Cooling is the transfer of heat from one place to another, keeping the temperature in that place at a temperature below the ambient temperature.

Cooling process has been used for air-conditioning purposes between ambient temperature and 1C, for commercial purposes between 10 C and -40 C for cold storage, and for industrial purposes at various temperatures. One of the most important requirements of these is a comfortable environment. For this, a temperature below the ambient temperature is required during summer, which is provided by cooling machines.

The Chinese used cooling for the first time in the history of humanity. They crushed the ice from frozen lakes, compressed them into large wells and took out the ice molds to use during the summer.

The Romans and Greeks filled large jars with water, buried them in the ground. The cooled soil surface cooled the jars in the night so that they can meet their cold water needs during the day from the cooled jars.

In 1775, Glasgow University professor William Cullen found out that his hands became cool when he put ether on and started to work and laid the foundation of the first mechanical cooling. William Cullen

tbuilt an ice machine based on suction principle in 1775, based on pure coincidence. Many scientists have built ice machines with this principle, but they did not enter the industry as they were too expensive and large in size.

In 1834, an American engineer named Jacob Perkins developed a practical ice machine in London. Ice machines operating with this principle have been put into use for thirty years.

In the meantime, machines working in places without electrical energy were focused on and the French Ferdinand CARSE invented the absorption system in 1885. In 1886, WINDHUSEN developed an installation operating with carbon dioxide gas and reached -80 degrees. Upon these developments, wooden refrigerators were built and food was stored with ice in the houses.

Since cooling with ice is difficult, scientists started to work on a mechanical cooling system. The first small refrigerator was made by J.M. Larsen Company in 1910. However, there were great difficulties in use since there is no thermostat. In 1913, KELVINATOR manufactured and launched the first thermostatic refrigerator. In 1930, R-12 gas was found and the foundation of CFC refrigerants was laid. In 1935

HCFC based fluids were developed by finding the R-22 refrigerant.

In 1989, R-134 A and R-123 refrigerants were found, and HFC based fluids that do not damage the ozone layer were developed. In the early 1990s, double and triple alternative refrigerant mixtures were developed to replace R-22 and R-502. Since 1913, refrigeration technology has been constantly developing and has become an integral part of life in today’s environment.

Major Water Cooling Systems:

• Cooling by melt formation
• Cooling by expansion of gases
• Thermoelectric cooling
• Cooling by vortex tube
• Magnetic cooling
• Paramagnetic cooling
• Humidified cooling
• Absorption cooling
• Vacuum cooling
• Steam injector cooling
• Vapor compression cooling

Kaynak: Prof. Dr. Hüsamettin BULUT – and Air Conditioning Technique Lecture Notes - 2011