set two addenda (h and d) for review that would allow the use of these class A2L refrigerants.

FLAMMABILITY PREVENTION MAINTENANCE REQUIREMENTS Risk assessments according to ISO817:2014 internationally, the Dangerous Substances and Explosive Atmospheres Regulation (DSEAR) in the UK, or ATmospheres EXplosible (ATEX) in Europe. Evidence of training and competence of the persons working on and handling flammable refrigerants Limit of refrigerant used Refrigeration system must not exceed a set of limits that take account of flammability, location type (plant room, indoor, ventilated spaces, open space), access (presence of humans), and application (human comfort or process). These limits are set locally and vary over time (see example of Propane below). Example: Limit of Propane - classified as A3 The International Electrotechnical Commission (IEC) 60335 has increased the amount of propane allowed in refrigeration systems from 150 to 500 grams but the local regulations (e.g. European regulation EN60335) are yet to be implemented. The International Code Council will likely adopt the requirements in ASHRAE 15 when finalised (Sheff, 2020).

Toxicity ISO 817 and Europe’s EN378 regulations comprise dispositions to protect occupants from the risk of asphyxiation in case a leak in a refrigeration system occurs in a sleeping accommodation such as a hotel or dwelling. •

ISO 817 provides a measure of toxicity of refrigerants and sets limits based on Acute-Toxicity Exposure Limit (ATEL) or Oxygen Deprivation Limit (ODL) or Operational Exposure Limit (OEL) and associated guidelines from ASHRAE 34. Refrigerants are defined by toxicity as A (lower toxicity – OEL > 400ppm) or B (higher toxicity – OEL < 400ppm).

•

EN 378 follows ISO 817 toxicity and flammability classification and indicates in the maximum allowable concentration of refrigerant in a room. This standard defines four limits: • • • •

QLMV: Quantity Limit with Minimum Ventilation in kg/m³ QLAV: Quantity Limit with Additional Ventilation in kg/m³ Flammability charge limit in kg/m3 RCL: Refrigerant Concentration Limit in kg/m³

Refrigerants & Environmental Impacts

3 Selection Implementation | Safety

Highly Flammable

Flammable

Midly Flammable

A2L

R1234 yf

R1234 ze

R32

No flame propagation

R22

R134 a

R718

R290

ASHRAE Flammability Classification

R410 a

R744 R407 c

R717

B2L

R513 a

ISO 817 Toxicity Classification

Figure 9 Classification of Flammability and Toxicity

ACCEPTABLE AMOUNT OF REFRIGERANT IN A DISTRIBUTED SYSTEM CALCULATION 1. Consider the volume of the smallest space served by the installation. For instance, EN378 assumes that 100% of the refrigerant volume in the installation could leak entirely into any single room traversed by any pipe or component in the system. 2. Then define the maximum refrigerant that can safely leak into this space. 3. Limit the refrigerant volume to this number. Therefore, the total system refrigerant content cannot exceed the volume that would cause a refrigerant concentration above the stated limit in the smallest occupied room served or crossed by the system. Example: Limit of refrigerant volume in sleeping accommodations: In practice sleeping accommodations (hotels, dwellings) are the highest risk areas as asphyxiation can occur when an occupant is asleep. This requirement is also a function of the ventilation requirement and considers the buoyancy of the refrigerant (lighter or heavier than air). For example, following EN 378, a 80mÂł room should be served by a system containing no more than 2kg of R32 to avoid exceeding concentrations of 0.025kg/mÂł.

Toxicity and flammability mitigation measures Refrigerants with high flammability (A3) are generally unsuitable for retrofitting into older AC systems. Some of the lower GWP refrigerants have the highest flammability, such as propane (see Figure 9). These gases are suitable for small systems (e.g. most fridges use propane) but are not suitable for larger systems such as VRV/VRF systems.

BEST TOXICITY AND FLAMMABILITY MITIGATION MEASURES Installation split into smaller multiple systems: this reduces the refrigerant charge per systems to the lowest of either flammability or toxicity limit. In some cases, due to long pipe runs or small rooms, this is not economical or practical, the limit exceeded provided a leak detection alarm is positioned in each accommodation concerned. Refrigerant Alarm: Where such limits are exceeded, a refrigerant alarm must be installed. It must be inspected at least once a year. It must at least sound an alarm to warn the occupant. Water based, air systems or hybrid refrigerant/water systems: Their specification to reduce the presence of refrigerants in occupied or internal spaces can reduce or eliminate these risks.

Refrigerants & Environmental Impacts

Practical Considerations In multi-tenant buildings with commercial tenants, contracts can impose on tenants a set of rules on the maintenance of the installations in their sub-tenancy to ensure any modification is performed by only approved companies. In multi-residential properties however, it is more difficult to control the refrigeration installation in each dwelling and access to the installation in residential properties is more difficult. As a result, the risk of systems damage and leakages is greater. Leakages in one property can affect many other properties. It can result in costly liabilities for tenants and landlords.

