Striving for a better living environment is definitely humanity's responsibility for all kinds of species on Earth.

Under the Montreal Protocol of 1987, we pledged to repair the hole in the atmosphere by minimising the ozone depletion potential (ODP) Index. The hole is recovering but this is only the beginning for the global warming potential (GWP). Thanks to the Paris Climate Change Agreement and the Kigali Amendment, GWP was addressed.

Following CFC refrigerants, both HCFC and HFC refrigerants are going to become history. In past years, world-leading companies in the industry provided funding for the invention of next-gen refrigerants. A comprehensive study was then started into new refrigerants with low ODP, low GWP, high operating efficiency, short atmospheric life, low leakage rate and low toxicity. Studying hydrofluoroolefin (HFO) refrigerant series becomes a new trend.

We indeed have a few potential candidates at the moment and they are R452B and R513A refrigerants for high to medium pressure applications and R514A and R1233zd refrigerants for low pressure applications. R452B is used in unitary products while R1233zd, R514A and R513A are used in medium- to large-capacity chillers.

The above-mentioned refrigerants have been put into commercial and residential products and will soon play an important role.

All in all, there is no ideal refrigerant, only the right refrigerant for the right product at the right time, I believe.

This BS Blog is contributed by Ir K T Cheuk of the Building Services Division.