Pressure and humidity
In some special buildings the pressure and humidity of the spaces are also controlled. If humidity is not kept in check it can seep in through the walls of the building and spoil the contents of the building. For example, in genuine and high quality museums and art galleries, the pressures of the spaces are controlled with the aim to protect the invaluable and delicate paintings.
Also in the indoor swimming pool spaces, humidity sensors are provided to keep in check the humidity level.
For this purpose special humidity sensors are provided which measure relative humidity. Dehumidifiers that keep in check the humidity level are installed in such special places.
Pressure of a space or zone is kept under control mainly to prevent air borne contaminants from entering the building. We use the benefit of differential pressure for this.
In hospitals that treat TB (tuberculosis) diseases, it is imperative that pressure of the spaces and zones are kept in check. The spaces are particularly kept under negative pressure as compared to surrounding areas to prevent the TB germs from proliferating to surrounding areas.
Similarly, kitchen, toilets, smoking rooms, chemical laboratories etc are also kept under negative pressure to contain the smell which can be removed by supplying extra forced air.
In the next article we will take the topic further and learn about the designing consideration for zoning a HVAC system.