Ventilation: Its importance and techniques to improve it
We spend about 90% of our life in indoor spaces, so it is important that the air we breathe in them are healthy! There are air pollutants with different origins, such as the activities of people, facilities, furniture, construction materials, cleaning products. Some of them generate discomfort, like smells. Others are even dangers for our health, such as allergens, radon gas, volatile organic compounds. There is only one way to keep our air in good condition: to renew the indoor air at regular intervals.
However, indoor air quality is not the only reason why it is important to ventilate. Depending on where our building is located, correct ventilation can help maintain the temperature and the interior humidity.
Air renewal can be done in different ways: natural passive methods, where the air moves by the wind and the difference of pressure and temperature; mechanical methods, where the movement of air is caused by appliances; or in hybrid methods, where both systems are used but are activated according to circumstances.
01. AIR QUALITY
Air renewal can be done passively, depending on when you decided to do it, by opening the windows. Mechanical systems will consume some electricity, but the air entrance will be controlled, and there will not be a risk of stagnant air. There are several types of systems that are easy to install.
02. PASSIVE THERMAL COMFORT
There are different ways to obtain the best thermal performance in our homes. One of them is to generate the movements of air indoors. It will depend on your area, but it is possible that in a place with warm temperatures we could avoid or reduce the use of conditioned air by a good implementation of the following systems:
Temperature and pressure difference:
This is the more implemented strategy: natural cross-ventilation. In this case, the speed of air entry and air exit is triggered by the difference in temperature or pressure that exists between the different faces of the building in which the windows are located. If the wind in the area does not have enough speed, you can increase its speed by placing smaller windows on the face through which the air will evacuate the building.
To work properly, we recommend that the windows face each other but not be aligned, in this way the air path will drag all the fluid in the room. The height of the openings should also be taken into account. If they are at the same level as the people, adjust them with your comfort when the wind passes over them, to give them a feeling of freshness. Also, if the window where the air will exit is in the upper part of the room, it can drag out the hot air that tends to rise and stay near the ceilings.
It is important to have this strategy in the mind when we are planning new buildings because courtyards can collaborate to optimize this system.
Do not forget that these types of solutions are very interesting but not for all kinds of climates, if we are in extreme cold weather it may be more convenient to have a little more controlled air renewal system and more compact buildings. In addition, this strategy can generate some discomfort like the entrance of external noises.
- Temperature difference inductors
Another way to ventilate an interior is by generating temperature differences between the entry and exit areas of the air, which will increase its speed. It will increase the comfort of inhabitants and promote efforts to clean the indoor air.
One of the strategies to use is a solar chimney. It is a chimney usually installed on the top of the house, connected to the ventilation system. Its materials, because of their characteristics, increase the air temperature in the upper zone, in the area where the fluid will be removed. The hot air tends to rise and when the upper gates open its generally upward movement pushes the indoor air towards this exit, increasing the speed that it would normally have.
Another example is the Trombe wall. It is a very useful strategy for heating in cold areas. It is a system connected to the wall, consisting of a glass and a background with dark colored material that raises its temperature when it absorbs the sun's rays. A greenhouse effect will be generated indoors by heating the air. In turn, the system has two gates that connect to the interior of the building, one on the upper section of the wall and the other lower down, that allows the air to enter and exit the interior. The other two allow the hot air to be evacuated to the outside on summer days. If the inner ducts and the evacuation are open, an effect similar to that of the solar chimney is generated: the difference of the air temperature increases the speed and air renewals are allowed in less time.
- Dynamic pressure inductors
Another way to help ventilation is by pressure inductors. An example is wind towers. They are used in warm and dry areas. They consist of towers that capture the wind in high areas, the air is humidified when passing through water, and enters the building with lower temperature and higher humidity.
These are some of the ventilation strategies that can be applied to generate comfort in a building. We must not forget that the choice will depend on each work and the climate where it is implemented. Surely there is one that adapts to your house!