Today there are two refrigerants in use for residential cooling: refrigerant 22 (R-22), which is freon 22, and refrigerant 410 (R-410), which is freon 410. R-22 has been is use for many years and is most likely what you have in your system currently. R-22 is claimed to be destructive to the ozone layer. The government has mandated that in 2010, manufacturers will not be able to manufacture any more systems using R-22. In the year 2020, manufacturers will not be able to manufacture R-22 and in the year 2030 , the homeowner will not be able to buy R-22

R-410 is claimed not to be destructive to the ozone layer and is now in use in residential systems. R-410 runs under a very high pressure and is more expensive than R-22 at the present time. A system which uses R-22 cannot use R-410, nor can a system which uses R-410 use R-22.

Which one is better? At this point the only real advantage that I can verify is that R-410 saves the ozone layer. The systems designed to use each of these refrigerants are capable of delivering the same level of cooling. In other words, a 4 Ton R-22 system will cool the same amount as a 4 Ton R-410 system.

If you wish to learn more about R-410, the Honeywell has a web site at http://www.410a.com that talks about R-410 and ozone depletion.