When natural cooling does not solve the problem, forced air cooling, ie forced air cooling, is required. Forced air cooling is the use of fans to blast or ventilate, improve the air flow speed inside the equipment, and achieve the purpose of heat dissipation. The form of forced air cooling is mainly convection heat dissipation, and the cooling medium is air. Forced air cooling is widely used in medium and high-power electronic equipment because it has several times more heat transfer capacity than natural cooling. Compared with other forms of forced cooling, it has a simple structure, low cost, easy maintenance, etc. advantage.
The forced air cooling system of the whole machine has two forms: blast cooling and exhaust cooling.
The blast cooling is characterized by large wind pressure and concentrated air volume. It is suitable for the case where the heat distribution in the unit is uneven, the wind resistance is large and the components are large.
The characteristics of exhaust cooling are large air volume, small wind pressure, uniform air distribution, and wider application in forced air cooling.
For the ductless cabinet, the whole cabinet is equivalent to a large air duct. It is required to be sealed around the cabinet. The wall should not be opened. Only the inlet and outlet are allowed. Considering the rise of hot air, the exhaust fan is usually installed in the upper part or the top of the cabinet, the air outlet is facing the atmosphere, and the air inlet is installed in the lower part of the cabinet. This air-cooled form is often applied to equipment with less wind resistance on the cooling surface of each component in the cabinet. For equipment with heat-sensitive or non-heat-resistant components in the airflow rising part, the air duct must be used to avoid the airflow and flow into the air inlet in the required direction, usually on the side of the cabinet, and the air outlet (exhaust port machine) is in the cabinet. top.