What Is a Cooling Device?
A cooling device is a device that cools the temperature of a certain space.
In the past, forced air circulation by fans and the use of vaporization heat by sprinkling water were used to lower the temperature of a space. After electricity became widespread, fans with simple structures became popular.
In recent years, air conditioners have become the most common type of cooling device. Air conditioners are devices that exchange heat between space and outside air. They have become widely used in homes because they can be used for both cooling and heating by rotating the compressor in the opposite direction.
Uses of Cooling Devices
Cooling devices are widely used in industrial and residential applications.
Room air conditioners are a typical example of home use. In recent years, one household has been equipped with at least one room air conditioner. Refrigerators can also be considered home cooling devices. Although the shape is different, the mechanism is the same as that of room air conditioners.
For industrial use, there are examples of refrigerators that use antifreeze solutions. They are used for cooling processes and heat-generating equipment. Industrial cooling devices use dozens of times more environmentally hazardous refrigerants such as chlorofluorocarbons than room air conditioners, so they are subject to legal obligations such as periodic inspections, installation notifications, and installation permits.
Principle of Cooling Devices
First, consider the mechanism of a fan or blower as a forced-air cooling device. A fan sends out cool air by turning an impeller with a motor. It serves as a cooling device because the air temperature around an object does not rise.
Next, we consider air conditioners. An air conditioner consists of a compressor, a heat exchanger, and a blower installed outside the room. This is generally called an outdoor unit. A heat exchanger and a blower are also installed indoors. This is generally called an indoor unit. Refrigerant, which repeatedly vaporizes and liquefies according to pressure fluctuations near normal temperature and pressure, is sealed in the air conditioner, and cooling is performed by vaporization heat when the pressure in the system is fluctuated by a compressor. When the pressure of the refrigerant is increased outside the room, it liquefies and releases heat. The released heat is vented to the atmosphere by an outdoor blower. The liquefied air expands and vaporizes inside the room, removing heat from the room. The indoor blower circulates the cooled air throughout the room.
Next, a chiller is a device that maintains room temperature below 0°C. Its mechanism is similar to that of an air conditioner, designed to reduce indoor temperatures. However, the cooling speed is not fast enough for the blower, and the temperature of the outdoor unit rises too high. Therefore, the water-cooling method is sometimes used. Instead of discharging into the atmosphere, water with high thermal conductivity is used as a refrigerant. The water is cooled by a device called a cooling tower. If indoor air is also averse to solidification, antifreeze is circulated.
Cooling devices generally use a heat exchange system with a compressor, but Peltier effect cooling devices also exist. This cooling device uses a substance that becomes cold when an electric current is applied. They are rarely sold as compact cooling devices.