7 Ways a Dehumidifier Can Improve Indoor Air Quality

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7 Ways a Dehumidifier Can Improve Indoor Air Quality

A large portion of U.S. residents live in a generally humid climate. For those of us who do, controlling the humidity levels in our homes is probably something we don’t really think about very often.

Modern AC systems, of which we rely on heavily, are designed to pull moisture out of the air. But do these systems pull enough of the moisture out to bring home humidity levels down to where they should be? For most of us, the answer is no.

Controlling home humidity levels aids in improving indoor air quality in many ways. Many of the pollutants responsible for poor indoor air quality are directly affected by increased moisture levels in our home’s air. Dehumidifiers work to lower this moisture level and improve indoor air quality. Ideally, humidity should be anywhere from 35% to 50%.

Any level above 50% tends to support the growth of mold and helps dust mites thrive. Both of which are major contributors to overall poor indoor air quality.

Let’s take a look at some of the ways a dehumidifier can improve indoor air quality by lowering the humidity levels in your home.

 – Bacteria and Viruses tend to do better in higher humidity environments. They also tend to stay airborne longer.

 – Mold and Mildew thrive in moist conditions. These allergens and irritants can grow quickly and they can have some pretty adverse effects on the human body.

 – Dust mites need high humidity to survive and thrive. Dust mites can cause all sorts of respiratory symptoms from minor eye irritation to severe respiratory problems.

 – Volatile Organic Compounds (VOCs) levels tend to increase in higher humidity. VOCs can affect your health in many adverse ways.

 – Odors can linger in humid air longer. Odor causing substances tend to be water soluble and tends to mix well with water vapor in the air. Water vapor tends to hang around in air perpetually.

 – Highly humid rooms tend to make rooms feel unpleasant and stuffy. These conditions can lead to poor sleep, fatigue, and headaches.

 – Higher humidity encourages insect populations. Roaches need humidity to breed and survive so humid homes offer an ideal environment.

How does a dehumidifier work?

Dehumidifiers are similar home AC systems in the way they work. Your home’s AC system pulls in air and blows it across a set of cooling coils.

This causes the moisture in the air to condense on the coils where it collects and drops off into a drip pan. The resultant water is carried off to a drain that eventually ties in to your home’s sewer system.

Meanwhile, the now-cold air is cycled out of the AC system and into your home, thus having the effect of pulling moisture out of the air (dehumidifying) and cooling the home at the same time. 

Dehumidifiers do the same thing to pull moisture out of the air but with one difference. The cooled air is forced through another set of coils that actually heats the air back up before it is expelled.

You may be asking yourself why this is done. Well, it has something to do with what needs to happen in order for the first set of coils (cooling) to actually get cold.

During this process a great deal of heat is generated. In home systems, this heat is dealt with outside the home where a fan pulls air through another set of coils.

With a dehumidifier, there are no connections to the outside. This heat has to be dealt with inside the unit. That is what the cooled air does. It flows over this second set of coils, cooling the system but warming the air back up.

The water that is pulled out of the air is collected in a tank on the unit. It must be emptied or with some units, a drain to a sink or tub can be used to avoid having to empty the water.

There is also an air filter that filters the intake air before it flows across the cooling coils. This is to prevent dust buildup on the coils which could damage the unit.

What are some other benefits of using a dehumidifier?

In addition to the numerous ways a dehumidifier can improve indoor air quality, there are some other benefits to using one of these devices in your home.

 – Dehumidifiers help your home AC run more efficiently. By pulling moisture out of the air, a dehumidifier does part of the job that the AC system usually does. The AC doesn’t have to work as hard and that saves energy.

 – High humidity can adversely affect your electronic equipment. Moisture can affect the electronic circuitry that makes your TVs, computers, and other devices function properly.

 – Metal tends to rust more easily in humid environments. This can affect any number of things in your home from tools and weapons to structural components of the home itself.

 – Wood tends to swell in high moisture conditions. This can cause warping of wood products in your home.

 – Paint and wall paper can come loose and peel in humid conditions. Paint doesn’t adhere to damp wood very well and the glue used to hold wall paper can degrade in the damp conditions.

 – Rooms feel more comfortable at lower humidity levels. Moisture in the air makes temperatures feel warmer than they really are.

What size dehumidifier should I buy?

Dehumidifiers are sized by how may pints of water they can remove from the air per day. So, a 60 Pint/Day unit is going to be able to remove twice as much moisture from your air than a 30 Pint/Day unit.

As far as sizing for your particular application I am going to recommend getting a unit with the highest pint per day rating that you can afford. This will give you the most versatility in where you can use the dehumidifier.

Using an oversized unit makes the dehumidification process actually more cost effective because the unit runs for shorter times while removing more moisture.


Dehumidifiers can improve indoor air quality in many ways. By reducing moisture, you can stop mold growth, inhibit dust mite populations, decrease VOC levels, and slow bacteria and viruses from spreading.

Maintain your home at a humidity level of 35% to 50% for best results. A drier home is a more comfortable home and a healthier home as well.

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