Analysis of ground air supply and top air supply

How It Works: Heat Recovery Ventilator
The Air Pollution in Southeast Asia

Analysis of air supply method
1.1 First, we analyze from the principle of air. Polluted air generally has more particles, carbon dioxide, etc., which means that the weight of the polluted air must be heavier than fresh air. Then, due to the influence of gravity, the polluted air is generally the lower layer of the indoor air.

Ventilation system

So according to this situation, we use the installation method of ground delivery, which can make the dirty air exhaust from the ground and fresh air into the top. This is the most logical approach. The operating room of the hospital is also so dry, but the home decoration is fresh. We have to consider the actual situation. If the home improvement fresh air does not use this method, why not recommend it? The reason is very simple. The environment in the home is complicated. There are more dust and other small debris. The exhaust vent is placed on the ground. The pressure at the exhaust vent is generally small, so the debris is easy to enter the exhaust duct. One year, it is easy to cause debris accumulation in the exhaust pipe, which cannot be cleaned.

Roof installation and Ground installation


1.2. What about the fresh air installation method using top delivery and return? Still the same, starting from the composition of the air, we just said that the dirty air will be heavier than the fresh air, so the dirty air will be in the lower part of the house. At that time, fresh air will be above it, because the weight of fresh air is lighter than the dirty air, and top air means that the air is discharged at the top. What kind of air is discharged? It must be the air at the top, that is, the fresh air at the top is exhausted.

Window type fresh air fan

Although the supply and return air vents can be installed diagonally in the room to generate the relative airflow principle, fresh air is first covered on the top, so the exhaust air must first be discharged from the top.


How to solve this problem? That is, the power of the supply air is higher than the power of the return air, so that the amount of air sent in is excessively discharged. In this way, the fresh air will slowly fall into the dirty air, “dilute” the dirty air, and after a long time, the effect of indoor air purification will be achieved.

1.3 In addition, let’s talk about the way to send back the fresh air installation. In fact, I think this installation method is more reasonable, but the requirements for the fresh air motor are relatively high. Many brands on the market can’t do ground ventilation. Why can’t many brands do ground ventilation? The reason is that the ground pipes are flat, the pipes are smaller, and the pipes are much smaller than the top-supply pipes, and the pipes are small and long, resulting in very large resistance, especially the power of a certain Japanese brand motor can not meet the requirements, This results in insufficient power and small fresh air volume.

Installation of duct fans



Finally, let’s talk about the benefits and rationality of air supply. We still analyze it according to the analysis method just now. Everyone knows that the dirty air is at the bottom of the house. Then the fresh air comes in at the bottom. Since the weight is lower than the dirty air, the fresh air will float up. The fresh air sent into the room at the same time “dilutes” the dirty air, so that the dirty air can be diluted in a short time, and the installation method of the top return or the top row installation is very good. The three-dimensional diagonal airflow in the room allows the indoor air to be fully purified, and the dirty air can be discharged out of the room in a short time.

So if your home uses a combination of air conditioning + floor heating, then the ground air supply is a more comfortable choice. If cooling and heating rely on air conditioning, we will choose a more economical mode-top supply air.