You may have heard that a drawback of gas furnaces is they tend to make the air in a house drier. Is this true, and is it something you need to consider when thinking about replacing your current furnace?
The answer is a bit complicated. The short version, if you don’t want to hang around for the longer explanation, is that older types of gas furnaces can contribute to drier indoor air (although they do not directly dry the air) while newer ones do not. If you’re looking to have a new gas furnace installed, our technicians offer the quality furnace service in Houston, TX that will ensure you have the right unit for your needs. If dry air is still a problem in your home, regardless of the type of furnace you have, we can help with installing a whole-house humidifier.
How an Old Furnace Can Dry the Air in a House
The operation of a gas furnace—combusting natural gas to warm air and then sending the air into the house—has no effect on the level of moisture in the air, so a gas furnace cannot be said to “dry out the air.” However, the older style of furnace, known as an atmospheric furnace, can contribute to lowering indoor humidity levels.
You can tell you have an atmospheric furnace if you can look into the furnace cabinet and see the blue light from the burners. This means the furnace’s combustion chamber is open to the air in the house, and this is where the burners draw the air necessary for combustion to occur. By using the air in the house for combustion, the furnace creates an indoor air deficit where the air pressure in the house is lower than the pressure outside. This is known as negative air pressure. When this happens, outside air pushes indoors to create a pressure balance. Not only does this mean colder air moving indoors, it means drier air moving indoors: the air during winter tends to have lower humidity. The overall result is a house with drier air.
The Sealed Combustion Furnace
The way a newer furnace avoids this issue is with sealed combustion. Rather than have the combustion chamber open to the air of the house, it’s sealed off and instead draws the air it needs for combustion through a PVC pipe that goes to the outside. This not only prevents creating negative air pressure, it improves the furnace’s efficiency by preventing the burners from losing extra heat. In fact, the improved efficiency is one of the biggest benefits of sealed combustion.
Still Having Dry Air Problems?
A sealed combustion furnace may not solve all your problems with dry indoor air. If your home has struggled with dry conditions, you may need to have a central whole-house humidifier installed. These devices give you precision control over humidity levels so your house doesn’t become too humid. Talk to our specialists to find out more about how we can help you balance your home’s humidity.
At AC Comfort, Your Comfort Is Our Business! Reach out to us for furnace replacement and other heating help.