Consequences of too dry air
It is important to monitor the humidity level in a home, especially in vulnerable people (respiratory problems, rhinitis, asthma, keratoconjunctivitis, etc) for which real adverse health impacts can be observed:
- Chapped lips
- Dry and red eyes
- Irritant contact lenses
- Dry and flaky skin (dermatitis)
- Tingling in the throat, dry cough
- Mucous membranes of the nose and throat dry or irritated
- Irritated respiratory voices
- Increased risk of infection (spread of viruses such as influenza)
- Decreased immunity
- Lungs retain less oxygen
- Sensation of cold at normal temperature
- Increased static electricity
- Increased irritation and irritation to tobacco smoke
- Increased dust concentration in air
Optimum moisture content
A person can hardly feel 40% or 60% relative humidity. The feeling of discomfort appears below 30% or above 70%.
The recommended moisture content in a home is between 40% and 65%.
The action of air humidity on health in commercial buildings appeared in issue 10/1992 of the journal Heating Ventilation Packaging ):
- Zone 1 to avoid drought problems
- Areas 2 and 3 to be avoided with regard to the development of bacteria and micro-fungi
- Zone 3 to be avoided with regard to the development of dust mites
- Zone 4 corresponding to the hygrothermal comfort polygon
Why is the air so dry in our homes in winter
Measurement of the relative humidity in air is expressed in% and is close to the ratio between the absolute humidity carried by the air and the maximum absolute humidity it can carry when saturated. Thus, this quantity characterizes the power of the air to absorb water vapor before it condenses.
It is generally understood that the heater dries out the air. In fact, heating the air does not alter the absolute humidity carried by the air. However, at the most the air is warm, at the maximum moisture it can carry increases.
Let’s take a simple example. It is 0 ° C outside and the relative humidity is maximum (100%) as in case of rain. If the house is completely ventilated, the outside air with its relative humidity of (100%) replaces the air in the house. This air is then heated to 10 ° C. The amount of water contained in the air remains constant, but the relative humidity is reduced from 100% to 50%. At 20 ° C it increases to 26% and at 25 ° C it is only 19%!
This is why the air is practically always too dry in the winter in a house. Some activities do, however, increase this amount of moisture (laundry, shower, kitchen …), but this is often insufficient.
Of course, to measure the moisture content, it is necessary to be equipped with a hygrometer.
The solution to a too dry air is of course to find a way to evaporate water in the air.
I tested humidifiers for radiators. With a capacity of about 0.4 liters, they empty in about a week. I did not really notice any measurable variation in humidity with this type of humidifier (I had 4 in the same room).
As Taotronics humidifier reviews ad recommendation from friends, I tried the TaoTronics ultrasonic humidifier. It is capable of evaporating more than 4 liters per 24 hours. It is almost 70 times more efficient than a radiator humidifier. With this one, it is possible to adjust the moisture content of the part to the desired value. In short, I’m pretty happy.