Which year did Volvo stop using Freon in its AC systems ?

My 1994 945TG came with the new A/C solution, if that helps.

It was either 1992 or '93 that the new refrigerant was being used, of any vehicle sold in Canada.

vehicle sold in

All 1993 Volvos had non-CFC A/C.

THis is another reason why a 1993 Volvo 240 is the best 240.

Right. All 92 Volvos used R12, all 93s R134a. I know this is true for North America, and I believe it is true worldwide.

"Freon" is a Dupont trademark for hydrocarbons where some number of the hydrogen atoms have been replaced with fluorine, chlorine and/or bromine. The naming rules (e.g., Freon 12, Freon 134a etc.) are a bit complicated, but the formula for most can be arrived at by adding 90 to the number and noting that the resulting number interpreted as follows: first digit is the number of carbons, second digit is the number of hydrogens and the third digit the number of fluorines. The number of chlorines is gotten by taking the difference between the sum of the number of hydrogens + fluorines and substracting from the total number of available bonds to carbon. E.g., Freon 12 gives 102 as the number, which is 1 C, 0 H, 2 F and 2 Cl (4-2 since C has four bonds available). So, Freon 12 is CCl2F2 or dichlorodifluoromethane. 134a gives 224, so 2 C, 2H and 4F--only 6 bonds available since the C are bonded to each other--so Freon 134a is C2H2F4. The 'a' has to do with exactly how the F's and H's are bonded to the C's ("isomers").

That's the simplified version--a lot of words but pretty easy when you get the hang of it (assuming you've any reason to want to get the hang of it!). So--134a is still a "Freon", just not the one with which most are familiar.

It only cost me $175 to convert the A/C on my '92 240 the other day. And that was using new, real Volvo parts!

That said, I'd rather it was a '93, sure.

-jeff