Homes in humid climates often require a dehumidifier in addition to your heating, ventilation, and air conditioning (HVAC) system. High relative humidity can encourage the growth of mold and bacteria, cause allergic reactions and respiratory infections, and even damage furniture or your house structure. The main purpose of a dehumidifier is to remove excess moisture from the air and maintain comfortable humidity levels in your home.
Dehumidifiers come in a range of sizes for different types of rooms. But if you want to dehumidify multiple rooms or the entire house at once, this is possible with a whole-house dehumidifier. However, if you go for a whole-home unit, buying and installing it will not be as easy and cheap as a stand-alone portable dehumidifier. The placement of your unit can affect its efficiency and effectiveness and you want to make sure you’re getting the most out of your investment.
Finding the right unit and installing it into your existing HVAC system may seem like a daunting task to do on your own, but you can always hire a professional for the best results. But if you want to save a little on the costs, we’ll guide you with these general steps in whole-house dehumidifier installation.
Why You Need a Whole House Dehumidifier
As mentioned, dehumidifiers come in a variety of sizes and with different features. Using a high-capacity dehumidifier for the whole house will benefit the entire family in many ways.
Adding a whole-house dehumidifier to your HVAC system gives you greater control over the humidity and temperature in all the rooms in your home. For instance, during hot and humid days, your air conditioning may not be as effective in maintaining indoor comfort. While an air conditioner cools down the air, in turn, it also helps reduce the humidity, but only up to a certain level. Too much moisture in the air makes the job a lot harder, leading to faster wear and tear in your AC and even higher cooling bills.
Meanwhile, on cold rainy days, you may not even need to run an air conditioner. Thus, the cold air contains heavy moisture, making the room feel clammy and potentially causing mold growth and dust mites. Running the AC may help reduce the humidity, but since the temperature is lower, it will end the cycle too soon without draining enough moisture.
High relative humidity can be uncomfortable no matter the temperature. Instead of turning up your air conditioner, you can use it together with a dehumidifier to maintain a comfortable humidity level, thereby saving more energy.
A dehumidifier removes moisture and odors for better indoor air quality. It eliminates mold spores, dust mites, and other common allergens in the air. This reduces the risk of allergies, asthma attacks, and other respiratory issues.
Dry air also preserves the structural integrity of your house, especially drywall and hardwood floors that are vulnerable to excess moisture. Maintaining ideal relative humidity levels throughout your home helps prevent condensation, rust, corrosion, and pest infestation.
Finally, unlike portable dehumidifiers, a centralized dehumidifier can cover the entire house through ductwork, providing fresh air ventilation. Although it costs more on your initial purchase, investing in a whole-house dehumidifier saves you money in the long run, as opposed to buying multiple portable units for each room in the house.
How to Install a Whole-House Dehumidifier
Find the Right Size Dehumidifier
When choosing a dehumidifier for the whole house, the most essential feature you must consider is the capacity of the unit. Some factors that determine the right size for your space are the total area and the humidity levels.
Measure the total dimensions of your house and compare it with the unit’s recommended coverage area. Make sure the dehumidifier you choose can cover all the rooms you want to dehumidify. Whole-house dehumidifiers typically range from 70 pints up to 200 pints in capacity, which can cover anywhere from 1,800 to 6,000 square feet total area.
Pick Installation Method
You have two options for installation: hire a professional HVAC technician or do it yourself. Professional installation is always recommended to make sure everything is done properly, but DIYers with the right set of tools can also do this task with minimal difficulty. Professional installation may cost at least $500 up to $1,000, while a DIY job will cost around $600 for the tools you may not already have.
Whichever you choose, the process follows more or less the same steps. However, note that your manufacturer may not honor the warranty if the unit is not installed by a licensed HVAC contractor. Check the product warranty guide before anything else.
Choose Location to Install Whole-House Dehumidifier
A whole-house dehumidifier can be connected to your existing HVAC ductwork to control indoor humidity throughout the entire house, working together with your central heater or furnace and air conditioning unit The best way to install this type of dehumidifier is by adding a dedicated return duct that sends the air from the rooms into the unit. You may also attach the unit to an existing return duct. Connect the dehumidifier to your HVAC supply plenum to send the dehumidified air back to the main air stream released to your rooms.
There must be a dedicated HVAC closet for all your equipment and ducting. This can be in your basement or in the narrow space between your floor and the ground called the crawl space. Manufacturers design compact, horizontal dehumidifiers especially for this purpose.
