Monday, December 19, 2016

Do You Need Humidifiers, Dehumidifiers, or Both?

With winter upon us, many people notice drier indoor air. They may experience cracked skin, chapped lips, dry eyes, and sinus pain. Cold air is unable to retain much moisture to begin with, but heating the air through an HVAC system only makes it drier. Many households operate humidifiers during this time, but if moisture levels become too high in winter, you may experience window condensation and an increase of mold and mildew spores. It’s important for both comfort and health to strike the right balance in a home’s humidity level year-round.

Recommended Relative Humidity

Moisture levels in your home are measured by relative humidity (RH). A hygrometer is a relatively inexpensive, small instrument that can be easily purchased at most hardware and home merchandise stores. Hygrometers come in both analog and digital models. Some include thermometers, measuring the temperature of a given room as well as humidity, and some even feature alarms that sound when the humidity is outside a comfortable range.

Indoor air should ideally have a relative humidity level somewhere between 30-50%. In winter, the level may need to be around 40% or below to avoid window condensation and mold growth.


Humidifiers add moisture to the air, usually by propelling a fine mist into the air. In winter, if the humidity level in a home falls below 30%, you or your family may experience some of the physical symptoms above. You may also notice static electricity, or the wood and leather in your home becoming dry and susceptible to cracks. Drier air feels colder, as well, so bringing up the humidity level can make you feel warmer in winter. Humidity levels can vary from room to room, so be sure to measure each room individually, and identify which rooms will benefit from a humidifier.    

Too much humidity, however, is problematic. When using humidifiers, make sure the relative humidity in each room stays within the comfort range. Heavy moisture in the air can cause a buildup of mold and dust mites, exacerbating allergy symptoms. Signs of too much moisture in the home include damp stains, blistering paint, visible mold growth, the presence of a musty or stale odor, and window condensation. If you notice signs of high humidity around your home, or consistently see high readings on your hygrometer, you may need a dehumidifier. 


Dehumidifiers pull moisture out of the air, often by collecting the water from the air in a tank. It is important to change the tank daily to prevent mildew and bacteria from growing. If your home measures over 50-60% humidity, a dehumidifier will bring the level back down into a more comfortable, healthy range.   

Because humidity levels vary so much throughout the year, and even from room to room, many people choose to use both, depending on the season. Some households run a humidifier in winter, and a dehumidifier in a damp basement, for example, or in spring or fall, when the air conditioner isn’t running. If you don’t run your HVAC system very often in summer, you may choose to run a dehumidifier for comfort, or to reduce moisture in certain areas of the house.  

At Wheeler’s Heating and Air Conditioning, we care about your home’s indoor air quality. Serving the Ozarks, we are a family-owned and operated business providing residential indoor air quality products, as well as furnace, heat pump, and air conditioner repair and installation. Please visit our site or call (417) 839-9240 today to find out more!