How Your Furnace Humidifier Actually Works (and Why You Should Have One)

During the cold, wet months of the year, installing a furnace humidifier in your home might seem unnecessary. When you heat your home with a furnace, it distributes warm dry air, which can lead to dry lips, chapped skin, scratchy throats and other uncomfortable symptoms. By knowing how a furnace humidifier works and its benefits, you might find that it is exactly what you need to make your home feel more comfortable throughout the year.

What a Furnace Humidifier Does 

A furnace humidifier does exactly what its name implies—adds moisture to the air that your furnace distributes. The equipment mounts to a furnace’s hot air supply and is connected to a home’s ductwork and water supply, allowing it to work in conjunction with your HVAC equipment. The water vapor that the unit produces travels through the ductwork and into the home. After you set the humidistat to the humidity level that you desire, the furnace humidifier maintains those levels by turning itself off and on accordingly.

The way a humidifier works varies by type. Common types of furnace humidifiers include:

• Bypass humidifier: Bypass humidifiers are generally installed on an air-return duct.
  They draw warm air from the ductwork and blow it over a water panel, or evaporator pad, using the pressure that the supply and return ducts naturally create. The air absorbs the moisture in the panel and returns it to the furnace, which directs the humid air into the home. This type of humidifier only works when the furnace is on.
• Fan-powered humidifier: With a fan-powered, or flow-through, furnace humidifier, the humidistat’s sensor detects when air is too dry, opens the solenoid valve and activates a fan. The solenoid valve allows water to enter the water panel, or moist pad. Because of the air movement produced by the fan, the water flowing through the panel vaporizes. The fan then directs the water vapor into a home’s ductwork. Water that does not vaporize exits the equipment through a drain line. Once the air reaches the set relative humidity level, the solenoid valve closes, discontinuing the flow of water into the panel. This type of humidifier does not need to be installed on bypass duct, making it ideal for small spaces. In addition, it can operate when the furnace is off.
• Steam humidifier: A steam furnace humidifier heats water until it produces steam, similar to an electric kettle, even if the furnace is not on. The system’s blower moves the humidified air through the ductwork and into the home.
• Drum Humidifier: A drum humidifier has an evaporator pad, or sponge drum, that rotates in the unit’s water pan, introducing water into a stream of air. This action humidifies the air passing through the equipment and distributes it through the ductwork.

Why Install a Furnace Humidifier in Your Home

Improved Air Quality

When the air in your home is adequately moist—with relative humidity levels of 40 percent to 50 percent—particles that negatively affect the mucous membranes are less likely to be present. These particles include dust, allergens and other irritants. Increased humidity levels also help keep dust mites, as well as bacteria and viruses that thrive in arid conditions, at bay. If you have a cold or flu, humidity in the air may reduce your symptoms and help you recover faster.

Improved Comfort

Arid conditions can make your eyes, lips and skin feel dry. Prolonged exposure can cause skin to crack, feel itchy or become chapped. Increasing the humidity level in your home with a furnace humidifier can help heal your skin, as well as make your eyes, sinuses and throat feel more at ease. Furthermore, it also reduces static electricity, preventing the painful shocks you experience from doing everyday activities, like opening doors.

Lower Energy Costs

Moist air feels warmer than dry air, which is why an otherwise mild summer day can feel unbearable when humidity levels are high. When you add moisture into the air in your home, you’ll find that you can lower the thermostat a few degrees, still feel comfortable, and save up to 5 percent on your heating bill.

Preserve Your Belongings

When ambient conditions are too dry, paint, plaster, wood, artwork, instruments and other items can warp or crack because they expand and contract with changes in temperature and relative humidity levels. Using a furnace humidifier helps you maintain constant conditions throughout the year, reducing the risk of damage to your items and home.

One of the most convenient benefits of furnace humidifiers is that you can install them on existing HVAC equipment, so you don’t have to wait long to reap their benefits. To learn more about the advantages of a controlled-humidity environment or to schedule a consultation, get in touch with AAA Heating and Cooling today.