We all know about the importance of furnaces and hot water tanks. How could we forget them? We quickly discover when they stop working. The most important appliance people forget about doesn’t remind them when it stops working. Some homes don’t even have them. Forget this one appliance and your house can smell. Forget this appliance and your health, especial your children’s health, can be problematic. Forget this appliance and you're inviting mold. . . and insect infestations. Forgetting to install and run a dehumidifier in your basement can create a sick house.
Many times people think dehumidifiers are only necessary in leaky basements. And while it is true that dehumidifiers rarely run during the winter in Ohio, they are absolutely necessary once it starts warming up outside. Cleaning and maintaining your dehumidifier should always be near the top of your spring cleaning list.
So what makes a dehumidifier so important? It’s all about relative humidity. Relative humidity is the amount of moisture air can hold at a particular temperature. Hot air holds more water than cold air. You know how we often get dew in the spring mornings? Dew happens because as the air temperature drops at night less moisture can be held. When the temperature goes down while the amount of moisture in the air remains constant, the relative humidity percent increase. At 100% relative humidity moisture starts to condense which is when dew occurs.
Molds and insects love dew. But, they don’t actually need liquid water like dew to survive and grow. High air moisture levels (also called high relative moisture) is sufficient for mold and insects to thrive. InterNACHI along with Jeffery May, author of My House Is Killing Me, recommend keeping relative humidity levels to between 30% and 50%. The sweet spot is 50% relative humidity. Below 30% humidity people can start to develop sinus problems. Above 60% and molds start growing. The InterNACHI chart below shows why 50% humidity is the best goal.
Ideally your humidifier should empty directly into a floor drain or pump. In my house, the dehumidifier drains directly into the condensate pump from the furnace and A/C. Wilken Sheet Metal set this up for me when they put in a new HVAC system a few years ago. I set it at 50% humidity and let it run.
Two things are required to keep this system running. First, the filter on the dehumidifier needs cleaned to keep maximum airflow. Second, the pump reservoir needs cleaned out.
You can see a lot of slim growing in the bottom of my condensate pump. Standing water like this can foster bacteria growth more so than the typical molds we think of. When you clean out your pump make sure to use a disinfectant so things don’t grow back as fast.
Dehumidifiers also help prevent one of the most likely causes of indoor allergies. At above 50% relative humidity dust mites start to flourish. Dust mites are soft bodied microscopic insects that require moisture to stay alive. They can live off high humidity or the moisture our bodies give off. Most allergies to dust mites come from their fecal pellets. These pellets often become airborne as we disturb surfaces in our homes. As you sit down on your couch air is expelled from the cushion, along with dust mites and dust mite fecal pellets. While the fecal pellets and dust mites are airborne we can unknowingly breathe them in. Keeping the humidity low is the best cure for dust mites.
Dehumidifiers are often overlooked as a necessary appliance. Humidifiers get all the attention but dehumidifiers keep you and your house healthy. Keeping 50% relative humidity in your home keeps your home healthier by preventing mold, insects, and allergens. As part of your spring cleaning make sure your dehumidifier is in good working order and set to 50%.