Set Up a Drainage Method
Most residential dehumidifiers offer an option for continuous draining via gravity. This is a useful feature if you don’t want to have to check the unit multiple times a day, especially if it’s in an inconvenient location like a crawl space or basement. One possible downside with this is that you need the unit near a sink or drain. Gravity drainage will only work if the unit is placed higher than the drain. For this reason, you can elevate the unit with risers or simply pieces of wood or metal.
Some high-capacity dehumidifiers also come with an internal pump that automatically pushes out the condensate. You can have the drain hose run up to a window to release the water out of a basement window or to your sump pump. For whole-house dehumidifiers without this feature, you can purchase an external condensate pump. Dehumidifier brands like Aprilaire and Santa Fe offer condensate pumps for specific models. Typically, the pump can release water up to 15 feet high.
Select the Humidity Level
After setting up your dehumidifier, you can input your desired humidity level on the unit’s panel or through a remote humidistat. The ideal range of indoor humidity levels is from 35% and 45% RH. Anything below 30% is considered too dry, and above 50% is too humid. Depending on the ambient temperature, you may adjust the level accordingly.
Maintenance for Whole-House Dehumidifiers
Whole-home dehumidifiers usually require little maintenance, but it always helps to take extra care for your appliance. First, make sure to follow the manual as the manufacturer gives you all the instructions for installing, using, and maintaining the unit.
Dehumidifiers come with a filter that protects the machine and its components from dust and other particles in the air. For every model, there is a recommended period after which the filter must be cleaned or replaced. You should also check on other components and clean them from dust or grime. Simply wipe them down with a damp cloth, then vacuum the inside if possible. The coils must also be cleaned at least once a year. You’ll need a professional cleaning service for this.
Most dehumidifiers work best in warm temperatures around 59-86°F unless specifically designed for colder conditions. When the temperature drops to 41°F or below, the unit will automatically defrost, but you should also check for frost to be sure. Operating your dehumidifier in cool conditions may sometimes cause ice to build up inside the machine. This can compromise the unit’s performance and even cause permanent damage.
Best Whole-House Dehumidifiers
Capacity: 100 PPD
Coverage: 5,500 sq. ft.
Dimensions: 34 x 15.42 x 17.1 inches
Weight: 64 lbs.
Aprilaire offers a range of commercial dehumidifiers for crawl spaces and whole-home applications. The Aprilaire E Series offers a wide range of energy-efficient dehumidifiers.
The E100 is granted the Energy Star Most Efficient certification, with an IEF of 2.35L/kWh, removing up to 100 pints of moisture per day.
With a 265 CFM airflow, this whole-house dehumidifier can cover an area of up to 5,500 square feet. It operates from 41°F to 104°F with automatic defrost to prevent ice buildup. One downside is it doesn’t come with a built-in pump, but if you really need this functionality, Aprilaire offers an external condensate pump.
Capacity: 90 PPD
Coverage: 2,600 sq. ft.
Dimensions: 24.8 x 13.78 x 15.75 inches
Weight: 57.2 lbs.
AlorAir is also a known brand of efficient crawl space dehumidifiers. One of them is the AlorAir Sentinel HDi90. This powerful and efficient dehumidifier is Energy Star certified with an impressive energy factor of 2.69L/kWh.
It removes up to 90 PPD on average conditions, and 198 PPD at saturation. With an airflow rate of 210 CFM, it can cover a 2,600 square feet area. It also comes with a built-in condensate pump.
Capacity: 98 PPD
Coverage: 2,300 sq. ft.
Dimensions: 19.5 x 32.375 x 14.5 inches
Weight: 81 lbs.
Another top dehumidifier for crawl spaces is the Santa Fe Ultra98 (formerly Ultra Aire). Although this powerful dehumidifier is not Energy Star certified, it comes with a decent energy factor of 2.95L/kWh.
It can remove 98 pints of moisture per day from whole homes up to 2,300 square feet. This unit processes air at a maximum 320 CFM and operates effectively down to 49F. One drawback is it doesn’t come with a built-in pump.
The right whole-house dehumidifier can go a long way in preserving the structure of your house and improving the air quality for everyone’s health and comfort. Whole-house dehumidifiers can cost anywhere from $1,000 up to $3,000 or more, depending on the brand and capacity. Professional installation will add at least $500 to $1,000 to your expenses, plus other tools you will need.
Once you find the right unit for your home, it’s highly recommended to hire a licensed HVAC technician when installing your dehumidifier to ensure it’s done properly and you can consult them in case any issue occurs.