The Best Furnace Humidifiers for House Wide Comfort

A furnace humidifier works in a very similar way to the free standing room humidifiers that you can have sitting in a room. Yet, they are installed directly into your HVAC system and work to humidify the air around the whole house.

They are a fantastic option for you if you live in a particularly dry climate, or in a home that is suffering from a lack of moisture in the air.

This dry air can often aggravate allergies and health conditions such as asthma. Dry air can also leave many people feeling uncomfortable in their own home, resulting in dry eyes and sinuses.

In this article, we are going to answer some routine questions about furnace humidifiers and compare some of the most popular units. We consider some of the most important factors such as installation, cost and square footage of your home.

Quick Picks: Best Furnace Humidifier Reviews

Aprilaire 700 Humidifier
  • Coverage: 4,200 sq.ft.
  • ROE: 0.75G/hr
  • Operation: Automatic
  • High Performance!
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Honeywell House Humidifier
  • Coverage: 4,200 sq.ft.
  • ROE: 0.75G/hr
  • Operation: Manual
  • High Efficiency!
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Aprilaire 500 Humidifier
  • Coverage: 3,000 sq.ft.
  • ROE: 0.5G/hr
  • Operation: Hybrid
  • Affordable!
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Air Bear Trion
  • Coverage: 4,200 sq.ft.
  • ROE: 0.5G/hr
  • Operation: Automatic
  • Compact!
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*All links above will take you to the latest prices on or you can read our in-depth furnace humidifier reviews below.

Need help with a repair or install? Get a free estimate online from top local home service pros in your area.

The newest Aprilair Automatic Humidifier model on the market is the 700 and it differs from previous models in the line by having a higher rate of evaporation (ROE) at 0.75 gallons per hour.

This is also higher than most models that you can buy, making it extremely efficient and effective at adding moisture to the air in your home.

This unit is designed to service properties that are up to 4,200 square feet in size and have multiple levels too, it’s definitely a powerhouse among home humidifiers.

What’s is since it’s automatic you don’t have to monitor the moisture levels yourself it will do this for you and keep your home at a comfortable level of humidity.

The device can be easy to install if you know what you’re doing but if you’re not experienced in DIY HVAC you may want to consult with a professional. For those of you who are installing at yourself you may need to do some research on how to wire it up properly and safely.

To top it all off, it runs quietly; you won’t hear a peak out of this machine at all! This device is highly rated among previous buyers and recommended around the internet for the satisfaction buyers experience with this product due to how well it adds moisture to the air in the home.

Honeywell is a much loved brand when it comes to HVAC units and it’s no different for their furnace humidifier.

It’s powerful enough to work for a building up to 4,200 square feet in size, easy to mount and can even be applied to a forced air furnace system.

What’s handy is the unit does come with a humidistat, so there’s no need to buy one separately unless you would rather have a digital one but this will be able to set the desired humidity level you wish to achieve.

The Honeywell whole house humidifier is built to cost you little in maintenance by having a flow through design, a PerfectFlo water distribution tray and uses little water, resulting in the device staying cleaner, for longer periods of time.

This unit is particularly recommended for those with fibre glass type ducts as this product can be installed by using support strips to go inside the ducting when mounting the humidifier. As a whole previous buyers love this product as it keeps the ait in their home moist when it’s needed most with little water usage.

If you’re on a budget, want to save a bit of cash on your humidifier purchase or would rather have some control over its operation, the Aprilaire 500 might be the choice for you.

It’s still just as loved and highly rated as the newer model but you would be missing performance-wise.

The 500 takes a step down from its younger sibling by only being effective for a building of 3,000 square feet in size.

This is 1,200 square feet smaller than the 700 but if that’s all you need than there shouldn’t be any issue there, it’s still effective.

It has an evaporative rate of 0.5 gallons per hour, a little less than its counterpart but still decent in comparison to other similar products on the market. Other than those details, this humidifier installs in pretty much the same way as the 700, so it may be wise to have a qualified technician do this for you.

The main difference from the 700 is that this humidifier has the ability to be controlled manually if installed as such as allows you to switch between three different modes that control the output of its operation.

Another great option for your home humidification needs is offered by Air Bear.

This is a mini atomizing humidifier that, like the others, mount in your ducts right by the output of your furnace.

This humidifier is not as high powered as the others, it is miniature after all, which makes it great for smaller properties that does not need to spend as much energy or water to humidify their home air.

It’s also perfect for those with smaller ducting that can’t fit a full sized unit.

The product page states that it works to the proficiency of 12.5 gallons per day which when divided by 24 gives us 0.5 per hour, that’s as much as the Aprilaire 500. Which is not bad considering its size.

