September 4, 2021

How Does a Furnace Humidifier Work?

Automatic Compact Furnace Humidifier in Calgary, AB

How A Furnace Humidifier Functions

Suppose you own a furnace at your home. In that case, you’re probably aware that the heating system has several components that work together to heat your house. The furnace consists of a thermostat, ductwork, heat exchangers, blowers, and a humidifier attached to the end of your supply ductwork to moisten the air inside. How does a furnace humidifier work? You’ll see.

Attaching a humidifier to your HVAC system plays a crucial role in adding moisture to the indoor air. Therefore, purchasing a humidifier for your furnace is a smart choice since it will help you maintain the humidity level of the indoor air.

How does a humidifier work? In this post, we will show you the different types of humidifiers, how they work, and the benefits they offer.

Not all humidifiers function the same. Your humidifier could create and supply steam to the furnace’s airflow, hold a water reservoir, or use freshwater.

How a Furnace Humidifier Works

During winter, we are most likely to experience cold, dry conditions at home, which will send a chill across the rooms onto our bodies. The furnace humidifier is specifically adapted to introduce moisture into cold air before it’s warmed and distributed back in the house.

The humidifier is usually attached to your furnace’s water supply and ductwork, thus combining with the rest of the system in cooling the whole house. Having a humidifier at home affirms that your indoor air will be adequately heated, thus achieving the desired comfort level.

Types of Humidifiers


The Bypass humidifier attaches to the return air ducts of your furnace to withdraw heated or warm air from the ductwork. This furnace humidifier is known to be cost-effective since they don’t require any motors to run.

The bypass humidifier depends on the air blown by the blower to carry some moisture when passing over the water panel before the warm air flows through the supply vents. This humidifier is known for its affordable energy usage costs and minimal chances of experiencing mold since the humidity is carried through the ductwork only.

One disadvantage of a bypass humidifier is that it must move the moisturized air back into the furnace before distributing the air throughout the house, making it less effective.


The humidistat measures the moisture in the air. When the humidity drops below an acceptable level, the humidistat signals the steam humidity to increase the moisture in the air.

The steam humidifier heats water in a reservoir. The water turns to steam. Subsequently, the furnace circulates the moisture into the home at a low speed.

Steam humidifiers are seemingly expensive upfront and challenging to operate compared to others.

Why does my furnace short cycle?


Typically, a flow-through humidifier mounts to the furnace’s cold-air return duct. The flow-through humidifier turns on when your home’s moisture level falls below a certain level. Water moistens the evaporator pad. Warm air from your furnace moves through the evaporator pad. The warm air absorbs moisture to create humidified air. Air then flows through your ductwork and into your home.

The flow-through humidifier is popular with homeowners since it is more reliable, less expensive, and has less electricity.

Why You Should Install a Humidifier

Apart from providing an answer to your frequently asked question, ‘how does a furnace humidifier work?’ We’ll also check out a couple of reasons that might force you to install a humidifier for your furnace or HVAC.

Save energy costs

Moist air brings a certain sense of warmth into the house than dry air, which can usually make the room seem even colder. When air humidity rises in your home, you’ll set your thermostat a few degrees lower and be comfortable, thus saving up to 5% of your energy costs. It also helps to clean your furnace and upgrade to a high efficiency furnace.

Achieve certain comfort levels

During winter, the cold climate dries the air, which affects your eyes, skin, and lips. Over time, dry conditions can lead to cracking, chapping, or itchy skin.

To handle such complications, we recommend raising the humidity in your house with a humidifier to moisturize and heal your skin and eyes and put your throat at ease. As we all know, prevention is better than cure.

Maintain indoor air quality.

Having just the right amount of humidity in the air will improve the air quality of your house. If the moisture levels range from 40-50 percent, the dust, debris, or even allergens are minimal in the air.

The humidifier helps get rid of bacteria and dust pests adapted to the cold and dry surroundings. Therefore, the furnace humidifier plays a crucial role in reducing the chance of getting allergies and flu due to dry cold conditions.

How Does a Furnace Humidifier Work?

How does a furnace humidifier work? In this post, we’ve outlined why you need a humidifier in your house. Moreover, we’ve identified the various humidifiers that attach to your furnace and their benefits.

Take your time when choosing a humidifier for your home, or contact an HVAC professional to advise you. Purchase an affordable whole-house humidifier to ensure your family’s health, comfort and energy savings this upcoming winter.