Humidity Control in Residences

Maintaining relative humidity below 60% for residential houses in humid climates promotes a healthy indoor environment. Yet, for such homes, these lower humidity levels are difficult to maintain with conventional recirculation air conditioning units. By introducing a separate vapor compression unit to pre-condition outside air, indoor relative humidity can be controlled. This new air conditioning system combines a ventilation unit with a conventional recirculation air conditioning unit. Although successful in maintaining indoor humidity levels below 60%, the new air conditioning system will require more electric energy to provide the additional dehumidification. However, this penalty is shown to be offset by reductions in sensible load during a summer week, which should result in lower energy consumption and peak electric demand during that period. The performance of this new air conditioning system is demonstrated using FSEC 3.0, a building energy simulation program developed by the Florida Solar Energy Center, to simulate the heat and moisture transport occurring within a prototypical residence located in Austin, Texas