Dehumidifiers use a heat pump (similar to an air conditioner's heat pump) or chemical adsorbents to take off moisture from the air without cooling the air.
A heat pump dehumidifier uses a fan to draw indoor air over a heat change coil. The coil is roughly freezing. The water in the air condenses on the coil and is drained. A second heat change coil reheats the air, which the dehumidifier exhausts into the room.
A heat pump dehumidifier dumps heat lost from the compressor and fan motors into the air. It returns to the indoor air the heat generated by the dehumidifier turning water vapour to liquid.
Chemical adsorbent dehumidifiers
This type of dehumidifier is designed for hot, humid climates and is not assuredly excellent for use in Canada.
Chemical adsorbent dehumidifiers discharge moisture from the air with a "desiccant"--a drying agent such as silica gel. The desiccant is on a heat change wheel. A detach air loop dries the wheel and exhausts the hot, damp air outdoors through extra ducting.
A chemical adsorbent dehumidifier uses more vigor than a heat pump dehumidifier. It is only cost-effective when it uses natural gas for heat exchange--and then only if natural gas is ready at a low summer rate.
Homemade dehumidifier
Some inventive people use bags of road de-icing salt to discharge moisture from the air. The wet salt explication drips into a pan or floor drain, drying the air. Because the salt runs off with the water removed from the air, it must be replaced. The ideas has no bright parts.
If you try this homemade dehumidifier, remember that salt is very corrosive to metals and quite hard on the skin.
Dehumidifying ventilators
This type of dehumidifier has a sensor-controller and exhaust fan. You set the sensor-controller to run when humidity reaches a set level. A dehumidifying ventilator is particularly efficient if the humidity source is in your basement.
Dehumidifying ventilators don't recover heat but they use less electricity than heat pump dehumidifiers. They are not efficient in hot, muggy weather, as they bring more exterior air into the house. They can be efficient in cold weather.
A dehumidifying ventilator depressurizes your basement, which can cause combustion gas spillage. Make sure your heating undertaker of a package deal checks the venting for your gas furnace, water heater and wood-burning appliances. Consider using a carbon monoxide warning device if you setup a dehumidifying ventilator.
Choosing a Dehumidifier
Dehumidifier purchase costs
Heat pump dehumidifiers are complex, low-production machines and are not low-cost items. Spring seems to be the best time to buy: in the last few years dealers have held sales early in the spring with savings of to 0.
The more water a dehumidifier holds --which is measured in litres or U.S. Pints a day--the more it costs. You pay more for extra features.
In 2000, you can expect to pay in the middle of 0 and 0 for a unit rated at 10 L (21 U.S. Pints or 2.1 imperial gal.) a day--suitable for a small house with a moderate moisture problem. The price rises to in the middle of 0 and 0 for a unit with a capacity of 20 L (42 U.S. Pints or 4.3 imperial gal.) a day--suitable for a large house with more severe problems.
Running costs for both units are about the same if they both have the same Efficiency Factor. The next section explains the Efficiency Factor.
Don't try to save money by buying a unit that does not have automatic defrost. If a room is too cool, a dehumidifier can frost over and stop removing moisture. A frosted-over dehumidifier left running for a long time will break down.
Get a unit with a two-speed fan. They are quieter at lower humidity, which reduces the nuisance factor. Test all units in the store for noise level, especially if you plan to use one in or near a bedroom.
Introducing Dehumidifiers and their FunctionWatch Free Tennis Online Brush DC Motor What is a Conforming Loan Definition