BEST MULTIPLE TENANCY BUILDING OPTION Installing water-based systems is generally preferred because a system can more easily be built in phases. A floor or a part of a building can be left with capped water connections for a tenant to subsequently extend the heating/ cooling system from the connection with pre-defined contractual obligations. A water-based system is also easier to meter. Hybrid system when using VRF has the potential for the refrigerant element to remain in the Landlord system, and each hydro box can be used as the split between landlord and tenant. This keeps tenant systems to water based only and allows each demise to be amended independently without effecting other tenants. Standard VRF means that refrigerant needs to be run into each demise. For a clean separate a separate system should be provided for each tenant, which will lead to larger riser and plant space requirements. If a common system is adopted then careful management and monitoring needs to be adopted as any tenant issue has the potential to disrupt the whole building, and a leak in any area is exposed to the full volume of the refrigerant charge from an exposure perspective.

Cost and space Space and cost considerations can favour the choice of a system. Figure 5 shows how medium size distributed refrigeration systems (in particular VRF system) generally comprise greater refrigerant volumes per capacity whilst offering no low-GWP refrigerant alternatives. Yet these systems are often favoured for their spatial and installed costs.

COST AND SPACE RECOMMENDATIONS Natural refrigerant potential: Some natural refrigerant such as ammonia have greater capital and/or maintenance costs yet offer operational savings to the final user which can be attractive to developer/end-user. The availability and cost of natural refrigerants equipment (with low GWP) is likely to evolve favourably through the combined effect of market forces and the quota regulations. Specifiers should consider the longer term and notably the future cost of refrigerant top up and replacement for the products affected by the quota systems that tends towards the complete ban of some refrigerant beyond 2030, thus putting pressure on prices.

Certifications Some certifications include refrigerants aspects, but typically allocate limited weight to credit compliance: •

LEED 1 credit is available for “Enhanced Refrigerant Management”.

•

BREEAM New Construction 2018 3 credits maximum are available for “Pol 01 Impact of Refrigerant” if no refrigerant is used within the installed plant or systems or if refrigerant used comply with 3 different requirements.

•

GREENSTAR 1 credit is available for equipment using refrigerant with GWP under 10 with 0 ODP or if no refrigerant is employed at all or if the calculated total system direct environmental impact is under a certain value.

Selection Implementation | Practical Considerations

Ownership & maintenance in multi-tenanted buildings

Appendices

A1 Glossary AC

Air conditioning

ATEL

Acute-Toxicity Exposure Limit

ATEX

ATmospheres EXplosible

ASHP

Air Sourced Heat Pump

ASHRAE American Society of Heating, Refrigerating and Air-Conditioning Engineers CIBSE

