Air Conditioning Charging Procedures Review. Basic Refrigeration. Basic Refrigeration. Liquid Line. Liquid Line. Metering Device. Condenser. Low Side. Hi Side. Evaporator. Compressor. Saturation Temperature. What is Saturation Temperature?.
First things first…
You must verify that you have proper airflow!…and you must have the proper tools to do the job….
Air Flow is Critical
-Evaporator Pressure Drop
-Air – Velocity
Airflow Measurement(Temperature Rise Method)
(Red Book, Pg. 33)
T X 1.08*
*1.08 = constant number for std air. It’s a combination of a number of values that are in the complete equation. Std air is 70F, sea level
55,200 BTU output
60 X 1.08
Blower should always be on high speed?
The Right Stuff:
Digital Thermometer (one with Wet Bulb capabilities)
(390 PSIG & 115º F)
+ “Check the Enthalpy of the Evaporator Coil to verify system capacity…”
Total Heat Removed =
CFM X 4.5 X Change inEnthalpy (Heat Content)
Where’s the 4.5 come from?
It’s how many BTU’s are in one pound of DRY air (0%Rh)
Total Heat =CFM X 4.5 X Enthalpy Change
Difference = 6.79
800 X 4.5 X 6.79
= 24,444 BTUH !