In this guide

Central Humidifier Cost by Type

Central humidifiers come in three basic types, each of which has its own positive and negative attributes, as well as costs to consider. All three can help increase the relative humidity in your home, but they do so in different ways:

Drum Humidifiers

Drum humidifiers are the easiest to install, as well as frequently the least expensive. They use rotating evaporator pads to lift water from their reservoirs into the air stream, where it evaporates. This is effective, but very high maintenance, as it can cause mold growth. You need to clean the drum and change the pads regularly. They cost $200 to $350 on average.

Flow Through Humidifier

A flow through humidifier works with your furnace to distribute the moisture in the air. It may use electricity to work, but many do not require it, and while it needs constant water, it has a much lower risk of mold. Water flows through an evaporator pad, where it collects until it evaporates. This type of system is much lower in maintenance needs and costs $200 to $500 on average.

Steam Humidifier Cost

Steam humidifiers are the most effective, giving you better humidity control, with lower maintenance and lower mold risks. They use their own heat source to turn water into steam, which is then released into the air stream from your furnace. They will require an electrical power source, as well as a water source. These are the priciest to purchase and install with material costs of $700 to $1,000 on average.

Central Humidifier Cost by Capacity

Just like your furnace, your humidifier should be sized according to your home’s needs. A unit that was too small would struggle to add enough moisture to the air, while a one that was too large could increase your mold risks. Keep in mind that your home’s size is not the only factor that will determine your needs; how well insulated your home is, and whether or not you have a vapor barrier will play a role. The “tighter” your home is, the smaller the capacity you need. While there is some overlap between sizes, a general guide to finding the right one for your home is as follows:

Central Humidifier Cost by Power Source

Central humidifiers can either be powered, meaning that they use electricity, or bypass, meaning that they run off of your furnace with no added power. In general, any system that uses electricity will be more costly than a bypass, but both do have a range of costs.

Bypass Humidifier

Both drum and flow-through humidifiers may be bypass. These are also known as furnace humidifiers, and they use the air from your furnace to operate. They still need a water source to function, but with no electrical hook-up they cost less to purchase, install, and operate. They cost between $200 and $500 on average.

Powered Humidifiers

Any humidifier may be powered, including drum and flow through. Steam humidifiers, however, are always powered. This is because it takes a certain amount of energy in order to generate the heat needed to turn the water to steam. Because any system may be powered, they can have costs ranging from $200 to $1,000.

Central Humidifier Cost by Brand

Like all appliances, there are several manufacturers of quality central humidifiers. Each has their own quality, type, and cost to consider. Below are some of the costs related to the popular brands:

Honeywell Central Humidifier

Honeywell is well-known for their thermostats and other home heating and cooling appliances. They have a range of different systems as well, including both drum and flow through models. They do need to have professional installation to avoid voiding the warranty. They aren’t as sensitive to changing humidity in the air as other brands, so may take some experimentation to determine good levels, but can provide a good source of humidity without needing to bypass ducts. They cost $200 to $1,000 depending on the size and type.

Cost of Aprilaire Whole House Humidifier

Aprilaire is one of the most popular brands for whole house humidifiers. They make a wide selection of types including some steam units. They get consistently good reviews from users, who like the built-in humidistats and automatic shut offs. Depending on the unit you get, these can cost between $250 and $1,200.

Lennox Central Humidifier

Lennox is a recognizable brand of furnace, and they also make some central humidifiers. They’re less common than the other brands, and you will have fewer options. However, what they do make is very high quality with a long warranty. They can cost between $250 and $1,200 depending on the type you choose.

Emerson Central Humidifiers

If you want a top-of-the-line steam humidifier that will take up little space and work consistently, then you’re looking at Emerson. They don’t make as many variations in models as some of the other brands, but they do make high quality steam units that include humidistats and auto shut off. Because they specialize in this industry, their products tend to be higher quality in general. They cost between $700 and $1,200 depending on size.

Cost to Install a Whole House Humidifier

The exact installation process and the total cost of installation will vary widely, depending specifically on the unit you choose and the setup of your ducts. Most units install at the stack of the furnace, adding moisture to the air just as it leaves the furnace, but some will install in a return duct where it will humidify the air before it gets heated. Regardless, it must be installed where it can be connected to your cold water supply, as the unit will need continuous access to moisture.

