Effect of occupant behavior and air-conditioner controls on humidity in typical and high-efficiency homes

Winkler, Jon; Munk, Jeffrey; Woods, Jason

doi:10.1016/j.enbuild.2018.01.032

Title: Effect of occupant behavior and air-conditioner controls on humidity in typical and high-efficiency homes

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Abstract

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 study 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. 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.

Authors:

Winkler, Jon ^[1];

^[2];

^[1]

National Renewable Energy Lab. (NREL), Golden, CO (United States)
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Publication Date:: 2018-02-20

Research Org.:: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); National Renewable Energy Lab. (NREL), Golden, CO (United States)

Sponsoring Org.:: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Energy Efficiency Office. Building Technologies Office

OSTI Identifier:: 1424450

Alternate Identifier(s):: OSTI ID: 1423189

Report Number(s):: NREL/JA-5500-70268
Journal ID: ISSN 0378-7788

Grant/Contract Number:: AC05-00OR22725; AC36-08GO28308

Resource Type:: Accepted Manuscript

Journal Name:: Energy and Buildings

Additional Journal Information:: Journal Volume: 165; Journal ID: ISSN 0378-7788

Publisher:: Elsevier

Country of Publication:: United States

Language:: English

Subject:: 32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; indoor humidity; low-load; moisture buffering; effective moisture penetration depth; humidity; building energy modeling; moisture

Citation Formats


                    Winkler, Jon, Munk, Jeffrey, and Woods, Jason. Effect of occupant behavior and air-conditioner controls on humidity in typical and high-efficiency homes.  United States: N. p., 2018. 
Web.  doi:10.1016/j.enbuild.2018.01.032.

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                    Winkler, Jon, Munk, Jeffrey, & Woods, Jason. Effect of occupant behavior and air-conditioner controls on humidity in typical and high-efficiency homes.  United States.  https://doi.org/10.1016/j.enbuild.2018.01.032

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                    Winkler, Jon, Munk, Jeffrey, and Woods, Jason. Tue .  
"Effect of occupant behavior and air-conditioner controls on humidity in typical and high-efficiency homes".  United States.  https://doi.org/10.1016/j.enbuild.2018.01.032.  https://www.osti.gov/servlets/purl/1424450.

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@article{osti_1424450,

  title        = {Effect of occupant behavior and air-conditioner controls on humidity in typical and high-efficiency homes},

  author       = {Winkler, Jon and Munk, Jeffrey and Woods, Jason},

  abstractNote = {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 study 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. 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.},

  doi          = {10.1016/j.enbuild.2018.01.032},

  journal      = {Energy and Buildings},

  number       = ,

  volume       = 165,

  place        = {United States},

  year         = {2018},

  month        = {2}

}

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