REDUCE ENERGY COSTS BY UTILIZING CEILING HEAT.

In winter, upper levels of industrial plants are progressively warmer than the worker zone; the temperature increases approximately 2 percent for each foot of height. In the past, moving warm air from the ceiling to the worker level rapidly enough to counter its tendency to rise was difficult and costly because all of the required air volume had to be moved through the fans. Entrainment, coupled with adequate throw and fan capacity, is the solution for the problem of mixing the upper high-temperature air with the cool floor air. An axial flow high-pressure fan equipped with a nozzle, which doubles the velocity, can move large amounts of air with relatively small fan volume. Entrainment ratios of 20 to 30 are possible. The article discusses considerations and calculations for selecting axial flow fans for this particular type of application.