Good ventilation brings in enough outdoor air to dilute emissions from indoor sources and carries indoor air pollutants out of the house. But opening doors or windows today in the daytime can be horrific. In earlier days, some 25 years back, when you open the doors or windows, you could get fresh air from the trees along the melodious chirping of birds from outside. But today when you open the door, you will get polluted air along with the irritating noises from outside. You can’t even afford to close the doors or windows always, as indoor air quality is one of the major health concerns for many people living in urban areas these days.
Earlier, houses were built on large spaces and there used to be lot of open spaces with trees between houses. Plenty of quality fresh air with oxygen was available as there was very less pollution outside. Today the scenario is quite opposite. Due to urbanization, trees are vanishing and outdoor air is being polluted by motor vehicles, construction sites (dust, cement, sand), garbage dumps, unclean roads, burst opened sewage lines, exhaust pipes from neighbors sewage etc.
Humans are the main sources of indoor air pollution releasing Carbon dioxide. Apart from humans the other sources of indoor air pollution include combustion sources such as oil, gas, kerosene, coal, wood, tobacco smoking, building materials and furnishings such as wet or damp carpet, furniture made of certain pressed wood products and products used for household cleaning and maintenance, personal care and other equipment. Indoor air polluted due to these sources has to be diluted, but you can’ t open the doors as outdoor air is more polluted than indoors.
Apart from outdoor air pollution, sound pollution today is very disturbing. When you open doors, you will hear heavy noise from busy traffic, street hawkers, dogs, processions, people shouting etc and construction sites such as drills and hammers if any. They cause severe inconvenience, distract attention, and in some cases may lead to headache and high blood pressure.
Eliminating or controlling the sources of pollution can solve the problem at both homes as well as offices. However, it is impossible. It is OK for people living at elevated apartments in high-rise buildings, as the pollution may not reach them. But for others, there is a need of some solution, which provides proper ventilation and prevent sound and air pollution coming from outdoors. There are some ventilators available in the market that filters outdoor air and brings in fresh air reducing sound pollution. They are called as Energy Recovery Ventilators (ERVs) and are designed to use with Air Conditioners. When the outside temperature is comfortable like in winters, you could only switch on the ERV and not use the AC at all. One should be aware of these products to live in a pollution free environment, as natural ventilation is a problem in urban areas.