Natural ventilation is a method of allowing fresh outdoor air into indoor living spaces by natural means without the use of air conditioning units and other types of mechanically driven devices. It is the process of changing or replacing stale or noxious air with fresh air in any space to provide high indoor air quality to control temperature, replenish oxygen, remove moisture, odors, smoke, heat, dust, airborne bacteria and carbon dioxide.
Ventilation is important as it reduces unhealthy air pollutants, such as formaldehyde and radon. It reduces excessive moisture and humidity levels, which can lead to mold growth and can cause structural damage. Ventilation reduces naturally occurring odors in the house from pets, cooking, smoking, and other everyday living activities.
While buying or moving to a dwelling, we often consider factors like exterior and interior of building, paint, space, location, building finishes, tiles, ceramics, bath room and electrical fittings etc, but we never ponder on the ventilation aspect. Perhaps this is due to having air conditioners in almost all buildings of the country.
Ventilation is provided through openings such as windows, ventilators and doors. Because of central cooling systems, most people don’t open windows and doors as often. Therefore, air conditioning has become the only principal mode of ventilation in urban surroundings.
A home’s natural ventilation rate is unpredictable and uncontrollable due to the openings, depending on dwelling location, size and number of openings in wind direction. Thus, one cannot rely on natural wind only to ventilate a house uniformly.
Ventilation is needed for removing water vapor produced by respiration, burning, and cooking, and for removing odors. If water vapor is permitted to accumulate, it may damage the structure, insulation, or finishes. In the absence of adequate ventilation, irritating or harmful contaminants can build up, causing occupant discomfort, health problems and reduced performance levels.
Harmful pollutants from a variety of sources can contribute to building-related illnesses. Ventilation systems that are improperly operated or maintained can contribute to sick building syndrome (SBS) which may cause symptoms like dry mucous membranes, eyes, nose and throat irritation. These disorders lead to increased occupant sickness and reduced work efficiency.
The advantages of natural ventilation are many and can have a tremendous positive impact on its occupants, building and the environment. It is suggested that natural ventilation is to be used on optimum basis keeping following aspects in mind:
- Use fans at appropriate locations to blow air from the cool side of the dwelling to the hotter side.
- Don’t keep your windows closed.
- Do occasional air wash of your dwelling.
- Open windows for durations, depending on the sunlight and its intensity.
- Cross ventilation in a dwelling will enhance air quality and will avoid it to become a sick building.
- Provide fountains, pools or swimming pools outside the dwelling which can act as transition spaces where air is naturally cooled before passing through interiors.
A proper design, operation and maintenance of the ventilation system is essential in providing indoor air that is free of harmful concentrations of pollutants. Improvements in indoor ventilation may substantially increase an individual’s health, moral and productivity.