A little science lesson


the science behind every Venta Airwasher

The effects of dry air

  • Dry heater air causes dry mucous membranes. Bacteria and viruses cannot be trapped and the danger of infection, catching cold and allergic respiratory disease increases.
  • Breathing dry air is harder on the lungs and makes it more difficult for oxygen to enter the blood. Symptoms can include tiredness, headache and reduced concentration.
  • Wooden furniture, parquet floors and musical instruments can crack when exposed to dry air.
  • The indoor air can contain millions of fine particles invisible to the naked eye. Dust also rises in dry air.
heizkoerper

A heated 30 sq. ft. room needs approximately 5 liters of water per day to have the medically recommended humidity level.

Water bowls on heaters are much too small and unhygienic. There are various humidifying systems for humidifying the air to the optimal level.

Break

The physics of humidifying

Humidity is the proportion of water vapor in the air. There are two kinds of humidity, absolute humidity and relative humidity.

The absolute humidity is a measurement for the maximal possible content of water vapor in the air. It is given in grams per cubic meter (g/m³).
This value depends on the temperature of the air, since warm air can absorb more moisture than cold air can. This is why the maximal air moisture level is higher in the summer than in the winter.

The relative humidity (RH) is the ratio of water vapor content to the maximal possible water vapor content. The relative moisture is given as a percentage. When the air is saturated, the relative humidity is therefore 100%.

The following table and figure show how much water (absolute value) can be absorbed by air at various temperatures.

grafik-physik-en

Example:

At 20 °C, the air has a maximal water vapor content of 17.3 g/m³. This means that during the colder times of year in particular, during which there is a major difference between the temperature of the air indoors and outside, water must be actively added to the air. In a room heated to 25 °C, the air can absorb 23 g/m³ of water, while 0 °C cold air cannot absorb much moisture and only contains 4.84 g/m³ of water. Opening the windows during the colder times of year makes the air inside even drier, since the cold air from outside hardly contains any water and requires more moisture once it has been heated.

Break

Saturation concentration of steam in the air as a function of temperature.

°C rF 40% 45% 50% 55% 60% 65% 70% 75% 80% 85% 90% 95% 100%
– 5 °C 1.3 1.46 1.62 1.78 1.94 2.21 2.27 2.43 2.59 2.75 2.92 3.09 3.24
0 °C 1.94 2.18 2.42 2.66 2.9 3.14 3.39 3.63 3.87 4.11 4.36 4.6 4.84
+ 5 °C 2.72 3.06 3.4 3.74 4.08 4.42 4.76 5.1 5.44 5.78 6.12 6.46 6.8
+ 10 °C 3.76 4.23 4.7 5.17 5.64 6.11 6.58 7.05 7.52 7.99 8.46 8.93 9.4
+ 15 °C 5.12 5.76 6.4 7.04 7.68 8.32 8.9 9.6 10.24 10.88 11.52 12.26 12.8
+ 20 °C 6.92 7.79 8.65 9.52 10.38 11.25 12.11 12.98 13.84 14.7 15.57 16.44 17.3
+ 25 °C 9.2 10.35 11.5 12.65 13.8 14.95 16.1 17.25 18.4 19.55 20.7 21.85 23
+ 30 °C 12.12 13.64 15.15 16.66 18.18 19.7 21.21 22.73 24.24 25.76 27.27 28.8 30.3
  • About humidity and dry air in your house

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    The effects of dry air

    • Dry heater air causes dry mucous membranes. Bacteria and viruses cannot be trapped and the danger of infection, catching cold and allergic respiratory disease increases.
    • Breathing dry air is harder on the lungs and makes it more difficult for oxygen to enter the blood. Symptoms can include tiredness, headache and reduced concentration.
    • Wooden furniture, parquet floors and musical instruments can crack when exposed to dry air.
    • The indoor air can contain millions of fine particles invisible to the naked eye. Dust also rises in dry air.
    heizkoerper

    A heated 30 sq. ft. room needs approximately 5 liters of water per day to have the medically recommended humidity level.

    Water bowls on heaters are much too small and unhygienic. There are various humidifying systems for humidifying the air to the optimal level.

    Break

    The physics of humidifying

    Humidity is the proportion of water vapor in the air. There are two kinds of humidity, absolute humidity and relative humidity.

    The absolute humidity is a measurement for the maximal possible content of water vapor in the air. It is given in grams per cubic meter (g/m³).
    This value depends on the temperature of the air, since warm air can absorb more moisture than cold air can. This is why the maximal air moisture level is higher in the summer than in the winter.

    The relative humidity (RH) is the ratio of water vapor content to the maximal possible water vapor content. The relative moisture is given as a percentage. When the air is saturated, the relative humidity is therefore 100%.

    The following table and figure show how much water (absolute value) can be absorbed by air at various temperatures.

    grafik-physik-en

    Example:

    At 20 °C, the air has a maximal water vapor content of 17.3 g/m³. This means that during the colder times of year in particular, during which there is a major difference between the temperature of the air indoors and outside, water must be actively added to the air. In a room heated to 25 °C, the air can absorb 23 g/m³ of water, while 0 °C cold air cannot absorb much moisture and only contains 4.84 g/m³ of water. Opening the windows during the colder times of year makes the air inside even drier, since the cold air from outside hardly contains any water and requires more moisture once it has been heated.

    Break

    Saturation concentration of steam in the air as a function of temperature.

    °C rF 40% 45% 50% 55% 60% 65% 70% 75% 80% 85% 90% 95% 100%
    – 5 °C 1.3 1.46 1.62 1.78 1.94 2.21 2.27 2.43 2.59 2.75 2.92 3.09 3.24
    0 °C 1.94 2.18 2.42 2.66 2.9 3.14 3.39 3.63 3.87 4.11 4.36 4.6 4.84
    + 5 °C 2.72 3.06 3.4 3.74 4.08 4.42 4.76 5.1 5.44 5.78 6.12 6.46 6.8
    + 10 °C 3.76 4.23 4.7 5.17 5.64 6.11 6.58 7.05 7.52 7.99 8.46 8.93 9.4
    + 15 °C 5.12 5.76 6.4 7.04 7.68 8.32 8.9 9.6 10.24 10.88 11.52 12.26 12.8
    + 20 °C 6.92 7.79 8.65 9.52 10.38 11.25 12.11 12.98 13.84 14.7 15.57 16.44 17.3
    + 25 °C 9.2 10.35 11.5 12.65 13.8 14.95 16.1 17.25 18.4 19.55 20.7 21.85 23
    + 30 °C 12.12 13.64 15.15 16.66 18.18 19.7 21.21 22.73 24.24 25.76 27.27 28.8 30.3

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