Chartered Institution of Building Services Engineers

CFC

Chlorofluorocarbons

European Norm

Embodied Carbon

Direct eXpansion

GSHP

Ground Sourced Heat Pump

GWP

Global Warming Potential

Hydrocarbon

HCFCs

Hydrochlorofluorocarbons

HFC

Hydrofluorocarbons

HFO

Hydrofluoro-olefins

HSE

Health and Safety Executive

HVAC

Heating, Ventilation and Air-Conditioning

IEC

International Electrotechnical Commission

IPCC

Intergovernmental Panel on Climate Change

ISO

International Organisation for Standardisation

ODL

Oxygen Deprivation Limit

OEL

Operational Exposure Limit

ODP

Ozone Depletion Potential

PFAS

Per- or poly-Fluorinated Alkyl Substances

QLAV

Quantity Limit with Additional Ventilation

QLMV

Quantity Limit with Minimum Ventilation

RCL

Refrigerant Concentration Limit

Sc PFCA Short Chain Perfluoroalkyl carboxylic acids UNEP

United Nations Environment Programme

VRF

Variable Refrigerant Flow

WLC

Whole Life Carbon

WSHP

Water Sourced Heat Pump

Refrigerants & Environmental Impacts

A2 Definitions

Chiller: Centralised refrigerant-based equipment which generates chilled water from the evaporator to provide cooling. Usual arrangements are packaged air-cooled units at roof level, or water-cooled units where chiller can be remote from the cooling towers. Direct Expansion (DX): individual refrigerant-based system split in two parts: a condenser outside and an evaporator inside which provides cooling. Outside air acts as the heat exchange source. It is also called a split system. Greenhouse gas (GHG): “gaseous constituent of the atmosphere, both natural and anthropogenic, that absorbs and emits radiation at specific wavelengths within the spectrum of infrared radiation emitted by the Earth’s surface, the atmosphere, and clouds. GHGs include carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6).” (ISO, 2018). Global Warming Potential (GWP): “index, based on radiative properties of GHGs, measuring the radiative forcing following a pulse emission of a unit mass of a given GHG in the present-day atmosphere integrated over a chosen time horizon, relative to that of carbon dioxide (CO2)” (ISO, 2018). Indicator to Earth’s rising temperatures, resulting in climate change. The given refrigerant GWP in this report are from the IPCC report v4 over a 100-years time horizon. Heat pump (HP): Refrigerant-based system which use a vapour compression cycle to create heating or cooling. Different types of heat pumps exist. An air-to-water air sourced heat pump (ASHP) provides heating and cooling and utilises water as the heat transfer fluid through the building, keeping the refrigerant charge solely within the ASHP equipment. A ground sourced heat pump (GSHP) is a water-to-water heat pump that is fed by a group loop. An exhaust air heat pump is a heat pump integrated within a Mechanical Ventilation with Heat Recovery unit; it uses the heat in the exhaust air, as a heat source to provide heat and domestic hot water to the building space, primarily in the residential sector. Operational carbon: GHG emissions which are emitted as a result of a building’s energy use. This typically includes GHG emissions associated with heating, hot water, cooling, ventilation and lighting systems, as well as energy used for cooking and by specialist equipment such as lifts. Ozone Depletion Potential (ODP): index measuring degradation to the ozone layer a substance can cause. ODP is defined as the ratio of global loss of ozone compared to the one due to the refrigerant R-11 (CFC) for the same mass. Refrigerant: substance which goes through phase transitions from gas to liquid to gas and used in vapour compression systems for heating and cooling purposes. The refrigerants in this report only apply to HVAC within buildings. Short Chain Perfluoroalkyl Carboxylic Acids (Sc PFCA): synthetic chemicals part of a wider group called perfluoroalkyl substances (PFAS), also known as “forever chemicals” because they are extremely hard to destroy. Little is known about the health and environmental consequences of PFAS, but there are growing concerns around their use. Variable Refrigerant Flow (VRF): Distributed refrigerant-based system with split condensers outside and evaporators inside, which can vary the amount of refrigerant flowing to each evaporator, enabling to adapt to the loads and comfort of each building space. This is effectively an Air-to-air ASHP split in two parts. VRF systems can provide both heating and cooling simultaneously when specified Whole Life Carbon (WLC): This includes embodied carbon and operational carbon, as defined above, The purpose of using WLC is to move towards a building or a product that generates the lowest carbon emissions over its whole life.

Appendices | A2 Definitions

Embodied carbon (EC): Greenhouse gas (GHG) emissions associated with the extraction, processing of materials and the energy and water consumption used by the factory in producing products and constructing the building. It also includes GHG emissions associated with the ‘in-use’ stage (maintenance, replacement, use, retrofit, repair) and ‘end of life’ stage (demolition, disassembly, waste processing and disposal of any parts of product or building) and any transportation relating to the above. The GWP impact of refrigerant occurs mainly during the use and disassembly phase.

A3 Refrigerant Information For the building industry using refrigerants in vapour compression HVAC systems, the ideal thermodynamic properties of a refrigerant are: • • • • •

Very low boiling point to allow it to evaporate into vapour with very little thermal energy applied A high heat of vaporisation to maximise output at lower volumes Moderate density in liquid form to reduce refrigerant weight High density in gaseous form to augment output and reduce pipe sizes and refrigerant volumes High critical temperature so that it does not become a supercritical fluid

The following section details different refrigerant which have been used in buildings over recent decades.

CFCs Chlorofluorocarbons (CFCs) were commonly used until the 1995’s. CFC ‘s use was phased out and banned by the Montreal Protocol in 1987. Production should have stopped from 2010 onwards, therefore it should be impossible to use CFCs for new systems. However, a study published in Nature in 2019, revealed “unexpected and persistent increase in global emissions of ozone -depleting CFC” (Rigby, et al., 2019). This suggest that existing equipment using CFCs are still leaking and/or that CFC is still being produced illegally for other applications than HVAC systems, such as aerosols. R12

GWP : 10 900 ; ODP : 0.82

General Description

Colourless gas, highly versatile. Original CFC still can be found in systems

Technical Use

Not applicable anymore

Drawbacks

Very high environmental impact

Usage recommendations

Not to be used

Commercial Availability

None anymore for HVAC applications

HCFCs Hydrochlorofluorocarbons (HCFCs) were created to replace CFCs with a lower impact on ozone depletion. However, HCFCs were also banned by the Montreal Protocol in 1987 because of the remaining impact on the ozone layer (ODP typically of 0.5) and should not be used. In Europe, HCFC recharge in existing systems was banned from 2015 onwards. However, it seems that typical HCFCs such as R22 still can be used in HFC blends in some parts of the world (http://www.unep.fr/ ozonaction/topics/hcfc_blends.htm). R22

GWP : 1700 ; ODP : 0.05

General Description

Chlorodifluoromethane, one of the main HCFC used

Technical Use

Not applicable anymore

Drawbacks

Very high environmental impacts

Usage recommendations

Not to be used

Commercial Availability

None anymore for HVAC applications

HFCs Hydrofluorocarbons (HFCs) were created to replace both CFCs and HCFCs after the Montreal Protocol to provide refrigerants with zero ODP. However, as an unintended consequence, this led in some case to a higher GWP than previous HCFC: R410a has a bigger GWP than R22 for instance. HFCs are currently widely used in the HVAC market. But efforts are being made to reduce its use. For instance, in 2015, the European F-Gas regulation was updated with the aim to reduce and phase out gradually HCFC sales by 79% in 2030 by imposing quotas. The intention is also to prohibit HFCs with a GWP above 150 in commercial use displays by 2022 and ban single split air conditioning systems containing less than 3kg of refrigerant with a GWP above 750 by 2025. Although not applied to HVAC systems, the European Mobile Air conditioning (MAC) directive prohibits refrigerant with a GWP above 150 in new cars and vans produced from 2017, which affects the overall production. These initiatives led to market price peak and it seems that an illegal market is appearing in Europe, suggesting that HFC are still a common trend. Refrigerants & Environmental Impacts

