If you live in a particularly dry climate, then a humidifier might benefit your family and your home. When humidity levels dip to extreme lows during the cooler months, however, the standard portable humidifier might not cut it anymore. This is where whole house furnace humidifiers come in.

Unlike portable humidifiers which are designed to cover smaller areas like individual rooms, furnace humidifiers are able to single-handedly service entire residences. Furnace humidifiers were designed to be attached to your home’s central HVAC system so that everyone in your home gets to enjoy the benefits of refreshing, moisturized air.

If furnace humidifiers are what you need, then you’ve come to the right place! In this article, we’ll be discussing the best furnace humidifiers that are available in the market today to help you make an informed decision when you’re ready to purchase.

  • Evaporative whole house humidifier
  • Water-saving, drain-free
  • Covers up to 4,000 sq. ft.
  • 17-gallon daily humidity output
  • Dual sensor 24/7 auto aode
  • 5-year warranty

  • Evaporative whole house humidifier
  • Covers up to 4,200 sq. ft.
  • 18-gallon daily humidity output
  • Manual humidity control
  • Convenient digital control
  • 5-year warranty

  • Evaporative whole house humidifier
  • Covers up to 2,800 sq. ft.
  • 17-gallon daily humidity output
  • Manual and automatic humidity control with digital humidistat
  • Patented KineticFlo water distribution system
  • 10-year warranty

  • Steam whole house humidifier
  • Covers up to 6,000 sq. ft.
  • 25-35 gallon daily humidity output
  • Digital automatic humidistat
  • Multiple installation options
  • 5-year warranty

  • Evaporative whole house drum humidifier
  • Covers up to 4,000 sq. ft.
  • 17-gallon daily humidity output
  • Flexible installment
  • 1-year warranty

  • Evaporative whole house fan-powered humidifier
  • Covers up to 4,500 sq. ft.
  • 18-gallon daily humidity output
  • Automatic humidity control
  • PerfectFLO water distribution tray
  • 1-year warranty


Th 400 Drainless Bypass Humidifier is our favorite Aprilaire whole house humidifier on the market today. This bypass in-duct humidifier works concurrently with your existing HVAC system to deliver humidified air throughout your home. It is capable of servicing homes up to 4,000 sq. ft. in size and has a daily humidity output of 17 gallons.

Because the 400 features a special drainless system, it costs a little more than the other Aprilaire  whole house humidifiers upfront. Long-term costs also remain a little high because its special water-conserving panel needs to be replaced at least twice a year on average, which is more frequently than regular water panels.

The Aprilaire 400 allows you to cut back on water consumption, though, in the long run. Thanks to its water-conserving panel, this model is able to use up to 100% of the water fed into the system. On top of all these, you get a powerful, energy efficient whole house humidifier with an array of useful features as well as automatic humidity control so you can set it and forget it.

Pros

  • Large residential coverage
  • High daily humidity output
  • Automatic humidity control
  • Drainless feature and special water panel minimizes water use
  • No standing water
  • Easy maintenance
  • Long warranty

Cons

  • Expensive
  • Professional installation needed
  • Water panel needs more frequent changing by a professional

Another favorite from Aprilaire is the 700 Whole House Fan-Powered Humidifier. This is Aprilaire’s most powerful whole house furnace humidifier available and is rated to cover up to 4,200 sq. ft. of space and pump out 18 gallons of moisture per day. The fan in this type of humidifier allows it to speed up the evaporation process as well as cover larger spaces as opposed to fanless ones.

Unfortunately, this much power comes with a pretty hefty price tag. In addition to upfront costs, you’ll also need to set aside a budget to have this installed by a professional, and you’ll also need to factor in the cost to replace the water panel twice a year at most.

Overall, though, the 700 is an excellent choice for anyone looking to cover larger homes. It requires very little space for installation and will run very quietly despite the powerful fan. It offers automatic humidity control and is relatively low maintenance. Backed by a 5-year warranty, you can rest assured that this will take care of any issues your home may have with dry air.

Pros

  • Large residential coverage
  • High daily humidity output
  • Automatic humidity control
  • Whisper quiet
  • Relatively low maintenance
  • Good for small spaces
  • Fan allows for increased evaporation
  • Connects directly to a water line
  • Long warranty

Cons

  • Expensive
  • Professional installation needed
  • Water panel needs to be changed once or twice a year by a professional

The GeneralAire 900A is part of the Elite Flow Through series and is also fan-powered like the Aprilaire 700 above. Unlike the 700, however, the 900A is capable of covering a considerably smaller space up to 2,800 sq. ft. size. Because it’s fan-powered, the 900A is still capable of producing up to 17 gallons of moisture per day.

