5 Best Furnace Humidifiers – 2021 Reviews

If you’re sick of constantly having to refill, clean, and lug around your portable humidifier, we have got something to show you. Turns out, using the best furnace humidifier allows you to keep your whole house comfortable with almost no hassle at all.

Maintaining the proper humidity level in your home during the dry season makes a huge difference in human comfort and health. You can totally use a portable humidifier for this purpose – there are a lot of brands and styles on the market. But no one portable unit can humidify your whole home, and they all require constant vigilance in terms of refilling the water tank and cleaning out the mineral build-up that occurs when water evaporates.

Enter the furnace (or whole house) humidifier. It utilizes the home’s HVAC system and water supply to deliver moisture throughout the area on a continual basis. We have done the research and discovered five great products – one of them is sure to be the best furnace humidifier for your home.

Why Humidity Matters

Air that is too dry can cause itchy skin and eyes, nosebleeds, and respiratory distress. You will become more vulnerable to colds and flu. When the humidity is maintained somewhere between 30-60%, breathing is easier, and you are less likely to get dehydrated, even if it’s hot.

Dry air can help keep your skin moisturized and definitely cuts down on the number of shocks you’ll receive from textile furniture and carpeting.

Benefits of Installing a Furnace Humidifier

In many climates, the cold winter months are the driest. This is also when we turn on our central heating system, which only further dries out the air. That’s why hooking a humidifier into the furnace can make such a huge difference – the heating and humidifying features work together to both warm the air and introduce much-needed moisture.

Over the years, furnace humidifiers have advanced with technology, making them easier to install and significantly cheaper to maintain. That makes them a great investment in the health and happiness of your family. Following are other important benefits of installing a furnace humidifier.

Save Money on Energy

Did you know that humid air actually feels warmer than it really is due to the moisture content? That principle can be applied to your home during the winter, too. When the relative humidity inside is maintained at an ideal level, you can bump your thermostat down by a few degrees without sacrificing comfort. Studies show that reducing your thermostat’s setting by just three degrees translates into a 5% savings on your heating bill.

Save Money on Maintenance

A lot is made of the danger that water can pose to wood fixtures and furnishings. And it’s true – too much moisture swells wood and can lead to mold growth and rot. But overly dry air can also damage wood, causing it to shrink and crack, leaving gaps around doors and windows and warping your floorboards. Proper humidity levels will help extend the life of all the materials in your home and protect the property’s resale value.

Improve Resident Health

Believe it or not, hydration is about more than just the water you have inside your body. Dry skin actually prevents the body from maintaining proper hydration and limits the ability of your immune system to defend against airborne irritants. Dry skin, therefore, is both a symptom and a cause of dehydration.

In cold weather, skin gets drier because there is much less humidity in the air. Keep your family healthier over the long winter by using a furnace humidifier to replace much-needed moisture as the forced heat strips even more of it from the air.

Types of Furnace Humidifier

A furnace mounted humidifier, otherwise known as a whole-house humidifier, connects to a forced-air HVAC system and delivers moisture throughout the home via its vents. This process is much more effective than a portable humidifier, which can tend to humidify only the area right around it, sometimes actually dampening surfaces nearby.

There are three basic types of furnace humidifiers available, and the one you choose will depend on your HVAC system, your budget, and your general preference. Also, remember that the best location for furnace humidifier units is near both the furnace and a water supply line. That can affect your ultimate choice as well.

The three types are:

1) Flow-through humidifier

This type connects to the home’s water supply and releases a steady trickle of water across a humidifier pad. Excess water is released through a drain pipe. Because there is a constant flow of freshwater, this type of humidifier tends to avoid issues with mold and mildew that can be present when there is standing water.

Flow-through humidifiers are usually less expensive and more reliable than the other types; they also use less electricity.

2) Reservoir or drum humidifier

This type of humidifier uses both a reservoir filled with water and a rotating drum covered with an absorbent pad. As the drum rotates through the water, the pad fills up, and a fan causes the moisture to evaporate. Then that moisture is pushed throughout the house along with forced heat.

