Hello. HVAC is not my area of expertise. My background is in industrial/agricultural engineering. However, I'm working a job that needs to cool supply air for a small laboratory that requires a high rate of fresh air exchange. They need the environment maintained at a DBT of 65ºF (humidity will be controlled via high-pressure nozzle system and will fluctuate based on user-input). I was hoping to run my calculations by someone in the HVAC field.
Air Flow- 300 CFM
Target Room DBT- 65ºF
Max Dry Bulb / Mean Coincident Wet Bulb Temp- 97.5 / 76.1ºF (37.85%RH)
Max Wet Bulb / Mean Coincident Dry Bulb Temp- 80.24 / 90.86ºF (63.46%RH)
Humidity Ratio: 0.0199 lb/lb
Spec Volume: 14.3173 cu.ft./lb
Enthalpy: 43.7257 Btu/lb
I know what my target dry bulb temperature is (65ºF), but how do I know what the resulting humidity level will be after the cooling coil? Should I just assume all the moisture will be pulled out of the air?
Here's my initial calculation based on the change in enthalpy (assuming 1% RH after cooling). I'm not sure the assumptions are correct, but is the formula correct?
Enthalpy: 15.7411 Btu/lb
300 CFM = 18,000 cu.ft/hr
18,000 cu.ft./hr / 14.3675 cu.ft/lb = 1,252.83 lbs/hr
43.7257 - 15.7411 = 27.9846 Btu/lb (delta enthalpy)
27.9846 Btu/lb x 1,252.83 lbs/hr = 35,059.95 Btu/hr
35,059.95 / 12,000 = 2.92 tons
Thanks in advance!