Whole House Dehumidifiers – Should You Buy One and How Much Do They Cost

If the inside of your home feels damp, you might be looking for ways to reduce its humidity. Humidity is the amount of water vapor in the air; you’ll usually measure it as relative humidity (for example, 50% RH). 

Warmer air can hold more water vapor than cooler air; the amount of water vapor it can hold is relative to the air temperature (hence the name relative humidity). This means you may have excessive indoor humidity levels in the summer as your air conditioner or heat pump cools down hot, humid air. 

Air conditioners and heat pumps are capable of dehumidifying the air, but they have limitations. If you live in an area with high average humidity levels, dehumidifiers are usually a necessary option.

This guide covers the basics of whole house dehumidifiers, when you would need one, how much they cost, and much more. For detailed answers to all of your dehumidifier questions, continue reading. 

whole house dehumidifier

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What is a Whole House Dehumidifier?

A whole-house dehumidifier lowers the humidity levels in the entire house. It connects to your central HVAC system, which means all the air that blows through your ductwork passes through the whole house dehumidifier first. 

How Do Dehumidifiers Work? 

While central air conditioners dehumidify the air, they are not the same thing as whole-house dehumidifiers. However, these devices work similarly. 
Before we explain how they work, let’s cover what condensation is first– the moisture that appears when warm air cools rapidly is condensation. 

When air cools, its extra moisture condenses into liquid water. A good example is water condensing on the outside of a cold beverage. This happens because warmer air can carry more moisture than cold air. And when the air temperature drops, the extra water vapor drops back into a liquid state on the cooler surface. 

When air conditioners cool your home, they also dehumidify it! And as you might suspect, it is because of condensation. 

A picture of showing how a dehumidifier works
A portable refrigerant dehumidifier

When the refrigerant-filled cooling coils inside AC units remove heat from the air, moisture in the air condenses onto the coils. The water drips from the coils into the condensate drip pan and drains outdoors or into a sump pit.  

The cooled air blows throughout your home. At the same time, the refrigerant within the cooling coils (which removed heat from your air) travels to the outdoor unit of the air conditioning system. The outdoor unit, or condenser, expels the heat to the outdoors. 

Whole-house dehumidifiers work the same way as air conditioners and use many of the same internal components. They cool air, water condenses, and collect the moisture in a reservoir (or it flows into a drain). 

However, they have one BIG difference. Instead of expelling heat outdoors, dehumidifiers add the heat back to the air. 

In summary, AC units and dehumidifiers use the same process with these key differences:

  • Air conditioners remove heat and dehumidify
  • Dehumidifiers dehumidify but don’t lower the temperature in the home

Whole-House vs. Portable Dehumidifier

a woman removing the water tank of a portable dehumidifier

Whole-house dehumidifiers are permanent installs that connect directly to the ducts of your HVAC system. They sit near your central AC unit and furnace (or heat pump) and drain outdoors or in a sump pit. They’re the most convenient option for lowering the humidity in your entire house. 

Note: A whole-house dehumidifier removes moisture from all of the air circulating through your HVAC system. On the other hand, portable dehumidifiers only remove moisture from the air immediately around it. 

Portable dehumidifiers are also more affordable but have limited dehumidification capabilities compared to a whole-house unit. But they are convenient to use since you can quickly move them between rooms. You should, however, have to empty its water reservoir frequently (especially in very humid conditions). Also, there are different ways to effectively use a dehumidifier. 

Who Needs a Whole House Dehumidifier?

a repairman fixing a HVAC ac unit

Homeowners that are experiencing high levels of indoor humidity could benefit from a whole-house dehumidifier because it effectively eliminates the clammy air in your home. 

But before your spring on a new whole-house dehumidifier, make sure your AC unit is working fine first. If it is removing adequate moisture but not sufficient amounts, then consider a dehumidifier. 

Usually, homeowners that live in humid climate zones use whole-house dehumidifiers in tandem with their AC units. 

Note: Homes in regions like most of the southwest U.S. don’t need extra dehumidification since the air is already dry. 

Additionally, most of the midwest and the northeast states have mild humidity levels that don’t require extra dehumidification. 

Sure, these regions are more humid than the Mojave Desert in California. However, most air conditioners in these regions with moderate humidity can remove enough moisture to keep your home comfortable without the help of a supplemental dehumidifier.  

Symptoms of High Humidity in Your Home

mold and mildew build-up on the wall

Perhaps you’re not sure if your home would benefit from a whole-house dehumidifier. In that case, it is helpful to understand the signs and symptoms of high humidity levels in your home. 

Here are the most common symptoms of  high indoor humidity: 

  • Moist air – a consistent, wet, and clammy feeling is a key indicator of high humidity
  • You feel hotter than usual – high humidity levels make the air feel hotter than the temperature on your thermostat
  • Condensation on your windows – condensation comes from the excess moisture in your air
  • Condensation on air ducts – your AC unit cools down your ductwork’s metal shell, which moisture will condense on; this is problematic if water condenses on ducts within your walls (hello mold!)
  • Mold – black mold spreads throughout humid environments
  • Mildew odors – similar to mold, mildew thrives in humid conditions
  • Respiratory symptoms – humid air carries pollen, mold spores, and other pathogens which can irritate and infect your respiratory system 
  • Wood rot and warping – Excessive moisture on wood furniture and the wood structure of your home could lead to rotting or wrapping

The easiest way to identify high humidity levels in your home is with an indoor humidity gauge (hygrometer). Hydrometers measure and display the air temperature and relative humidity of the air around them. The ideal indoor relative humidity levels are between 30% to 50% RH, according to the U.S. Environmental Protection Agency (EPA).