Drum humidifiers can use around 15 gallons of water per day, but because they only run in conjunction with your heating, the water in the reservoir may sit stagnant for large portions of that time. If your heat is only kicking on a couple of times in any given 24 periods, the water in the reservoir can sometimes develop bacteria that is then distributed throughout the home.

3) Steam humidifier

Sometimes the first two types of humidifiers that we’ve covered struggle to put out enough humidity to maintain appropriate levels. That’s because they rely completely on evaporation, which can take some time. The solution to that problem is a steam humidifier, which heats the water to steam using electricity.

This system does work faster than any evaporative humidifier, but it costs quite a bit more, too. The system itself is more costly, and then you have to consider the additional energy cost associated with using electricity to make steam.

TOP 5 The Best Furnace Humidifier for Your Home

Get familiar with the products we will review by exploring our chart of basic specs. Then read on for an in-depth description of each brand and its associated furnace humidifier pros and cons.

GeneralAire 1000A Humidifier

generalaire 1000a humidifier

One of the great benefits of using a furnace humidifier is that you rarely need to think about it. There is some general maintenance that needs to occur, mainly replacing the vapor pad a couple of times per year. With other whole house humidifiers you also need to pay attention to the outside humidity and shut off your humidifier when it is no longer needed.

The GeneralAire 1000A humidifier handles this job for you. The Gfx3 automatic digital humidistat calculates the dew point and triggers a bypass damper if you don’t need any more moisture inside. However, you can choose whether to set the unit to auto or manual for more control.

Built with strong automotive grade plastics, this flow-through humidifier is ideal for homes up to 3,000 sq. ft. It uses a fan to move air through the duct system and uses about 18 gallons of water per day. The GeneralAire humidifier manual that comes with the unit clearly details maintenance requirements and warranty details.

Pros

  • Easy to read display; intuitive controls
  • Runs quietly
  • Long 10-year warranty and responsive customer service

Cons

  • Works better with a hot water supply over cold
  • May need to have some fittings tightened during installation
  • Not recommended for DIY install

Honeywell HE360A Whole House Powered Humidifier

honeywell he300a1005 trueease fan powered humidifier

For larger homes up to 4,000 sq. ft., consider this model. It comes with an installation kit and clear directions, but unless you are familiar with the inner workings of your HVAC system and water supply, it is still better to hire a professional to get you up and running. This is wise advice gleaned from scouring Honeywell furnace humidifier reviews.

The Honeywell also contains a humidistat to control the relative humidity in your space. It is a drum humidifier, the benefit of which is that you do not need a drain nearby to use it. There is a floating ballcock much like the one in your toilet tank that maintains the proper amount of water in the reservoir. However, occasionally there can be a little bit of overflow, so many users recommend putting a bucket underneath.

When air flows into the by-pass of this humidifier, it is forced to pass through a water-soaked pad, absorbing moisture as it does. An internal fan makes this process more efficient. The humidity that then moves throughout the home is clean and pure. Because it contains a reservoir, this unit uses water efficiently. However, if your heat isn’t kicking on regularly throughout the day, the water could potentially become stagnant.

Pros

  • Clear front window allows you to see operation
  • Energy and water efficient
  • Covers a large amount of square footage

Cons

  • Can occasionally drip water
  • Not recommended if HVAC isn’t running regularly
  • Can be challenging to find replacement parts

Aprilaire 700 Whole House Humidifier w/ Automatic Digital Control

aprilaire 700m whole home humidifier, manual fan powered furnace humidifier, large capacity whole house humidifier for homes

This Aprilaire humidifier is a flow-through model that not only covers an astonishing 4,200 sq. ft., but also puts out up to .75 gallons of water per hour. This exceeds the capacity of many other units by 50%. It works quietly so you won’t ever be disturbed by it.

The Aprilaire is super easy to use with an automatic digital control. While some users have hooked it into a Nest system or other smart home feature, otherwise the digital control needs to be handled from the unit itself. That might not be ideal if your humidifier will go in a crawl space.

In terms of maintenance, all this humidifier needs is an annual check-up. Users report that the installation is so simple a homeowner can do it themselves. However, you could experience trouble activating your warranty if the installation was not done by a professional.

