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The three types of whole-house humidifiers: which one is right for you?

February 29, 2016 • By


The three types of whole-house humidifiers: which one is right for you?

Buying a whole-house humidifier is a big investment. Unlike portable humidifiers, these humidifiers are installed into your home and therefore require time, effort, and a little more money to set up and run.

You should consider purchasing a whole-house humidifier if you want your entire house to benefit from a balanced, healthy level of humidity in the air. With an imbalance of humidity, specifically dry air, people report suffering from many ailments. Particularly in winter, the dry air can lead to chapped lips, dry skin, sinus infections, allergies and much more. Moreover, with a good level of humidity in the air, you are less susceptible to illness, will recover quicker from fevers, will stop snoring and will even save on energy bills since you will feel warmer in your home.

People are often caught up deciding between  a whole-house humidifier and a portable humidifier. If humidity levels around your home are constantly low, you should consider getting a whole house humidifier rather than just a portable one. With a portable humidifier, you may fix the problem in one area of the house, but the issues will continue elsewhere. Statistics state that we spend on average 60% of our indoor time inside our house, and so a healthy home is essential!

How humid do you want your home?

Indoors the relative humidity should be kept above 30 percent at all times. This will help you avoid illness, help your furniture last longer and generally leave you and your family much healthier. Humans can be comfortable with a range of different humidity levels depending on the temperature. The range is usually somewhere between 30 percent and 60 percent.

If you live in a climate where the temperature is likely to fluctuate then you should pay careful attention to the relative humidity levels. Generally speaking during winter you should have levels around 30 percent, and during summer between 50 and 60 percent. Your own preferences will also come into play.

What are the different kinds of whole-house humidifiers?

Whole house humidifiers typically attach to your home’s air ducts. They may work independently or alongside your home’s heat cycle. Hot air that flows through your home is diverted into the humidifier. The humidifier processes the air with moisture and then blows it back out through the house vents.

There are three main types of whole house humidifiers. These are Bypass, Fan-Powered and Steam. Now let’s look at these types in more detail.

Bypass Humidifiers

Bypass humidifiers use a furnace to add moisture to the warm air in your home. They suck the warm air in from your home’s heat ducts, where it then passes through a water panel. Here, the air absorbs moisture. This air is then dispersed back into your home as steam.

Bypass humidifiers are usually installed on the Supply or Return part of your forced air system. Some bypass humidifiers, like the Aprilaire 400M, are very efficient at water conservation and will not lead to any water buildup around the unit. If your humidifier is not like this, however, it is recommended to buy a drainless bypass filter, which will reuse the water already in the unit, thus reducing the amount of water that is used and wasted.

Fan-Powered Humidifiers

Fan-powered humidifiers are very similar to bypass humidifiers. The difference is that the fan-powered humidifiers, as you may guess from the name, include a fan. This fan blows air across the water panel which increases the amount of evaporation that takes place. Power humidifiers can therefore produce much more humidity per day. In fact, the total increase can be more than a gallon of humidity each day compared to the bypass humidifier.

Since these humidifiers do not require a bypass duct, they can be installed in relatively small spaces. This makes fan powered humidifiers a great option if your home is built with its HVAC in the closet.

Steam Humidifiers

Steam humidifiers will increase the level of humidity in the air by heating up water until it boils. Once the water is boiled the steam from it will be pushed through your home’s vents by the system’s fan. This type of humidifier is the fastest and most efficient method of increasing and maintaining the right level of humidity in your home. Steam humidifiers also produce the most pure and natural humidity for your home, and will run regardless of your home’s heating situation.

So which type of whole house humidifier is the one for me?

Each type of whole home humidifier comes with advantages and disadvantages. Here we lay out some of them.

Bypass Humidifiers


The pros of the bypass humidifiers are that they are the least expensive and the easiest to install.


Bypass humidifiers require a lot of maintenance and parts will need replacing frequently. There is also an issue with standing water.

Fan-Powered Humidifiers


Unlike the bypass humidifiers, with the fan-powered humidifiers you do not have standing water. Fan-powered humidifiers are also relatively cheap and easy to install. There is little risk of mold.


Requires a water line and is always using new water. Not as efficient as steam humidifiers.

Steam Humidifiers

Pros: Steam humidifiers produce steam independently, making control of the humidity levels easier. There is a low risk of mold and they are generally the most effective of the whole house humidifiers.

Cons: Owing to their sophistication, they are also the most expensive and the most difficult to install.

Why buy a humidifier?

Humidifiers help balance the levels of humidity in your home. Moisture in a room is essential for staying healthy. During winter months a humidifier can also reduce your bills since humid air feels warmer, and you’ll end up using less energy in an attempt to stay cozy and warm.

A whole house humidifier is a very good option for people with large homes that want to get a good level of humidity throughout every room in their house. They require a bigger investment than the normal, portable humidifiers, but will give better results and require less frequent maintenance.