How a Humidifier Works

Humidifiers add moisture to the air in your home to reach optimal humidity levels, which in turn can improve the overall air quality inside.

two general categories of humidifiers

Whole-house humidifiers are connected to your existing HVAC system and your water line by an HVAC professional. They automatically control the humidity levels within your home. Portable humidifiers are standalone systems with single room coverage that typically require you to manually operate them for humidity control.

What is relative humidity?

Now that you know what humidity is, let’s talk about relative humidity, which takes the concept one step further. The term humidity is actual moisture in the air, whereas relative humidity is the measure of how much moisture the air could potentially hold at a given temperature. This means, if the relative humidity is 50%, the air is only holding moisture at 50% of its capacity. If relative humidity is at 100%, the air is holding all the moisture it can, like during a rainy day in the summer.

How to use a humidifier

Choose a properly sized system for your home. Just like your HVAC systems, a humidifier needs to be properly sized for the space it’s working in. Consider the total cubic footage of your home, the age of your home, the construction (new, old, tight, reinsulated etc.) to determine the right sized system for your home. Optimize your humidistat setting. When looking to invest in a humidifier, learn about the system and the settings available for you to use. Some humidifiers require you to manually control moisture levels while others can automatically do so. To use your humidifier to the best of its ability, select a model that meets your lifestyle needs. Maintain your system. With frequent use, your humidifier will likely start to accumulate mineral build up, dust, rust, or bacteria. The best way to avoid any cleanliness issues with a portable humidifier is to regularly wipe down your system, flush the reservoir, and fill it with fresh water. You can do this with most simple household solutions and a rag, but it’s always a good idea to consult your humidifier’s owner’s manual for exact maintenance instructions. If you have a whole-house humidifier, maintenance is typically performed annually by your HVAC professional. Select your optimal settings. When you invest in a humidifier, learn about the system and the settings available for you to use. Some humidifiers allow you to set up a schedule, while others give the homeowner the ability to control moisture levels. To use your humidifier to the best of its ability, make sure you customize it to your needs.

When to use a humidifier

You get dry skin or chapped lips in your home. You experience static shocks. You’re frequently dealing with sinus issues or nosebleeds in your home. You can’t sleep well throughout the night. Your home’s interior is becoming damaged (chipped paint, cracking wood moldings around doors and windows, sagging or separated wood floors.) You have consistent asthma or allergy flare-ups while inside your home. You have to turn your thermostat up to feel comfortable. Your plants are drying out.

Which type should you use?

The type of humidifier you should purchase depends on your personal preferences and needs. Consider factors such as the amount of space you want to moisturize (size of your home), your budget, the level of maintenance you can tolerate, the furnishings in your home (wood floor warranties can be void if you can’t prove humidity control), and your family’s needs (children, pets, etc.) to determine the best humidifier for you.

Benefits of using a humidifier

Reduced heating costs. Decreased health problems like sinus infections, asthma, and dry skin. Fewer static shocks. Better sleep and reduced snoring through the night. Less structural and interior home problems like chipping paint, cracked molding around windows and doors, and separating wood floors. Proper levels of humidity in all parts of the home. Proper humidity with minimal maintenance. Increased comfort and air quality within your home.

What does a humidifier do?

A humidifier adds moisture to the air in your home, with the end goal of optimizing indoor humidity levels. The term “humidity” simply refers to moisture in the air. The term relative humidity is the percentage of moisture in the air compared to what the air can hold at a given temperature. The optimal indoor humidity level is typically between 30% and 50%, according to the EPA, which means it’s best to have air containing between 30% and 50% relative humidity in your home.

What is a whole house dehumidifier?

A humidifier adds moisture to the air in your home, with the end goal of optimizing indoor humidity levels. The term “humidity” simply refers to moisture in the air. The term relative humidity is the percentage of moisture in the air compared to what the air can hold at a given temperature. The optimal indoor humidity level is typically between 30% and 50%, according to the EPA, which means it’s best to have air containing between 30% and 50% relative humidity in your home.

What is the ideal indoor humidity level?

