What Is a Humidistat and How Does It Work?

When it comes to keeping your home comfortable and healthy, controlling the humidity levels can be just as important as regulating the temperature. That’s where a humidistat comes into play. But what is a humidistat, and how does it work? HVAC.com discusses what a humidistat does, its purpose, and why it can be a crucial component in managing indoor air quality.

What Does a Humidistat Do?

A humidistat, also known as a hygrostat, is a device used to monitor and regulate the humidity level in your home. Essentially, it acts like a thermostat, but instead of measuring temperature, it measures the relative humidity, or the moisture content in the air, to ensure it stays within the desired range. 

The device works by sensing the current humidity level and adjusting your HVAC system (such as a whole-house humidifier or dehumidifier) to either add or remove moisture from the air to maintain proper humidity levels.

Humidistats are typically located near the thermostat or installed on the return air duct. In homes with fluctuating humidity, especially in areas with extreme weather, a humidistat helps keep indoor moisture levels in check to ensure comfort and prevent issues like mold, dust mites, and dry skin.

How Does a Humidistat Work?

At its core, a humidistat functions in much the same way as a thermostat but for humidity. When the humidity in your home exceeds or drops below your desired level – typically between 30-50% – the humidistat signals either your whole-house dehumidifier or humidifier to start up.

For example, in the case of a humidifier, if the air becomes too dry (a common problem during winter), the humidistat activates the humidifier to add moisture to the air. Meanwhile, during hot and humid summer months, if the humidity rises too high, the humidistat may turn on a dehumidifier to remove excess moisture from the air.

This automatic process ensures that the humidity remains within a comfortable range without you having to manually adjust the settings. A properly calibrated humidistat helps keep your indoor air comfortable and fresh with little effort, automatically adjusting your system throughout the day as needed.

What Is the Purpose of a Humidistat?

The purpose of a humidistat is to improve comfort, support your health, and protect your home and belongings by maintaining optimal humidity levels.

Health Benefits

Humidity plays a major role in your respiratory health. Too little moisture in the air can lead to dry skin, irritated eyes, and dry nasal passages, among other issues, while excessive humidity can cause mold growth, dust mites, and other allergens that can affect your health. A humidistat helps strike the right balance, ensuring the air is neither too dry nor too damp.

Preserving Your Home

Excess moisture can cause damage to your home’s structure, such as warping wooden furniture or promoting mold growth. On the other hand, low humidity can dry out wood and cause cracking or splitting in furniture, flooring, and even musical instruments. By balancing humidity levels, a humidistat helps protect your home from damage over time.

Energy Efficiency

Managing the right amount of humidity can also make your home feel more comfortable, which can reduce the need to adjust your thermostat as frequently. For instance, during winter, higher humidity levels can make the air feel warmer, allowing you to lower your thermostat and save on heating costs. In summer, proper humidity levels can help you feel cooler without cranking up the air conditioning.

Why Should You Consider Adding a Humidifier or Dehumidifier Controlled by a Humidistat?

If you live in an area with significant seasonal changes, where indoor humidity fluctuates greatly between winter and summer, adding a humidifier or dehumidifier controlled by a humidistat can help create a consistent and comfortable indoor environment year-round.

Here are a few reasons why you might want to consider installing one:

• Better Control Over Your Home’s Air Quality: A humidistat gives you more precise control over the moisture levels in your home, ensuring a consistent environment year-round.
• Improved Comfort: If you’ve ever experienced static electricity shocks, dry skin, or difficulty breathing during the winter months, a humidistat can help ease these uncomfortable side effects by allowing you to balance humidity levels.
• Reduced Energy Bills: By helping to maintain comfort at a lower or higher thermostat setting (depending on the season), a humidifier or dehumidifier controlled by a humidistat can contribute to energy savings.