Powered units may also need to be wired into your home’s electrical system, or, if there is a GFCI outlet nearby, you may be able to simply plug it in. In most cases, a template comes with the humidifier, and this is used to indicate where on the ducts to cut. The ducts are cut to accommodate the unit, it is connected to its water and/or power source, and attached to the duct. The entire process takes just under 4 to 5 hours on average, but can take less time for a simple drum unit, and more time for a complex steam system.

HVAC professionals typically charge $85 to $95 per hour, for costs of roughly $340 to $475. This makes an average total cost of $900 for a flow through humidifier break down into labor costing roughly $400, parts and connections to the pipe making up $100, and the unit itself costing around $400.

Cost of Adding Humidifier to Furnace

The cost of adding a humidifier to a furnace with a bypass setup rather than powered is pretty much identical, with the exception that you do not need to have a power source nearby. You will need to have a template, cut a hole in the duct as it attaches to the furnace, and install the system. Again, though the costs are the same, with a flow-through unit costing around $800 total, made up of $300 in labor, $100 for parts and connections to the pipe, and the unit itself costing roughly $400.

Ideal Home Humidity

For most homes, the ideal humidity level is going to be around 50%. In the winter months it’s common for humidity levels to naturally drop to 30% or 40%, which can make the air too dry. This is why a central humidifier can be beneficial.

Both low humidity and high humidity can lead to problems, however, which is why aiming for a balance of 50% is ideal.

Problems with Low Humidity

Low humidity causes the air to be dryer, which in turn can cause several potential health issues, as well as potential problems with your home and comfort level. These can include a higher risk of illness, as many viruses thrive in lower humidity, aggravation of issues such as asthma and allergies, and difficulty keeping warm at lower temperatures. Dry air can also contribute to static electricity and can cause damage to wood floors, windows, plaster, and paint. These materials may shrink or crack if the moisture level in the air gets too low.

Problems with High Humidity

Humidity that is too high can also lead to problems, which is why you should not use your central humidifier during the summer months when the air is naturally more humid. High humidity can cause issues that include mold, mildew, and bacteria growth that can cause health problems, as well as dust mite infestations and musty odors. Wood can absorb water, so wood floors and window frames can warp. Condensation and water stains can occur, as can peeling paint. Finally, high humidity can lead to a muggy or sticky feeling, as well as potentially labored breathing.

Humidistat vs Thermostat

If you install a central humidifier, you may find that it comes with a built-in humidistat. This is a gauge that controls how much moisture the unit is putting out, and lets you see at a glance what the current and desired levels are. It functions similarly in its reading, control, and output to a thermostat, but a thermostat controls your heating and cooling system, and not the humidity levels in your home. The humidistat controls only the humidity levels and not your heating and cooling system.

Humidistat vs Humidity Gauge

It’s important to keep humidity levels in check, not only for comfort, also but because having too much humidity in the home can lead to mold growth. For this reason, you will want to have a way to measure the relative humidity in the air to determine when to use the humidifier and when to turn it off.

There are two basic devices for doing this–a humidistat (or hydrostat) and a humidity gauge, sometimes called a hygrometer. Both will tell you what the humidity in your home is, but they work in different ways.

A humidity gauge is a stand-alone device that you can use to determine the humidity in a room of your home. You can either install it on a wall or move it from room to room. It’s only going to tell you what the humidity is, and it won’t control your system.

A humidistat is used on the unit itself. It will also read the humidity, but it helps you control it with a programmable unit allowing you to set a specific humidity, so the unit will turn itself on and off when those levels are reached.

Humidistats can give you better control over your system, while humidity gauges can help you determine manually whether one room needs more humidity than another. Humidity gauges will also help you take a look at the humidity from the weather.

Most central humidifiers come with a humidistat built in. There are some very basic units that don’t have them, and they tend to cost a little less, but it’s very common for most of the popular name brands to have one. A stand-alone humidity gauge is a good accessory to have that you can purchase for $20 to $50.

Enhancement and Improvement Costs

Bypass Gate

Humidifiers should ideally only be used in winter when the air is dry; in the summer, humidity levels are usually already high enough. A bypass gate allows the unit to be shut off during the summer months when the air conditioning is on. The air from an air conditioner would flow around the unit, rather than through it, so you aren’t adding moisture to air that doesn’t need it. Most higher-end units come with one installed; they cost about $100 more on average.

Automatic Digital Humidifier Control

Many units also come with a built-in automatic digital humidifier control, which monitors the humidity levels both inside and outside the home, adjusting as needed. This can give you greater control over the humidity in your home. With a glance you can tell what the humidity is, what the desired level is, and adjust as needed. A unit with this feature will increase the costs by roughly $100.