USA: Honeywell has announced the availability of its new Solstice L-41 low GWP refrigerant alternative to R410A in residential and light commercial air conditioning and heat pump applications.
The new HFO-based blend is known to have been part of Honeywell's development programme for some time and made its first public 'appearance' at Chillventa last year in a Haier air conditioning unit.

Solstice L41 is said to offer a 75% reduction in GWP compared to R410A's GWP of 2088. In addition, Honeywell says Solstice L-41 offers excellent energy efficiency, is cost effective and can be used in existing equipment designs with minimal changes. 

'Honeywell has been working closely with leading equipment manufacturers to optimize Solstice L-41 to meet the demanding requirements of both stationary air-conditioning and heat pump applications across a broad range of operating conditions,' said Tom Morris, director of commercial development for Honeywell Fluorine Products.  'Solstice L-41 will allow these manufacturers to offer more environmentally friendly air conditioning and heat pump systems to help address climate change.'

While the exact GWP has not been released, early development work claims a GWP of under 500 and a classification of A2L (mildy flammable).

Honeywell maintains that Solstice L-41 also offers significant advantages over R32, the HFC refrigerant recently named by Daikin as its choice to replace R410A in its air conditioning units in the Far East. L-41 has a lower GWP than R32 and, claims Honeywell, has lower discharge temperatures.  

Solstice L-41 is a blend of the HFO refrigerant 1234ze, which was first introduced in 2008 and has since been proven and commercialised for chillers, insulating foam, and aerosol applications. A new 1234ze manufacturing plant is currently under construction to meet the needs of equipment manufacturers, says the company.

Honeywell has not released details of the other constituent(s) of the blend but ACR News believes it is probably R32. If used in combination, and depending on the percentages, HFO1234ze with its GWP of around 6 and R32 with its GWP of 650 is likely to produce a blend under 500 as Honeywell have claimed for L-41. Also, Honeywell is known to have participated in earlier tests with two prototypes - L-41a, a 73%/15%/12% blend of R-32/R-1234yf/R-1234ze(E) and L-41b, a 73%/27% blend of R-32/R-1234ze(E).