relative-humidity

Relative Humidity: What Every Homeowner Should Know

Relative humidity is an important factor of the indoor air quality in your home. As such, it’s wise for homeowners to educate themselves about what relative humidity is, as well as how they can control it in order to protect their homes and family members.

As weather changes and temperatures move up and down the thermometer, relative humidity changes, as well. Homeowners should learn about how the humidity in their homes impacts air quality, wellbeing, and building structures. Excess moisture can damage the structural integrity of a house, plus lead to mold, mildew, and a wide variety of ailments for anybody living within. By controlling our indoor humidity, homeowners have the ability to prevent all sorts of problems.

What Makes Healthy Indoor Air?

Considering we spend the vast majority of our time inside, the indoor air quality of your home or office is so crucial that the EPA considers it a substantial environmental threat. In order for air inside a structure to be considered healthy, it should be:

  • Free of toxins
  • Fresh & well-ventilated
  • Less than 50% RH

In order to have fresh air, buildings must be well-ventilated to flush out pollution and airborne particulates. An air purifier is a great way to instantly improve the indoor air quality of your home. Outdoor air should flow in and out of a building, and allergens and harmful airborne particles should be kept at an absolute minimum.

What is Relative Humidity?

Relative humidity is a measurement of water vapor being held at a specific temperature compared to the amount it could hold. This calculation is usually expressed as a percentage. As temperatures rise and fall, the capacity of the air to hold the H₂O is impacted. The warmer the temps are, the more moisture the atmosphere can contain. When air cools down naturally, its moisture-holding abilities are diminished.

Once this happens, there are many variables that may affect an individual’s comfort level, such as their health, clothing, or physical activity at the time. Of course, everyone has their own personal preferences, but for the most part, humans are typically most comfortable when relative humidity stays between 20% and 60%.

While this may be the broad comfort range for your average person, however, it is not recommended to allow the relative humidity levels to rise above 50% inside your home.




What is the Ideal Humidity Levels For Homes?

Between 30-50%. To prevent mold growth, the EPA recommends keeping “indoor humidity below 60 percent (ideally between 30 and 50 percent) relative humidity.”

Depending on whether you’re using a heater or air conditioner to help control the temperature, homeowners may change the humidity levels in their home to make the air feel more comfortable.

Confused? The Paper Towel Metaphor.

If the concept of relative humidity seems confusing, you’re not alone. It may help to think of a concrete example such as a paper towel.

Have you tried to mop up a spill with a paper towel? After the towel is saturated, it can’t hold any more liquid. This would be considered 100% capacity; whereas if the sheet could still absorb a bit more, it would be a lesser percentage, such as 70%. Air’s capacity to hold moisture is similar to the paper towel’s; when it can hold no more, it has reached 100%, and this is known as its dew point.

How Can Excessive Humidity Affect Your Home?

You can use your senses to determine if your home has a problem with excess humidity. Unless you live in a dry desert, chances are you’ve noticed a few of these red flags:

  • Mold growth.
  • Warped boards or wood floors.
  • Musty smell, especially in crawl spaces, attics, and basements.
  • Bubbling or peeling paint.
  • Wallpaper peeling away from walls.
  • Stickiness on surfaces.
  • Condensation on windows or other areas.
  • Water stains on ceilings or walls.
  • Sneezing and other allergic reactions to inhaling dust mites.
  • Moisture build-up on ceilings or inside closets.
  • Frequently-fogged windows.

Is Excessive Humidity Unhealthy To Live In?

It is not healthy to live in a house that perpetually has too much moisture in the air. Many of these ailments develop as a result of mold exposure and other issues that homeowners face when there is too much humidity in their home.

For further research, here are a few studies that discuss the potential health effects associated with relative humidity.

  1. “Indoor air humidity, air quality, and health – An overview.” (PMID: 29398406)
  2. “Indirect health effects of relative humidity in indoor environments.” (PMID: 3709462)
  3. “The dichotomy of relative humidity on indoor air quality.” (PMID: 17499853)



Can A Dehumidifier Help With Relative Humidity?

Yes. If there is too much moisture inside your home or office, a dehumidifier can be utilized to help you remove the excess moisture and get your relative humidity back at an ideal level.

These devices have many uses and benefits for homeowners, but its most common purpose is to help extract H₂O from your indoor air, as well as help remove any musty odors that may be lingering as a result of too much moisture. Once that water has been removed, it will either be collected within the unit or pumped away automatically, depending on the type of dehumidifier you are using. To get rid of excess water by vaporizing it, an ionic membrane dehumidifier may be used.

Can A Humidifier Help With Relative Humidity?

Yes. Just as there are many reasons to remove moisture from the air, there are also many reasons why moisture in the air is beneficial. Striking the right balance of relative humidity is the key to having comfortable indoor air.

If your home is lacking humidity, you can help correct this by using a humidifier. Because they add moisture to the air, humidifiers can help alter the relative humidity levels in your home and make your indoor air more comfortable. These are especially important to use in the cold winter months, as you likely have a heater running which may be drying out the air. Just remember to clean your humidifier on a regular basis.

There are different types of humidifiers on the market, including:

  • Portable:

    These models are designed to humidify a space by forcing air to circulate through a wet pad, which then flows into the room in a fine mist.

  • Evaporating:

    A pan or absorbent pads are dipped into water, and then attached to a heating system. This causes moisture to evaporate into the environment.

  • Power:

    Water moves automatically into this unit to allow moisture to be circulated. A humidistat allows a homeowner to control the amount of water generated.

Where Household Moisture Comes From

The world is full of moisture; even your breath and body release droplets of water. While certain percentages of RH are desirable in an environment, too much can lead to trouble. Moisture moves through buildings in several ways:

  • Roof leaks
  • Rain water
  • Plumbing leaks
  • Steam from cooking
  • Steam from showers and bathtubs

No matter how your home becomes saturated with water vapor, condensation may occur on windows or other surfaces. This occurs more readily during chillier seasons. When moist warm air meets the cold glass of a window, it causes the air temps to drop, changes the relative humidity, and results in condensation.

Because a home’s relative humidity can impact family members’ overall well-being and the building structure, it’s crucial that homeowners educate themselves about this important component of air quality. If the RH percentage is kept in the proper range, health problems can be avoided or greatly minimized. For homes with too much moisture, a dehumidifier can create a safer and more comfortable interior. On the flip side, houses that are too dry can add water vapor with a humidifier. Armed with knowledge about humidity, individuals can live happily ever after in their homes.