A conditioned space has a sensible load of 4000 BTUhr and a

A conditioned space has a sensible load of 4,000 BTU/hr and a latent load of 9,000 BTU/hr and is to be maintained at 75 deg F, 50% rh. Outside air is at 90 deg F and 60% rh. Outside air is mixed with conditioned space air at a rate of 50-50 on a mass flow rate of dry air basis before it is delivered to the chiller. Air should be delivered to the conditioned space at 65 deg F.

Determine the relative humidity and volumetric flow rate (in CFM) of the supply air, and the cooling load on the chiller (in tons).

Solution

Determine the relative humidity and volumetric flow rate (in CFM) of the supply air, and the cooling load on the chiller (in tons).

relative humidity will be 9000 - 4000 = 5000

Volumetric flow rate = 0.60 * 9000 + 0.50*4000 = 7400