Buying a Dehumidifier

Deciding what type and size you require

If you have humidity in your home, there may be a number of root causes that you may need to deal with before purchasing a dehumidifier. You can measure the humidity in your home with a hygrometer or humidistat, and you can also check for the following tell-tale signs of an overly humid house: 

• Do you have condensation on your windows?
• Are there any damp patches on your walls?
• Is wallpaper peeling?

• Do you smell or see mold?
• Do smells, such as cooking odors, linger for a long time?
• Are your floorboards or furniture warping?
• Is your wood rotting or cracking?

Here is a list of things that may contribute to an overly humid home:

• Cracks in the walls of your basement.
• Leaking pipes or dripping taps.
• A weak bathroom fan.
• An unused bathroom fan or one that does not vent properly to the outside.
• An improperly vented dryer.
• Poor drainage (can be critical).
• Indoor aquariums.
• Indoor hot tubs.
• People who take long showers or baths.
• Lots of plants.

Other things that can increase the moisture in your air are doing dishes. Some actual figures are:

• Bathing and showering each add about ½ a liter of water to the air.
• Mopping floors and boiling cabbage adds 1 liter.
• And (get this) human breathing adds ½ a liter per hour to the air per person.

Sizing your dehumidifier
Here are the basics for determining the size of a dehumidifier. The measures are pints per 24 hours:

If your area is 500 square feet (with the doors and windows closed):

• Moderately damp: 10 pints per 24 hours
• Very wet: 16 pints per 24 hours

If your area is 1000 square feet:

• Moderately damp: 14
• Very wet: 23

If your area is 1500 square feet:

• Moderately damp: 18
• Very wet: 30

If your area is 2500 square feet:

• Moderately damp: 26
• Very wet: 44

If your area is 3000 square feet:

• Moderately damp: 30
• Very wet: 51