10 Best Furnace Humidifiers of 2021 Compared & Reviewed

Best Furnace Humidifier
Photo: Aprilaire

While a standard portable humidifier is often good enough for regulating the humidity in one standard size room, when you need to control the humidity levels for the entire house, you need something more effective. And this typically means investing in the best furnace humidifiers.

Furnace humidifiers are more powerful types that will connect to the air conditioning unit in your house or on the heating or ventilation systems.

These humidifiers are often larger and more powerful units that are hence more effective than the small portable models.

And to help you get a good one, here we look at some top-rated furnace humidifiers and provide a buying guide.

Best Furnace Humidifier Buying Guide

How to Buy the Best Furnace Humidifier
Photo: diychatroom.com

1. Type of Furnace Humidifier: Fan-Powered or Bypass

The first decision you will need to make when shopping for the best home furnace humidifier is the type to buy. Here you will have two main options, which are the fan-powered and bypass humidifiers with each having its merits and demerits.

– Fan-Powered

As the name suggests, the fan-powered furnace humidifiers will have a built-in fan that they use to distribute the moist air.

Hence, these are more independent units that will not rely on the furnace to run, which means you can use them whether the furnace is running or not.

There will be no ductwork required when installing the fan-powered humidifiers, which means you can install it directly. This makes installation easier and also means that you will not need to dedicate a lot of space to this humidifier.

These humidifiers are generally more efficient than the bypass types as they will release relatively more moisture into the air.

However, the presence of a fan makes it relatively louder when compared to the bypass type. And overall, this is also the more expensive of the two types.


  • Operates independently
  • Easier and quicker to install
  • Does not need much room


  • Relatively more expensive
  • Can be quite noisy

– Bypass

Bypass furnace humidifiers are reliant on the furnace since they do not have built-in fans for distributing the air. Hence, these models can only be useful when the furnace s running.

Also, you need a bypass duct for recirculating the air through your furnace for distribution. This means setting one up is a more complicated affair, and you will need to have more space.

Because the moisturized air has to follow a longer path before getting to your space, these humidifiers are also more prone to humidity loss.

That said, the absence of a fan ensures that these units will run more quietly, and because they rely on the furnace blower motor, they will use up relatively less electricity. Also, these are more affordable options, when compared to the fan-powered types.


  • Quieter operation
  • Uses less electricity
  • More affordable


  • Installation is more tedious
  • Only works when the furnace is running
  • Prone to moisture loss

2. Coverage Area of Furnace Humidifier

A good furnace humidifier for your home is one that will cover your space adequately. Hence, as you are shopping for one, you need to keep the space you intend to cover in mind.

Most models will provide coverage of anything from 2,000 to 5,000 square feet, which means there is something out there for any home size. Also, there are still a few top tier models that will cover even more area than this.

For smaller homes, a 2,100 sq. ft. coverage model like the Emerson HFT2100 should be good enough, while a wide coverage model such as the 4,200 sq. ft. Honeywell HE360A1075 will be ideal for larger homes.

3. Furnace Humidifier Max. Output

The maximum output of a furnace humidifier will measure the amount of air that the unit can evaporate into your home every 24 hours when you have the unit at maximum speed.

What makes the output important is that it will determine how effective the humidifier will be at controlling the humidity levels in your home.

Overall, the higher the output the better the humidifier, but it will mostly depend on the size of your house. For example, a 16-gallon output humidifier will be ideal for areas up to 4,000 square feet.

4. Furnace Humidifier Controls

It is important to make sure that the furnace humidifier you choose not only gives you full control over the humidification process but also has some simple controls.

Simple controls make operation easy, and here you need to make sure that if the unit has any function buttons, they should be clearly labeled and conveniently placed.

As you consider the controls make sure the model you choose has a built-in humidistat and a timer will also be a great addition.

Some models will come with digital controls that display the precise humidity levels in the air and allow you to set a specific humidity level.

Others will have manual controls, which might not be as precise as digital ones, but these units are more affordable.

