Most buildings today rely on forced ventilation. But there’s a recent trend where many architects and builders recommend taking advantage of natural ventilation. This system uses air pressure and buoyancy to keep the interior of a building cool. While the application, for now, may be limited to specific designs, there’s no doubt that there’s immense potential in using natural ventilation.
The recommended design for natural ventilation
The approach and technique used in maximising natural ventilation depend on a variety of factors. Two of the most vital components include the climate and building design. Also, carefully designing the openings and orientation of internal space will affect the intensity of ventilation received.
- The building ridge should sit perpendicular to the direction of summer wind. Although it’s possible to get data regarding seasonal wind directions, the value may be significantly different if the data was collected far away from the actual building site. Ideally, there should be little obstruction so that the summer wind can freely enter the building openings. Manual window openers should help control the amount of wind, especially during colder months.
- Natural ventilation works best with narrow building designs. Distribution of air inside wide buildings tends to be more challenging. With natural ventilation, the building width should be no more than 45 feet.
- Every room should have an opening for air supply and another for exhaust. The exhaust should be located high above so that the wind stack effect will be more effective. These elevated openings may be controlled using electric window openers.
- Occupants should be able to operate the windows. Adding window controls to the building is a critical design element for natural ventilation. Occupants should be able to close or open windows to increase or decrease the amount of air entering the building.
- Enhance stack effect using a ridge vent. This type of vent is placed at the highest point in the building or the roof. A ridge vent is an effective means to draw warm air out, whether induced by artificial fans or buoyancy.
- Building design should be optimised for maximum airflow. Apart from making sure that air flows in and out of the structure, airflow between each room or internal space should be given equal importance. If possible, doors should be left open to encourage free movement of air.
- Ventilate the attic. If the building has a loft, providing ventilation in this area will reduce heat transfer in the rooms below.
- Add fans to aid ventilation. In a naturally ventilated building, ceiling fans can help drop the temperature by a few degrees. Not only that, but fans also cost significantly less than mechanical air conditioning.
- Use natural ventilation at night to cool the building. If applicable, opening windows at night will help cool a building and reduce mechanical air conditioning reliance.
It’s essential to understand that using natural ventilation isn’t always a perfect strategy. There are times when occupants may feel some level of discomfort. That’s why many designers today still consider the importance of integrating both natural and mechanical ventilation for maximum comfort and energy efficiency.