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As temperatures continue to fall across the country, homeowners are on the lookout for ways to keep their homes warm and comfy. Staying comfortable in the winter isn’t just about keeping your house warm, however, you should also consider the humidity. Dry winter air can leave your nose and throat feeling scratchy – it can even contribute to respiratory infections. Maintaining proper humidity levels in your home is the key to winter comfort and a furnace humidifier is the perfect way to achieve it.

In this guide, we’ll explain exactly what a furnace humidifier is, how they work and provide some recommendations for you to consider.

Why Does Indoor Humidity Matter?

The term humidity refers to the amount of water vapor in the air. Cold air has a more limited ability to hold moisture as warm air which is why low humidity often becomes a problem during the winter.

While low humidity may not be a major health concern, it may cause you to lose moisture from your body through breathing and through the pores in your skin. This can lead to dry skin, chapped lips, itchy nose, and scratchy throat. It may even contribute to chronic respiratory infections by drying out the mucus membranes in the nose and throat, impairing their ability to filter out pathogens.

The ideal indoor humidity level ranges between 30% and 50%. You can purchase a simple hygrometer to measure your indoor humidity and if it’s consistently below that level, consider installing a furnace humidifier to raise the humidity levels in your home.

What Does a Furnace Humidifier Do?

Humidifiers take many forms from portable humidifiers that are good for allergies to whole-house humidifiers that work with your existing HVAC system. The main difference is that a portable humidifier only affects the humidifier in one room while a furnace humidifier provides a whole-home solution.

A humidifier for furnace systems takes one of several forms, though all of them produce steam which is then distributed throughout the home through the ductwork. The two primary types of furnace humidifier are bypass and evaporative, or fan-powered.

An evaporative or fan-powered humidifier for furnace systems exposes the hot air the system produces to a slow but constant stream of water. The heated air evaporates some of the water, increasing the amount of moisture in the air moving through the ducts. When it comes to furnace humidifier cost, evaporative models tend to be the most cost-effective.

Bypass furnace humidifiers are even more economical, and they don’t have any extraneous systems – they rely entirely on the furnace. Air simply passes through the humidifier’s evaporative pad to deliver moisture throughout the entire home.

What Should You Look For in a Furnace Humidifier?

Before buying a furnace humidifier, it’s important to consider the different options and to think about the various furnace humidifier pros and cons. The right humidifier for your home may vary depending on the type of furnace you have, the size of your home, and any additional features you want.

Here are five factors you should consider when shopping for a furnace humidifier:


Fan-powered furnace humidifiers are very efficient and can produce more humidity than a bypass system, but they are a little more expensive. The benefit is that they can be run even when the furnace isn’t on.

Coverage Area

This refers to the size of the house, generally measured in square feet. Match the coverage area of your furnace humidifier to the square footage of your home.


The maximum output per day of a humidifier describes the amount of water that can be evaporated within a 24-hour period at full speed. To give you some context, a max output of 16 gallons per day is generally enough for a 3,000 to 4,000 square-foot home.


Most furnace humidifiers require minimal maintenance, but it’s still important to check. Fan-powered furnace humidifiers require filters that need to be replaced once a year.


Take a look at how the furnace humidifier is controlled and how many options you have for customization. Some units have automatic controls based on a preset humidity level.

Once you’ve chosen a furnace humidifier, it’s important to install it properly. While some units may be simple enough, it’s never a bad idea to leave the job to the professionals. After installation, make sure you have the unit cleaned at least once a year to remove mineral deposits. Be sure to keep an eye on humidity levels as well – excessive moisture can lead to water damage and mold growth.

The Best Furnace Humidifier Picks to Consider

We encourage you to consider the furnace humidifier pros and cons for any model before you buy, but we also understand the sheer number of options can be overwhelming. To help you get started, we’ve assembled a small list of furnace humidifiers we recommend.

We recommend the following furnace humidifiers:

Honeywell HE300A1005 Humidifier

For its fully automatic function and generous output, this Honeywell humidifier is a great option for large homes. It has a maximum daily output of 18 gallons per day, giving it a large coverage area of 4,000 square feet. It comes with the HumidiPRO Digital Humidity Control system, so it runs automatically, and it is fairly easy to install by yourself.

Aprilaire 700 Humidifier

This well-trusted whole-home humidifier is perfect for large homes up to 4,200 square feet. With digital controls that display both temperature and relative humidity, this model is low-maintenance and easy to operate. It has a max output of 0.75 gallons per hour and only needs to be serviced once a year.

GeneralAire 1000A Humidifier

Designed for medium-sized homes up to 3,000 square feet, this fan-powered humidifier has a maximum output of 18 gallons per day. Because it is fairly simple, this unit may not require professional installation – it only requires 24V rather than the typical 120V. Just keep in mind that professional installation is required to take full advantage of the 10-year warranty.

Honeywell HE360A Humidifier

If you’re looking for an economical option for a larger home, this flow-through humidifier is worth your consideration. With a max output of 0.75 gallons per hour, this low-maintenance humidifier can cover up to 4,200 square feet. It can be mounted on the warm air supply or return air duct but due to its significant size, professional installation is recommended.

AIRECARE MA1201 Humidifier

As an alternative to a furnace humidifier, this console-style whole-house humidifier from AIRCARE is a convenience option. Rather than using steam from your furnace, it adds cool moisture to the air. This unit has a maximum output of 12 gallons per day and a coverage area up to 3,600 square feet. It has electronic controls and a built-in humidistat for convenience.

Whether you’re trying to combat low humidity or just make your home more comfortable for winter, a furnace humidifier is the way to go. Take what you’ve learned here to start shopping or consider one of the recommendations we’ve made above.