5. Noise Level of Furnace Humidifier

Even if you get the best furnace humidifier with all the impressive features, it will still not serve you well if it is very noisy. And so as you choose one you need to look at the noise level and go for something that does not make too much noise.

Overall, the bypass types will provide super-quiet operation, and if you are buying one, you will hardly ever need to worry about noise. However, for the fan-powered models, you need to check the noise rating keenly.

6. Maintenance

Like any other home appliance or fixture, you will need to maintain your furnace humidifier. As you choose one, you need to make sure it will give you an easy time when it comes to maintenance.

The maintenance procedure will vary from one model to the other and among the different types. For example, the fan-powered types will need seasonal cleaning to remove any bacteria growth.

A model that comes with clear maintenance directions will ensure you have an easy time when cleaning and maintaining it.

10 Best Furnace Humidifiers Reviewed




Aprilaire 600

1. Aprilaire 600 (Best Overall)

  • Programmable fan
  • Dual sensors
  • Permanent memory
  • Digital control
Aprilaire 500M

2. Aprilaire 500M (Best Budget)

  • Budget-friendly
  • Single sensor manual control
  • Fast installation
  • Compact design
Honeywell HE360A1075

3. Honeywell HE360A1075 (Best Flow-Through Design)

  • Flow-through design
  • Easy mounting
  • PerfectFLO distribution tray
  • Adjustable humidistat
Honeywell HM750A1000

4. Honeywell HM750A1000 (Best High Capacity)

  • 22 gallons per day output
  • On-demand humidification
  • Digital humidity control
  • Self-diagnostic tool
GeneralAire 5730

5. GeneralAire 5730 (Easy Maintenance)

  • Easy maintenance design
  • UV stable plastic housing
  • Automatic digital humidistat
  • Manual mode included
Honeywell HE300A1005

6. Honeywell HE300A1005 (Versatile Installation)

  • Versatile installation
  • HumidiPRO digital humidity control
  • User-friendly pad access
  • Reduced operational noise
GeneralAire 5137

7. GeneralAire 5137 (Industrial-Quality for Home)

  • Industrial quality construction
  • Easy to use dial
  • Optimal installation option
  • Humidistat included
Aircare MA1201

8. Aircare MA1201 (Dependable Console-Style)

  • Efficient console-style
  • Digital humidistat
  • Automatic shut off
  • Evaporative wick
Aprilaire 700

9. Aprilaire 700 (Wide Coverage Area)

  • 4,200 square feet coverage
  • Truly automatic control
  • 0.75 gallons/hour evaporative rate
  • Dual sensors
Emerson HFT2100

10. Emerson HFT2100 (Low Profile Bypass Design)

  • Low-profile unit
  • Reversible side panels
  • Durable thermoplastic cabinet
  • Universal humidistat

1. Aprilaire 600 – Best Overall

Aprilaire 600

Photo: Aprilaire

  • Type: Fan-powered
  • Coverage Area: 4,000 sq. ft.
  • Max. Output: 17 gallons/day
  • Dimensions: 16 x 10 x 15 inches

The programmable fan is what makes the Aprilaire 600 our best overall furnace humidifiers. With this function, you can be sure that you will always get superior air quality for your indoor space, and this is more so when you combine this with a whole-house air cleaner.

Programming the unit is also quick and easy thanks to the copy function that will allow you to set a different program for each day of the week.

This model has an automatic function that makes use of dual sensors to ensure it responds to both outdoor temperature and indoor humidity. And with the digital controls, you can easily keep track of things like humidity percentage and water panel change indicator.

In case of a power outage, you will not have to re-program your humidifier as it has a memory function that will ensure it preserves your settings.

Installing this furnace humidifier seems to take quite some time, and you should hence make sure you have enough time to spare. However, it is still quite a straightforward process.


  • Quick programming
  • Preserves the settings in case of a power outage
  • More efficient and effective dual sensors
  • Convenient digital controls


  • Longer installation time

2. Aprilaire 500M – Best Budget

Aprilaire 500M

Photo: Aprilaire

  • Type: Bypass
  • Coverage Area: 3,000 sq. ft.
  • Max. Output: 12 gallons/day
  • Dimensions: 15.63 x 10.25 x 13 inches

Being the cheapest models on our furnace humidifier review, the Aprilaire 500M is the perfect fit for you if you are looking for something that will save you some bucks.