The Pros and Cons of Whole House Dehumidifiers

Typically whole-house dehumidifiers are great additions to homes experiencing high levels of humidity. However, they do have some downsides too. Here are the main pros and cons of whole-house dehumidifiers. 

Pros

More Home Comfort

When the air in your home is less humid, it feels cooler. The reason is humid air transfers heat to you better, plus it inhibits your body’s evaporative cooling process. Both of these qualities make you feel warmer in high humidity. 

Note: Most people find indoor air humidity most comfortable at 30% to 50% RH. 

The same air temperatures at different relative humidities feeling hotter or cooler is the reason many weather forecasts have a “real feel,” “feels like,” or “heat index” temperature in their forecasts. This is because these weather reporters know the importance of relative humidity and its relationship to temperature!

Better Indoor Air Quality 

Besides decreasing your humidity, dehumidifiers also filter out some dust and pollen too. Additionally, the lower humidity level inhibits the growth of mildew and mold in your home. Mold and mildew not only smell gross, but they irritate your respiratory tract too. In some cases, a mold infection can lead to severe illnesses. 

Cleaner Windows

Since dehumidifiers keep the humidity in your home at adequate levels, it is very unlikely you’ll have condensation on your windows. Condensation can cause streaks and smudges, and when dust settles onto the wet drops, it will become dirty fast. 

As such, if you keep condensation at bay, your home’s windows will stay clean. 

Less Strain on Your AC Unit

Whole-house dehumidifiers take the load off central AC units. This is because the dehumidifier is collecting water that would otherwise overwhelm your air conditioner. 

Therefore, the condensate drain system, including the drain line and condensate pump, operates less often and has a longer service life.  

Cons

More Components & Maintenance 

A whole-house dehumidifier is yet another appliance that you will have to maintain. For the most part, dehumidifiers require minimal maintenance. 

Risk of Leaks 

Whole-house dehumidifiers collect water. In very humid areas, this can be a lot more water than you expect– in some cases, over 10 gallons a day. If your drainage system fails or develops a clog, your home can quickly get water damage. 

Cost

Like most good things, whole-house dehumidifiers are not free. They cost a decent chunk of change, which we’ll get into shortly. Along with their upfront cost, whole-house dehumidifiers have energy and maintenance costs homeowners should factor into their budgets too. 

What Does a Whole-House Dehumidifier Cost?

an electrician installing a whole house dehumidifier

On average, a whole-house dehumidifier costs $1,000 to $3,000, including installation. The price varies mostly depending on the size of your home and the local labor rates. 

For average-sized homes (about 1,500 to 2,200 square feet), dehumidifiers cost $1,750 on average. Dehumidifiers for larger homes above 2,200 square feet have average costs of around $2,750.

The size of the whole-house dehumidifier directly correlates to the size of the home. Smaller homes need less capacity; usually, a 70 pint per day unit is sufficient. For larger homes, we recommend 80 pint or larger dehumidifiers. 

House Size (sq ft)Water Removal (Pints Per Day)Average Unit & Install CostAverage Energy CostMaintenance Costs
Up to 2,20070$1,000$15/month$50/year
2,200 – 4,40080$1,750$20/month$50/year
4,400 – 5,500100$2,500$25/month$75/year
5,500 – 7,200130$3,000$30/month$75/year

Ways to Save Money on a Whole-House Dehumidifier

You can save money on whole-house dehumidifiers by using the following suggestions: 

  • Manufacturer rebates 
  • Rebates from your utility company
  • DIY installation 
  • Find an HVAC installer with a competitive rate
  • Purchase an ENERGY STAR certified system to minimize energy costs

Is an HVAC Dehumidifier Worth The Cost? 

Yes, an HVAC dehumidifier is worth the cost. Whole-house units prevent mold growth, wood rot, and warping. They also provide better indoor air quality and take some strain off of your air conditioner. 

If you were to rely solely on your AC unit to dehumidify your home, you’d face a substantial energy bill every month and an increased risk of equipment failure. 

Recommended HVAC Dehumidifier Brands

Deciding which brand of whole-house dehumidifier is suitable for your home can be overwhelming. With dozens of brands and hundreds of models, it can seem impossible to make a decision. 

That is why we put together our recommendations below on the best whole-house dehumidifier brands and models around:

If whole-house dehumidifiers are too expensive for you or you just want to dehumidify a small area, consider these tremendous portable dehumidifiers: 

If you want to maintain the ideal humidity level in your basement, we suggest reading our best dehumidifiers for basements guide. 

Whole-House Dehumidifiers – Are They Really Needed?   

Whole-house dehumidifiers efficiently remove excess moisture from the air in your home. They supplement your air conditioner’s dehumidification process and are very useful in climates with high humidity. Dehumidification is necessary to maintain ideal indoor air quality, prevent mold and mildew, and prevent wood rot damage to your home and furniture. 

If you’re on the fence on whether or not you need a dehumidifier, purchase a hygrometer and monitor the RH levels in your home. If you’re consistently over 50 or 60% RH, you’ll definitely benefit from a whole-house dehumidifier. 

About The Author

Jonathon is a mechanical engineer with over ten years of experience in the HVAC industry. He has hands-on experience with all types of HVAC systems.

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