What Should Your Furnace Humidifier Be Set to in the Summer?

Amy Pawlukiewicz
Written by Amy Pawlukiewicz
Updated July 26, 2022
Father and mother with son on sofa at home
Photo: Laetizia Haessig / EyeEm / EyeEm / Getty Images


  • The ideal home humidity level is between 30% and 50%.

  • You can measure your home humidity level with a hygrostat.

  • Appropriate humidity levels can mean better health, more energy savings, and preserving the wood in your home.

  • Consider investing in a whole-home humidifier, which costs between $100 and $300.

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During the winter, your furnace humidifier fights against dry air to keep your home balanced. But it also works quietly behind the scenes during the summer when you have the air conditioner cranked. This is a good thing. For maximum comfort, your furnace dehumidifier should run year-round to maintain an ideal “summer” humidity setting. Here’s what you need to know.

What Exactly Is Humidity?

While you may not actively think about it, water vapor floats around in the air in your home. This water vapor is measured in percentages and indicates how much water the air can hold before the water changes to liquid form, causing condensation. Controlling humidity in your home is important because while you want the benefits of having moisture in the air, having too much leads to problems like mold and mildew.

The Ideal Home Humidity Level

The right home humidity level should be between 30% and 50%

You’ll want to aim for 30% to 50% humidity in your home for the maximum comfort level. There are a couple of things you have to factor in when setting your home’s levels during the summer. 

  1. Indoor humidity is inevitable in humid climates, so you’ll need to adjust your settings.

  2. Running your AC unit will dry out the air in your home. 

Keeping the humidity levels in the right range is a balancing act, but it’s a good idea to start at 40% and make adjustments based on whether you have too much moisture in the air or not enough. Using this setting along with other summer HVAC tips should keep the air in your home comfortable.

How Do You Measure Humidity?

A digital temperature and humidity control
Photo: vladdeep / Adobe Stock

You can measure humidity levels in your home with a hygrometer device or an indoor humidity monitor. Most local hardware stores sell them, and the basic models usually cost around $15 to $25

Aside from springing for a hygrometer, watch for signs that indicate your humidity levels are off. If moisture forms on the inside of your windows, your humidity level is probably too high. If your plants (and your skin) are drying out, or you experience a shock when you touch a light switch, your levels are likely too low.

Benefits of Humidity

There are numerous benefits that you can get from keeping your home humidity at an appropriate level.

Better Health

Keeping your home’s humidity around 40% provides health benefits to you and your family. Humidity keeps your nasal passages and throat moist, preventing dry, irritated sinuses that can spark illness. You’ll also keep itchy eyes and dry skin at bay by keeping your humidity levels up.

Prevents Wear and Tear on Your Home

If your humidity setting is too high, you’ll create a damp environment where mold and mildew thrive. Set it too low, and your wood and furniture can dry out and crack. Are you working on building a dreamy home library? Low humidity levels also make it difficult to keep books in good condition, leading to cracking spines and dried glue.

Helps Save Energy 

The right amount of moisture in the air will make your home feel cooler, allowing you to set your air conditioner at a higher temperature. Increasing the thermostat even one or two degrees during the summer can make a difference in your energy bill.

Invest in a Good Humidifier 

One of the best ways to control moisture and humidity in your home is to invest in effective humidifiers for the summer. You can even install a whole-house humidifier if moisture (or lack thereof) is a particular concern in your home, but this is a project that will likely require the services of an HVAC contractor. A whole-house humidifier costs between $100 and $300, not including the cost of labor for installation.

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