Your furnace obviously plays a significant role in keeping your home comfortable throughout the cold-weather months. However, controlling the humidity level in your home also makes a major difference. In this article, we’ll examine the ways humidity affects your comfort and discuss your options for ensuring your furnace doesn’t make your home overly dry and uncomfortable.
Does Humidity Affect How Effectively a Furnace Heats?
The humidity level inside your house essentially has no bearing on how well your furnace performs. No matter if the air inside your house is extremely dry or overly humid, your furnace will continue to put out the same amount of heat and raise the temperature in your home at the same rate. Nonetheless, there is a direct correlation between relative humidity and your overall comfort level. That’s because dry air saps moisture out of your body, which can lead to issues like itchy skin and eyes as well as throat, nose and sinus irritation.
How Your Furnace Impacts Indoor Humidity Level
You may have heard that running your furnace causes the air inside your home to be much drier, but this is only partly true. The only way to truly dry air out is to remove moisture from it by cooling the air down to its dew point so that some of the water vapor it contains condenses into liquid water. Heat has zero impact on the total amount of moisture air contains, but it directly affects how dry the air feels. The reason has to do with the difference between absolute humidity and relative humidity.
Absolute humidity is just a ratio of the percentage of water vapor molecules in the air to the number of “air” molecules. Unless some of the water vapor is removed from the air through condensation, the absolute humidity level always stays constant no matter what the air temperature is. Relative humidity instead measures how much moisture there is in the air compared to the total amount of moisture the air could potentially hold. If you have a relative humidity level of 100%, it means the air is completely saturated and unable to hold any additional water vapor molecules. Even though the absolute humidity level remains constant, the relative humidity level always increases the colder the air is and decreases the warmer the air is. That’s because when the air is warmer, the “air” molecules are more spread out, so there is additional space for the air to hold more water vapor molecules. In simpler terms, warmer air always has the potential to hold more moisture than colder air.
Despite your house being insulated, the cold winter air outside always causes the indoor air to cool down. That’s why your furnace needs to run fairly often to continually heat the indoor air back up. The issue in terms of humidity is that heating the air causes it to feel drier since it results in the relative humidity level decreasing. The air still contains the same number of water vapor molecules, but they get more spread out as the temperature increases so that less of them come into contact with your body and you feel like the air is drier.
Options for Controlling Indoor Humidity in Winter and Improving Your Comfort
By far the most effective option for preventing your home from feeling overly dry during the winter months is with a whole-home humidifier. There are several different types of whole-home humidifiers, but they generally all work by causing water to evaporate so that they can then pump moist air out into your home’s ductwork. When your heating system runs, it then circulates the moist air into every part of your house to increase both the absolute and relative humidity levels throughout the entire home.
The other thing to note is that high-efficiency furnaces generally don’t contribute nearly as much to dry air issues as conventional furnaces do. All furnaces need a steady supply of air coming into them so that the burner flames receive sufficient oxygen. If the flames don’t receive enough oxygen, the gas flowing out of them can’t fully combust and the flames don’t produce nearly as much heat. The issue with conventional furnaces is that they just get the air they need from the surrounding area, which ends up creating negative air pressure inside the house that causes colder, drier air to rush in from outside through the various gaps in the house. Since the air coming inside is much drier, it results in the overall moisture content within the house decreasing.
High-efficiency condensing furnaces don’t create this issue since they pull air directly into their combustion chamber from outside. The dry outside air then flows directly back outside through the exhaust flue. That means less dry outside air flows into the living spaces, preventing the moisture content in the home from decreasing.
Campo Heating & Air Conditioning is a family-owned company that’s dedicated to providing reliable HVAC services in Carriere, MS, and the surrounding areas. Since 2015, we’ve developed a reputation as one of the area’s leading heating and air conditioning companies. No matter whether you need a new furnace, are looking to install a whole-home humidifier or need any other HVAC or indoor air quality services, give us a call to get the exceptional workmanship and outstanding customer service you deserve.