Residential dehumidification and ventilation systems research for hot-humid climates

Twenty homes were tested and monitored in Houston, Texas, U.S.A. to evaluate humidity controlperformance and operating cost of six different integrated dehumidification and ventilation systems that could be applied by production homebuilders. Fourteen houses had one of the six integrated dehumidification and ventilation systems and also met a high standard of energy efficiency criteria. Six houses were reference houses--three having the same high standard of energy efficiency measures and controlled mechanical ventilation, while three met code minimums for energy efficiency and did not have mechanical ventilation. Temperature and relative humidity was monitored at four living space locations and in the attic where the space conditioningequipment and air distribution ducts were located. Equipment operational time was monitored for heating, cooling, dehumidification, and ventilation. Results showed that energy efficiency measures, combined with controlled mechanical ventilation, change the sensible and latent cooling load fractions such that dehumidification separate from the cooling system is required to maintain indoor relative humidity below 60% throughout the year. The system providing the best overall value, including humidity control, first cost, and operating cost involved a standard dehumidifier located in a hall closet with a louvered door and central-fanintegrated supply ventilation with fan cycling.