This bypass furnace humidifier provides a maximum output of 12 gallons per day and will cover up to 3,000 square feet, which makes it good enough for a standard size home.

With the manual control system that makes use of a single sensor, this unit will also give you more control over the humidity, and you can easily fine-tune it to suit your needs.

What’s more, it comes in a more compact size to ensure it will easily fit into tight spaces. Because this is a bypass model, it will run more quietly when compared to other types out there.

The installation kit will not be included in the package, but this will not be a big deal given that the small price tag of this model.


  • Relatively more affordable
  • Fits into tight spaces
  • Simple manual humidity control
  • Fairly easy and quick installation
  • Quiet operation


  • Installation kit not provided

3. Honeywell HE360A1075 – Best Flow-Through

Honeywell HE360A1075

Photo: Honeywell

  • Type: Fan-powered
  • Coverage Area: 4,200 sq. ft.
  • Dimensions: 15.25 x 10.25 x 14 inches

The flow-through design of the Honeywell HE360A1075 keeps it clean for a relatively long time and will also ensure you get an easier time when it comes to maintenance.

Mounting this furnace humidifier is relatively easier when compared to others, and you should have it set up and ready to use in just a few hours.

An adjustable humidistat will also turn the unit on and off automatically to maintain your preferred humidity levels. With the PerfectFLO distribution tray, this unit will maintain high efficiency and use less water to save you money.

The instructions for wiring are quite wanting, and some newbies might have difficulties understanding them. However, with a few online videos to help you out, you should be able to figure things out. Also, the highly sensitive humidistat only takes some getting used to.


  • Remains clean longer and requires minimal maintenance
  • Quick and easy installation
  • Optimized efficiency and water usage
  • Automatic on and off


  • Wiring instructions are wanting
  • Humidistat is too sensitive

4. Honeywell HM750A1000 – Best High Capacity

Honeywell HM750A1000

Photo: Honeywell

  • Type: Fan-powered
  • Max. Output: 22 gallons/day
  • Dimensions: 18 x 10 x 7 inches

For those who live in areas with very low humidity levels and larger houses, the Honeywell HM750A1000 will be a perfect choice as it will provide a higher capacity. This unit has a maximum output of up to 22 gallons per day.

With the HumidiPRO digital humidity control, this humidifier will adjust automatically to your preferred humidity levels, and it will also be ideal for protecting against frost and window condensation.

On-demand humidification ensures that this unit can reach the desired humidity levels super-fast, and it will do this without making any noise as it is designed to provide quiet but efficient operation.

It also has a self-diagnostic tool that allows it to adapt to changing conditions and shows you the humidification stage and condition.

This Honeywell furnace humidifier is the priciest item on our list, but it is worth everything you pay with the higher efficiency and capacity.


  • Higher daily output
  • Adapts to changing condition
  • Fast and efficient humidification
  • Automatic humidity control
  • Quieter operation


  • Relatively more expensive

5. GeneralAire 5730 – Easy Maintenance

GeneralAire 5730

Photo: GeneralAire

  • Type: Fan-powered
  • Coverage Area: 3,000 sq. ft.
  • Max. Output: 18 gallons/day
  • Dimensions: 16.5 x 16 x 10.5 inches

You will never need to put a lot of effort into maintaining the GeneralAire 5730 as it comes in an easy to maintain design that will make the water panel replacements a breeze.

There is also an automatic digital humidistat that will allow you to set and forget about it, which is quite convenient. With this humidistat, the humidity levels will always be right as this unit will monitor and make the necessary adjustments.

Besides the automatic mode, this furnace humidifier also has a manual mode that will give you more control if you prefer a more basic operation. And with the UV stable plastic housing, you can have this unit near a UV lamp with no issues.

The fan seems noisy, but the sound is quite soothing and something you can live with. Also, this unit seems to use up more water, but this is typical of fan-powered humidifiers and should not be a deal-breaker.


