High indoor humidity is a common problem and can greatly contribute to indoor air quality issues. Your air conditioning system does help to reduce indoor humidity, but AC alone often isn’t enough to prevent moisture issues in more humid climates. The best way to overcome issues with high indoor humidity is to install a whole-home dehumidifier, and today we’re going to show you how these units work and how they can help to overcome certain indoor air quality issues.

How Whole-Home Dehumidifiers Work

Whole-home dehumidifiers are installed within the return air duct just before it meets the air handler compartment where the AC evaporator coil is located, and they work in conjunction with the air conditioning system to remove lots of excess moisture from the air flowing through the duct system. The most basic models will always run throughout the entire time your air conditioning is running and then automatically shut off whenever the AC does.

Some more advanced models are controlled by a humidistat, which is quite similar to your thermostat, except that it measures humidity level instead of temperature. With this unit, you can program the humidistat for your desired humidity level. In this case, the dehumidifier will only run when the humidity level in the home is above the desired level and will automatically shut off once the humidity is at or below what the humidistat is set to.

Most dehumidifiers also allow you to run them independently of your air conditioning. This can be useful in the spring and fall when your home may not be hot enough that you need to run your AC, but the humidity level is still too high. To run the dehumidifier without your AC, all you typically need to do is change the fan setting on the thermostat from “Auto” to “On.” When the fan is set to “On,” it will run constantly even if your AC is off so air is still drawn into the duct system and flows through the dehumidifier.

A whole-home dehumidifier is quite similar to an air conditioner in that it has an internal evaporator coil and compressor. The compressor works to supply cold refrigerant to the evaporator coil. The warm air flowing through the duct is drawn into the dehumidifier and forced over the evaporator coil, and the temperature difference between the warm air and the cold refrigerant that flows through the coil pulls much of the moisture from the air and causes it to condense into the water on the coil.

In most cases, the dehumidifier is connected to the AC condensate drain system so that all of the water collected by the dehumidifier flows into your sewage system or directly outside the home. The dehumidifier can also be set up with its so condensate drain lines that can again either lead into a floor drain or outside.

As the unit runs, the refrigerant absorbs some of the heat energy from the air, just as the AC evaporator coil does. This has the effect of slightly pre-cooling the air before it flows out to the AC evaporator coil, which can help to make your air conditioning system more effective and allow it to cool more quickly. In fact, studies have shown that using a whole-home dehumidifier can potentially lower the energy usage of your AC by 10% or more since the AC usually won’t need to run as long. Now that you know how whole-home dehumidifiers work, let’s look at the impact that this type of unit can have on your home’s indoor air quality.

Mold Prevention

One of the biggest benefits of using a dehumidifier is that it can help to prevent issues with mold growth, which can be a major issue that contributes to poor indoor air quality. Any time the humidity level in the home is too high, moisture can start to condense on any surfaces that are cooler than the air, such as inside the supply ductwork, on basement walls, floors, etc. All of this condensation can lead to water damage and potentially cause your walls and ceilings to discolor, paint to bubble, or wallpaper to start peeling.

The bigger issue is that, during the warmer months, this combination of warm air inside the home and condensation can quickly lead to mold forming. As mold grows, it releases millions of spores into the air that are then circulated into every part of the home by your air conditioning system. Mold can also start forming in your home during the winter, but this is usually less of an issue since colder air almost always contains less moisture.

Mold is a powerful allergen that can trigger bouts of coughing and sneezing as well as asthma attacks. Having lots of mold spores in the air can also make it more difficult to breathe and especially for people with respiratory ailments like COPD. Long-term exposure to mold has also been directly linked with an increased risk of developing asthma, which is always higher for younger children.

High humidity can also potentially lead to the growth of toxic black mold. Black mold is an especially big issue as exposure to it can lead to mycotoxicosis—also known as mold poisoning. Mold poisoning can lead to severe allergy symptoms and even severe illness in young children, the elderly, or anyone with a compromised immune system.

Fewer Issues With Dust Mites and Other Pests

A whole-home dehumidifier can also help to prevent issues with pests in the home. A wide variety of different insects and pests are attracted to warm, humid conditions. Any time your home is warmer and too humid, you’ll have far more dust mites on your furniture, bedding, and throughout the rest of the home, which can again cause major issues for people with allergies or respiratory problems.

Cockroaches also thrive in warm, moist conditions and may start nesting in your ductwork or other humid areas like your basement or even inside your walls. Silverfish, centipedes, earwigs, and pill bugs are just a few of the pests you’re more likely to have issues with if your home always stays too humid. All of these pests can contribute to poor air quality and breathing issues as their saliva, feces, and the body parts they shed are all major allergens and can trigger various symptoms.

What Is the Ideal Indoor Humidity Level?

Any time the humidity level in your home is above 60%, you have a greatly increased risk of issues with mold and pests. As long as the humidity level never rises above 50%, you really shouldn’t ever need to worry about condensation forming and allowing mold to grow or attracting pests. Ideally, the humidity level in your home should always stay somewhere between 35-50%. Anything below 35% is considered too dry and can cause leather on your furniture to crack or any wood in the home to crack or warp.

If you suspect your home is too humid, you can easily measure it with a portable hygrometer which you can pick up cheaply at most any home improvement or hardware store. Another option is to install a smart thermostat, as most of these units can also measure indoor humidity. Many smart thermostats can also be used to control your whole-home dehumidifier, and they also have the added benefit of helping to lower your cooling and heating costs.

At Variable Comfort Solutions, we can help you decide the best option for your home. We offer a complete range of heating and cooling services in addition to indoor air quality solutions. If you’re in the Huntington, WV area, call us today for all your home comfort needs!

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