Renxin Thermal Solutions

Thermal design, cooling methods and criterion equation of electronic equipment
Thermal design

Thermal design, cooling methods and criterion equation of electronic equipment

The thermal design of electronic products aims to control the temperature of electronic components in an appropriate and reliable way, so that electronic equipment can operate steadily in the working environment. To ensure reliable thermal dissipation, the temperature shall be strictly controlled below the specified maximum temperature. Moreover, the thermal design of electronic equipment shall be conducted simultaneously with circuit design and structural design to take all factors into account. Specifically, the cooling methods for thermal design of electronic equipment shall be designed with the following factors in mind: 1. Technical requirements for thermal design of product; 2. Thermal dissipation power of components; 3. The working environment of electronic equipment; and 4. Volume and surface area.

The common cooling methods for thermal design of electronic equipment include:
1. Free cooling (including heat conduction, free convection, radiation heat transfer)
2. Forced cooling (including forced air cooling, forced mixed liquid cooling)
3. TEC thermoelectric cooling
4. Heat pipe radiator

The cooling method is generally select according to heat flow cryptography and temperature rise requirements of equipment. Below is a reference diagram for cooling methods.

The diagram above lists the heat transfer coefficients corresponding to different cooling methods and the heat flux density below the temperature rise of 40℃. It can be seen from the diagram that the heat transfer coefficient of free cooling is usually 10 W/m2.℃. Therefore, to simulate heat dissipation in communication cabinet, you can directly set the wall of cabinet to “Wall” and enter the corresponding heat transfer coefficient (the heat exchange between outside air and cabinet shall be considered).
The table below shows different cooling methods and their heat transfer coefficients.


Cooling methods Heatt Ransfer Coefficients (W/m².℃) Heat flux density (W/cm²)
Free convection in air 6-16 0.024-0.064
Free convection in water 230-580 0.9-2.3
Forced convection (air) 25-150 0.1-0.6
Forced convection  (fluid) 3500-11000 14-44

Renxin.Thermal approaches thermal management differently to most other materials manufacturers. We have the capacity, depth of experience and the dedication needed to offer thermal solutions to our customer


Often mechanical or electronic engineers without thermal experience are tasked with managing the heat in the electronic assembles they are designing. This is where Renxin.Thermal can offer our expert knowledge. Suggested thermal designs provided by our engineers are derived from extensive thermal management experience that customers have learnt to trust. Renxin.Thermal is entirely independent and has the largest array of thermal materials available in the market from adhesives to heatsinks.

Renxin.Thermal  is committed to delivering our customer  the most cost effective and reliable thermal solutions available. Products range from heatsinks, Heatsink Design optimization,TEC devices, interface materials and thermal substrates plus many other materials that aim to complete your thermal solution. 
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