How Humid Should My House Be?

humidity level in home


According to the Environmental Protection Agency and the Center for Disease Control, the relative humidity inside your home should ideally fall between 30 and 50 percent. These government agencies do not advise arbitrary humidity levels. Humidity that falls outside their recommended levels can damage your house and electronics, as well as negatively affect your health!

The Risks of Low Humidity

Low humidity is bad for wood – i.e. the material which probably comprises a large part of your house. Even after it has been dried, wood will continue to shrink as it loses moisture. It’s easy to appreciate how this can cause property damage. If the wood in your furniture, floorboards, door frames and window panes shrinks too much in size, it can loosen and become permanently warped.

Low humidity can damage electronics. The ideal relative humidity for an electronics factory is 30 to 70 percent. This is because humidity levels below 30 percent pose a heightened risk of static electricity jumping from one electrical component to another. Sensitive components such as circuit boards are easily destroyed by static!

Low humidity also poses several health risks. Moisture in the air acts as a barrier to aerosols that can carry dangerous bacteria including S. pneumoniae (pneumonia), S. albus (sinus infection) and S. haemolyticus (strep throat). Low humidity may also put you at greater risk of contracting influenza, as well as cause discomfort by drying out your eyes, throat, nasal passages, and the skin surrounding your hair and nails.

The Risks of High Humidity

Just as low humidity can shrink wood, so too can high humidity force it to swell and expand. High humidity can also damage your home by peeling its paint and causing condensation to collect on window glass, the latter of which may seep into your walls. Electronics are also at risk of becoming damaged by high humidity, as circuitry may corrode when it is exposed to moisture for extended periods of time.

The greatest threat associated with high home humidity is black mold. Interestingly, no single species is correctly referred to as “black mold,” just as no single species of bird is accurately called a “seagull.” That said, the fungus most frequently identified as “black mold” is S. chartarum.

Black mold’s effects on property are obviously undesirable. Just a light film of black mold on a wall looks hideous. But when black mold is allowed to propagate long enough, it can gradually destroy drywall, floorboards and wooden studs to an extent that may cause walls and ceilings to collapse! Mold may also spread to ductwork where it can cause the HVAC system to become increasingly inefficient and eventually break.

Mycotoxins produced by black mold may harm some people’s health – especially if they already have weakened immune systems. Prolonged exposure to black mold can worsen symptoms of allergies and asthma, irritate the nose, eyes and skin, and cause headaches, nosebleeds and body aches. Truly, black mold is a health hazard.

Adhering to the recommended 30 to 50 percent indoor relative humidity range is the best way to prevent the colonization and spread of black mold in your home. This is because black mold can only grow when indoor humidity exceeds 55 percent – the reason why 50 percent is the acceptable upper limit of humidity.

How to Control Indoor Humidity

To begin controlling your home’s humidity, you must first know what it is. Fortunately, hygrometers are inexpensive instruments. You can purchase a reliable digital hygrometer for less than $10.

When your home’s humidity exceeds 50 percent, attempt to lower it by taking colder showers and keeping pots covered and turning on your range exhaust while you are cooking. You may also remove potted plants from your home if the problem persists. When your home’s humidity falls below 30 percent, consider hanging your laundry to dry indoors, leaving the tub full after bathing, or placing a tray of water in front of a space heater or ventilation duct.

Dehumidifiers and humidifiers provide the most convenient solution for controlling your home’s humidity. A simple plug-in device offers the most cost-effective approach, although adding an integrated dehumidifier or humidifier to your home’s HVAC system is far more convenient. These devices’ built-in hygrometers allow them to constantly monitor your home’s humidity and automatically adjust it to your preferred level.

Perfect Your Home’s Humidity With Our Contractors

If you live in the greater Sioux Falls, SD area and wish to enjoy ideal indoor humidity all year long, then we welcome you to contact PrairieSons today. We can easily install the dehumidifier and/or humidifier your HVAC system needs to fully protect your home and your health!