Heat Pump 101
Recovering refrigerant from a heat pump
- Get a recovery tank 
- Pump it down to 250 microns . It will not collapse under air pressure. It is E-4 order of 1 atmosphere.
- This is a good one - Heat Pump University - . Invite this Mister to teach at OSE.
- Adding refrigerant, and diagnosing superheat, subcool at end