Pros

  • Easy to follow installation instructions
  • Can be linked to a smart home thermostat
  • Excellent water output

Cons

  • Can use a lot of water
  • Requires a larger duct opening than many units
  • Fan can be noisy

Air Bear Humidifier

air bear air-bear-265000-001 trion duct mounted atomizing 24v humidifier mister-mini

The Air Bear humidifier works a little bit differently than evaporative units. It uses no pads or filters. Instead, it pumps a fine mist of atomized water directly into the warm air supply duct of your HVAC. The warm air keeps the water from condensing as it moves through the home.

There is a built-in humidistat and temperature switch that automatically shuts down the unit if the temperature in the warm air duct is not high enough to keep the mist from condensing. For that reason, this humidifier is not recommended for systems where the supply air does not reach 120 degrees.

One of the nice benefits of this product is that you can change the mist capacity by using a larger or smaller nozzle. That makes it customizable to homes of many different sizes. Installation is also simple with push-to-lock fittings. The tilt-out mounting makes accessing the unit for maintenance easy, too.

This unit is compact in size, making it ideal for tight spaces. Though there is no true portable whole house humidifier – because it needs to stay connected to the furnace and water supply – this one is small enough that you’ll barely notice it.

Pros

  • Compact size
  • Efficient use of water
  • Easy installation and maintenance

Cons

  • Only works with really efficient heaters
  • Works better with a scale reducing filter added to the water line
  • Covers only 1,500 square feet

Emerson HSP2000 Whole House Steam Humidifier

emerson hsp2000 whole house steam humidifier

For the most efficient distribution of humidity in your home, you will want a steam humidifier. This Emerson model has a rated output of 13 gallons per day, but it doesn’t rely on your forced air heater to run. When the built-in humidistat senses that the air is too dry, the steam humidifier is triggered. A thermal switch is wired to simultaneously turn on the furnace blower (not the heat).

Though steam humidifiers do use more electricity than other types, the release of steam can help to maintain the air temperature in your home. It could be that your furnace doesn’t need to kick on as often with the Emerson installed. Properly humidified air also keeps people feeling comfortable at slightly lower temps.

The Emerson is a 120-Volt whole house humidifier with flushing timer and filter, meant for use in spaces no smaller than 1,400 square feet. Though no upper space limit is published by the company, users have reported that it works well to cover spaces as large as 4,500 square feet. The manufacturer recommends having your water quality assessed before installation to ensure that the heating element won’t corrode prematurely.

Pros

  • Works independently of the heat
  • Auto flush feature helps keep the line clear
  • Can cover up to 4,500 square feet

Cons

  • Needs to be installed professionally
  • Tricky to clean
  • High operating cost

Maintenance Tips for Furnace Humidifiers

There are several different kinds of furnace humidifier, but the flow-through, reservoir, and stream types are the most commonly used. They also tend to need the most maintenance to operate properly. We will go through some standard maintenance required by each type specifically. This section aims to answer the following questions:

  • How do you tell if your furnace humidifier is working?
  • What parts need to be replaced regularly?
  • What cleanser is recommended for cleaning?
  • When should you call for professional help?

Reservoir OR Drum Style Humidifier Maintenance

This type of humidifier uses a reservoir pan that fills with water. Afloat controls the level to ensure it does not overflow or completely empty. A drum covered with an absorbent pad rotates through the tank, and a fan blows air through the damp pad to cause evaporation. Your HVAC system does the rest in terms of distributing the moist air throughout the home.

The advantage of a reservoir-style humidifier is that it is usually the least expensive to purchase and operate. However, you’ll find that it requires a lot of regular maintenance. The pad can become hardened by sediments in the water and stop absorbing water, so it will need to be cleaned or replaced regularly. And water that sits too long in the reservoir can start breeding bacteria, so the reservoir needs regular attention.

Before you begin, turn off the power to the furnace and close the water supply tap valve that leads to the humidifier.

