What Should A Humidifier Be Set At In Winter And Summer?

The importance of a humidifier for people who live in arid areas or cold and dry winter months can never be overstated. It could make you feel much better in winter or summer. But many of us don’t know how to set it in these two seasons.

In general, you can set the humidity level between 35% to 45% in winter and turn it off in summer. If you need to use a humidifier in summer, a 45% to 55% setting would be good.

So why we need to change the humidifier settings according to seasons, and how to adjust the settings. I am going to touch on all these related questions to help you have a firm understanding of this topic.

What is relative humidity?

what is relative humidity

We often talk about humidity levels when discussing anything related to humidifiers. So what is it exactly?

The humidity level represents the indoor relative humidity. It describes how much water vapor is in the air compared to how much water the air can hold. 

For example, the air can hold 0.5 gallons of water at most, and the relative humidity level is 40% now. It means that the water in the air at present is 0.2 gallons.

In addition, the higher the temperature, the more water it can hold. So people tend to feel the air more humid in summer than in winter as it can hold more water naturally.

But in general, we will feel comfortable in a relative level of humidity between 35% to 55%.

Why do we need to change humidifier settings in winter and summer?

People who care about the winter and summer settings are likely to have a furnace humidifier installed. These humidifiers in the HVAC system are not as accessible as other portable units, and you don’t want to adjust them every so often. 

So it is important to set a proper humidity level and let it run all the winter or summer. But you should also adjust the settings if you have a portable one. 

In winter, the humidity outdoors is low, and when the heating system is on, it will dry out the air even further. So staying at home in the winter months could mean agony. In this case, you should open the humidifier and let it add more moisture to the air.

However, the air outdoors is humid in many areas. You can get the same moist air by simply opening the windows and doors. Therefore, you don’t need to use a humidifier at all. You may need a dehumidifier instead.

Another downside of using a humidifier in summer is that it can cancel out the air conditioner as it provides cold air by increasing the indoor humidity. 

That’s why people often try to set the humidifier in winter and turn it off after the cold climates.

What should a humidifier be set at in winter?

It is hard to give a single clear-cut answer to this question because different people have different comfort levels. In addition, you should also consider your pets, electronics, and furniture.

Usually, 45% is a sweet spot, but 35% to 40% would be a good baseline. 

The general rule of thumb is that you shouldn’t get any condensation on your windows or other objects. The condensation is a sign you set the humidity level too high.

The condensation could lead to an array of damages in your home. For instance, the condensation can roll down into the frame, get into the wall, or the inside of electronics, resulting in wood rot and mold growth, and so on.

You should decrease the humidity level a bit whenever you see the condensation. However, you should also check if you have dry skin and eyes, sore throat, or any other symptoms of dry air. If yes, then you should increase the humidity accordingly.

What should a humidifier be set at in summer?

The air outdoors is more humid in summer. Many regions in America have a relative humidity level of around 40% to 60%. The relative humidity in the morning can even be as high as 80%. 

Based on these figures, you don’t need to use any humidifier in most cases. You can just set it off if you have a furnace humidifier.

In fact, people may need to use a dehumidifier or AC instead to decrease indoor humidity. When the humidity level is over 60%, mold, bacteria, and dust mites will thrive, posing health risks to us. 

If you have to use a humidifier, then setting it to 40% to 50% would be great. Due to the high temperature outside, the condensation is harder to form in summer. But you should also examine the conditions of your home and your body.

For example, if you find the smell of mildew or mold or feel the air is clammy, these could be the signs of high humidity. 

How to set a furnace humidifier in winter and summer?

A furnace humidifier is an add-on to your HVAC system to adjust the humidity level all over the house. You can also call it a whole-home humidifier.

Most furnace humidifiers these days have a humidistat to monitor the humidity level and modify how much water vapor is released into the air accordingly. There are a few levels for you to choose from “off” to “max humidity.” 

You can label it with a “W” and an “S” to indicate what is the best settings for winter and summer and follow the instruction every time you need to set the humidifier.

There is another knob on the dust. You should turn it on to allow the humidifier to function and turn it off when not in use. Typically, you will set it off and open the AC in summer.

Note that you should clean the humidifier before and after you set it to make sure the air in your home is not full of harmful contaminants. 


This post discussed the humidifier settings in winter and summer.

In winter, you can set it between 35% to 45%, but you should also observe if there is any condensation. If it happens, then you should lower the set humidity level. Or, if your symptoms, such as dry skin or parched throat, are not relieved, you may need to increase the setting a bit. 

In summer, you may need to turn off the humidifier completely as the humidity outdoors is already in the ideal range or even too high. What you need at this moment may be a dehumidifier or an AC. For those humidifiers that have a built-in gauge, it may stop working automatically. 

If you have to use a humidifier for any reason, the ideal setting would be between 40% to 50%. But still, you should adjust it according to your health conditions and the conditions of your furniture. 

You can label your humidistat of furnace humidifiers with a “W” and an “S” so that you can know the best settings every year easily without constant adjusting.

A home that is too humid or too dry will lead to adverse effects on your home and your health. You can set your humidifier starting at 35% and increase it gradually until you find the best settings for your home. 

About The Author

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Liz Yang is the founder of Airsmartly. She has been working at home for a few years and realizes that the performance of the HVAC system plays such an important role in our life. She has tested dozens of products in person, like humidifiers, air purifiers, dehumidifiers, and ACs, and wants to share tips about using or troubleshooting these products with you. Her uncle is an HVAC expert with over 30 years of experience in the field, and often offers assistance when she is unsure how to handle a situation. He is also in charge of reviewing the articles on this site.

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