Dehumidifiers near you

Natural Resources Canada describes portable dehumidifiers as units that treat a single room and can be moved easily, and whole-home dehumidifiers as systems that use the home's air ducts to dry one or more rooms and are often permanent. ENERGY STAR certifies both kinds.

A portable unit suits a basement, a laundry room or a cottage that turns clammy every summer. A whole-home unit makes more sense when several levels feel damp, when a finished basement is part of the living space, or when emptying buckets and moving machines around has worn thin. It usually sits near the furnace or air handler and ties into the duct system, so it needs a technician to plan the connection, a permanent drain and a proper electrical supply.

Excess humidity below grade rarely shows up as water on the floor. It shows up as smells, condensation and slow damage to whatever is stored down there. A hygrometer, a small gauge that reads relative humidity, turns a hunch into a number you can act on.

Health Canada recommends keeping indoor relative humidity between 30% and 50%, and its mould guide advises running a dehumidifier in damp areas such as basements, and whenever moisture condenses on cold surfaces or humidity rises above 50%. Summer is when basements struggle: warm outdoor air carries a lot of moisture, and when it meets cool foundation walls and floors its relative humidity climbs and water can condense.

In winter the picture usually reverses, since cold outdoor air holds little moisture and heated indoor air tends to run dry. Many homes only need a dehumidifier from late spring to early fall, but a basement drying out after a flood, new concrete or a lot of indoor laundry can need one longer. Let the humidistat and a hygrometer guide you rather than a fixed schedule.

Natural Resources Canada explains that a dehumidifier's capacity is usually given in litres per day and depends on two factors: the size of the space and its current conditions. A large, very wet basement needs more capacity than a small room that is only slightly clammy, and a unit that is too small runs all day without reaching its setting. For a whole-home model, the technician also looks at the volume of the house, the ductwork and how humidity differs from one level to the next.

Drainage deserves as much thought as capacity. A full bucket shuts the unit off until someone empties it, so most basement installations drain continuously instead.

A dehumidifier in a damp basement can run for long stretches all summer, so efficiency matters. Natural Resources Canada says an ENERGY STAR certified dehumidifier uses nearly 15% less energy on average than a standard model. Every certified model has a built-in humidistat: you set the relative humidity you want, and once the room reaches it, the unit cycles on and off to hold that level.

Setting the humidistat lower than you need burns electricity without making the space any healthier. Choose a setting within the 30% to 50% range, then adjust it based on what the hygrometer shows and whether condensation or mustiness returns. Natural Resources Canada's list of certified dehumidifiers is a good place to compare models.

A dehumidifier deals with moisture that is already in the air. It can't stop liquid water from coming through a cracked foundation, seeping in where the floor meets the wall, or rising through a slab where drainage has failed. Running one against an active leak mostly hides the problem: the room feels drier while the wall behind the finished drywall stays wet.

Puddles after heavy rain or snowmelt, damp patches low on the walls, white chalky deposits on the concrete or wet floor edges all point to water entry. Deal with that first by checking gutters, downspouts and grading, then have the foundation assessed; our basement waterproofing page covers the options, from crack repair to interior and exterior drainage. Once the water is stopped, a dehumidifier is the right tool for keeping the space dry.

Natural Resources Canada advises keeping dehumidifier filters clean and checking them regularly so air can flow freely. The rest of the routine is short and set out in the owner's manual. Unplug a portable unit before cleaning it.