Bacteria

Pathogenic microbes are present only in the vicinity of patients with related diseases.
Ventilation considers maintaining atmospheric conditions which are comfortable for the human body. The amount of air required for sufficient ventilation depends on factors like size of the room, number of persons on factors like size of room, no of persons occupying the room & impurities present in the room. In order to limit the concentration of carbon dioxide to less than 0.02%, each individual is advised to have at least 3000 c.ft.air per hour. In case of sick persons it is advised to be increased to 3750 c. ft. If the space available per head is a fraction of the required minimum then the air will have to be changed frequently e.g.300 c.ft.requires air to be changed at the rate of 10 times per hour. It is observed that warm air, after rising to the height of 12 feet, gets cooled & falls down again. Thus for a floor height of about 12 feet, the floor space should be 1/12 th of the total cubic space.