GREEN RESOURCES
Natural Ventilation
Natural Ventilation
Natural ventilation uses natural forces of wind and buoyancy to deliver sufficient fresh air and air change to ventilate enclosed spaces without active temperature controls or mechanical means. Fresh air is required in buildings to alleviate odours and improve indoor environmental quality.
When carefully designed, natural ventilation can reduce building construction costs and operation costs by reducing the energy consumption for air-conditioning and circulating fans. Provision for naturally ventilated lobby areas, corridors, lift cores, staircases should be encouraged.
Types of Natural Ventilation
There are basically two methods of natural ventilation that can be employed in a building which are cross ventilation (wind driven) and stack ventilation. Both are caused by naturally occurring pressure differences. However, the pressure differences that cause wind driven ventilation uses the natural forces of the wind whereas stack ventilation is caused by pressures generated by buoyancy as a result of the differences in temperature and humidity.
Proper orientation and layout of building can fully utilize prevailing wind conditions to achieve adequate cross ventilation. In Malaysia, the prevailing wind comes from two predominant directions; that is the north-east during the Northeast monsoon season and south to south-east during South-west monsoon season. Hence, buildings designed with window openings facing the north and south directions have the advantage of the prevailing wind conditions that would enhance indoor thermal comfort. Meteorological data on the more precise wind direction and velocity of the site location can also be used as the basis for the design.
To produce better stack ventilation, maximise the vertical distance between the lower inlet opening and the upper outlet opening. The ventilation rate is proportional to the area of the openings which should be kept roughly the same size.
Natural ventilation uses natural forces of wind and buoyancy to deliver sufficient fresh air and air change to ventilate enclosed spaces without active temperature controls or mechanical means. Fresh air is required in buildings to alleviate odours and improve indoor environmental quality.
When carefully designed, natural ventilation can reduce building construction costs and operation costs by reducing the energy consumption for air-conditioning and circulating fans. Provision for naturally ventilated lobby areas, corridors, lift cores, staircases should be encouraged.
Types of Natural Ventilation
There are basically two methods of natural ventilation that can be employed in a building which are cross ventilation (wind driven) and stack ventilation. Both are caused by naturally occurring pressure differences. However, the pressure differences that cause wind driven ventilation uses the natural forces of the wind whereas stack ventilation is caused by pressures generated by buoyancy as a result of the differences in temperature and humidity.
Proper orientation and layout of building can fully utilize prevailing wind conditions to achieve adequate cross ventilation. In Malaysia, the prevailing wind comes from two predominant directions; that is the north-east during the Northeast monsoon season and south to south-east during South-west monsoon season. Hence, buildings designed with window openings facing the north and south directions have the advantage of the prevailing wind conditions that would enhance indoor thermal comfort. Meteorological data on the more precise wind direction and velocity of the site location can also be used as the basis for the design.
To produce better stack ventilation, maximise the vertical distance between the lower inlet opening and the upper outlet opening. The ventilation rate is proportional to the area of the openings which should be kept roughly the same size.
