Hello,
We are having a new heating and air conditioning system put in our home.
We have had three contractors give us prices, and 2 of them have included systems using the new Puron refrigerant. The 3rd contractor who is supposed to be excellent, said they are not using the Puron yet, he said by the time the freon is completely phased out, it will be time for us to purchase a new air condtioning unit.

Is this true?

Or should I consider one of the other contractors?

Thank you,
Adevlin

I think you can look at this problem as either pay now or pay later. R22 is going to get more expensive as time goes on. R410A systems (Carrier calls it Puron) might be a little more expensive initially. I'd go with the Puron system, but make sure the lines are either replaced or flushed because the oils are not compatible.

See: What You Should Know about Refrigerants When Purchasing or Repairing a Residential A/C System or Heat Pump | Ozone Depletion - Regulatory Programs | U.S. EPA
In 2010, you cannot buy R22 in new equipment.

HVAC systems might easily have a lifetime of 10-15 years. I had an gas Heating and AC system go nearly 40 years without needing freon. Minimal problems with preventative maintenance.

Base your SEER of your AC on just how often you use AC/Heat pump and the price of electricity.

You can cnsider dual fuel systems where gas can serve as backup for a heat pump. It might be a little difficult to compare. Ground water heat pump systems often give you the best efficiency.

I know, more than you asked.

Keep itSimpleStupid had the best idea (Ground water heat pump systems often give you the best efficiency.) If you can afford it.