How to Improve Ventilation
Ventilation should ensure a thermal environment that is comfortable and free from risk of infection.health and fitness Updated: May 28, 2003 21:03 IST
Ventilation has to do with air supply inside buildings.
Ventilation essentially is the replacement of used air by a supply of fresh outdoor air. It also deals with the quality of incoming air with regard to its temperature, humidity and purity. Good ventilation should ensure a thermal environment in the interiors that is comfortable and free from risk of infection.
What happens to air in occupied rooms?
There are some interesting aspects to the atmosphere within buildings, especially when occupied.
The changes in air in a confined place are both chemical and physical.
When there people in a room more carbon di-oxide is released into their. It has been observed that in a mixed gathering each person exhales 0.6 c ft of carbon di-oxide every hour. These are the chemical changes involved.
The room heats up perceptibly. Humidity increases because of the sweat and the exhaled air. Sweat also produces odour. The flow of air is impeded and this makes the room stuffy. People also release bacteria into the air, when they cough or sneeze. All these cause physical changes in the air.
Apart from this, very specific pollutants are found inside rural and urban buildings. A Tata Energy Research Centre study observes "Key pollutants in urban buildings include nitrogen dioxide, carbon monoxide, radon (from building materials, water and soil), formaldehyde (from insulation), asbestos, mercury, man-made mineral fibres, volatile organic compounds, allergens and tobacco smoke - as well as health damaging organisms like bacteria."
Many of us feel uncomfortable in crowded rooms without really being able to say what it is that annoys us. The above factors, apart from psychological, are responsible for this annoyance factor. In poorly ventilated rooms people feel unable to concentrate, complain of drowsiness and headaches. This is called the Sick Building Syndrome. People who live or work in such places are more prone to infection.