The fresh air supply system is often mentioned as one of the effective methods to remove dirt and harmful substances. So what is fresh air supply system? Standard fresh air supply ? The same issues surrounding fresh wind will be answered through the article below.
In the simplest terms, fresh wind is the unpolluted outdoor air. In fact, fresh wind plays a very important role in balancing life and ensuring human health.
According to the laws of biology, humans breathe in O2 gas, releasing CO2 into the environment. If there is only CO 2 gas, people will feel extremely uncomfortable and tired, so it is necessary to have fresh wind, provide enough O 2 gas to feel comfortable. Especially in an air-conditioned environment, closed space, limited natural air exchange, so to ensure O2 gas for the exchange process, it is necessary to have a certain amount of fresh air. In many cases, lack of O2 will lead to dizziness, nausea, even life-threatening.
Normally, there are two methods of supplying fresh air: forced ventilation and natural ventilation. Each type has a different structure and operating principle. Specifically:
Natural ventilation mainly uses ventilation umbrellas or louvers.
Forced ventilation, with this form, usually uses a fan to discharge the air containing a lot of CO 2 to the outside. Instead, there are types of air rich in O2. And to ensure that the correct amount of fresh air is provided, it is necessary to calculate according to a separate standard according to the TCVN standard.
Based on the TCVN 5678-2010 standard, it clearly stipulates the standards of fresh air supply for each type of commercial, civil, industrial building or each specific construction area. Based on the design standards of Vietnam, the minimum amount of fresh air is 20m3/person/hour. Therefore, the design requirements of the fresh air system need to comply with and ensure exactly the above standards
The fresh air supply system is built to do the following main tasks:
Eliminate toxic substances and impurities contained in the room to the outside quickly. Specifically, in the living space, the main toxic substance is CO 2 . Besides, it also does the job of removing excess moisture and excess heat to the outside. Usually we often use ceiling exhaust fans, wall exhaust fans to do the above 2 tasks. Along with that is the supply of oxygen necessary for human activities.
For spaces that are not very large but have many people living and closing the door, at this time the amount of air is not enough to maintain and meet the amount of air consumed, right now we need to use a fresh air supply fan. In contrast, for spaces with few people living, the door is not closed, we can use exhaust fans, clean air is quickly filled due to pressure difference.
The fresh air supply system helps to expel toxic substances and impurities contained in the room to the outside.
As mentioned above, how much fresh air supply depends on the specific requirements and scope of each project. It is possible to list some commonly used options for apartments and office buildings such as:
According to Vietnamese standards, the amount of fresh air supplied to the air conditioner needs to be at least 10% of the total circulating wind volume, reaching a minimum of 20m 3 /h/person. And to know exactly how many people can be arranged in a square meter, you need to refer to the TCVN of the construction ministry. In case of supplying fresh air by mechanical method, it is possible to use a fan to supply the air-conditioned space, preferably to the return air duct. In addition to calculating the system and standards for fresh air supply, it is also necessary to calculate the design of the wind channel and select the air outlet. This is the next important step after the required ventilation volume has been calculated. Calculate the air channel, determine the air outlet and the number of pipes connected to the inside of the device. By calculating the number of air vents, you will know how much flow is through each vent, what is the size of the duct and how much is the vent.
Basically, calculating the fresh air supply system is not as difficult as you think. With just a few simple steps, you can calculate the amount of fresh wind needed. You can also ask for the help of reputable and capable units.