Best Way To Install Whole House Dehumidifier (HVAC Technicians Use These Methods!)

Tired of that nasty sticky feeling every time you enter the house? Guess, it’s time to get that whole-house dehumidifier rolling.

Maintaining a comfortable home throughout the year should not be complicated. Installing a whole-house dehumidifier can protect your home from the effects of high humidity such as mold build-ups, allergies, and more.

The best way to install a whole-house dehumidifier is to add a “dedicated return to supply” duct into your existing HVAC system so it will completely dehumidify the entire house, with less static pressure, stable dew point, and lesser air conditioning maintenance.

You can do this by asking your trusted HVAC company to install or re-install your unit. Dehumidifiers installed a few years back may have used the older type of installation, but those who have done this recently have already benefitted from this dedicated-return-to-supply method.

It does take a lot of technical background to do such installation and may come at a higher price. But of course, in the name of comfort and healthy indoor quality, you can make wise investments!

I have here a detailed guide on how you can make the most of your whole-house dehumidifier!

Why Do You Need to Install A Whole-House Dehumidifier and Not Just Rely On The Air Conditioning Unit?

Many of my readers are asking me why do they need to install a dehumidifier when they can simply use the air conditioning unit to remove excess air moisture.

Little do they know that there are things that the AC cannot do that the dehumidifier can absolutely fill in!

Although both the air conditioning unit and the dehumidifier remove the extra moisture in the air, dehumidifiers, however, do not cool the room or the house.

In fact, dehumidifiers release warm air back into the indoor atmosphere by around 10-15 degrees. They remove the moisture by reheating the air to further dry it.

Quick Facts About Whole-House Dehumidifiers

It pretty much goes this way, when the humid air in a room enters the dehumidifier, it goes through the cooling coils up to its dew point, which will result in releasing its moisture.

The dried air is transferred into the heating coils with the mixture of potential heat of condensation, which by the way, is a typical result of the process. Apart from the heat generated by the dehumidifying process, you also need to consider the additional heat generated by the unit’s compressor.

Now, going back to the question of why do you need to install a whole-house dehumidifier when you can use the AC, my answer is depending on your humidity needs.

If you are living in Florida, for example, where the relative humidity is at its peak during these times, usually, around May to September, then you probably need to install a whole-house dehumidifier to keep your sanity. Kidding!

Year-round issues with high humidity can cause stress on your health, children, furniture, pets, and the overall house structure.

Remember, you get these benefits upon installing a whole-house dehumidifier:

  • Fresh air ventilation and comfortable air quality
  • Add more value to your home by keeping the overall structure
  • Reducing the workload of the HVAC system, thus extending its lifespan
  • Quiet and mess-free operation since it will be tucked with the HVAC system and out of your sight
  • Easily controlled via remote control settings

The downsides I see so far about installing a whole-house dehumidifier are the cost of the installation, which is quite expensive, ranging from $1000-2000, and you can’t even take the unit with you upon moving.

However, the pros of having this unit installed outweigh the cons, especially when your main goal is to live comfortably.

How to Install a Whole-House Dehumidifier?

Basically, if you have done the installation prior to 2018, whole-house dehumidifiers are simply tied into your HVAC’s existing return duct system. This is called the “return to return” installation type.

The return duct is composed of a network of pipes into which the heated or cooled air goes in and out and through the house.

This return duct is an important element in maintaining balance for efficient heating and cooling condition in each room.

What happens in this kind of installation method is that when the system is running and the AC is off, the dry air accumulates more moisture from the AC's evaporator coil and is then pushed back into your home, causing a lot of static pressure.

For the dehumidifier to be effective in this kind of installation, the unit activates the air handler fan to help move the air throughout the system.

Although this installation method worked in many homes, the dehumidifier will have to work harder and anytime soon, will cause trouble to your entire HVAC system.

I don’t know if you have noticed but with this installation method, the usual report or complaint is the AC and the dehumidifier cannot completely remove high humidity.

This is because both devices are pushed to work hard on the same path or pipes. Fortunately, experts have found an ideal solution to this installation issue.

So, What's the Best Way to Install Your Whole-House Dehumidifier?

Best Way to Install a Whole house Dehumidifier

HVAC experts highly recommend a dedicated “return to supply” type of installation after various testing and troubleshooting.

Although, homeowners are already aware and quite contented with the old method of adding the dehumidifier into the HVAC system, this type of installation is not ideal.

Tying the whole-house dehumidifier onto the HVAC system can actually prevent your dehumidifier and your air conditioner from performing excellently.