The biggest problem with this unit is that it is so expensive despite having below average specifications. As with most furnace humidifiers, the 900A will also need to be installed by a licensed professional. The vapor pad — which is what GeneralAire calls their water panel — will also need to be replaced annually.

Nevertheless, with the GeneralAire 900A, you’re getting a high quality device. While it may not be as powerful as the Aprilaire models, but you’re getting twice as long a warranty period with GeneralAire as well as optional manual or automatic control. It’s energy efficient as well and is easy to maintain. Additionally, with this model you get GenerAire’s Patented KineticFlo water distribution system, which ensures even distribution of water across the vapor pad.

Pros

  • High daily humidity output
  • With Patented KineticFlo water distribution system
  • With manual and automatic humidistat
  • Optional automatic humidity control
  • Easy to install and maintain
  • Energy efficient
  • Long warranty

Cons

  • Expensive
  • Coverage area is not as large as with other brands
  • Needs to be installed by a professional
  • Vapor pad needs to be replaced annually

If you don’t mind spending an arm and a leg on a steam humidifier, you might want to consider the GeneralAire RS25 Elite Steam Humidifier. This model is a monster of a device fully capable of covering extremely large homes up to 6,000 sq. ft. It can pump out up to 35 gallons per day, which is probably one of the highest daily outputs on the market today.

As previously mentioned, the RS25 is grossly expensive, and a lot of homeowners may steer clear of it purely based on its price. In addition to the upfront costs, you’ll need to shell out cash to have it installed by a licensed professional. Its steam cylinder also needs to be replaced annually by a licensed professional, too.

With all things considered, the RS25 is definitely an extravagant purchase. It definitely makes up for it, however, in performance, durability, convenience, and quality. It’s backed by a reassuring 5-year warranty so you know GeneralAire stands by their product.

Pros

  • Large coverage area
  • High daily humidity output
  • Integrated smart monitoring drain pump assembly
  • Multiple installation options
  • Manual and automatic humidistat
  • Automatic humidity control
  • Automatic flush with inactivity
  • Maintenance indicator
  • Long warranty

Cons

  • Very expensive
  • Needs to be installed by a professional
  • Steam cylinder needs to be replaced annually by a licensed contractor


Honeywell is famous for a lot of home appliances such as air purifiers and humidifiers. Admittedly, their furnace humidifiers aren’t as popular as their other products, but the HE120A is priced competitively enough for us to give it a chance. It’s rated to cover 4,000 sq. ft. of space and has a daily humidity output of up to 17 gallons per day.

Unfortunately, the HE120A is only backed by a 1-year warranty which often isn’t a good sign, especially considering the durability issues that come with this model. Aside from those issues, the HE120A only offers manual humidity control. Its evaporation pad needs to be replaced annually, too.

What makes the HE120A so great, however, is that it’s a simple enough device that you don’t need a professional to install it for you. The model installs easily with the installation kit and instructional videos provided with the unit. Aside from easy and flexible installation, the HE120A is affordable and easy to maintain.

Pros

  • Affordable
  • Large coverage area
  • High daily humidity output
  • Professional installation not required
  • Flexible and simple installment
  • Two drain options (floor drain or no drain)
  • Low maintenance

Cons

  • Short warranty
  • Durability issues
  • Manual humidity control
  • Evaporation pad needs to be replaced annually

The HE360A is another furnace humidifier from Honeywell that’s rated to cover up to 4,500 sq. ft. and a daily humidity output of 18 gallons per day. The HE360A is a flow-through humidifier that doesn’t need any bypass ducting. Because it comes with its own installation kit, you can install it yourself.

Like the HE120A, however, the HE360A is backed by a measly 1-year warranty. On top of this, several users have complained of durability issues with it, along with complaints regarding the frequency with which they had to replace the humidifier’s evaporation pad.

Overall, the HE360A is a straightforward enough device with a humidistat that allows you to either set your desired humidity level manually or automatically depending on the surrounding environment. The PerfectFLO water distribution system is big plus, too, and ensures that water is evenly distributed throughout the humidifier’s evaporation pad.

