Secondary Author(s)

Shirey III, Don B.; Raustad, Richard

Report Number




Cooling; Buildings; Dehumidification; Residential; Humidity; HVAC


This study evaluated the impacts of conventional and advanced cooling and dehumidification equipment on residential indoor humidity levels and annual energy consumption using whole building computer simulations. The life-cycle cost premium for the various advanced systems was also estimated. Building models were developed for a standard HERS Reference house, meant to represent current residential construction practice, and a High-Efficiency house that would likely qualify for a federal tax credit. The different houses were simulated in seven southeastern U.S. cities and with two ventilation/infiltration scenarios: 1) variable or natural infiltration alone, and 2) mechanical ventilation that complied with ASHRAE Standard 62.2-2004. The simulations accurately considered several key factors that affect dehumidification performance and space humidity levels, including: 1) duct air leakage and thermal losses, 2) the impact of part load latent capacity degradation with various supply air fan control and ventilation strategies, and 3) the impact of space over cooling and other novel dehumidification control strategies. The study results indicate that energy-efficient, properly-ventilated homes in humid climates need equipment options or configurations that can provide a modest amount of additional dehumidification capacity while coordinating their operation with conventional cooling and ventilation systems. Several of the advanced dehumidification systems evaluated as part of this study provided improved energy performance while maintaining proper indoor humidity levels, but some have a high first cost which yields relatively high life-cycle costs. The research team believes that alternative designs for some of these options can be developed to reduce first cost.

Date Published


Local Subjects

Buildings - Cooling; Buildings - Dehumidification; Humidity; Buildings - HVAC; Buildings - Residential


FSEC Energy Research Center® Collection



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