Air cooled condensers of air-conditioning/refrigeration systems installed in the vicinity of inhabited areas are usually provided with acoustic treatment to minimize the noise nuisance generated. For air cooled condensers equipped with fan cycling control Note, care should be taken in the design of fan discharge ductworks connecting to acoustic silencers to prevent air short-circuiting during fan cycling.
Using a condenser with three pairs of cooling fans (see Fig. 1) as an example. The first pair (1 & 2) will be in constant operation, while the second (3 & 4) and third (5 & 6) pairs will be cycled on and off in stages in response to the ambient temperature variation.