Measure Guideline: Supplemental Dehumidification in Warm-Humid Climates

Rudd, Armin¹ 

[1] Building Science Corporation, Somerville, MA (United States)

关键词: residential;    Residential Buildings;    BSC;    Building America;    dehumidification;    supplemental dehumidification;    cooling;    enhanced cooling;    condenser reheat;    sub-cooling reheat;    dehumidifier;    ventilation;    hot-humid;    relative humidity;    humidity;    elevated humidity;    humidity control;    humidity set point;    moisture generation;   

DOI  :  10.2172/1220346
RP-ID  :  DOE/GO--102014-4502
PID  :  OSTI ID: 1220346
Others  :  Other: 6937

美国|英语

来源: SciTech Connect

【 摘 要 】

This document covers a description of the need and applied solutions for supplemental dehumidification in warm-humid climates, especially for energy efficient homes where the sensible cooling load has been dramatically reduced. Cooling loads are typically high and cooling equipment runs a lot to cool the air in older homes in warm-humid climates. The cooling process also removes indoor moisture, reducing indoor relative humidity. However, at current residential code levels, and especially for above-code programs, sensible cooling loads have been so dramatically reduced that the cooling system does not run a lot to cool the air, resulting in much less moisture being removed. In these new homes, cooling equipment is off for much longer periods of time especially during spring/fall seasons, summer shoulder months, rainy periods, some summer nights, and winter days. In warm-humid climates, those long-off periods allow indoor humidity to become elevated due to internally generated moisture and ventilation air change. Elevated indoor relative humidity impacts comfort, indoor air quality, and building material durability. Industry is responding with supplemental dehumidification options, but that effort is really in its infancy regarding year-round humidity control in low-energy homes. Available supplemental humidity control options are discussed. Some options are less expensive but may not control indoor humidity as well as more expensive and comprehensive options. The best performing option is one that avoids overcooling and adding unnecessary heat to the space by using waste heat from the cooling system to reheat the cooled and dehumidified air to room-neutral temperature.