The heating season is going and many people face indoor air quality problems during this time. A reduced level of air humidity (dry air) causes discomfort, affects health, work ability and sleep quality. One of the solutions to this problem is regular room ventilation and installation of an air humidification device which ensures optimal air humidity.
In the framework of this article we will talk about the effect of air humidity on human health, the role of water in the operation of air humidifiers as well as consider what kind of water is most suitable for air humidifiers.
The effect of air humidity on human health
The effect of air humidity on the human body depends on the temperature:
- If the air humidity is high but the temperature is low: the heat output of the body increases and the possibility of catching a cold increases.
- If the temperature is high and the air humidity is high: the moisture does not evaporate from the surface of the skin and the body can quickly overheat.
- At low air humidity and low temperature: a person usually does not feel discomfort.
- If the air temperature is high and the air humidity is low: the body secretes water more, the mucous membrane of the mouth remains dry, breathing is difficult, dry cough and hoarseness may occur.
Research conducted by researcher Antonius Arundel and other authors confirms that low air humidity contributes to respiratory tract inflammation, eye irritation as well as the spread of viruses. Low air humidity irritates the surface of the eye, causes rhinitis and dryness in the respiratory tract, thus weakening the body’s defense mechanism against infectious viruses (e.g. flu).
In addition, studies have shown that most of the health problems related to relative air humidity are minimized by maintaining the indoor air humidity level in the range of 40-60%. The survival and activity of infectious bacteria is reduced when exposed to air with a relative humidity between 40% and 70%. Allergic mite populations are negligible at relative humidity below 50% while most allergenic fungi are unable to reproduce at humidity below 60%.
How do humidifiers work?
To understand why water plays an important role in the operation of air humidification devices it is necessary to look at the principles of operation of these devices. Although there is a wide variety of humidifiers on the market, they are mainly divided into 3 types: evaporative, steam, and ultrasound.
The simplest humidifier is a cold air humidifier which uses a fan to blow dry air through a filter filled with water. A certain amount of water evaporates into the air, thus cooling and humidifying it.
A steam humidifier evaporates water and releases micro-droplets of water into the air. Such air humidifiers are rarely used on a daily basis as they consume a lot of electricity and are dangerous for families with children due to hot water and heat.
The most common is an ultrasound humidifier. The principle of its operation is based on the fact that the water poured into the tank is fed in parts to the ultrasonic device where it is divided into microdrops and with the help of a fan is directed from the humidifier body to the outside. Due to the size of the droplets they do not settle on surfaces but stay in the room until the air humidity reaches the specified air humidity.
Cold humidifiers are the most appreciative (least demanding) of the water composition while steam and ultrasound humidifiers require the purest water possible.
The role of water in a humidifier
There are several problems that can be caused by poor quality water in a humidifier. First, lime deposits. Ultrasound evaporation is very close to the boiling point, the formation of calcium and magnesium carbonate sediments is inevitable. A layer of lime can interfere the operation of the humidifier and cause accelerated water evaporation and frequent maintenance. Second, a “fog” may appear in the room where the humidifier is operating and deposits may appear on the surface of the furniture (the result of hard water). There are also cases when the water stands for a long time and microbiological contamination occurs in the humidifier.
What kind of water does a humidifier need?
Water for humidifiers should not be cloudy and should contain as little hardness and iron salts as possible. The absence of microbiological contamination in the water is also important. The optimal solution for humidifiers is distilled or reverse osmosis water because both contain a minimum amount of salts and cannot create scale and other negative effects.
Can I use tap water in a humidifier?
The answer to this question depends on the filter in the humidifier. If the air humidifier contains a filter that softens the water and removes mechanical particles from it, then tap water may be used. The only drawback of such air humidifiers is that the filters must be changed regularly (once every 3-6 months, depending on the quality of the water).
Read also: How to choose Ecosoft reverse osmosis filter?
