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Achieving Ideal Home Humidity

Home Humidity

Most people pay close attention to indoor air temperature. Feeling uncomfortable due to temperature is an easy problem to identify. However, it can be harder to connect humidity to home issues or discomfort. It does have several potential effects on both, and this guide will explain more about those. You will learn about symptoms of high humidity in a home. Also, you will learn about ideal humidity levels to reduce negative health effects and feel more comfortable.

What Is Relative Humidity?

You will often hear of relative humidity when you read about indoor humidity control. Humidity is the air’s amount of water vapor. Relative humidity measures the water-air combination in relation to the maximum potential amount.

Why Is My Home Humidity So High?

What causes high humidity inside a home? Several factors can contribute. Improper ventilation and lack of humidity control in a humid environment are two common causes. Poor insulation, indoor activities and lack of vapor retardants can also contribute. Indoor humidity issues can be harder to control for people in humid climates like the South.

How Does Humidity Affect Me and My Home?

Before delving into the ideal home humidity levels, it is important to understand the effects of humidity. There are several potential concerns when humidity levels are above or below certain points.

Concerns With High Humidity

Bacteria and mold thrive in environments with higher humidity. Studies show that infectious bacteria do not thrive when relative humidity is under 70%. When humidity is above 50%, dust mites are minimized. Many people are allergic to these mites, and humidity at 80% or higher is ideal for them to thrive. Most fungi do not thrive unless the humidity is above 80%. 

What are signs of high humidity in a house? These are some potential signs of high humidity issues:

  • Aggravated allergies
  • Visible mold
  • Mildew smell
  • Foggy windows
  • Soft or rotting wood
  • Clammy or moist air

Concerns With Low Humidity

Humidity that’s too low can also be problematic. While mold and bacteria may not thrive, the effects can be detrimental to your home and health. These are some potential effects of low home humidity:

  • Aggravated respiratory issues
  • Dry or cracked skin
  • Dry eyes and nose
  • Cracked furniture or paint
  • Peeling wallpaper
  • Static electricity

What Are Ideal Home Humidity Levels?

The ideal range for a comfortable humidity level is between 30% and 50%. The Environmental Protection Agency (EPA) recommends keeping indoor humidity below 60%. To minimize negative health effects, the ideal home humidity range is between 40% and 60%. Using that average house humidity range as a guide, you can select a target percentage that fits your needs. For instance, if your kids are allergic to dust mites, 45% may be ideal. As noted in a previous section, dust mites are minimized at levels under 50%. So, what is considered high humidity? What percentage is high humidity? Any level above 60% may be too high, and 70% or higher is definitely too high.

How to Control Indoor Home Humidity Issues

The solution for finding an acceptable humidity level in a home depends on the problem. If you are unsure what your home humidity level is, you may need a humidity meter or special thermostat. You may need a dehumidifier for a home that is too humid. For one that is not humid enough, you may need a humidifier.

Humidity Gauge or Thermostat With Humidity Control

What measures humidity? The answer is a hygrometer. If you have an older system or use window AC units, you may need to purchase one. You can use dehumidifiers or humidifiers as necessary to reach your target humidity level. Also, you may need to use the troubleshooting tips later in this guide if you have trouble maintaining ideal humidity. If you have an HVAC system, consider a smart thermostat with humidity control.


What does a humidifier do? Humidifiers are devices that you put water in to create a fine mist. Common types are whole-home humidifiers and smaller tabletop humidifiers. What are the benefits of a humidifier? It may help relieve dry eyes, dry nose and some respiratory issues. Many people who live in dry climates and have children or infants with respiratory issues use room humidifiers. However, it is important to follow the care and cleaning instructions properly. When humidifiers are not cleaned or used properly, they help microorganisms grow and can disperse them in the air.


dehumidifier may be necessary for some people to control humidity. Most window air conditioners and HVAC systems have humidity control. However, those who use swamp coolers or do not have air conditioning may need a dehumidifier. There are different sizes of units that correspond with various room sizes. A dehumidifier is especially beneficial if you have a basement. Mold often starts in basements at around 60% humidity and can spread. While a dehumidifier will not kill mold, it can help prevent it or limit the spread of it. Professional remediation services often include using fans and dehumidifiers to dry the air and stop mold growth.

Troubleshooting Common High Humidity Issues

By now, you know the reasons to control humidity. You also know the uses and benefits of hygrometers, dehumidifiers or humidifiers. However, using a dehumidifier alone does not always solve the issue. These are two common questions and solutions.

Why Is My House So Humid?

There are several ways you can decrease humidity in a house. Depending on outdoor humidity, these control measures may or may not significantly reduce humidity without a dehumidifier. These are some steps to take:

  • Vent clothes dryers outside.
  • Use exhaust fans in bathrooms and kitchens.
  • Use storm windows or insulation.
  • Cover dirt floors in crawlspaces with plastic, and make sure crawlspaces are ventilated.
  • Eliminate carpeted floors if possible.
  • Look for leaks or seepage sites to fix.

Why Is My House So Humid With the AC On?

Perhaps you already have a humidity gauge or humidity monitor on your HVAC system. You may be experiencing high humidity problems despite taking all the steps in the previous section. There are several possible reasons why that happens.

High humidity in a house with the AC running can be caused by improper unit function. The AC removes humidity by way of an evaporator coil. When moist air inside your home moves across it, the coil removes the moisture. This makes the air less humid. To ensure proper function, have your AC serviced every year. HVAC professionals should do this for safety reasons and because they have the right equipment. However, you can clean around the unit regularly to prevent buildup of leaves or debris.

Humidity changes outdoors can also temporarily increase indoor humidity. For instance, rainstorms on hot days raise humidity outside, which increases humid air inside. Another cause can be cooking indoors without ventilation. If you boil several large pots of food on the stove, humidity goes up.

Ready to tackle low or high home humidity issues? Find everything you need to reach an ideal home humidity at your nearest Kempker’s True Value and Rental store!

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