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.

What is a humidifier?

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.

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.

Indoor Air Quality4min read

How to Change Indoor Humidity Levels

Explore quick and easy ways to achieve the ideal indoor humidity.

Published:
January 4, 2024

Indoor humidity plays a crucial role in maintaining a comfortable and healthy living environment. From preventing mold growth to ensuring optimal respiratory health, controlling indoor humidity is key. In this comprehensive guide, we will delve into the factors influencing indoor humidity levels, the ideal humidity range, and practical strategies on how to adjust humidity to create a balanced and comfortable atmosphere within your home.

What is Humidity?

Before we explore methods to change indoor humidity levels, it's essential to understand what humidity is and why it matters. Humidity refers to the amount of water vapor present in the air. It is a critical factor in determining the comfort, health, and overall well-being of indoor environments. Humidity levels are typically measured as a percentage, representing the ratio of the actual amount of water vapor present in the air to the maximum amount the air can hold at a given temperature.

What is High Humidity?

High humidity in HVAC refers to a situation where the indoor relative humidity levels are elevated beyond the desired or comfortable range. The recommended indoor relative humidity for comfort typically falls between 30 percent and 60 percent. Anything above this range can be considered high humidity when it comes to HVAC.

High humidity levels can lead to discomfort, reduced indoor air quality, and potential issues such as mold growth and condensation. It can make the indoor environment feel sticky, cause musty odors, promote the proliferation of allergens, and even impact the efficiency of cooling systems.

The Best Humidity Level for Your Home

Maintaining the right indoor humidity is crucial for both comfort and health. The recommended indoor humidity level typically falls between 30 percent and 50 percent. This range helps prevent issues such as mold growth, dust mites, and respiratory discomfort.

However, the ideal home humidity level changes with the seasons. In the summer, your family may feel most comfortable indoors with a humidity level hovering at 30-40 percent. When the environment reaches 50 percent or higher, you’ll notice the air begins to feel sticky.

During the winter, however, the desired level can be adjusted to 40-50 percent. The cooler air that fills winter days is often dry, so a higher humidity level in your home can help you avoid seasonal challenges like dry and itchy skin.

Factors Influencing Indoor Humidity

Relative humidity refers to the amount of moisture, or water vapor, present in the air. If you live in a tropical or coastal climate, the outdoor humidity can make summer temperatures feel much hotter. The same is true for your home. The feeling of heavy stickiness or heat can turn your home into an uncomfortable, damp space. Several factors contribute to indoor humidity levels, and understanding these factors is the first step in effectively changing the humidity in your house.

Temperature:
- Humidity levels are closely tied to temperature. Warmer air can hold more moisture, resulting in higher humidity levels. Conversely, cooler air has a lower capacity for moisture, leading to lower humidity.
Ventilation:
- Insufficient ventilation can trap moisture indoors, leading to elevated humidity levels. Proper ventilation, including the use of exhaust fans and cross-ventilation, is crucial for maintaining balanced humidity.
Activities:
- Daily activities such as cooking, showering, and even breathing contribute to indoor humidity. These activities release moisture into the air, affecting overall humidity levels.
Water Intrusion:
- Leaks, seepage, or water damage can introduce excess moisture into the indoor environment, leading to high humidity levels and potential mold issues.
Seasonal Changes:
- Humidity levels often fluctuate with the seasons. Winter air tends to be drier, while summer air can be more humid. Understanding these seasonal variations is essential for effective humidity control.

How to Change Humidity in Your House

Now that we've covered the basics, let's explore practical strategies to change the humidity in your house and create an environment that promotes comfort, health, and well-being.

