What is the ideal indoor humidity level and how to manage it

Ideal indoor humidity

Indoor air quality is highly dependent on the humidity level inside. It should stay between 35% and 55% with around 45% being the ideal indoor humidity level. During the winter time the levels are naturally lower than during the summer time, and can decrease even more with high indoor temperature. Levels can drop down to even 20%. During cold times the recommended levels are a bit lower, 30% to 40%. Anything above 45% and the humidity in the air starts to condensate on cold surfaces in your home such as windows and even in the structures creating a whole other set of problems. Humidity levels should be monitored regularly on a reliable humidity meter. The most common reason for too high levels is poor ventilation.


Low Humidity – What problems does it cause and how to fix it

Dry air affects especially the respiratory system.  Symptoms might include…

  • Nasal Irritation. Can cause anything from mild discomfort to headaches. It may also interfere with sleep causing snoring.
  • Dry throat. Dry throat is most commonly observed in the morning
  • Sleepiness. Dry itchy throat, coughing and sneezing doesn’t mix well with sleep
  • Nose bleeds. Poor indoor air quality can lead to what seem to be totally random nosebleeds.
  • Dust. Dust hovers around more and issues caused by dust increase
  • Skin Irritation. Dry, flaky skin and chapped lips can become an issue
  • Shrinking in wood structures. Hardwood floors for example shrink due to dry air and gaps show up between the floor boards.
  • Increased chances of inflammation of the mucous membrane


Humidifiers can help

Air Humidifiers are a sure way to increase the humidity level inside your home to reach the ideal indoor humidity.  Choosing the right type depends on the size of the area you want to add moisture to and your budget. Central humidifiers humidify the whole house and are built directly into your home’s heating or conditioning unit. Portable humidifiers are more affordable and can be placed in any room you want. Poorly maintained humidifiers can also spread microbes so keep the humidifier clean and don’t leave the water standing when not in use. Some types of humidifiers have antibacterial components and materials to avoid such issues. Humidifiers that heat the water and vaporize it are usually more hygienic. Always check safety around humidifiers especially with small children in the house. The hot water can cause burns. Always adhere to manufacturer instructions and maintain your unit in the proper manner.

You can also temporarily increase humidity with a few tricks such as leaving the laundry out to dry in the living space or leaving bathroom door open while the shower dries out.  Also house plants release moisture in the air.

High humidity and how to decrease it

High humidity in it self is not harmful to health and temporary humidity is fine but in the summer time especially the house humidity rises with the outside humidity levels and can climb too high…

ideal home humidity

  • Effects mostly the house and it’s structures.
  • Encourages growth of mold, mildew and fungus.
  • Causes sleep discomfort. Moisture can’t evaporate from the skin as easily which makes you hot and uncomfortable
  • Dust mites. Keeping the relative humidity below 50% considerably reduces the growth of dust mites.


Household activities such as cooking and washing laundry also increase humidity.  Good ventilation is key number one. If you have no exhaust fans or ventilation system, open a window.  In a addition to changing the HVAC filters regularly, the air quality can be improved with the help of dehumidifiers. They are most commonly placed in specific areas that require moist removal such as basements or bathrooms without windows. Dehumidifiers come in many different sizes utilizing different technologies.


==> Here you can check out our guide on choosing the right indoor humidifier