Fan, thermal management definition
Thermal management is a process that involves managing and controlling the heat generated in a device or system. It is designed to ensure that equipment operates within an acceptable temperature range to prevent overheating from negatively impacting performance and reliability.
Thermal management methods include heat dissipation, fan cooling, liquid cooling, thermally conductive materials, etc., to effectively disperse or remove heat from the device. Thermal management is important in a variety of fields, including electronics, industrial equipment, automotive and aerospace.
The role of fans in thermal management and design considerations
Fans constantly move air in contact with your device or heat sink to eliminate pockets of hotter air that don't remove heat as effectively as fresh, cool air. Like radiators, fans come in many shapes, sizes, and voltage levels. Shape and size are related to airflow, usually measured in cubic feet per minute (CFM).
Depending on design needs, some fans further provide speed control that can be used in a feedback system to actively adjust CFM. While fans reduce the size of the required heat sink and are relatively inexpensive, they are active devices that require power, have moving parts, are more prone to failure, and can be very noisy.
How fans cool electronics
Fans cool down through active and passive cooling. Active cooling uses fans to blow air over electronic components, while passive cooling relies on air convection and heat sinks to dissipate heat.
What are the main components of a fan?
Electric motor: The core component of an electric fan that generates the power to rotate the fan's blades. This can be a direct current (DC) or alternating current (AC) motor, depending on the design and purpose of the fan.
Blades: The blades of a fan are the part connected to the motor and they rotate to suck in and expel air. The shape and number of blades affects the fan's performance and airflow.
Chassis: The casing is the casing that surrounds the fan and usually has an air inlet and outlet. It is designed to influence air flow and direction.
Bearings: The fan's bearings are responsible for supporting and keeping the blades rotating smoothly. The quality and lubrication of the bearings will affect the lifespan and noise level of the fan.
Circuit Board: Some fans may have a circuit board that controls fan speed, monitors temperature, or provides other functions. These boards are usually connected to the electric motor and powered by an external power source.
Cords and plugs: Fans often come with cords and plugs to connect to a power source or control system.
Is the thermal manager important?
Good thermal management, just like the human body's need to maintain a proper body temperature, is critical for electronic devices. It helps extend the life of your device, improve performance, avoid possible problems, save energy, and provide users with a better experience.
Just like we keep our bodies healthy to extend our lives, electronic devices need to be kept at the right temperature to prevent them from being damaged by high temperatures. When the device works at a suitable temperature, it performs better, avoiding possible collapse problems caused by overheating, and also reducing energy waste.
This helps ensure devices operate at normal temperatures, are quieter and more reliable, and provide a better user experience.
How heat energy can be transferred:
Conduction: The transfer of thermal energy from a high-temperature area to a low-temperature area through direct contact of matter, through collisions between atoms or molecules.
Convection: Through the flow of liquid or gas, hot air or liquid rises and cold air or liquid falls, forming a convection cycle. Typically used for heat dissipation, such as in liquid cooling systems.
Radiation: It is transmitted through electromagnetic wave radiation. It does not require a medium for conduction. It is transmitted in the form of light or other electromagnetic waves. It can be transmitted in a vacuum, such as sunlight transmitting heat energy to the earth.
Phase Change: When a substance changes phase (such as from solid to liquid or liquid to gas), thermal energy is absorbed or released, as in evaporation and condensation.
What are the ways to cool electronic components?
Radiators, fans, liquid cooling, heat pipes, and phase change materials are the different ways and components used for cooling electronic components. Radiators are made of metal and dissipate heat by increasing their surface area.
Fans are used to cool components by moving air and can be mounted directly or in combination with a radiator. Liquid cooling systems include radiators, pumps, and pipes that absorb and dissipate heat through liquid coolant.
Heat pipes are sealed metal tubes that contain liquid coolant to absorb and dissipate heat. Phase change materials absorb and release heat as they change between liquid and gas. These methods and components can be used to maintain the proper temperature of electronic components.
What temperature is too hot for electronics?
Operating Temperature: Most electronics operate properly within the temperature range of 0°C to 40°C (32°F to 104°F). This is a room temperature range suitable for many home and office environments.
Storage temperature: Electronics can typically be stored at temperatures from -20°C to 70°C (-4°F to 158°F), including when not in use.
High Temperature Limits: The high temperature operating limits of most electronics are typically around 50°C to 55°C (122°F to 131°F). Above this temperature, the device may experience performance degradation and risk overheating.