Even though your humidifier should be operated on clean and fresh drinking water, the water will still contain a few bacteria. This is normal and in accordance with even the highest standard of drinking water regulations such as the DVGW in Germany or EPA in North America. If these bacteria are allowed to proliferate to a higher concentration, there might be the right that the bacteria enter the air we breathe.
Most of the bacteria found in drinking water are completely harmless, but a few of them can be pathogen – or cause different diseases, if they enter our lungs.
Bacteria are small single-celled microorganisms that are found everywhere in our surroundings, in the air, water, soil, our food, even the human organism. Bacteria are so small that they cannot be seen with the naked eye. They are between 0.2 and 50 microns (millionths of a meter) in size. Once bacteria gain access to a growth-place and nutrition, they can proliferate. The proliferation is very much influenced by environmental factors such as temperature, pH value of the water, flow velocity of the water or choice of piping material, just to name a few. In addition, growth is also influenced by any number of (cleaning and disinfection) chemicals.
International and local regulations generally set limits for the maximum number of bacteria in drinking water, and in general it must not contain any disease-causing bacteria. For total bacteria in drinking water the maximum is set to 150-200 cfu per ml of water, which are able to proliferate at 22°C and 50 bacteria per ml which are able to proliferate at 37°C.
These limits apply to drinking water entering your home from the central pipe running outside your house. Experience and measurements have repeatedly shown that the bacterial count can easily be higher within the house, e.g. in basements or technical rooms due to stagnation of water or changes of environmental parameters such as temperature.
When this water is used for drinking, it is typically not posing a health problem because our stomach acid and organism is equipped to fight a relative high number of bacteria.
We do not have the same protection in our lungs, so it is important that the aerosols generated from the humidifier do not contain further bacteria, when they enter the air we inhale.
One of the most dangerous bacteria that exists in water for humidification is Legionella Pneumophila. It is found naturally in our surroundings and can also occur in low numbers in drinking water. If they are allowed to proliferate to a higher concentration they can be dangerous, if we inhale aerosols containing these bacteria.
The good thing about Legionella is however, that they do not occur water systems alone, but always in combination with a large number of other bacteria. Condair has determined optimal maintenance cycles for your humidifier which are programmed into the units. If these cycles are followed and thus your humidifier kept clean and maintained according to the instructions in the manual, the total number of bacteria is kept at a minimum, and hence the risk for Legionella being able to proliferate. The better the hygiene the lower the risk.