R290 Charging Instructions for Central Air Conditioners Determine the capacity of your system from the nameplate It should state the capacity in ounces Usually between 50 and 90 If it uses R33, Envirosafe R290 would be the proper replacement refrigerant If it uses R12 or 134, then use our Industrial 12aWHY R290 GLOBALWARMING POTENTIAL (GWP) is a relative measure of how much heat a greenhouse gas traps in the atmosphere It compares the amount of heat trapped by a certain mass of the gas in question to the amount of heat trapped by a similar mass of carbon dioxide WHY R290 Refrigerant GWP ODP R404A 3922 0 R134a 1340 0 R290 Propane 3 0 R290 Pressure/temperature charts say 0*C/32*F R290 55 PSI R12 30 PSI R134a 28 PSI At either of these pressures (R12/R134a) the pressure of the evap would be low enough to freeze I would want to get my 'low' side above 55psi to avoid freezeups
The Homemade Heat Pump Manifesto Page 114 Ecorenovator