It’s easy to mount and install with push-to-lock fittings and a tilt out nozzle assembly granting easy access for cleaning and maintenance. Previous buyers vouch for this product and rate it highly making it well worth checking out.

Need help with a repair or install? Get a free estimate online from top local home service pros in your area.

How Can a Furnace Humidifier Help You?

Your Furniture

It’s not just people who are put at risk in dry air; wooden furniture is also composed of small amounts of water which dry air forces out. This shrinks the wood causing its shape to be altered and for it to become cracked and damaged, significantly reducing the lifespan and overall condition of it.

Having a whole house humidifier works for wood in much the same way it does for your body, it reduces the amount of water being sapped by the dry air. This can stop the warping of floorboards, the damage to furniture and the misshaping of doors.

Static Shock

Static shocks can be funny when they occur once in a blue moon but if it happens persistently, it becomes really annoying very quickly. Your body actually has the capacity to hold static charges of up to 20,000 volts. You may be surprised, but this can really cause issues with electronic devices in your home.

Static shocks are more prevalent in dry air conditions and their occurrence can be reduced by having an air humidity level of at least 35% which can easily be achieved if you are equipped with the a decent unit.

Your Health

Dry air can pose a problem to the health of those who reside in the household for it can make the throat feel dry, dehydrate the skin and cause or aggravate respiratory conditions.

People often blame the cold weather for the spread of colds, flues and other winter associated illnesses but the season is not directly at fault in most cases. It’s in the winter that people tend to turn on the furnaces which makes the air in the home dry out and this leads to an increased occurrence of respiratory infections.

The dry air irritates and weakens the thin membranes in the nose, throat and respiratory tract; locations of the body susceptible to infection. The airborne viruses and bacteria then have a much easier time gaining entry into the areas they aim to infect.

When coupled up with there being a lot of particulate matter in the air due to an unclean HVAC system, or an uncontrolled open fire, it can cause havoc! Many people use coil cleaners or UV lights for their AC, whilst using a soot vacuum for their open fireplaces to keep debris out of the air.

The additional moisture that’s put into the air by your humidifier helps to prevent these kinds of infections by ensuring the weak membranous tissues that are at risk come into contact with moisture making it less vulnerable to attack from pathogens.

Financial Savings

It’s a fact that moist air feels warmer than dry air, this is as true in the summer as it is in the winter. 

So when you switch on your furnace to heat up the house in a dry air environment, you’re actually using more energy to get to the desired temperature than if you had an ideal humidity level costing you more money in energy bills.

How Furnace Humidifiers Work

The whole house humidifiers are installed within the ducting of your HVAC system just after the furnace so that the heat can interact with the water. This means that furnace humidifiers will only be able to work when the furnace is in operation.

They play an important role in households during the winter, when the furnace is switched on which can result in the air around the home becoming really dry. It is said that the humidity rating of the savannah desert is 24% but homes can be much less.

The models presented above are all the flow through type as opposed to the reservoir type, they are the best furnace humidifiers partly because there is a significantly lower risk of microorganisms colonizing the standing water and being distributed throughout the home.

They connect to the air return duct and to the furnace via a humidifier supply take off duct. Heated air is diverted into the humidifier which in turn evaporates water from the evaporation pad. The water cools in the air during its distribution adding moisture the air supply in the house.

Furnace Humidifier Components

They can vary between models, but the following are the main components that none could work without:

Types of Furnace Humidifiers

There are a few different types of furnace humidifiers which are outlined below:

This type depends on a source of water be available within a reservoir as the name suggests. They’re not as efficient as the other types and the reservoir is vulnerable to being colonized by pathogens.

The humidifier is connected to an existing water pipe for its water supply. The water is then held on an evaporation pad/plate to be evaporated by warm air being blown through it.

These humidifiers rely on their own generated heat source to evaporate water and expel steam into the air. These are generally the most expensive to purchase and to run but are the most efficient.

When is a Furnace Humidifier Best Used?

If you have a manually operated one before, in which you can control the air moisture yourself, make sure to keep an eye on the humidistat when you’re using your furnace.

The desirable relative humidity of a home is between 30% and 50% so if you see it drop below that, it’s time to turn the humidifier on.

You shouldn’t have to worry about anticipating the drop and turning the humidifier on beforehand as the best furnace humidifiers kick in and work to a noticeable affect very quickly.

About the Author

Dave Miller is a HVAC technician with over 10 years in the industry. Dave created HeatTalk with the ambition for it to become a resource for individuals looking for answers, whether they be a layman, student or a professional.