What is relative humidity?

In the mold remediation world, we often talk about keeping relative humidity in check. Relative humidity is the amount of water vapor that is in the air compared to how much water the air could actually hold at any given temperature. With heavy rains and humid air in spring, summer, and fall, potential issues related to microbial growth can occur. This is because the percentage of water in the air has increased. According to the EPA, you should keep your indoor relative humidity between 30-50%, and most industry standards and professionals agree with these recommendations. In addition to limiting microbial growth, keeping relative humidity low can also aid in discouraging pests and dust mites.

How humidity changes during winter

During winter months, however, relative humidity can dip too low since cold air holds less moisture. When your home is sealed up and the heat is on, your indoor air can become very dry. This low humidity will eventually start to affect an occupant’s health. Low relative humidity can cause static electricity, dry out your skin and hair, allow germs and viruses to thrive, and can make occupants more susceptible to colds and respiratory issues. Many homeowners already have humidifiers on their HVAC systems or have standalone humidifying units. Unfortunately, both of these options can harbor unwanted microbial growth. Also, not all homeowners have or can afford these additional humidifying options. However, there are a few beneficial ways to create relative humidity in your home without using humidifiers or causing excess microbial growth. Below are five additional ways to add natural relative humidity to your indoor air.

Get cooking

Specifically stove-top cooking – and winter is the perfect time for soups and stews! The moisture released into the air during cooking can help bring your relative humidity to more ideal levels. Using a kettle to heat water for tea and coffee can also help add moisture to your home air. An added bonus from home cooking is you can cook healthier meals, spend time with your family, and save money from eating out.

Air dry your clothes and dishes

Rather than using your dryer or keeping your dishes in the dishwasher to dry, place the items in the open air. Get a clothes line or drying rack for your laundry. Exposing wet clothes and dishes to dry air will allow the moisture to evaporate. Like tip #1, you will also save energy and money when not running your dryer!

Buy house plants

House plants release moisture into the air during a process called transpiration. Certain house plants are also known to help improve indoor air quality. Indoor plants can remove pollutants from the air by absorbing gasses through their leaves and roots. If you celebrate winter solstice or Christmas, this is the perfect opportunity to bring a live plant into your home. Along with releasing moisture into your dry air, essential oils will also be introduced into your living space. Essential oils can improve moods, boost immune systems, and are a safer alternative to candles and incense.

Bath time

Use the moisture from showering and bathing to add moisture to your indoor air. If showering, do not use the bathroom exhaust vent to remove the moist air from your home. Instead, open the bathroom door after showering and allow the moist air to filter into your home. If you take a bath, leave the bathwater sit in the tub after you are finished and drain the tub once it has fully cooled down. This extra time allows the warm water to evaporate into the air and create more humidity in your home.

Give your pet extra water

Since dogs and cats are also affected by low levels of humidity, having extra bowls of water around your home will give them more opportunities to stay hydrated during the winter months. I have found that setting bowls of water around supply registers can add moisture to the air. When the warm air moves over the surface of the water bowls, it helps the water to evaporate, keeping you and your furry friends hydrated during months of dry indoor air.

Other ways to gauge humidity

Although there are many ways to add moisture to your indoor air, you should find what works best for your lifestyle and situation – experiment! Once again, I must stress that these techniques to raise relative humidity are most effective in the winter months. The dry, cold air during Pennsylvania winters is the leading cause of moisture deficiencies in the home. Since relative humidity changes depending on the temperature, these same techniques used at other times of the year could be directly responsible for microbial growth. To monitor relative humidity levels, I recommend purchasing a hygrometer, a small relative humidity sensor, that helps detect your relative humidity levels on each level of your home.