A GWP : 2088 ; ODP : 0

General Description

Blend of R32 (50%), R125 (50%)

Technical Use

Suitable for high pressure systems

Drawbacks

High Pressure system only, high GWP, slightly toxic, mix of refrigerant

Usage recommendations

In VRF system and systems with scroll compressor (smaller loads). Due to be phased out in 2022 with current quota causing rapid cost increase

Commercial Availability

Very widely available. Substituted by R32

R407c

GWP : 2107 ; ODP : 0

General Description

Blend of R32, R125 and R1234a. R32 brings heat capacity, while R125 decreases flammability, and R124a reduces pressure

Technical Use

Can act as replacement of R22

Drawbacks

Not considered flammable but can be risky in case of fire

Usage recommendations

Chiller installations and some heat pumps

Commercial Availability

Widely available

R134a

GWP : 1430 ; ODP : 0

General Description

Tetrafluoroethene. Pure refrigerant. Non-flammable and non-explosive. Typical replacement of the CFC R-12

Technical Use

Low pressure refrigerant

Drawbacks

High GWP, quota system, not as well suited to high temperature, cost increasing, due to be phased out in 2022

Usage recommendations

Larger chillers and heat pumps with screw or centrifugal compressors

Commercial Availability

Widely available, possible Replacement by R-513-XP10 and R-1234yf

R32

GWP : 675 ; ODP : 0

General Description

Pure refrigerant used which is a component of R410A CH2F2, it is a replacement fluid for R410A, used in high pressure system in particular on VRF system. It is a transition refrigerant likely to be replaced with lower GWP refrigerants in the future it is suitable beyond 2022

Technical Use

HVAC applications, small to medium system

Drawbacks

Designated “A2L,” meaning it is “mildly flammable” High pressure, therefore is not allowed by EPA in the US at the moment Not to be used

Usage recommendations

Used in VRF system, chillers and heat pumps in higher pressure systems as a replacement for R-410A notably with scroll compressor

Commercial Availability

Commonly used in Japan – more and more in UK for air conditioning - Korea . Adopted by Daikin, LG, Toshiba, Fujitsu, Panasonic

Appendices | A3 Refrigerant Information

R410a

HFOs As HFCs are being phased out in Europe through the F-Gas Regulation, new refrigerants with lower GWP and zero ozone depletion impacts are emerging. In fact, in Europe, the EU commission points out explicitly to several new blends with lower GWP which are Hydrofluoro-olefins (HFOs). Much of the intellectual property associated with production and usage of HFO are owned by US companies, such as Chemours and Honeywell. China and Japan are also big producers of HFOs. R513a (XP10)

GWP : 631 ; ODP : 0

General Description

Blend of R-1234yf and R-134a

Technical Use

Only HFO which is not “mildly flammable” as classified A1 non-flammable, direct substitute for R134a, lower cost than R-1234 closer match to R-134A

Drawbacks

Blend is more difficult to top up. Due to be phased out in 2022 in Europe

Usage recommendations

Used in chillers as an alternative to traditional higher GWP options

Commercial Availability

Relatively new to market but appears to be widely distributed

R1234ze

GWP : 6 ; ODP : 0

General Description

Tetrafluoropropene

Technical Use

HVAC, industrial cooling, supermarkets

Drawbacks

Designated “A2L” meaning it is mildly flammable

Usage recommendations

Replacement for R-134A for low pressure heating and cooling systems. Causes slight reduction in capacity

Commercial Availability

Manufactured by Honeywell, Du Pont and Chemours. Available at a cost premium from leading heat pump manufacturers including Daikin, Climaveneta/Mitsubishi, Danfoss, Aredale, Rhoss

R1234yf

GWP : 4 ; ODP : 0

General Description

2,3,3,3 -Tetrafluoropropene. HFO most used in the world. US, China and Japan are the main producers. Becoming widely used in the car industry since the phase out of R134a within cars – therefore production is increasing

Technical Use

Replacement for R-134A for low pressure system in HVAC

Drawbacks

Designated “A2L” meaning it is mildly flammable

Usage recommendations

Replacement for R-134A for low pressure heating and cooling systems. Causes slight reduction in capacity

Commercial Availability

Lower cost compared R-1234ze used in split system . Manufactured by Honeywell, Chemours, Arkema. Climaveneta uses it for some products

Refrigerants & Environmental Impacts

A GWP : 2 ; ODP : 0

General Description

Opteon XP30 (blend of HFO 1336mzz(Z) (74.7%) with trans-1,2-dichloroethene (25.3%)

Technical Use

Low pressure centrifugal chillers for commercial and industrial HVAC and refrigeration applications

Drawbacks

Not flammable, but is classed as having higher toxicity, with on OEL (Occupational Exposure Limit) of 323ppm

Usage recommendations

Replacement potential for R-123 in centrifugal water cooled chillers. Non-flammable (ASHRAE classification - B1)

Commercial Availability

Manufactured and distributed by Chemours and adopted by Trane and other chiller manufacturers