  1. Loosen nuts or remove clips that secure the humidifier cover. Remove it to expose the inner workings.
  2. Check the pad. If it has become hardened, try to clean it with a 1:3 solution of water and vinegar. A product that dissolves calcium deposits might also be necessary. If cleaning doesn’t work, replace the pad.
  3. Drain the reservoir and clean it thoroughly as well. Turn the water supply back on, allow the reservoir to completely fill, and verify that the float is maintaining the proper level of water. You can tell that the water is low if the rotating drum does not fully wet the absorbent pad. An adjustable screw will allow you to raise or lower the height of the float if needed.
  4. Verify that the water supply hose fits tightly and is not leaking. If needed, you can tighten the connection with an adjustable open-end wrench.
  5. Turn the furnace’s power supply back on. Allow the humidifier to run as needed over the course of the next hour, then check to make sure the water level is still correct. Adjust the float as needed.

Flow-Through or Drip Style Humidifier Maintenance

A flow-through humidifier (also called drip-style) doesn’t keep a reservoir filled but instead constantly drips water onto an evaporator pad. Therefore, it usually requires a drain to catch any water that is not evaporated but instead drips out of the pad.

This type of humidifier is reliable and cost-effective. It is not prone to bacterial growth in the same way as a reservoir type. It also requires less maintenance. But, flow-through models use more water than other types and will need new evaporative pads on an annual basis.

Before you begin, turn off the power to the furnace and close the water supply tap valve that leads to the humidifier.

  1. Open the clips that hold the distribution manifold and inlet feed tube in place at the top of the unit. The inlet tube should separate from the distribution manifold so that you can remove it from the housing and access the evaporative pad.
  2. Clean away mineral deposits from the water distribution manifold. If it is made of metal, this job may require a chisel or flathead screwdriver. If it’s plastic, a regular abrasive scrubber should suffice.
  3. Check the condition of the evaporator screen pad. If it has a scale on it, use a 1:3 solution of vinegar and water or else a product made to dissolve calcium. Soak the pad until the build-up can be easily rinsed away. This type of pad should be replaced annually.
  4. Verify proper function by making sure that the humidistat calls for humidity appropriately. You can do this by opening the water supply and returning power to the furnace. When the furnace kicks on, the water valve should open and release water through the tube. During the test, make sure to hold the tube so that the water flows down the drain.
  5. If everything is working, reassemble the unit. If not, call for professional repair.

Steam-Style Humidifier Maintenance

A steam humidifier for furnace use guarantees that your home will receive critical moisture even if the heater doesn’t kick on very often. It uses electricity to heat water to boiling and then distributes the steam throughout the house with your HVAC’s blower system.

An advantage of this type of humidifier is that no standing water means no mold. Steam humidifiers also require less maintenance and control humidity with greater precision. However, they do require a dedicated electrical circuit and are costly to operate.

Before you begin, turn down the humidistat to ensure that the system does not fire up while you are servicing it.

  1. First, drain the water in your unit. Refer to the manual to find the precise steps for your model. This could involve shutting off the power.
  2. Wait for the unit to fully cool before removing the lid.
  3. Remove the overflow pan, loosening the mounting screw if necessary.
  4. Remove the main drain tube to determine whether or not it is clogged. Depending on your water type, there could be deposits obstructing flow.
  5. Check the overflow tank for lime deposits.
  6. Examine the metal water discharge tube and water supply tube.
  7. Use a 1:3 solution of vinegar and water or a scale-removing product like Lime Away® to clean any of the above parts that appear to be obstructed or coated.
  8. Reassemble your humidifier, making certain that any O-rings are positioned correctly.
  9. Refer to the user’s manual for instructions on how often to replace the water filter.
  10. Remember to turn the power back on (if off) and reset the humidistat to your desired level.

Conclusion

Proper humidity makes a huge difference when it comes to keeping residents comfortable and healthy. Not only will you have better resistance to cold and flu germs, but you won’t be constantly shocked by your carpeting either! A furnace humidifier is a fantastic tool that utilizes your existing HVAC system to deliver much-needed moisture throughout the house. We have covered several different types and hope that we’ve helped you find the best furnace humidifier for your home.

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