A dehumidifier collects water vapor from the air, decreasing the humidity of the surrounding area. Dehumidifiers include both portable and whole-home dehumidifiers. Portable dehumidifiers can be easily moved from one room to another, while whole-home dehumidifiers are often used in conjunction with a home’s HVAC system and are designed to be connected to ductwork. Dehumidifiers work by using a refrigeration system to cool air to the point where moisture in the air condenses.
Congress established the current standards for dehumidifiers as part of the Energy Independence and Security Act (EISA) of 2007, and they took effect in 2012. The standards specify a minimum energy factor (EF) that varies based on dehumidifier capacity (pints/day). EF is expressed in terms of liters of water removed per kWh of electricity consumed.
In 2016, DOE finalized new standards for dehumidifiers, which will take effect in 2019. The new standards are based on a new metric, integrated energy factor (IEF), which incorporates energy consumed when the fan is running while the refrigeration system is off and standby power consumption, in addition to the energy consumed by the refrigeration system. The new standards are also based on an improved test procedure that will better reflect the actual energy consumption of dehumidifiers used in homes. Currently, dehumidifiers are tested at an ambient temperature of 80 F. With the new test procedure, dehumidifiers will be tested at 65 F, which better reflects typical basement temperatures.
About 13% of US homes use a dehumidifier. Dehumidifiers just meeting the current standards can consume as much as 1000 kWh per year, or roughly twice the energy use of an average new refrigerator. The efficiency of dehumidifiers can be improved through the use of more efficient compressors and larger heat exchangers.