R1233zd

GWP : 1 ; ODP : 0

General Description

Trans-1-chloro-3,3,3-trifluoropropene - (E)CF3-CH=CCIH

Technical Use

Low pressure and low temperature usage

Drawbacks

Designated â&#x20AC;&#x2DC;A1â&#x20AC;&#x2122;

Usage recommendations

Primarily water-cooled low pressure centrifugal chillers. Replacement for R123

Commercial Availability

Manufactured by Honeywell. Available from York, Trane, Carrier, Daikin in USA

Appendices | A3 Refrigerant Information

R514a (XP30 )

Alternatives refrigerant with GWP <5 This section details alternatives natural or hydrocarbons refrigerants with a GWP lower than 5 and ODP of 0, which are gaining momentum such as: Ammonia, Propane, C02 and Water.

AMMONIA (R 717)

GWP : 0 ; ODP : 0

General Description

Ammonia (NH3) is a natural refrigerant approximately 15-20% more efficient than its HCFC counterparts, low cost and abundant. It is an irritant to eyes and skin, has a strong odour which makes leaks easily detectable and requires safety measures in internal plant room containing chillers. It is one of the first refrigerant used in the history of refrigeration. It is not a pollutant; in fact, it is a fertiliser. Ammonia corrodes copper, therefore in canâ&#x20AC;&#x2122;t be used in VRF systems and cannot operate in hermetic compressors (i.e. compressors where the motor is in an enclosure under refrigerant pressure) because the copper windings on the motor would corrode. Ammonia chillers require external motor (i.e. centrifugal compressors). The ammonia molecule is small, therefore the prevention of leakage along the shaft between compressor and motor is difficult

Technical Use

Used in a lot of low temperature applications like CO2, where HFOs are not the best fit. Its high efficiency allows for the reduction in heat exchange surface area, smaller pipe sizes and refrigerant charges. New products are in development to overcome the problem of compatibility ammonia / copper, this include semi hermetic compressor (i.e. the copper in outside the refrigerant circuit); Hermetic compressors with aluminium motor windings (not subject to ammonia corrosion) and separating hood compressors (i.e. permanent magnets rotors located in a pressurised enclosure) with stator externally (i.e. the copper windings are outside the refrigerant circuit)

Drawbacks

Toxicity and flammability, which can be deadly if it exceeds 300 ppm. R-717 is classified in the B2 safety group (for toxicity and flammability) in ASHRAE Standard 34-2010

Usage recommendations

Used in large refrigeration/chiller plants or in small packaged chillers. Requires sprinklers in internal plant rooms

Commercial Availability

Star Refrigeration, Azena, Evapco, Budzar Industries, and GEA

PROPANE (R 290)

GWP : 4 ; ODP : 0

General Description

Natural hydrocarbon refrigerant - used in many parts of our daily life, such as refrigerators, air conditioning or even hairspray

Technical Use

Works with high flow temperatures (75oC in hot water from heat pump is possible) so improves COPs at higher flow temp Safety measures must be implemented in heat pump and after-sales service processes, similar to Gas boilers Spark free tools needed

Drawbacks

Highly Flammable and risk of suffocation. Moreover, it is a by-product of natural gas processing and petroleum refining, therefore linked to the oil industry

Usage recommendations

Suitable for large refrigeration/chiller plants or in small packaged chillers

Commercial Availability

Vaillant (aro Therm heat pumps), Gree (Asa), Dimplex (Edel). Not very common in the US so far

Refrigerants & Environmental Impacts

A GWP : 1; ODP : 0

General Description

By-product in several industries, with a very low viscosity and very good heat transfer coefficient

Technical Use

CO2 is mostly used for heating hot water but also for low temperature refrigeration such as ice sinks and grocery refrigeration systems. CO2 requires cooling instead of compression to change from liquid to vapour

Drawbacks

The primary constraint that limits the production of CO2 based systems is the high operating pressure (up to 1500 psi) which requires specialised compressors. In addition, CO2 systems have unique maintenance requirements due to their high rate of expansion with small temperature fluctuations

Usage recommendations

CO2 is suitable for large industrial applications with cascade/hybrid (HFC/ CO2) systems such as in a marketplace where freezer/refrigerator circuits are needed Suitable as well in small residential heat pump water heaters (HPWHs) that can provide domestic hot water and heating hot water CO2 is also very suited for retrofit of higher temperature heating, as can produce up to 70°C heating water

Commercial Availability

Panasonic, Daikin, DENSO, Sanden, Itomic, Mitsubishi Heavy Industry, Mitsubishi Electrics, Sanyo, and Hitachi, Mayekawa – but mostly for Japanese’s markets and residential market

Water (R 718)

GWP : 0; ODP : 0

Technical Use

High grade Cooling (e.g. data centre)

Annual EER is over 11. 20 to 45 kW per unit

Drawbacks

Cannot cool lower than 15°C flow temperature at 35°C ambient Ratio between high/low pressure of 7,2 (R134a: 2,8) and suction volume of 60 m3/s (R134a: 0,3 m3/s) for a cooling capacity of 100 kW and an evaporation temperature of 4°C

Usage recommendations

Data centres - Industry/electronic

Commercial Availability

UK : https://greenthermalenergy.com/areas-of-application/

Appendices | A3 Refrigerant Information

CO2 (R 744)

A4 Refrigerant Leakage Refrigerants released into the air by leakage can damage our ozone layer and contribute to global warming – the scale of impact varies significantly between refrigerants. Leakage can occur during all life cycle stages but is the most prominent during the use phase. The less leakage, the better.

