Description
CFC (Choloro-Floro-Carbons) contains ozone depletion chlorine. Example: R-12, R-502.
HCFC (Hydro-Choloro-Floro-Carbons) contains less ozone depletion chlorine than CFC. Example: R-22, R-408, 409A, 401A, 402A, AND 402B)
HFCS (Hydro-Floro-Carbons) no chlorine contains. Example: 134A 404A 410A 507 Refrigerants.
RULES OF THUMB
1 kilowatt = 3.413 btu (British thermal units)
1 btu = heat needed to raise 1lb water 1°F
One ton = 12,000 btu/hour
Air leaves AC unit at 55°F
Airflow required to space is approx 1 cfm/ft2
AC units has nominal capacity of 400 cfm/ton