After finishing the construction of cooling tower and before running the cooling tower commercially, the cooling tower at no-load condition is tested. So, it is a meaningful study to estimate the fan brake horsepower and air volume at fan under the condition of no water flow. Let's see these through the actual sample.

Example 18-1: Determine the fan bhp and air volume at the no-load condition under the assumption that the fan efficiency remains unchanged from the design conditions. The ambient dry bulb temperature is 63^oF and relative humidity is 68%.

(Solution)
The fan bhp at no-load condition could be estimated by three ways as described before. That is, constant fan pitch, constant fan bhp or constant gas. The constant fan pitch would be most proper choice of estimating the fan bhp and air volume at the no load condition. Below results were obtained by the method of constant fan pitch. The fan bhp @no load condition is considerably increased while the air volume is slightly increased. So, this is why the fan test must be carefully done at the no load and cold weather conditions.

Download Example File: ID-NOLOAD/TOWER, Version 1.03, File Size  (no_load.zip)