Leakage data Refrigerant leakage can occur at different steps of the life cycle (Figure 3), such as: • • • •

Manufacturing Transport from manufacturer to distributor and from distributor to site/pre-charging unit location Pre-charging/Charging/Recharging/Repair/Maintenance/Decommissioning the HVAC system Transport of reclaimed refrigerant to suppliers

Data which quantifies refrigerant losses at each stage is difficult to source at this time. A study on heat pumps based on IPCC data reports that loss of charge during manufacture could be between 1 and 3% and during decommissioning between 9 and 55% depending on the type of installation and level of care (Eumonia Research & Consulting Ltd, 2014). It is however known that refrigerant loss of charge is likely to happen mostly during the system use phase. Leakage can occur due to different causes: • Joints can weaken over time due to on-going pressure in the system (made worse by over pressure); • V ibrations; this could come from a fan or compressor not being isolated/balanced properly and transmitting vibration into the pipework - joints again will be the most susceptible; • Corrosion of the copper pipework over time; • If the system becomes frozen due to incorrect operation or poor frost protection this can damage the joints; • For certain tasks, including building renovations, the system will need to be de-gassed and re-gassed, during both these processes there is a risk of leaking some of the charge. Finding actual measured data to quantify refrigerant loss and calculate the environmental damage resulting from this turns out to be a tough nut. In Europe, the EU-F gas regulation requires owners/operators to keep a “logbooks” of HVAC systems using more than 3kg of refrigerant, to keep track of refrigerant, but it appears that they are of poor quality and hardly exploitable. Different maintenance operators have been contacted during this study to understand actual leakage data, but without success. Suppliers could be a good source of information concerning top-up refrigerant (not pre-charge as done by manufacturers), but the ones contacted did not reply. Based on published data (see table opposite), the following assumptions concerning annual refrigerant leakage could be assumed as follows: Product

Annual leak rate – low

Annual leak rate – medium

Annual leak rate – high

Centralised and individual systems – where no refrigerant is initially charged on-site

3.8%

Distributed systems where a large amount of refrigerant pipework is installed and filled onsite

10%

The following table lists annual leakage rates reported from various studies:

Refrigerants & Environmental Impacts

A Type of plant

TM56 - Resource efficiency of building services

Air-cooled chiller

Upper

Lower

Upper

Lower

Upper

Lower

Upper

Lower

Upper

10%

Lower

Typical

Upper

Lower

Typical

Upper

Lower

Typical

Upper

Unitary split

Typical

15%

Small scale chillers

Typical

10%

Heat pumps

Typical

Lower

n/a

Rooftop

Split system

VRF system

Chillers

Roof top packaged systems

Split systems (single and multi) BREEAM 2018

date of paper

Lower

Water-cooled chiller

Methods of calculating Total Equivalent Warming Impact

Annual leak rate

Impacts of Leakage from Refrigerants in Heat Pumps

Typical non-domestic

Heat pumps

Typical domestic Upper continued overleaf

3.80% 3.5% n/a

2014

2012

2018

2014

Appendices | A4 Refrigerant Leakage

Reference

Type of plant

Annual leak rate

Cold Hard Facts 3

Small AC sealed-

Theoretical leak rate

HW heat pump: domestic-

Service rate

Small AC: Split:

Theoretical leak rate

Single split: non-ducted

Service rate

Medium AC

Theoretical leak rate

Split system: ducted

Service rate

VRV/VRF split system

Service rate

Multi split

Service rate

Large AC

Theoretical leak rate

Large AC <350 kWr

Service rate

Large AC >350 & <500 kWr

Service rate

March (1991) as cited in BNCR36: Direct Emission of Refrigerant Heat pumps Gases

Lower

Upper

10%

Haydock et al (2003) as cited in BNCR36: Direct Emission of Refrigerant Gases

Lower

Upper

Typical

ETSU (1997) as cited in BNCR36: Direct Emission of Refrigerant Gases

Heat pumps

date of paper 2.5% 2% 3.5% 2% 2.7%

4.5%

Evaluation of the leakage rates Stationary refrigeration and of 11,000 refrigeration systems air conditioning equipment in Hungary (34) cited by Schwarz >3 kg.