  • Simple maintenance
  • Set and forget design
  • Manual mode gives you more control
  • Can be used near UV lamps


  • The fan is a bit noisy
  • Uses up a lot of water

6. Honeywell HE300A1005 – Versatile Installation

Honeywell HE300A1005

Photo: Honeywell

  • Type: Fan-powered
  • Coverage Area: 3,000 sq. ft.
  • Max. Output: 18 gallons/day
  • Dimensions: 16.8 x 15.5 x 10.3 inches

Honeywell HE300A1005 is a versatile furnace humidifier that will work for a wide variety of situations, and you can install it almost anywhere. And the installation is more labor and time-saving.

With the reduced operation noise, you will get a comfortable and adequately humidified room without having to withstand too much noise. To make things even better, this unit has user-friendly pad access that will make maintenance a breeze.

This model also offers greater operational efficiency, and it will include an automatic damper and status indicators. And with the HumidiPRO digital humidity control, you can dictate the level of humidity more precisely.

If you live in a water-scarce area or in localities where water bills are high, this might not be the ideal humidifier for you as it seems to use up a lot of water. However, overall it is still quite efficient.


  • Works for a wide variety of situations and jobs
  • Faster installation
  • Delivers a quieter operation
  • Easy maintenance and upkeep
  • Highly efficient operation


  • Uses a lot of water

7. GeneralAire 5137 – Industrial-Quality Home

GeneralAire 5137

Photo: GeneralAire

  • Type: Fan-powered
  • Coverage Area: 3,000 sq. ft.
  • Max. Output: 18 gallons/day
  • Dimensions: 14 x 16 x 10 inches

While furnace humidifier are not the priciest home appliances, you still need to make sure that what you buy gives you value for money by serving you long enough. With the industrial-grade construction of the GeneralAire 5137, that is just what you get.

Its construction includes a UV stable automotive-grade plastic housing that will provide many years of great service in any environment.

Also, this humidifier has been designed to deliver optimal efficiency as it installs on the warm air plenum to make humidification faster and efficient. And you will hardly notice this unit when in operation as it offers a super-quiet operation.

The easy to use dial also makes this one of the best home furnace humidifier because, together with the humidistat, they will ensure you will have full control over your home’s humidity levels.

There is a lot of water wastage with this furnace humidifier, which can lead to higher water bills. But, operating it only when you need it should help minimize the water wastage.


  • Highly durable build
  • Warm air plenum installation for maximum efficiency
  • Quieter operation
  • Easy to use dial
  • Precise humidity control with humidistat


  • Lots of wasted water

8. Aircare MA1201 – Dependable Console-Style

Aircare MA1201

Photo: Aircare

  • Type: Fan-powered
  • Coverage Area: 3,600 sq. ft.
  • Max. Output: 11.44 gallons/day
  • Dimensions: 20.5 x 21.5 x 14.5 inches

Console-style furnace humidifiers like the Aircare MA1201 are always more dependable and will be very useful in any home. Also, this is a more efficient humidifier that will include some nice wheels for more mobility.

Another element that will make this one of the best furnace humidifiers out is that it has a digital humidistat that will automatically adjust the humidity levels and keep it ideal.

With the automatic shut off, it will help conserve more energy by shutting down when the desired humidity level is reached and when the tank is empty for safety.

With a wick to trap then mineral deposits, this will be an easy machine to clean up, while the absence of belts and pulley ensure you get as mother operation.

When on the highest speed level, the fan on this unit can get quite loud, but the sound should be okay once you get used to it. And because it goes through the water fast, you will need to refill it more often, but the good news is that it is easy to refill.


  • Efficient and reliable
  • Maintains precise humidity level
  • Shuts off automatically for safety
  • Easy to clean design
  • Smooth overall operation


  • Fan can get loud
  • Requires more frequent refills

9. Aprilaire 700 – Wide Coverage Area Furnace Humidifier

Aprilaire 700

Photo: Aprilaire

  • Type: Fan-powered
  • Coverage Area: 4.200 sq. ft.
  • Max. Output: 18 gallons/day
  • Dimensions: 16 x 11 x 18 inches

If you have a larger space than you need to humidify, the Aprilaire 700 will be a good buy as it covers up to 4,200 square feet, which is one of the widest coverage on our furnace humidifier review.

