Fan Coil Selection

Some designers size fan-coil units for nominal cooling at the medium speed setting when a three-speed control switch is provided. This method ensures quieter operation in the space and adds a safety factor, in that capacity can be increased by operating at high speed. Sound power ratings are available from many manufacturers.

Only the internal space heating and cooling loads need to be handled by the terminal fan-coil units when outside air is pretreated by a central system to a neutral air temperature of about 70°F. This pretreatment should reduce the size and cost of the terminal units. All loads must be considered when outside air is introduced directly through building apertures.