Average

2013 Annual Conference of the Institute of Refrigeration LEC Leakage & Energy Control System by VDFK

74,000 refrigerant units in different applications

Average

Commercial chillers

Upper

15%

Residential & light systems

Upper

10%

International Institute of Refrigeration

2016

10%

3.16%

1991

2003

2007

2010

2013

<2017

Leakage and Performance When refrigerant leakage occurs during the use phase due to maintenance or equipment failure, the equipment becomes less efficient and less reliable. A refill will be required to restore proper function, which increases the environmental impacts of the system over its lifetime. A study from the UK Department of Energy and Climate Change (Eumonia Research & Consulting Ltd, 2014) on heat pumps reports that a refrigerant charge reduction of: • 10% leads to a relative coefficient of performance (COP) reduction of about 3% in heating and 15% in cooling operation • 40% would reduce the relative COP by around 45% in heating mode and 24% in cooling operation • 50% is considered catastrophic and the system is unlikely to function properly Many manufacturers warn that their heat pumps will not operate with a charge lower than 40%. A reduction in COP implies an increase of operational carbon emissions and potentially a higher bill at the end of the month, therefore it is important to ensure that systems are always properly charged.

Refrigerants & Environmental Impacts

Europe The first F-Gas regulation, adopted in 2006, required appropriately qualified personnel to carry out leakage checking for all stationary systems but did not go much further. In 2015, this regulation was updated with the following requirements concerning leakage: • • • •

Operators should take all precautions feasible to minimise leakage (article 3) Operators should unsure equipment repair, recharge when leakage occurs People working on refrigerant based equipment should be certified (article 3) Leakage checking should be become mandatory with a frequency based on refrigerant GWP (no longer based on total charge) and whether leak detection is installed within the system (Article 4) • Systems with a refrigerant charge equivalent to 500 tonnes of CO2 or above should have a leakage detection and be checked once every 6 or 12 months (article 5) • Leak detection reports, the “f logbook”, should include quantity and type of fluorinated gas, the initial charge, refill, maintenance, whether the refrigerant have been recycled or reclaimed, measures from the decommissioning, with dates and identity of person doing the work (article 6) Different bodies exist to ensure the F-Gas requirements are implemented, for instance: • European Partnership for Energy & the Environment (EPEE) at the European level • REFCOM at the UK level

North America United States The Clean Air Act is the US allow systems to leak at a 15% rate for HVAC systems before requiring service (Ehrlich, 2017). The EPA is in charge to enforcing the Clean Air Act. The South Coast Air Quality Management District (SCAQMD) with its Rule 1415.1 requires leak inspection, record reeking and annual reporting for any refrigeration systems with a charge greater than 50 pounds and using a high GWP refrigerant. In California, the CARB’s Refrigerant Management Program (RPM) complements this Rule 1415.5 (California Air Resource Board, 2020). More information can be found here: https://ww2.arb.ca.gov/our-work/programs/refrigerant-managementprogram/about. This section will be extended in a future update.

Canada This section will be added in a future update.

Mexico This section will be added in a future update.

Australasia This section will be added in a future update.

Appendices | A4 Refrigerant Leakage

Legal Aspects

A5 Refrigerant Recovery Most refrigerants can be reused multiple times without affecting the performance of the HVAC system. However, it does not necessarily imply all refrigerants are reused 100%.

Recovery Data As with refrigerant leakage, data varies greatly depending on the sources (see table opposite). Based on these sources, the following average assumptions can be used: End of life recovery rate best scenario

End of life recovery rate – medium

End of life recovery – worst

Centralised and individual systems – where no refrigerant is initially charged on-site

99%

98%

90%

Distributed systems where a large amount of refrigerant pipework is installed and filled onsite

99%

98%

97%

Product

The table p.53 lists end of life recovery rates sourced from various studies.

Legal Aspects Europe

The new F -Gas regulation (EU) 517/2014 (effective in 2015), in its article 8 mentions that operators should ensure that the recovery of fluorinated gases take place by persons holding relevant training and certificates (specified in article 10). This training needs be provided by each member states. In the UK, this would be a DEFRA approved training and certification company. With regards to fire and toxicity limits, EN378 “Refrigerating systems and heat pumps : Safety and environmental requirements” is the current European standard for refrigerant gases. BS EN 378 list toxicity and flammability limits according to space function, location, and refrigerant and ventilation. BS EN 60335 deals more specifically in the safety of refrigerant in equipment and appliances.

North America United States Clean Air Act (US), section 608 requires evacuating “any piece of equipment that contains an ozone depleting refrigerant before that equipment is disposed of”. There are economic incentives applying for large systems refrigerant recovery but none for smaller equipment. The California Air Resources Board (CARB) estimates that only 2% or less of refrigerant is recovered from smaller airconditioning units—and this is in California, which has the best recovery and enforcement in the country. In the rest of the U.S. and other areas with lax enforcement, refrigerant recovery is probably far less. This section will be extended in the next update.

Canada This section will be added in a future update.

Mexico This section will be added in a future update.

