How Much Does It Cost to Install a Central Humidifier?

If you have dry air in your home, particularly during the winter, you can add a central humidifier to the ductwork in your existing HVAC system to help. Central humidifiers work to increase the relative humidity in your home consistently, with the aim of making it more comfortable.

There are several types and sizes of central humidifiers, which can impact the cost of the project.

Installing a central humidifier costs, on average, $600 to $1,000 with the average homeowner spending around $800 on the professional installation of a flow-through humidifier.

Central Humidifier Installation

Recommended Humidity Levels for a Home

Keeping your home’s air comfortable for you and safe for the house’s structure depends on maintaining a stable humidity level. The EPA suggests that your home maintains less than 50% relative humidity. In the winter, this goes down to 30% - 40%. Improper humidity levels can cause issues with your house and your health.

problems Associated with Low Humidity

• Risk of illness: many viruses thrive in low humidity
• Worsening of conditions like asthma and allergies
• Static electricity
• Damaged wood floors, windows, plaster ¹, paint, etc.
• Needing higher temperatures to feel warm

problems Associated with High Humidity

• Mold and mildew growth
• Bacteria growth
• Dust mite ² infestation
• Musty odors
• Warped wood floors, window frames, etc.
• Water stains
• Condensation
• Peeling paint
• “Muggy” or “sticky” sensation
• Labored breathing

Humidifier Types

There are three types of humidifiers to choose from depending on the method to create humidity:

• Drum humidifiers use their drums (rotating evaporator pads) to lift water from the reservoir into the air stream, where it’s evaporated.
• Flow-through humidifiers send water flowing through a porous evaporator pad, where it collects and is evaporated.
• Steam humidifiers use their own heat source to warm water into steam, which is then released into the air stream.

Powered or Bypass Humidifiers

Humidifiers are either powered or bypass types. Powered humidifiers simply run on electricity and they will always fall at the higher end of the price ranges per type.

Bypass humidifiers have a duct that reaches out from the humidifier and attaches to the forced air furnace on the other side. They rely on the warm air coming from the furnace to evaporate water.

Drum and flow-through humidifiers can be bypass or powered types, while steam humidifiers are always powered. Skuttle, Hamilton, and Aprilaire are common brands that make all types of humidifiers. Honeywell and Aircare are popular flow-through and bypass humidifier producers.

Capacity Options

The capacity you should choose depends on your home’s size. The table below provides guidelines for suitable capacities:

Labor of Installing a Central Humidifier

HVAC technicians generally charge $50-$70 per hour. Central humidifier installation usually takes between 3.75 and 4.75 hours ($187.50-$332.50).

The time required depends on the humidifier size and type. A 10-gallon drum humidifier takes the least amount of time, while a large steam humidifier will take longer. The larger your home size and humidifier size, the higher the installation cost will likely be.

Humidistat vs Humidity Gauge

It’s important to keep humidity levels in check, not only for comfort but because having too much humidity in a home can lead to mold growth. For this reason, you may want to have a way to measure the relative humidity in the air both 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 humidifier.

A humidistat is used on the humidifier itself. It will also read the humidity, but it helps you control the humidifier, with programmable units 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 humidifier, 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.

Some central humidifiers will come with a humidistat built-in. These will tend to cost a little more, around $50 - $100 more than a unit without them, while a humidity gauge is a stand-alone unit that you can purchase from $20 - $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. A bypass gate allows the humidifier to be shut off during the summer months when the air conditioning. Most higher-end units come with one installed, they cost about $100 more on average.

Automatic Digital Humidifier Control

Many units can also come with automatic digital humidifier control, which monitors the humidity levels both inside and outside the home, adjusting as needed. This will increase costs by roughly $100.

Additional Considerations and Costs

Maintenance. Your humidifier will need regular maintenance to keep running properly. You should do your own minor maintenance every month (cleaning, adding water), but have your humidifier professionally maintained at least once per year. HVAC maintenance visits usually cost $70-$100.

Climate. Homes in climates that are naturally humid may not require a central humidifier. In fact, adding a humidifier in these climates may put your home at risk of mold development.

Weatherstripping can prevent the loss of humidity through gaps on the sides of doors and windows. If your house loses a high amount of humidity this way, this is a good alternative to installing a central humidifier. It’s also a great way to ensure that humidity produced by your new central humidifier from being lost. Enough weatherstripping materials to seal a home can be bought for about $100. Weatherstripping can be a DIY project, or you can hire a handyman to do the job ($60-$90 per hour). The project can usually be completed in 4 hours ($240-$360).

Energy bills. Installing a central humidifier can help you save on energy bills. Maintaining a higher humidity level 4 in the home can help you feel warmer at a lower temperature. This means that you won’t need to turn your heating up so high. The EPA estimates that you can save 4% on your heating bills for every degree lower you set your thermostat ³.

Remodeling Terms Cheat Sheet

¹ Plaster: A paste composed of sand, water, and either lime, gypsum, or cement, which forms a smooth hard surface on walls, ceilings, and other structures upon drying

² Mite: Small, often microscopic invertebrates that mostly live in the soil or water. Some mites are parasitic and live on plants and animals.

³ Thermostat: A device that senses and regulates temperature by turning heating and cooling devices on and off