The purpose of a dehumidifier is to lower the humidity of the air in your home. Humidity is a measure of the moisture suspended in the air at any given time. Moisture levels are higher during different seasons. In Massachusetts, humidity levels are much higher in the summer than in the winter.
Home dehumidifiers are mostly used to dry air in the basement or crawlspace. These areas are prone to high humidity levels because they are below ground. It is not uncommon for the saturated ground outside of foundation walls to cause seeping or leakage through the walls.
The condensation is what allows a home dehumidifier to work. The dehumidifier typically consists of a metal or plastic cabinet that contains a fan, a compressor, metal coils and a collection pan. There is also a humidistat that allows you to set the level of humidity you desire within a room.
The fan draws air into the unit, and it passes over the coils. The coils are often set up as a two-stage process. In the first stage, the coils are very cold. As the air passes over the cold coils it condenses and collects there. From here the water drips into the collection pan. As the air continues on through the unit, it hits the second stage of coils which uses the heat generated by the compressor to re-heat the air and deliver it back in to the room.
In the meantime, the collection pan fills with water. The shut off is triggered when the water reaches a certain level. Sometimes, rather than a collection pan, home dehumidifiers have a fitting that can attach to a hose so that the water can run out of the unit to a drain of your choice.
Understanding the basics of how a home dehumidifier works is important so that you can determine which type of unit to buy for your home. A high quality, low maintenance unit is the best choice for most homes. Compare home dehumidifiers carefully before investing in them, this is an important piece of equipment.