Understanding relative humidity is essential for the safety of your home. A humidifier is a great appliance for comfortable living, but you need to know how to safely operate it. Dry air can damage your body and household items, moist air is also a problem. In climates where moist air is a problem, dehumidifiers have been introduced.

What relative humidity level should you use? The rule of thumb is 30-50%.

Your humidifier may come with some sort of humidity meter. If you cannot find one specifically for your model of humidifier, check out your local hardware store for a hygrometer.

When the air is too dry:

During winter, when the heat is on, the relative humidity in your house can become very low. This is because heated air can hold much more moisture than cold air. So, as the air in your home heats up, it becomes “thirsty” and begins sucking moisture out of surrounding surfaces: plants, walls, furniture, books, paintings, human bodies, everything. Whenever we heat air we dry out the air to uncomfortable and damaging levels.

By keeping the humidity above 30%, you can normally turn down your thermostat a few notches. Your heated air will feel warmer, creating a safer, more efficient environment.

When the air is too wet:

The reason to use a humidifier is simple. The reason to keep the humidity under 50% is not so obvious.

Dust mites, the culprits behind allergies, love moist air. When the relative humidity of a home climbs above 50%, dust mites begin rapidly multiplying. This can cause allergic reactions in sensitive people.

Mites aren’t the only unwelcome guests that can infest your home. Fungi and mold become prevalent when the relative humidity of a home reaches 75%. Fungi and molds can cause asthma attacks and rhinitis (inflammation of mucous membranes of the nose) in some people.

You should also reduce setting if moisture forms on windows, walls etc, or if there is dampness around the area of your humidifier. Keep in mind that you don’t need to be concerned it this temporarily happens due to cooking, showering, etc.

Summing up:

If you get nothing more out of this article, make sure to remember that the humidity levels of your house need to be within the 30-50% humidity bracket. Regulate your humidity with your humidifier’s built in humidity meter or by a hygrometer from any good hardware store.