COOLING PERFORMANCE CAN BE CHECKED WHEN THE OUTDOOR TEMP IS ABOVE 65 DEG F.
TO CHECK COOLING PERFORMANCE, SELECT THE PROPER INDOOR CFM, ALLOW PRESSURES TO STABILIZE. MEASURE INDOOR WET BULB
TEMPERATURE, OUTDOOR TEMPERATURE, LIQUID AND SUCTION PRESSURES. ON THE PLOTS LOCATE OUTDOOR TEMPERATURE (1);
LOCATE INDOOR WET BULB (2); FIND INTERSECTION OF OD TEMP. & ID W.B. (3); READ LIQUID (4) OR SUCTION (5) PRESSURE IN LEFT COLUMN .
EXAMPLE: FIRST STAGE
(1) OUTDOOR TEMP. 82 F.
(2) INDOOR WET BULB 67 F.
(3) AT INTERSECTION
(4) SUCTION PRESSURE @ 800 CFM IS 339 PSIG
(5) DISCHARGE PRESSURE @ 800 CFM IS 141 PSI
ACTUAL:
SUCTION PRESSURE SHOULD BE +/- 3 PSIG OF CHART
DISCHARGE PRESSURE SHOULD BE +/- 10 PSI OF CHART
DWG.NO 4YCZ5060E
INDOOR ENTERING WET BULB CURVES TOP TO BOTTOM
71, 67, 63 AND 59 DEG F.
Cooling with Thermal Expansion Valve
INDOOR ENTERING WET BULB CURVES TOP TO BOTTOM
71, 67, 63 AND 59 DEG F.