As the heat content of return air drops, the suction pressure drops opening the APR Control. The hot gas gets sent into the desuperheat chamber then back to the suction line. A liquid injection hot gas valve mixes liquid with the HG (in the desuperheat chamber) when the mixed gas temperature rises to 60F.
The APR Control derates the evaporator coil capacity extending the run time while keeping the active portion of the coil at a constant temperature (below dewpoint) thereby dehumidifying during the extended run period. Watch the video below for more information.