After a comprehensive testing and development programme, Toshiba is introducing a new generation of luxury residential air conditioning systems based on the refrigerant R32.
The refrigerant has a much lower Global Warming Potential (GWP) than R410A, commonly used in air conditioning systems. The GWP of R32 is 675 compared to 2088 for R410A, representing less than one third the impact.
Toshiba’s initiative is partly in response to the recently revised F-Gas Directive, which encourages the use of refrigerants with a GWP of less than 750 in single split systems with a charge less than 3kg.
In addition, R32 not only has a lower GWP, but can deliver an equal capacity to R410a with a refrigerant charge 30 per cent smaller. As a result, total CO2 emissions can be reduced by around 77per cent.
The new refrigerant will be used in Toshiba’s new Mirai premium range of residential wall-mounted air conditioning split units, being launched at the end of May. They will be available in capacities from 1.5 to 4.5kW.
David Dunn, Toshiba director and general manager, said: “Many end users are looking to adopt greener, lower GWP technology. When combined with the advanced features of Mirai, R32 is an attractive option that is more environmentally friendly while delivering superb comfort.”
He added: “As most people will be aware, R32 is classified as slightly flammable under certain, specific conditions. However, following thorough testing and evaluation, it is now widely accepted within the industry that as long as good practice is followed, any risks are exceptionally small and can be managed – and fully acceptable in the light of the significant environmental benefits.”
Toshiba has been producing R32 units for the Japanese market since 2014. To date, some 225,000 units have been installed, without incident. Across all manufacturers, there are more than 5 million R32 units installed in Japan alone.
Toshiba’s new Mirai range features a number of technical advances, including dustless operation due to a special coating on the cooling coil, a larger heating capacity, and exceptionally quiet operation due to a 13per cent increase in fan size.
Units are designed to eliminate potential sources of ignition, and are equipped with brushless motors and a power relay instead of contactor. To reduce flame propagation, both indoor and outdoor units have fireproof steel enclosures surrounding the electrical systems.
For installers and service engineers working with R32, the refrigerant is classified as flammable and needs to be handled accordingly. Correct procedures are explained in the Hydrocarbon Safe Handling Course, which is a top up on the standard F-Gas qualification. Toshiba also advises technicians to inform their insurance company and check that tools such as vacuum pumps and recovery systems are suitable for use with R32.
Looking ahead, Toshiba has no plans at this stage to introduce R32 on larger systems in the UK, as it believes the optimum application range for the refrigerant on technical and performance grounds is probably in smaller units.
Toshiba will continue to offer air conditioning systems across its range on R410A, due to its proven performance and efficiency benefits, plus the service advantages of a single refrigerant on sites with multiple types of systems.