Do You Need A Dehumidifier For HVAC System Or Furnace?

There are a few types of dehumidifiers. Rather than using a portable dehumidifier in each room, you can opt for installing a dehumidifier for the HVAC system or furnace in some cases. 

This guide will go over the important information you need to know about HVAC dehumidifiers, like their pros and cons, so you can decide whether or not you need them.

What is an HVAC dehumidifier?

An HVAC dehumidifier refers to a dehumidifier that is attached to the HVAC system. It is also known as a whole-house dehumidifier and furnace dehumidifier. 

By removing the water vapor that circulates in the HVAC system, it can lower the humidity level in your entire house. 

Most whole-home dehumidifiers are compressor models, which draw excess moisture from the air through a chilled coil.

When the air passes through the coil, the water vapor will condensate on the coil due to the low temperature. The condensate will get into the water bucket or drain outside. 

Do furnaces come with dehumidifiers?

No, furnaces don’t come with dehumidifiers by default. Before installing the HVAC system, you should discuss with your HVAC company whether you want a furnace with a dehumidifier.

Luckily, later installing a dehumidifier on your original HVAC system is also pretty easy. By adding dedicated return ductwork to the supply, the dry air produced by it will get into your house. 

While it is not as complicated as installing an HVAC system, you should hire a pro to do it if you don’t have the expertise in the field. 

Pros of using a whole-house dehumidifier 

Now that you know you can add an HVAC dehumidifier whenever you want, it’s time to decide whether you really need one. Knowing the advantages and disadvantages is critical for making the best decision.

Let’s take a look at the advantages first. 

Control mold growth

Mold and mildew thrive in humid environments. Mold spores, when inhaled, can cause a variety of respiratory problems, including congestion, difficulty breathing, and even asthma attacks.

By running a furnace dehumidifier, the humidity level of your entire house can keep at a proper level, keeping the mold at bay. 

Reduce dust mite

Dust mites are another pollutant that thrives in spaces with high humidity. Likewise, dust mites can cause allergic reactions, posing health risks to many people. 

Improve comfort 

Most of us don’t feel comfortable in a space with clammy air. For example, we don’t like to spend too much time in the basement because it’s usually the most humid place in the house.

Turning on an HVAC dehumidifier will help to solve this problem. You will feel great regardless of which room you want to go to because it sends out air dry to every room of your house.

Protect furniture and structural integrity

Wood can absorb moisture in the air, and people like to use wooden furniture at home. 

When furniture is exposed to moist air for an extended period of time, it swells and warps. Wet stains will also appear on the surface.

In addition, the wood rot fungus will proliferate and eat wood, affecting the structural integrity gradually. 

A whole-house dehumidifier can keep wood furniture in good condition and prevent the growth of harmful fungi.

Save cooling cost 

The dehumidifier can make you feel cool by lowering the humidity level because the sweat can evaporate faster in dry air, which will take away the heat during the process. 

Accordingly, you may not need to turn on the air conditioner so early in the summer, saving cooling costs in the long run. 

Cons of using a whole-house dehumidifier 

Do you feel excited about the benefits of a whole-house dehumidifier you can reap? Calm down! There are some potential disadvantages you need to keep in mind. 

High upfront cost 

If you are tight on budget, purchasing an HVAC dehumidifier may not be a good idea. The cost of a whole-house dehumidifier is much higher than a portable dehumidifier. 

It will cost you at least a thousand dollars, if not a few thousand dollars.

Increased electricity charge

In general, dehumidifiers are not appliances that use a lot of electricity. However, a whole-house model can leave a noticeable impression on the electricity bill with time since it is responsible for collecting excess water in your house. 

Do you need to install a dehumidifier if your HVAC system has central AC? 

do you need a dehumidifier if hvac system has central ac

The answer to this question is it depends. 

Central air conditioners, as you may be aware, have a dehumidifying function that can remove moisture while operating. It is not, however, as effective as a dehumidifier.

Therefore, for those who live in a relatively dry climate and only need to combat moisture issues in summer, you may not need to install an HVAC dehumidifier. That is, running a central AC is adequate to remove the excess moisture in the room. 

However, if you live in a very humid area where the air is still musty and clammy in the spring, fall, and winter, installing a dehumidifier is necessary because running a central AC to dehumidify the air during these seasons is expensive and will make you feel cold.

Sometimes, the room is humid when the AC is on. It could be because the AC is too small to handle such a large number of water droplets.

This will also occur if the AC is oversized because it can quickly lower the temperature and shut off without having enough time to draw moisture from the air.

In this case, running a furnace dehumidifier together will help with improving comfort. 

Conclusion: do you need an HVAC dehumidifier?

HVAC dehumidifiers can improve overall comfort in your home, protect furniture, and keep mold and dust mites at bay. It is not, however, a must-have for everyone.

A stand-alone dehumidifier is much more affordable for those on a tight budget. Furthermore, if only the basement or attic has moisture issues, a whole-house dehumidifier is not required.

If you live in a very humid climate, you will need an HVAC dehumidifier because it can make you feel much better all year without having to turn on the air conditioner.

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Liz Yang is the founder of Airsmartly. She has been working at home for a few years and realizes that the performance of the HVAC system plays such an important role in our life. She has tested a lot of products in person, like humidifiers, air purifiers, dehumidifiers, and ACs, and wants to share tips about using or troubleshooting these products with you. Her uncle is an HVAC expert with over 30 years of experience in the field, and often offers assistance when she is unsure how to handle a situation. He is also in charge of reviewing the articles on this site.

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