Do dehumidifier’s dehumidify in the winter?
Aprilaire dehumidifiers are designed to control airborne moisture in areas where the ambient indoor temperatures are 65F-80F. If the ambient air temperatures are lower than 65F, there is less moisture in the air because colder air doesn’t hold as much moisture as warmer air. As a result our dehumidifier’s will remove less moisture at lower temperatures.
Dehumidifier’s, including Aprilaire dehumidifier’s are not designed to pull moisture off a surface. This includes windows, walls and floors. In order for any dehumidifier to attempt to remove moisture, the moisture needs to be in the air.
During the Summer time our Aprilaire dehumidifier’s are designed to maintain an indoor relative humidity of 45% at an indoor ambient temperature of 75F( 52F dew point). Typical winter time conditions in a home are 70F indoor ambient temperature with a relative humidity of 35% (41F dew point). The lowest dew point Aprilaire dehumidifier’s will attempt to achieve is 40F dew point. As a result our Aprilaire dehumidifier’s usually will not operate in the winter time.
Moisture will form on windows anytime the surface temperature of the window is lower than the dew point temperature of the ambient air. For example indoor ambient conditions of 70F and, 40% Relative Humidity have a dew point temperature of 44F. When the outside temperature is 0F and the surface temperature of the glass at 43F, condensation will form on the windows because the glass surface temperature is below dew point temperature. In comparison, indoor ambient conditions of 70F and 30% Relative Humidity has a dew point temperature of 37F. When the outside temperature is 0F and the glass surface temperature is 43F no condensation will form on the windows because glass surface temperature is above the dew point temperature.
To remove moisture from windows during the winter time, a ventilation product is recommended.
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