Humidification is also guaranteed to be simple and efficient as this unit uses dual sensors, and it has a fully automatic design that ensures the humidity levels will be regulated automatically.

The 0.75 gallons per hour evaporation capacity is one of the highest on our list. Besides offering quick and simple maintenance, this model also has some highly useful indicators that will include humidity percentage, water panel change indicator, and a service needed alert.

There is quite a lot to do when installing the Aprilaire 700, which means it will take quite some time. However, the process is easy for anyone to figure out.


  • Covers a wide area
  • High enough evaporation capacity
  • Efficient dual sensors
  • Fully automatic controls
  • Handy indicators included


  • Longer installation

10. Emerson HFT2100 – Low Profile Bypass Furnace Humidifier

Emerson HFT2100

Photo: Emerson Thermostats

  • Type: Bypass
  • Coverage Area: 2,100 sq. ft.
  • Max. Output: 14 gallons/day
  • Dimensions: 13.5 x 9.6 x 12.5 inches

Limited space should not prevent you from installing a humidifier in your home because the low-profile Emerson HFT2100 can be installed in the tightest spaces.

Besides the low-profile design, this unit is also more versatile as it has reversible panels that will make it possible to have right or left-side bypass installation. And you can easily keep track of the humidity levels in your home thanks to the universal humidistat.

Water distribution will also be more efficient to minimize waste and ensure excellent humidification. You can also be sure this machine is designed for a long service life as it has a durable thermoplastic cabinet that is resistant to both rust and corrosion.

Replacement pads for this furnace humidifier are relatively more expensive, but you will not need to replace them very often as they are highly durable. Also, the installation seems to be quite tedious, but you should still be able to hack it with some patience.


  • Great for situations where space is limited
  • Allows for both left and right bypass installation
  • Improved water distribution
  • Highly durable and rust-resistant housing
  • Efficient humidistat


  • Expensive replacement pads
  • More tedious installation

How to Install a Furnace Humidifier?

How to Install a Furnace Humidifier
Photo: funender.com

Once you land that perfect furnace humidifier for your home, you will also need to install it properly for the best service. But while you can always call in a professional to help out, you can still do it on your own, and here is what to do.

Step 1: Mark and Cut Holes

The first step is to map out a hole where you will install the humidifier. Once the holes are marked, you can then drill them out.

Most manufacturers will provide a template and instructions on how to go about this step.

Step 2: Cut Out Hole for Humidistat

Next step you need to make another hole for the humidistat.

Mostly it will be above where the humidifier will be installed, and once you have the hole you can secure the humidistat in place with the provided mount plate and screws.

Step 3: Install Humidifier Electrical

With the humidistat in place, you can now set up the electrical for the humidifier. It is at this step that you will need to connect the furnace control with the humidistat by following the manufacturer instructions.

Make sure to follow the manufacturer’s instructions for the wiring.

Step 4: Install Furnace Humidifier

Once the wiring is fully setup, you will be ready to install the furnace humidifier.

Here you should attach the humidistat to the solenoid valve using the nuts and also attach the wire ends.

Step 5: Install the Water Line

The last step will be to install the water line that will deliver the required water to the humidifier.

Given the different humidifier types and models, what to do here will vary, and so you need to follow the specific instructions provided.


Furnace humidifiers are unbeatable when it comes to maintaining optimal humidity levels in your home. But like any other home fixture, you need to get the best furnace humidifier for excellent service.

Choosing one should be easy as we already do the hard work for you with our reviews. And from our list of product, the Aprilaire 600 takes our top overall spot as it has a lot to offer from a programmable fan to a wide enough 4,000 square feet coverage.

The Aprilaire 500M, on the other hand, is our best budget model, and it is what we recommend for homeowners shopping for something inexpensive but still efficient and reliable.