Effect of occupant behavior and air-conditioner controls on humidity in typical and high-efficiency homes
Increasing insulation levels and improved windows are reducing sensible cooling loads in high-efficiency homes. This trend raises concerns that the resulting shift in the balance of sensible and latent cooling loads may result in higher indoor humidity, occupant discomfort, and stunted adoption of high-efficiency homes. This paper utilizes established moisture-buffering and air-conditioner latent degradation models in conjunction with an approach to stochastically model internal gains. Building loads and indoor humidity levels are compared for simulations of typical new construction homes and high-efficiency homes in 10 US cities. The sensitivity of indoor humidity to changes in cooling set point, air-conditioner capacity, and blower control parameters are evaluated. The results show that high-efficiency homes in humid climates have cooling loads with a higher fraction of latent loads than the typical new construction home, resulting in higher indoor humidity. Reducing the cooling set point is the easiest method to reduce indoor humidity, but it is not energy efficient, and overcooling may lead to occupant discomfort. Finally, eliminating the blower operation at the end of cooling cycles and reducing the cooling airflow rate also reduce indoor humidity and with a smaller impact on energy use and comfort.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); National Renewable Energy Laboratory (NREL), Golden, CO (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE), Office of Buildings and Industry. Building Technologies Office
- Grant/Contract Number:
- AC05-00OR22725; AC36-08GO28308
- OSTI ID:
- 1424450
- Alternate ID(s):
- OSTI ID: 1423189
- Report Number(s):
- NREL/JA-5500-70268
- Journal Information:
- Energy and Buildings, Vol. 165; ISSN 0378-7788
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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