Yes, it felt like spring this weekend. I am not wearing long johns to work anymore.
Summer is on its way and with the heat of summer the phone will be ringing. Many of you are going to realize your air conditioning is not doing its job anymore. When did it stop doing its job? That you likely don’t know. It probably would’ve happened anywhere between October and March.
I got thinking about air conditioning a little earlier this year because my air conditioning recovery, evacuation and recharge machine broke down a month ago and I decided not to fix it. No, I am not getting out of the air conditioning business. On the contrary I am updating my equipment because there is a new refrigerant used in many late model vehicles that my old equipment could not work with.
That new automotive refrigerant of choice is R1234yf. The refrigerant is the secret to cooling the air in your vehicle or for that matter your house as well. The process of state change from liquid to gas and gas to liquid is exercised in a closed system. Heat is drawn from the air inside your vehicle by changing the liquid refrigerant to a gas and then that heat is expelled to the atmosphere changing the refrigerant back to a liquid from a gas. The key to moving that heat around is a compressor driven by either your engine or an electric motor. If you care to learn more check out refrigeration and the second law of thermodynamics. Don’t sweat the details.
R1234yf started replacing R134a (still the refrigerant in most vehicles on the road today) in model year 2013. Fifty per cent of 2018 model year vehicles were so equipped.
Why the new refrigerant? Environmental reasons. For me, being in the air conditioning business since 1996 this is my second refrigerant change. When I started the refrigerant in automobiles was R12. R12 was an ozone depleting substance (ODS). Remember those days when the news was all about the hole in the ozone layer? R134a was the replacement refrigerant of choice at the time because the refrigeration characteristics were similar to R12 but it was not an ozone depleting substance. Vehicles with R134a refrigerant began rolling off the assembly lines in the early nineties. My first air conditioning machine dealt with both R12 and R134a refrigerants.
Climate science has changed and global warming and climate change are now the more prevalent concerns. Unfortunately R134a has a very high global warming potential (GWP). It traps heat in our atmosphere. Not when it is contained in your air conditioning system but when it leaks out. GWP is a scientific number referenced to carbon dioxide whose potential is 1. R134a has a potential of 1300.
R1234yf again was developed to have similar refrigeration characteristics to R134a without the GWP problem. The manufacturers only require minor modifications to their vehicle air conditioning systems to work with the new refrigerant. The GWP of R1234yf is very close to one, essentially the same as carbon dioxide.
Automotive air conditioning technology marches on. My new air conditioning machine again must deal with two refrigerants. Best to keep all our customers cool.
Trail’s Ron Nutini is a licensed automotive technician and graduate of mechanical engineering from UBC. E-mail: firstname.lastname@example.org