Air Conditioning and Dehumidifiers: The Friendly Rivals

by Erik North on October 10, 2012

Post image for Air Conditioning and Dehumidifiers: The Friendly Rivals


Huge swathes of the country condition air to make sweltering hot weather manageable and they are also blessed with incredibly humid weather. When I first moved to Maine, some friends asked why? I mean other than the hiking, biking, skiiing, golf, lobster, plentiful microbrews, great fishing, somewhat accessible ocean (I’ve never understood the extreme value of oceanfront property…Maine is like 90% oceanfront), Maine also has great weather. In other words, a real hell-hole.

But I did live in Minnesota for years which is one of those states (think 10000 lakes) where as soon as you cracked your house door, your shirt glues itself to your skin in an epoxy of sweat, humidity and cotton. Unless you live in one of those ‘it’s a dry heat’ climates, you’ll be dealing with humidity.

The most common means of dehumidifying your house is, *ahem*, a dehumidifier. Maybe you could’ve guessed that one. There are many ways to reducing moisture or removing humidity from a building but the most common is the mechanical dehumidifier. And it is one of the worst energy hogs out there.

How Does A Dehumidifier Work?

How does a dehumidifier work? Sounds like a good section title. The very basics are exactly the same as that of an air conditioner but purposed differently. A liquid refrigerant like freon runs through a cooling coil, expanding from a liquid to a gas in a evaporator/expansion valve and condensing back into liquid in a compressor/condenser. The evaporation piece cools the refrigerant coils tremendously and air borne moisture condenses on the cool metal. The condensate water is drained away, pulling moisture from the air.

Like it was alluded to, this process is almost identical to what happens in an air conditioner. The only functional difference is that air conditioners direct cool air into the house and vent out warm air and condensation. A dehumidifier pulls out the moisture by itself and vents both cool and warm air into the building.

So what does this mean? If you are air conditioning a house, you are already dehumidifying. And if you’re already air conditioning then adding another expensive, costly to run machine may not be the answer. If your house has humidity issues, there are many ways to tackle their reduction before one resorts to plugging in yet another appliance.

{ 1 comment… read it below or add one }

Bill Japinga August 23, 2013 at 3:46 pm

You never need both an air conditioner and a dehumidifier. Both Appliances will remove humidity from you indoor air space. Air conditioners are typically more efficient. (Partly because they are required to have efficiency info at their point of sale?) I could see running a dehumidifier in a location which was inherently cool, yet has a high humidity. (Where using an air conditioner would leave with too low a temperature. (Of course, you could try raising the temperature a few degrees (heat pump? as we are still looking at relatively warm air outside – just not warm enough that we need an air conditioner.


Leave a Comment

Previous post:

Next post: