Why should you be concerned about indoor air quality?
Indoor air quality means the air quality within buildings. It typically relates to the health and comfort of the people living in the house. 
In this article we are focusing on indoor ambient conditions, such as humidity and temperature. These factors can make it favorable for molds and other allergens to grow.
Air humidity is one of the factors affecting how we feel the temperature. Besides, relative humidity depends on the temperature. Warm air is able to bind more water than cold. Adjusting the indoor humidity and fine tuning the temperature often goes hand in hand.
Indoor air humidity
Humidity is the amount of moisture or water vapor in the air. Relative humidity tells how much water there is in the air relative to how much it can actually contain.
Humid air (high humidity) or dry air (low humidity) can have adverse effects on our bodies.
Some signs of too humid indoor air include
- feeling sweaty or hot
- frizzy hair
- sleep interruptions
- respiratory problems
- asthma and allergy problems
Too dry indoor air may cause
- irritated skin
- dry eyes
- chapped lips
- bloody nose
- itchy throat
- asthma and allergy problems
You might experience the signs soon after the exposure to the air pollutants, or years later. The immediate effects are usually short term and treatable.
Dry indoor air
During winter, indoor air is almost always rather dry. When the temperature drops significantly under zero, the relative humidity can decrease down to 20%. Proper relative indoor humidity during winter time is between 20% and 40%.
High indoor temperature increases the dryness of the air. High room temperature is sometimes the reason behind dry indoor air. It’s recommend to keep the room temperature under 22°C (72°F). The relative humidity increases when the indoor temperature is decreased.
Humidity readings over 45% during winter are typically caused by human action (cooking, laundry, etc) and improper ventilation. In that case, the humidity starts to condense to windows and other cold surfaces. In worst case scenario, the humidity starts to condense to the structure of the building. This will most likely cause some health concerns later on.
How to address too dry indoor air?
One solution to address indoor humidity problems is to start using a device called humidifier. A humidifier increases the moisture levels by creating water vapor or stream.
Using a humidifier requires regular maintenance. If not maintained properly, the device can start to spread microbes in the air. The most hygienic humidifier is one that creates vapor by heating water.
Humid indoor air
During summer, the indoor air relative humidity follows the outdoor humidity and typically ranges between 50% - 70%. The ideal range for indoor humidity during summer time is about 30% - 50%.
Indoor relative humidity must be kept under a level where it starts to form microbes in the building or in surfaces. The humidity should not be over 60% constantly.
The relative humidity decreases as temperature rises. It’s doesn’t make sense to increase the temperature inside house during summer. But, you might apply higher temperatures in garages or storage rooms to decrease the humidity.
How to address too humid indoor air?
The most important thing in avoiding too humid home is to make sure that the ventilation is working properly. In areas where moisture is created, such as in bathrooms and kitchen, the ventilation is especially important. Washing machines and dryers increase the temporary humidity levels too when in use.
If you cannot affect the ventilation or use extra fans, you could try using air conditioner. Air conditioner removes the warm humid air and replaces it with dry cooler air.
Another option is to use a dehumidifier. A dehumidifier collects and removes excess moisture from the air. A dehumidifier is most often used in shower rooms or in basements because they are the most problematic areas. As with the humidifiers, a dehumidifier requires regular maintenance to keep it clean.
How to get humidity readings?
The majority of adverse health effects caused by relative humidity would be minimized by maintaining indoor levels between 40% and 60% . The Environmental Protection Agency (EPA) suggests to keep the relative indoor humidity between 30 and 50 percent .
That’s why it’s important to measure the indoor air for too dry or humid air, and act accordingly.
It’s very much recommend to watch the humidity levels before and after starting to use a (de)humidifier. This is to make sure the air is not made too dry or too humid with the help of these devices.
Meazurem is perfect tool for monitoring the humidity levels. Meazurem monitors and tracks the ambient conditions in your house. You can check the instant conditions with your phone.Introduction to Indoor Air Quality
: Indirect health effects of relative humidity in indoor environments
: United States Environmental Protection Agency Mold Course