Australasia This section will be added in a future update. Refrigerants & Environmental Impacts

A Type of plant

TM56 - Resource efficiency of building services

Air-cooled chiller

End of life recovery rate

date of paper

90% 70% Water-cooled chiller

90% 80%

Rooftop

70%

2014

80% Split system

90% 50%

VRF system

90% 80%

Methods of calculating Total Equivalent Warming Impact

Chillers Roof top packaged systems

70%-95%

2012

95%

2018

80-85-75 %

2014

Split systems (single and multi) BREEAM 2018

Unitary split Small scale chillers Heat pumps

Impacts of Leakage from Refrigerants in Heat Pumps

Heat pumps

Cold Hard Facts 3 (32)

Small AC sealedHW heat pump: domesticSmall AC: Split: Single split: nonducted

85% (95% set as the max technical recovery rate)

80% (95% set as the max technical recovery rate)

Medium AC Split system: ducted VRV/VRF split system

80% (95% set as the max technical recovery rate)

Multi split Large AC Large AC <350 kWr Large AC >350 & <500 kWr

85% (95% set as the max. technical recovery rate)

2016

Appendices | A5 Refrigerant Recovery

Reference

A6 References California Code of Regulations, 2018. Final Regulation Order: Prohibitions on Use of Certain Hydrofluorocarbons in Stationary Refrigeration and Foam End-Use, California State: CARB. ASHRAE, 2019. ANSI/ASHRAE Standard 34 : Safety Standard for Refrigeration Systems and Designation and Safety Classification of Refrigerants Australian Government - Department of Agriculture, Water and the Environment, 2020. Ozone Protection and Synthetic Greenhouse Gas Management Legislation. [Online] Available at: http://environment.gov.au/protection/ozone/ legislation/ [Accessed 2020]. Booten, C., Nicholson, S., Mann, M. & Abdelaziz, O., 2020. CEMAC is operated by the Joint Institute for Strategic Energy Analysis for, s.l.: CEMAC (Clean Energy Manufacturing Analysis Center). BRA, October 2012. Guide to Flammable Refrigerants, Issue 1 California Air Resource Board, 2020. Refrigerant Management Program. [Online] Available at: https://ww2.arb.ca.gov/ our-work/programs/refrigerant-management-program/about [Accessed 2020]. Mitsubishi Electric CPD Webinar on Low GWP Refrigerants in chillers. 23 April 2020. [Film] s.l. Ehrlich, B., 2017. The Cost of Comfort: Climate Change and Refrigerants. Building Green. Environmental Investigation Agency, 2019. Doors Wide Open: Europeâ&#x20AC;&#x2122;s flourishing illegal trade in hydroflurocarbons (HFCs), s.l.: EIA UK. Eumonia Research & Consulting Ltd; Centre for Air Conditioning and Refrigeration Research of London Southbank University, 2014. Impacts of Leakage from Refrigerants in Heat Pumps, s.l.: UK Department of Energy & Climate Change. European Commission, 2015. EU legislation to control F-gases. [Online] Available at: https://ec.europa.eu/clima/policies/fgas/legislation_en [Accessed 2020]. European Partnership for Energy and the Environment, 2014. THE NEW F-GAS REGULATION, s.l.: EPEE. Government of Canada, 2020. Ozone-depleting Substances and Halocarbon Alternatives Regulations: consultation 2019. [Online] Available at: https://www.canada.ca/en/environment-climate-change/services/canadian-environmentalprotection-act-registry/consultation-2019-modification-ozone-depleting-substances-regulations.html [Accessed 2020]. Gray, E. & Stein, T., 2019. 2019 Ozone Hole is the Smallest on Record Since Its Discovery. [Online] Available at: https:// www.nasa.gov/feature/goddard/2019/2019-ozone-hole-is-the-smallest-on-record-since-its-discovery [Accessed 2020]. Hawken, P., 2017. Drawdown: The Most Comprehensive Plan Ever Proposed to Reverse Global Warming. International Energy Agency, 2020. Doors Wide open, s.l.: EIA. ISO, 2018. ISO 14064-1:2018/ Greenhouse gases - Part1: Specification with Guidance at the organisation level for quantification and reporting of greenhouse gas emissions and removals Oekobaudat, 2018. Process Data set: Refrigerant R410a. [Online] Available at: https://www.oekobaudat.de/OEKOBAU. DAT/datasetdetail/process.xhtml?uuid=988bb7c3-0a15-4626-a6c0-0883d4ff33dd&stock=OBD_2020_II&lang=en [Accessed 2020]. Pickard, H. M. et al., 2020. Ice Core Record of Persistent Short-Chain Fluorinated Alkyl Acids: Evidence of the Impact From Global Environmental Regulations. Geophysical Research Letters. Rigby, M., Park, S. & Saito, T., 2019. Increase in CFC-11 emissions from eastern China based on atmospheric observations. Nature, Volume 569, p. 546â&#x20AC;&#x201C;550. Sheff, J., 2020. Code Uncertainty Puts Safe Refrigerant Transition At Risk. [Online] Available at: https://www.achrnews. com/articles/143110-code-uncertainty-puts-safe-refrigerant-transition-at-risk [Accessed 2020]. UK Department for Transport, 2015. Average CO2 emissions of newly registered cars, Great Britain. [Online] Available at: https://www.gov.uk/government/publications/new-car-carbon-dioxide-emissions [Accessed 2020]. UNEP, n.d. What is the ozone layer? [Online] Available at: https://ozone.unep.org/ozone-and-you#ozone-layer1 [Accessed 2020]. University of Bristol, 2020. Emissions of potent greenhouse gas rises, contradicting reports of huge reductions. [Online] Available at: https://phys.org/news/2020-01-emissions-potent-greenhouse-gas-contradicting.html [Accessed 2020].

Refrigerants & Environmental Impacts

A Appendices | A6 References