The best way to install a whole-house dehumidifier is to create its own pathway that will be connected to the HVAC system.

There are actually two ways that you can do this. Check this out:

Dedicated Return to Supply Installation Method

The dedicated return to supply method is perhaps the best way to install a whole-house dehumidifier because it offers way too many benefits not just for you and your home but to the entire HVAC system as well.

To be specific, the unit will not use the air handler fan that forces the air into the evaporator coils. Instead, the dehumidified air is released directly into the supply.

The conventional method of dehumidifier installation causes high static pressure which lets your unit work harder. What’s great with the “dedicated return to supply” method is that there’s lesser interference between the dehumidifier and the air conditioning unit.

This simply means that you’ll have a more efficient stand-alone dehumidifier that can keep up with the entire HVAC system, although they are somewhat connected.

Coming home will never be the same again once you have done this mode of dehumidifier installation with all the benefits you can actually receive.

The Only Side Effect of this Method is…

The air that is released indoors feels warm. But, that is not a big deal. Dehumidifiers, in fact, really discharge warm air making your fan or the air conditioner more efficient.

Your cooling appliances no longer have to exhaust a lot of energy just to give you your desired coldness. This is not much of a concern, to be honest. You can simply switch on the AC or the electric fan while running the dehumidifier.

With the presence of a dehumidifier, you get the most comfortable indoor environment, especially this season.

To have a better picture of how to best install a whole-house dehumidifier here’s a quick video you can watch:

Notice that in the video, they have elevated the unit using steel hanging bars in the attic and placed a draining pan under.

Dedicated Return to Existing Return Method

There is another method to install the whole-house dehumidifier apart from the return to return and dedicated return to supply methods. Using a “dedicated return to an existing return’ method is also possible.

Your whole-house dehumidifier has its own return pipes attached to the existing HVAC return.

However, this type of installation will still use the air handler fan which will move the dehumidified air throughout your home by pushing the air over the evaporator coil.

Which by the way does not have much benefit as the dedicated return to supply method has. This method is effective in removing excess air moisture but not as promising as the best installation type.

Check out this video on how to install "dedicated return to the existing return" method:

Is it Worth the Cost of Whole-House Dehumidifier Installation?

Before I go ahead and answer this commonly-asked question, let me help you assess your need.

Here are some of the basic bulleted questions you can ask yourself:

  • Do you have humidity problems year-round?
  • Is the humidity issue isolated or is the entire household suffering from high humidity?
  • Have you tried using a portable dehumidifier? If the portable unit did not resolve your humidity needs, maybe you have issues with the size or capacity.
  • How much is your budget?

I do not mean to persuade you into getting a whole-house dehumidifier when in fact, you don’t actually need it. My intention is to right-fit you into the most ideal option.

The issues with high humidity can be expensive if taken for granted over time. Not to mention the health risks it can impose; that is why if you can control and get rid of it anytime soon, then the better.

Here’s a detailed table guide on how much it costs you to have a whole-house dehumidifier and the total cost of your energy consumption.

Unit Cost
Installation Cost
Energy Cost (Per Month)
$1,000 - $2000 (Depending on the brand and features)
$485 - $800 (Depending on the HVAC company)
$6 - $12 (Depending on your city/state)

If you do not have issues with high humidity all-year-round, then you do not need to have a whole-house unit installed. A portable room dehumidifier can resolve seasonal humidity issues.


Installing a whole-house dehumidifier can be life-changing especially when you have been trapped in a high-humid house for so long. Although there are many things that you should consider prior to having one, there is one sole benefit that you should aim for and that is - Fresh air ventilation.

Achieving this is possible by having a properly installed unit. Remember that installation makes a big difference in the overall experience. I hope I was able to give you insights on what is the best way to install a whole-house dehumidifier.

Having a “dedicated return to supply” type of installation will discharge the dry air directly into the HVAC supply, instead of pushing it into the air handler. You can re-install your whole-house unit and follow this set-up.

With this installation, you avoid the necessity to run the air handler fan that causes static pressure on the dehumidifier. It also avoids way too many problems that may occur in the future. Plus, you can save a lot since it won’t hassle your AC in working too much and the air handler fan from pushing the dry air into your home.

The only thing you need to consider is the cost of the installation. Yes, it is expensive but, installation is a technical job so to speak, that is why only professionals or skilled people can install the whole-house unit smoothly. A DIY is possible if you got some excellent background in HVAC installation and troubleshooting. But, I don’t recommend a DIY, unless of course, you are an expert yourself!