Pros

  • Large coverage area
  • High daily humidity output
  • PerfectFLO water distribution system
  • Professional installation not required
  • Automatic or manual humidity control
  • Low maintenance

Cons

  • Expensive
  • Short warranty
  • Durability issues
  • Evaporation pad needs to be replaced frequently

Whole House Furnace Humidifier Buyer’s Guide


Why You Need a Furnace Humidifier

Standard portable humidifiers are usually enough for most people, but for people who need heavy-duty humidification, like those with large homes with inhabitants who suffer from respiratory symptoms, then a furnace humidifier might be a better choice.

Furnace humidifiers can cover entire homes, so you don’t have to worry about low humidity levels in different parts of the house. Furthermore, furnace humidifiers are infinitely more low maintenance compared to portable humidifiers, which have to be deep-cleaned weekly. In contrast, furnace humidifiers will only need to be cleaned once every season.

How To Determine if a Furnace Humidifier is for You

There are several signs to look out for when it comes to determining whether you need a humidifier. Your home might be a strong candidate for a whole house humidifier if you have:

  • An existing HVAC system
  • Drooping or dying plants
  • Curling wallpaper corners
  • More frequent allergy symptoms and asthma attacks
  • More frequent coughing bouts and nosebleeds
  • Chapped, cracked, or bleeding lips
  • Presence of static electricity
  • Cracking in wooden materials or furniture

Types of Furnace Humidifiers

There are 3 main types of whole house furnace humidifiers:

Bypass – This type of furnace humidifier works by drawing warm air from your home’s furnace and allows it to pass through the water panel to activate the evaporation process. The air is moisturized and then distributed throughout your home. These models can either be installed in the supply or return plenum of your forced air handling system. These types require a floor drain, but drainless bypass humidifiers are also available.

Fan-Powered – Fan-powered humidifiers work the same way as bypass humidifiers but include a fan that speeds up the evaporation process by blowing air across the water panel. Thanks to this fan, this type of humidifier is able to produce about 1 gallon more moisture daily than bypass humidifiers. These types don’t require a bypass duct so they can be installed in small spaces.

Steam – This type of furnace humidifier adds humidity to the air by electrically heating water to create steam even without the help of a furnace. The steam is then distributed throughout your home with the help of the system blower. Steam humidifiers are the fastest and most efficient at humidifying entire homes. They work as needed and independently of your HVAC system.

Maintenance of Furnace Humidifiers

As previously mentioned, furnace humidifiers tend to be more low maintenance compared to portable humidifiers. Most furnace humidifiers use an evaporative system which requires the use of a water panel or evaporative pad. Because these pads tend to accumulate minerals and impurities from water, they lose their efficiency over time.

With that said, it’s best to replace the water panel at least once a year or more if necessary. If the water panel is washable, you can clean it with cold water gently. Other than replacing the water panel, you can also clean the humidifier’s outer body. You can do this by taking a cloth dipped in warm water or diluted vinegar and wiping the body with it. The same goes for the humidifier’s components. Of course, it’s best to check your humidifier’s instruction manual first.

FAQ

What is a water panel and what does it do?

The water panel goes by different names (evaporative pad or vapor pad) and is considered the heart of the whole-house humidifier. The water panel provides the moisture needed to humidify your home as the air passes through it. When the humidifier detects that there’s a dip in moisture, water is applied to the water panel and the air from the furnace blows through it, starting the evaporation process. The air picks up the water from the water panel and the moisturized water is then distributed throughout your home.

How often should I change my furnace humidifier’s water panel?

Water panels need to be changed at least once a year depending on the model and how frequently the humidifier is used. Some types of water panels are washable, which means you can just run them under cold water to clean them. Most water panels aren’t washable, though, and should be replaced.

What is the ideal humidity range for my home?

30% – 50% is the humidity level recommended by the EPA and is the level at which mold spores are unable to grow. For more information on maintaining the ideal humidity levels at home, read our guide here.

Final Thoughts

Furnace humidifiers help you and your whole family curb the negative effects of dry air. What makes furnace humidifiers so great is that everyone in your home benefits: every room will be blanketed by comfortable humidity that’s much needed during the cold winter months.

All the humidifiers on this list have redeeming qualities, but our favorite is still the Aprilaire 400. Its water-conserving feature makes it a very attractive option, especially during a time when water conservation is becoming increasingly important. Aside from this feature, it boasts all the other features you would want and expect from a furnace humidifier at this price point.

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