HEAT PUMPS


HVAC replacement and the F-gas phase down


Tim Mitchell A


Tim Mitchell from Klima Therm explores the changing regulatory landscape and the latest high-temperature heat pumps off ering high effi ciencies, operational excellence and future-proof refrigerants.


series of developing regulations is re-shaping the landscape for installers and building managers dealing with fl uorinated gases (F-gases), commonly used in HVAC, refrigeration and commercial heat pumps. Driven by environmental mandates to reduce greenhouse gas emissions in the EU, the changes involve a staged phase-down of high global warming potential (GWP) refrigerants. As refrigerants are phased out and service


restrictions are introduced, older HVAC systems can quickly become expensive to run and maintain. In addition to poor energy effi ciency and risk of downtime, engineers and FMs must also anticipate the risk of refrigerant unavailability, service bans and non-compliance.


F-gas regulations explained The modern hydrofl uorocarbon refrigerants (HFCs) are all fl uorinated gases, collectively known as F-gases. They replaced chlorofl uorocarbons (CFCs) and other ozone-depleting substances from the late 1980s onwards, but unfortunately, we now know that many F-gases carry a high global warming potential, up to 23,000 times worse than CO2


. A second wave


of regulatory action is now underway to reduce the use of these refrigerants in favour of lower-GWP alternatives and natural refrigerants like carbon dioxide, ammonia and hydrocarbons. The EU fi rst introduced F-gas regulations in 2006


and strengthened them in 2014. Signifi cant new restrictions were introduced to the EU in 2024, aiming for an 80% reduction in F-gas emissions by 2030 and a complete phase-out by 2050. Following Brexit, GB retained the EU 517/2014 F-Gas Regulation and has also adopted the Kigali amendment to the Montreal Protocol, which is broadly similar to the EU 2024 regulation. DEFRA is developing a GB-specifi c framework for implementation from 2026 onwards.


Refrigerants under pressure The following refrigerants are at the centre of phase- down impacts because of their high global warming potential (GWP):


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Selection requires careful assessment of the ASHRAE refrigerant safety classifi cations (A or B for non-toxic or toxic, respectively, then 1, 2L, 2 or 3 for escalating


■ R404A (GWP 3,922) and R507A (GWP 3,985) – these are already restricted for many commercial refrigeration applications


■ R410A (GWP 2,088) - still widely used in VRF/VRV and split systems, but under signifi cant phase- down pressure


■ R134a (GWP 1,430) - standard in chillers but now facing quota-driven supply and cost issues.


Lower-GWP alternatives include: ■ R32 (GWP 675) - widely deployed in split and packaged systems, off ering higher effi ciency and reduced charge compared to R410A.


■ HFOs (R1234yf, R1234ze, GWP <1) - growing adoption in chillers; A2L classifi cation (refrigerants with low toxicity and mild fl ammability) requires careful risk assessment.


■ Blends (R513A, R450A) - mid-GWP options for retrofi tting R134a systems in some applications.


■ Natural refrigerants (carbon dioxide, ammonia, and hydrocarbons) - ultra-low GWP, high effi ciency, but with design, safety, and regulatory challenges, including toxicity, fl ammability, and high pressure.


fl ammability), operating pressures and compatibility with existing plant room layouts.


Hidden costs There is no getting around the fact that plant replacement is expensive, but holding on to ageing HVAC equipment can also be costly. Market prices for legacy refrigerants continue to rise - R134a has increased 200% since 2014, and R410A increased 17% year-on-year at the end of 2024. F-gas requirements surrounding leak detection, record-keeping and service bans are tightening, with


systems that contain more than fi ve tonnes of CO2 equivalent subject to regular checks. Replacing lost refrigerant is expensive and unpredictable, a factor that must be weighed against the lifecycle cost of a new low-GWP system.


Modern heat pumps and systems using low-GWP


refrigerants (like propane, R32, HFOs, or natural refrigerants) off er high effi ciency and regulatory compliance. Upgrades can potentially reduce running costs by 20–40% compared to legacy systems, with savings compounding over time and reducing exposure to volatile energy prices.


Specifi cation considerations When specifying replacement plant, engineers must


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