Heating & Cooling, Home Inspection

Should You Install a Whole House Humidifier on Your Heat Pump (Explained)

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Hubert Miles

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If the air inside your home is considerably dry, a humidifier is crucial to a comfortable interior living space. A whole-house humidifier becomes even more convenient if you have a heat pump. But there’s more to heat pumps and humidifiers than their functions.

To reach the ideal humidity level inside your home, you can install a whole-house humidifier on a ducted heat pump. A steam humidifier works best with an air-sourced heat pump. When installing a whole-house humidifier, you should consider the following:

  1. If you have a dual-fuel heat pump system where gas heat is utilized during winter months, a whole-house humidifer is highly recommended. The colder the outdoor temperatures the drier the air will become.
  2. If you live in an arid climate such as in the mid-west states where annual rainfall levels are low, a whole house humidifer is highly recommended.
  3. If you live in a moderate climate with sufficient annual rainfall, (such as the southern states) the money spent on a whole-house humidifer would be better suited in making your home more air-tight so the heat pump performance improves.

You can not use a whole-house humidifier with a ductless mini-split heat pump as no air ducts connect the whole house humidifier.

I found it interesting how these two home devices work together, so I did some comprehensive research about it. Here’s everything I learned about whole-house humidifiers and heat pumps:

Can You Put a Humidifier on a Heat Pump?

You can put a humidifier on a heat pump. Regulating the humidity will relieve dry and itchy skin, avoid a sore throat or cough to dry air, and prevent wood flooring and furniture damage. Automatic humidifiers will even adjust the humidity in your house according to the temperature. 

However, there are also some drawbacks to putting a humidifier on a heat pump. Manual humidifiers add uncontrolled humidity to your house. As a result, their settings have to be changed hours in advance. To avoid uncontrolled and uncomfortable indoor humidity, you will have to keep up with current weather patterns. We recommend the Aprilaire 800Z 800 Whole Home Steam Humidifier available at Amazon.

Follow these steps to install a humidifier on a heat pump:

  • Turn off your furnace
  • Using a steel cutter, cut a hole the size of the humidifier on the furnace
  • Set the humidifier on the opening, and use four self-tapping screws at the corners to secure the humidifier
  • Connect the furnace exhaust with the humidifier intake with a supply line
  • Connect the water to the humidifier then turn the water on
  • If you are using the humidifier on the intake line, connect the valve on the right to your furnace
  • Place the humidistat on the heat pump and connect power to it from the humidifier
  • You can add a pressure sensor by putting it into the furnace air exhaust and into the humidifier 

Do You Need a Humidifier with a Heat Pump?

The humidity level in your house should be around 30 to 60 percent. You should have no clammy skin, dry eyes, and static electricity while being comfortable. If your home is too humid, you could smell a musty odor, or there might be condensation on the window panes, which is why many people are considering getting a dehumidifier.

There are two schools of thought on this. The first one says that you don’t need a humidifier. You don’t need a dehumidifier because heat pumps already have a dehumidifying effect. Heat pumps dehumidify the air as it lowers the temperature. Many say this leads to better results than a fan or evaporative cooler. 

The second school of thought says that heat pumps only dehumidify when they reduce the temperature. Crawlspaces and unvented rooms can gather excess humidity on an exceptionally mild day. Since these rooms will not dehumidify themselves, you may need to:

  • Improve ventilation in this area
  • add a dehumidifier

Still undecided on getting a humidifier with a heat pump? Here are pros and cons to consider:


  • Creates better indoor comfort during the winter
  • Will humidify your entire home
  • Can be controlled from thermostat
  • Are reliable when properly maintained


  • More expensive than portable humidifiers
  • Can create mold when not installed correctly
  • You can’t take a whole-house dehumidifier with you when you move
  • Requires professional installation
  • Requires more routine maintenance

Whole-house humidifiers have been used for decades to add humidity where none exists, and some even use their humidifiers year-round. Despite the commonality of using a whole-house humidifier, there is still some controversy about whether it is better to run a whole-house humidifier or not. We will explore the advantages and disadvantages of running a whole-house humidifier below.

Advantages of Running a Whole House Humidifer

An adequately installed whole-house humidifier can be a worthwhile addition to your home.

A whole-home humidifier adds moisture to dry indoor air, preventing dryness in your throat and sinuses and helping prevent illnesses such as colds, cases of flu, and allergies. By adding moisture to the air you also add more water vapor. The added water vapor helps fight against respiratory issues such as dry and sore throats, colds, and flu cases.

A humidifier can also help with skin conditions such as eczema by adding moisture to the air. It can improve indoor air quality by assisting your air filters in reducing air-borne particles. It can also make your home feel more comfortable overall.

Whole-house humidifiers that have automatic settings can be controlled and regulated by smart thermostats like Nest or ecobee. Additional work is required to do this, which will generate better performance from your humidifier. The thermostat can raise and lower the output based on the outside temperature and relative humidity.

In addition, a whole-home humidifier helps protect wood flooring and furniture from cracking or splitting by maintaining humidity in your house.

Disadvantages of Running a Whole House Humidifier

Studies show that over half of all houses in America have a problem with excess humidity levels.

An example of excess humidity is condensation inside the home, causing health issues such as mold or mildew growth on walls, ceilings, basements, attics, and areas where moisture builds up and forms condensation.

Mold in houses can be potentially harmful to people, particularly those who suffer from asthma or allergies. However, no one is immune to mold, and excess mold can make all occupants sick if not managed.

While a whole-house humidifier adds moisture into the air, it also causes your home’s humidity to rise. When this happens, you must ventilate your house somehow, such as opening a window to let out the excess moisture. Air-tight homes may also need a fresh air exchanger to help manage and prevent the buildup of excess humidity.

Excess humidity in homes with whole-house humidity is likely caused by not installing the unit correctly and not setting up the outdoor sensor to the humidity control panel.

As Reuben Saltzman states in the above video, the root cause of most problems with whole-house humidifiers is that most homeowners don’t go through the hassle of adjusting manually adjusting the humidifier based on the outdoor temperature.

While it is beneficial for a humidifier to run throughout the year and add moisture into the dry winter air, some dangers come with adding too much water vapor into the environment. If you decide on running a whole-house humidifier, make sure you or your installer puts in the outdoor sensor connected to the humidity control panel.

It might be wise to research how much humidity should be in your home and get advice from someone who can help or guide you through this process. You must remember that these systems require upkeep and maintenance; otherwise, they can leak or spill water into your home.

Final Thoughts

When the heat comes on in the winter, the air inside your house tends to become very dry. Fortunately, a whole-house humidifier can solve this problem since it will keep the moisture under control. The main drawback to manual whole house humidifiers is that they will constantly humidify to saturation. Unless you want to continually change the humidistat almost daily at certain times of the year, it is best to get a smart whole-house humidifier. 

If you’re still unsure what you need to do, we recommend tracking daily humidity levels in your home for one calendar year.

If you see humidity levels below 30% on the majority of the days, talk with a professional about installing a whole-house humidifier.

If you see humidity levels higher than 60% the majority of the days, you may need to improve your ventilation or install a dehumidifier to help reduce humidity in your home.

Photo of author

Hubert Miles

I've been conducting professional home inspections since 2002. I'm a licensed Home Inspector, Certified Professional Inspector (CPI), Certified Master Inspector (CMI), and FHA 203k Consultant. I started HomeInspectionInsider.com to help people better understand the home inspection process and answer questions about homeownership and home maintenance.
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