On the critical topic of life safety, choice of refrigerant is a very important consideration a designer should be very cognizant about.  ASHRAE Standard 15-2004 duly assigns two character alpha-numeric designations to denote refrigerant safety.  Two characters make up this designation – an alphabet denoting increasing level of toxicity (A or B) and a number denoting increasing flammability (1, 2 or 3).  That being said, a refrigerant labeled B3 according to this standard would imply high toxicity and flammability. This refrigerant, if used, would require additional consideration in mechanical system design.

On the topic of refrigerant safety, how important would refrigerant choice be in the car you drive every day?  The September 2010 ASHRAE Journal reported that American automaker General Motors will now use a new refrigerant HFO-1234yf as a replacement to HFC-134a. This will happen in all GM models beginning 2013.  As it turns out, refrigerant safety is a given here; the actual driver was not safety, but global warming potential.  It was reported that HFC-134a stays in the atmosphere for the whole of 13 years, but HFO-1234yf a mere 11 days.  Does this mean an immediate end to the pollutant? Not so fast according to the US based Society of Automotive Engineers (SAE), which says HCF-134a is not going away anytime soon.  This is because HFO-1234yf is not a direct refrigerant replacement and HFC -134a will still be needed to service existing vehicles.

More importantly the US EPA still needs to certify it as non-toxic.  Therefore pending approval, you can rest assure your new GM 2013 car will be doing a good job protecting our planet.

By, Cameron Sherwood–  CTTC Refrigeration Chair, 2010-2011