Growing international momentum against the use of HFC refrigerants has prompted a surge in UK demand for and interest in low Global Warming Potential (GWP) options, such as propane R290 and HFOs, according to cooling specialist Klima-Therm.
The company reports a significant increase in orders and enquiries for alternatives to HFCs following the F-Gas review in Europe and the recent US announcement of a ban on high GWP HFCs in chillers from the start of 2024. The US ban includes common mainstream refrigerants such as R134a, R410A and R407C.
“It is clear that time is running out for HFCs. Given the scale of investment involved, end users considering major capital spend on new and replacement chillers simply can’t afford to be exposed. The history of refrigerant phase-outs teaches us that deadlines are almost always brought forward, as the industry readies itself ahead of planned changes.
“This is now happening, and end users are seeking reassurance about plant longevity not just in mechanical terms, but in terms of legislation. With the trend now strongly against HFCs, or at least high GWP HFCs, it is rational to seek to future proof businesses, which explains the spike in enquiries about alternatives.”
Propane and HFO R1234ze have been a particular focus for Klima-Therm, with one high street retailer alone purchasing over 200 such machines to date. The chillers’ combined cooling capacity is just over 32MW, “sufficient to freeze over the lake in Regents’ Park”, suggests Mr Mitchell, “just to give you some idea of the scale of low GWP cooling we now have in operation across the country.”
With years of experience of servicing and maintaining these chillers in the field, the company reports that reliability is as good “if not better” than HFC machines, due to their more robust, industrial type build.
“There is a growing recognition that the biggest restriction on growth in use of propane and other flammable refrigerants is not performance, reliability or safety issues, but the legislative framework on flammables that limits maximum charge size.”
EN378:2008 currently sets relatively restrictive flammable refrigerant charge size limits depending on system factors. However a 2014 revision to the ISO 817 standards established a new lower flammability category that will soon be mirrored in the forthcoming revision of EN378. The aim is to extend use of A2L refrigerants by allowing larger refrigerant charges subject to certain risk reduction measures being put in place. This would benefit HFOs but leave propane charges limited as now.
As a general rule, however, propane is more suitable for use in smaller machines where charge size limits are less of an issue, while HFOs are more applicable to larger machines, such as Turbocor-based chillers, says Mr Mitchell. HFO is not considered ideal for used in fixed pumping devices, such as screw or reciprocating compressor systems, due to the relatively large quantities of refrigerant that need to be moved to achieve the same effect compared with hydrocarbons.
Regarding respective costs, prices have settled down following the initial very high cost of HFOs when launched onto the market. Typically, a well specified, high efficiency HFO machine has had a premium of around 50per cent compared to a completely standard HFC chiller, virtually in line with a propane machine, he says.
“However, with a suitable application and comparable core specification, some HFO machines carry almost no premium at all over traditional HFC options. For example, our new K-Turbo machines offer world-beating efficiency at a similar price point to a typical Turbocor-based machine using HFC refrigerant. This puts HFOs in a strong position, as they aren’t considered to have the same potential safety risks as HCs, and with comparable pricing and conventional servicing, they offer a pretty much seamless transition away from HFCs to a safe, efficient, low carbon future.”