While the best humidity level for your home is a subjective number, the best indoor humidity ranges between 30-50% according to the Environmental Protection Agency (EPA). The best humidity level for the home in winter to keep your home warm and cozy is somewhere between 30% and 40%, In summer, between 40-50% should be comfortable.

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Whole House Humidifiers

Discover Trane’s best whole house humidifiers. Trane offers a variety of fan-powered humidifiers, steam humidifiers, and bypass humidifiers. These humidifier systems operate with most HVAC systems to provide moisture and create the perfect humidity level for your home.

What to look for: home size, how much water is emitted in a day, and special features.

See our whole house dehumidifier options.

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Why choose a Trane whole-house humidifier

Sometimes called a furnace humidifier because of its common location next to the furnace, Trane humidifiers are backed by our innovative technology and dedication to energy efficiency.

If you live in a dry climate or an area with long, dry winters, you know that low humidity can cause dry skin, dry hair, chapped lips, and exacerbate a cough. Low humidity can also damage wood floors and furniture.

A whole-house solution makes everyone feel more comfortable and protects your home.

A variety of humidifiers for your house

All 3 types of our whole-house humidifiers connect to a water supply to draw in water as needed. When the thermostat sends a call for humidity, water releases into the humidifier. The humidifier then operates until the desired humidity level is reached, and then shuts off.

Options include:

Fan-powered humidifier
Bypass humidifier
Steam humidifier

Work with your Trane dealer to find the right solution for your home.

A host of whole-home humidifier benefits

Whole-house solution
Eliminates the need for portable humidifiers
Maintains a comfortable humidity level automatically
Can help with dry skin, allergies, respiratory health, and more
Can be controlled via the Trane Home App
Low maintenance – more on that below

Ease of maintenance

If you’ve ever used a portable humidifier, including a cool mist humidifier, you know you need to clean it at least weekly to avoid mold or mildew growth. You also need to replenish the water reservoir frequently.

In contrast, a whole-house humidifier is very low maintenance. Since it is connected to your home’s water supply, you never need to worry about replenishing the water. You will need to change the humidifier pad yearly. A steam humidifier may require more maintenance, and it should be performed by an HVAC technician.

Learn more about humidifiers

Humidity Control FAQs

What is humidity?

Humidity is the amount of water vapor in the air - whether you are indoors or outdoors. Higher humidity can make you feel hot and sticky, while lower humidity can make your skin, lips, and eyes feel dry.

What is considered high humidity?

Among other things, the American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE) sets indoor humidity standards and guidelines. They say that anything above 60% is considered high indoor humidity.

What should the humidity be in my house?

The Environmental Protection Agency (EPA) recommends indoor humidity levels between 30-50% for optimal comfort. Between 30-45% in the winter should keep you warm and comfortable while between 40-50% in the summer should provide a comfortable home.

How does humidity impact indoor air quality?

Humidity levels that are outside the optimal range can potentially negatively impact your home, your health, and your indoor air quality (IAQ). High humidity can provide an environment for mold, mildew, and dust mites to thrive. This can exacerbate allergies and make it harder for people with asthma to breathe.

By contrast, low humidity can allow bacteria, viruses, and other pollutants to move more freely in the air. Keeping the indoor humidity levels between 40-50% can help prevent respiratory infections caused by bacteria and viruses.

How do I control my indoor humidity?

The best way to achieve the ideal indoor humidity at home is by investing in a whole-house humidifier or dehumidifier, depending on the issues you are experiencing. Humidifiers and dehumidifiers work behind the scenes to keep your home at optimal humidity levels, so you don't have to think about your home's humidity.

You can measure and monitor their indoor humidity levels with a digital humidity meter (hygrometer) which you can find at most hardware stores.

What is a humidifier?

A humidifier is a supplementary HVAC system component that controls the humidity levels in your home by adding moisture into the air. Humidifiers aim to keep your home within the optimal humidity level range of 30% to 50% humidity. A whole-house humidifier can be a wise investment for people in colder climates and dry climates.

Humidifiers can help lower the risk of airborne virus particles spreading in your home. Plus, they can help you mitigate health issues like skin and throat irritation, nose bleeds, and static shock/electricity, as well as home issues like cracked wood and chipped paint.

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