When our homes get too cool or warm, we look to our heating and cooling systems to make your home more comfortable. But what if we told you that your furnace or air conditioner isn’t affecting the temperature?

Relative humidity also plays a role. So, what is relative humidity and why should you care about it? Read on to learn the answers to all of your humidity questions down below.

What Is Relative Humidity?

To understand relative humidity, you first need to understand humidity (or absolute humidity). Humidity is the quantity of water vapor present in the air. In other words, how wet or dry the air is.

Relative humidity (RH) is the measure of water vapor present in the air in relation to the amount of water vapor the air can hold. For example, if you see a reading of 100% relative humidity, that means the air is completely saturated with water vapor and cannot hold any more moisture at that temperature.

Why Do We Measure Absolute and Relative Humidity?

Let’s say the temperature of the air in a room with 100% relative humidity rises. Because the air in the room is now warmer, it can now hold more moisture. This would cause the RH to lower, since the amount of water vapor in the air hasn’t changed, but the air’s capacity to hold water vapor has.

Absolute humidity doesn’t give you the whole equation. Because absolute humidity is based on the moisture content in the air, the number is the same no matter the temperature.

What absolute humidity doesn’t take into account is the air temperature. Cold air can’t carry as much moisture as warm air; it takes less water vapor to saturate cold air. So a cold room will reach 100% humidity faster than a warm room will.

Why Is Relative Humidity Important?

Humans are very sensitive to the amount of moisture in the air. As a result, environments with too much (or not enough) humidity feel very uncomfortable.

Why is this? Well, if a room or environment is very humid with a high relative humidity level, the sweat our bodies produce in an effort to keep cool and maintain our internal temperature won’t evaporate into the air. Therefore, we feel hotter when RH is high. The opposite is true when the RH value of a room is low — we’ll feel much cooler than the actual room temperature.

Considering this, you should start to see why relative humidity is an important measurement when trying to regulate your home’s temperature and create a more comfortable environment. Through relative humidity measurements, heating and cooling professionals are able to better understand which humidifier or climate system is best for your home and what setting they both should run at.

In addition to helping with efficient heating and cooling, RH levels are important to consider in order to prevent mold build-up and minimize condensation on windows.

What Is Considered “Good” Relative Humidity?

Anything between 30-60% relative humidity is considered a comfortable environment. When designing home heating and cooling systems, your professional should keep this in mind as maintaining an RH below 60% ensures that condensation doesn’t build up on your home’s windows and you won’t be too hot in your own home. In fact, they may even recommend installing a whole-home humidifier to help control your home’s RH levels. This is especially helpful during the winter months when RH levels can drop extremely low in northern climates.

To ensure your home’s RH is within that 30-point range, we use a combination of temperature control and dehumidifying. This allows us to control both the capacity and quantity of water vapor on the air. This is also why a majority of HVAC appliances include humidity control devices or functions.

No One Likes to Be Hot and Humid

Humidity is a big influence on how comfortable we are in our own homes. As a result, it’s critical that your local heating and cooling professional takes careful consideration of the relative humidity of your own home. Without it, you’re negating all the work your furnace or air conditioner puts in.

Need help getting your home’s humidity under control? Check out our whole-home humidifiers or give us a call at 612-825-6867 or contact us to have your home’s humidity evaluated and adjusted.