he AC cooling capacity varies with outdoor temperature, so we can vary the blower’s capacity to move that cooling off the coil. The Sensible cooling capacity also changes with indoor humidity. When it is very humid inside the house more of the cooling is used for dehumidification and less is for dropping the temperature of the air, so the air flow rate can be reduced. As the capacity of the refrigeration circuit changes (due to temperature or indoor humidity), we can change the capacity of the blower to move this cool air off the coils. We are constantly monitoring the coil temperature with the thermistor on the coil. We never let the coil get too cold, since this would increase the lift and also ice the evaporator.
Here is a link to independent testing by an ARI certified laboratory which shows at low lifts the EER increase by about 1.
Intertek EER Performance Test Report
Here is a link to independent testing by an ARI certified laboratory which shows at the improvement in humidity removal (due to the reduced air flow, more time for air on coil).
Intertek Humidity Test Report-2012
Here is a detailed paper if you want more information.
QwikSEER® White Paper Jan-2013
