COMMERCIAL HEATING, COOLING AND VENTILATION; LIFE SCIENCES SPECIAL FEATURES This month: Battersea Power Station, CO2 heat pumps, heating with hydrogen, labs on the high street THE PROPANE ALTERNATIVE TO BOILERS Could a new range of reversible air source heat pumps employing propane refrigerant reflect a growing shift towards low-GWP gas boiler replacement solutions? Phil Lattimore reports on Swegons Geyser Sky T he current energy crisis is putting an increasingly urgent focus on the economic, as well as environmental, imperative to consider replacing gas-fuelled space heating and domestic hot water (DHW) with allelectric alternatives. Looking to address this growing demand for more environmentally friendly solutions, Sweden-based manufacturer Swegon has introduced a new range of reversible air source heat pumps (ASHPs) that employs low-global warming potential (GWP) natural propane (R290) as a refrigerant. Swegons Geyser Sky Hi HP R0 range of reversible ASHP solutions has been developed for homes and small commercial buildings, with the units capable of delivering high-temperature hot-water output at up to 78C and designed to be suitable replacements for gas boilers, with a low-ozone impact. Using new-generation inverter compressors to modulate heating or cooling capacity, the threestrong range is designed to meet the highest seasonal European Ecodesign ErP efficiency standards, according to the manufacturer. The units can operate down to ambient temperatures of 20C with outlet water at 60C, Swegon says. Propane refrigerant With the phase-down schedule for fluorinated greenhouse gases (F-Gases) under EU regulations continuing to be implemented within post-Brexit UK regulations, the requirement to reduce hydrofluorocarbon (HFC) refrigerants employed in heating, ventilation, air conditioning and refrigeration applications has seen a shift towards lower-GWP refrigerants. The target to implement a reduction of 55% of greenhouse gas emissions by 2030 has led to firms introducing natural alternatives such as CO2 (GWP = 1), propane (GWP = 3) and ammonia (GWP = 0), which are not restricted under the F-Gas regulations and have a far lower impact on ozone levels. According to Stefan Lay, cooling and heating product manager for Swegon UK and Ireland, the manufacturer has opted for the natural gas propane for its thermodynamic properties, as well as its lower GWP. Propane was one of the naturally occurring refrigerant gases used in the early days of air conditioning and refrigeration, until nonflammable and non-toxic synthetic refrigerants were developed from the 1920s onwards, gradually replacing the natural gases. Coming full circle, Swegon chose propane over CO2, as use of the latter was considered to be more complex because of its extreme operating pressures and other properties. The company is currently investing heavily in developing a range of propane-based solutions. While the use of propane as a refrigerant is increasing within the sector, a key challenge recognised by the European Commission and the wider industry is the skills shortage for the safe and effective installation of low-GWP refrigerants. Skill is the key to any successful installation, and the UK industry is severely lacking in knowledge of chillers and heat pumps in general, says Lay. However, he continues: It will be the same as installing a normal unit, but with extra considerations as it contains propane, which is flammable. Installers and service engineers should complete additional training regarding the use of flammable refrigerants and be properly equipped to work safely with the unit. www.cibsejournal.com November 2022 51 CIBSE Nov 22 pp51-52 Swegon heat pump.indd 51 21/10/2022 16:25