Using Field-Metered Data to Quantify Annual Energy Use of Residential Portable Unit Dehumidifiers

In the United States, portable unit dehumidifiers most commonly are used in basements during humid summer days in northern climates.1 Dehumidifier operation and energy consumption differ among households, depending on frequency and duration of use, user-selected settings, and outside environmental conditions. Few metering studies, however, have been performed to measure the energy use of dehumidifiers in American homes. To expand the understanding of dehumidifier energy use as related to outdoor temperature and humidity, Lawrence Berkeley National Laboratory (LBNL) undertook a field study that collected energy consumption data on portable unit dehumidifiers, along with information regarding climate conditions, housing characteristics, and consumer behavior.

The field-metering study, which focused on households that use mechanical/refrigerative dehumidifiers in the New England and Middle Atlantic areas, acquired real-time data on the energy consumption of portable unit dehumidifiers during two successive humidity seasons (2012 and 2013). An initial summary report was published in December 2012. The current report further analyzes the data, collected in support of achieving three goals: (1) to develop a model that mathematically describes a relationship between dehumidifier operation and climate conditions as defined by temperature and relative humidity; (2) to develop distributions of hours of dehumidifier operation for three operating modes: standby and off, fan-only, and compressor plus fanb ; and (3) to describe how individual consumers' selection of dehumidifier capacity for a given space, consumers' selection of humidity level, and the method of condensate removal affect energy use. More importantly, understanding the operation and energy use of portable unit dehumidifiers in real-world applications will help characterize the increasing residential energy consumption associated with those appliances. For this report we did not analyze the effects of consumers' selection of dehumidifier capacity or consumers' selection of humidity settings. The effects of those factors on energy use will be reported after further analysis of the survey data.