Removing heat pump/purge air?

[DanS]

I have a plumber/hvac company replacing my heat pump with a propane heater. They said I need to purge the air. Is this correct, and how would I do it? Is there air to be purged in a heat pump?

[Poconos]

Have no idea what they mean by 'purging air' but they probably mean recovering the refrigerant. I know the law says the old stuff R-12, R-22, and others in that family cannot be released into the atmosphere and the law may apply to the newer stuff like R-134a too. No big deal in any case. They hook their recovery equipment to the system and suck the refrigerant out before opening the lines for disassembly. The equipment to do this isn't cheap so it is something 'you' would not do. Look on the unit and somewhere the type of refrigerant should be stated. I'm curious. Newer refrigerants are supposed to be ozone layer friendly whereas the older ones are not....at least 'they' say.
Al

[cleancloths]

Well you could always "accidently" purge everything before they get there and tell them it is empty because of a leak.

[DanS]

I just turned it off and he removed it. I don't think there was any air to purge.