Why Ventilation Design is Important?

Before Urbanization and Industrialization in Bangladesh there was no need of Mechanical Ventilation to maintain sufficient air circulation in the room. Even now this can be seen in the Remote rural areas where people are living comfortably without fans. The Southern Breeze is pleasant and comfortable enough in Bangladesh to keep the whole house well ventilated. But in the busy cities like Dhaka, where the structures are crammed together obstructing natural wind flow, architectural design principles need to be incorporated to provide proper ventilation in the space. On the other hand, ling ago, natural raw materials like clay, mud and hay were used to build the houses, which allowed flow of fresh air from all directions, since the walls were porous. The use of reinforced concrete now insulates the rooms thus, Ventilation in today’s homes has become more important than it was for homes that existed long ago.

How to Ventilate the Spaces: Cross Ventilation

In the City we all live in in pre-designed and constructed high-rise apartments. Some of us have a piece of land which we handover to developers. In these cases, we often emphasis on luxurious interior design and often overlook whether the layout offered by the developer or the design of the apartment we are choosing to live in, incorporates the principles for properly ventilating the rooms. So, how do we check that? The most important factor regarding this matter, when choosing an apartment or accepting a design from a developer or architect, is to confirm about Cross Ventilation.

Cross Ventilation is also known as Wind Effect Ventilation since the idea is to use wind-driven effect to ventilate the home and to keep them cool. There needs to be pressure differences between one side of a building and the other. Air is drawn into the building on the high-pressure (or upwind) windward side and is drawn out of the building on the low-pressure (or downwind) leeward side. The windward side flow of the wind causes the required introduction of natural air in the rooms, thus providing ventilation. There are different types of Cross Ventilation and to understand if a room has cross ventilation, you can crosscheck with the following diagram:

The difference in wind pressure affects the overall ventilation within the building. In Bangladesh, the most effective form of Cross Ventilation is to have the two openings in opposite walls with the inlet to be located in the south facing walls.

Use of Greeneries

Indoor plants will not only adorn your interiors but also improve the air quality inside the rooms. Simple House Plants like the Devil’s Ivy or more commonly known as the Money Plant in Bangladesh are good examples of house plants to be kept indoors. If you have a room or a balcony close to your room, keep a few plants including Orchid, Ivy, Peace Lily, Dracaena, Chinese Evergreens or even Aloe Vera. In a month, you can actually feel the difference in the air quality.

Mechanical Ventilation and Others:

As discussed in our previous blog, Mechanical Ventilation or Artificial Ventilation are introduced in Home design. Since in Dhaka City, buildings are located at close proximity, so, different types of Mechanical Ventilation Systems are necessary.

On the other hand, proper window designs are important so that there is optimum air flow in the rooms. Windows near the center of the windward side walls are more effective because pressure is highest there and diminishes toward the edges as the wind may move around the corners. Louvers are also more efficient in allowing more airflow compared to that of windows.

Ventilation is an extensive subject where each item can be discussed in detail. There are methods of Cross Ventilating your home. There are many articles on the use of House plants to keep your home well ventilated and so on. Proper Ventilation is crucial for the wellness of body, mind and spirit for everyone and thus should be given its due attention.

by Siam Mim