Use a Dehumidifier or humidifer:
- Dehumidifiers are effective devices designed to reduce excess moisture in the air. They extract water vapor and collect it in a reservoir, helping to maintain optimal humidity levels. Place dehumidifiers in areas prone to high humidity, such as basements, bathrooms, or laundry rooms. If your home is too dry, a humidifier can add moisture to the air.
Install Ventilation Systems:
- Proper ventilation is crucial for maintaining balanced humidity levels. Install exhaust fans in kitchens and bathrooms to expel moist air outside. Consider a whole-house ventilation system to ensure consistent airflow throughout your home.
Seal Leaks and Repair Water Intrusion:
- Identify and repair any leaks or water intrusion points in your home. Addressing these issues prevents excess moisture from entering, reducing the risk of high humidity and associated problems.
Utilize Air Conditioning:
- Air conditioners not only cool the air but also dehumidify it. Running your air conditioner helps regulate both temperature and humidity, creating a more comfortable indoor environment.
Use Humidity-Controlling Appliances:
- Invest in appliances that control humidity, such as hygrometers and humidistats. These devices measure humidity levels and can be programmed to maintain a specific range, providing automated control.
Strategically Place Houseplants:
- Certain houseplants, such as spider plants and peace lilies, can naturally absorb excess moisture through a process called transpiration. Strategically placing these plants in areas with higher humidity can contribute to a more balanced indoor environment.
Open Windows and Doors:
- Encourage natural ventilation by opening windows and doors, especially during periods of lower outdoor humidity. This allows fresh air to circulate, helping to balance indoor humidity levels.
Use Moisture-Absorbing Materials:
- Incorporate moisture-absorbing materials like silica gel or desiccants in areas prone to humidity issues. These materials can help absorb excess moisture and maintain an optimal environment.
Adjust Daily Activities:
- Be mindful of activities that contribute to indoor humidity. Ventilate well while cooking or showering, and avoid overwatering indoor plants. Small adjustments in daily routines can have a significant impact on maintaining balanced humidity.
Monitor and Adjust:
- Regularly monitor indoor humidity levels using a hygrometer. Adjust your humidity-control devices based on readings to ensure that your home's environment remains within the recommended range.

Signs of Poor Indoor Humidity

The right balance of moisture in the air in your home will make your space more relaxing and enjoyable. When the humidity level begins to increase or decrease outside the recommended range, you may notice personal and environmental changes. Indicators of poor indoor humidity include:

Signs of Low Humidity

Skin irritation
Throat or nasal irritation
Bothersome allergies
Restless sleep
Cracked wood floors
Chipped paint
Electronic parts become brittle and break

Signs of High Humidity

Asthma complications
Congestion, sneezy, runny nose
Restless sleep
Mold growth
Increase in dust mites
Warped wood floors
Rot or mold on wood furniture

If you notice these humidity-imbalance red flags within your home, use the tips below to create a more comfortable environment.

How to Improve Indoor Humidity Levels

Achieving and maintaining optimal indoor humidity levels is essential for creating a comfortable and healthy living space. By understanding the factors influencing humidity, utilizing appropriate tools and appliances, and implementing strategic adjustments, you can take control of your indoor environment. Whether it's investing in a dehumidifier, improving ventilation, or making small changes to daily activities, these steps can contribute to a balanced and harmonious indoor atmosphere for you and your family.

For a hands-off approach to managing your indoor humidity level, rely on a thermostat designed with sensors that monitor it for you. The Trane ComfortLink® II XL1050 has a thermostat humidity setting and constantly optimizes the temperature and humidity in your house by adjusting compressor and fan speeds as needed.

In order to improve the low humidity levels in your home, try simple practices like using radiant heating devices in the winter, steaming clothes rather than ironing, and adding a humidifier to your heating and cooling system.

For high humidity levels, be sure to use the bathroom and kitchen fans to eliminate moist air from the space. It's also important to regularly change your HVAC and home air filters, cover pots and pans while cooking on the stovetop, and temporarily place houseplants outside or secluded in one space. You may also consider a whole home dehumidifier for improved indoor humidity year-round.

Trane Solutions

When a Trane Comfort Specialist® installs or replaces your HVAC system, you get more than the high-quality heating and cooling system that’s become synonymous with the Trane brand. Our highly trained professionals know what size of unit is best for your home.

If your HVAC system is too small, it continuously runs, increasing your energy bill and never reaching a comfortable temperature or regulated humidity level. When an HVAC unit is too large for a home, the system doesn’t run long enough to properly dehumidify the air, leaving your home with high levels of moisture that will feel uncomfortable.If the humidity level in your home is constantly fluctuating, contact a Trane dealer to identify the root of the problem and offer an energy-efficient solution that fits within your budget.