Thermostat meaning, function, types and the origin of thermostats

Cars, refrigerators, gas boilers, air conditioners and many other machines need a temperature regulation system. The thermostat is the device used to keep the temperature of a machine within the appropriate limits for its proper functioning.

The regulation of this device allows the electrical systems related to the temperature of the machines (for example, air conditioners or water heaters) to adapt to the ambient temperature. Most of them are electronic, although some are metallic. Many of these devices are now digital and can therefore be programmed so that the temperature of the machine remains within a certain threshold over time.

Thermostat meaning of a car

It is a component of a control system that is responsible for opening or closing an electrical circuit depending on the temperature. It is used in the automotive industry, in internal combustion engines, to regulate the flow of coolant that returns to the radiator depending on the engine temperature, thus cooling or heating the vehicle's engine.

The thermostat device is located next to the coolant pipe and in this way it is possible for the liquid that goes to the radiator to maintain the correct temperature. The thermostat of a car is used so that when the engine is cold, it prevents the antifreeze in the engine from exceeding the ideal operating temperature.

With this system the car works with the correct degree of temperature and, at the same time, a more moderate fuel consumption is produced and the vehicle's emissions are more optimal. Thus, if the thermostat does not work correctly, the car's engine will deteriorate as a whole.

Thermostat function

The thermostat is a very important element of the engine cooling system, responsible for regulating the temperature in them. The main function it performs is to regulate the supply of necessary coolant through a valve that opens or closes depending on the engine's working temperature.

In addition to regulating the temperature and flow of coolant, it also influences the fuel consumption of vehicles, since when the temperature is low, the supply of fuel has to be greater. And therefore, if it influences consumption, it will also affect the level of polluting emissions from the vehicle.

Finally, it is used in air conditioners to turn on or off their compressor.

Thermostat operation

When the engine is at low temperatures, the thermostat prevents the coolant from circulating between the engine and the radiator, allowing the engine to reach the ideal operating temperature in the shortest possible time. Once this temperature is reached, the hot coolant returns to the radiator to cool down, thanks to the fact that the thermostat opens the bypass valve, thus preventing the engine from overheating.

Thermostat types

Three types of thermostat can be found today:

1. Capsule thermostat: They do not contain any type of electronic system, they work thanks to the expansion of an encapsulated wax. As the temperature increases, the wax expands and thus moves the gate that opens the duct. On the contrary, if it cools down, the wax contracts again, closing the gate.

2. Bellows thermostat: This type of thermostat is not based on the expansion of liquids but on the volatility of alcohols. When the coolant heats up, the alcohol evaporates and expands the bellows allowing the liquid to pass through.

3. Electronic thermostat: They are the type of thermostats most used today. They are controlled by the engine control unit. They are more complex than the previous ones since they require more connections, but the operation itself remains the same.

The origin of thermostats

Already in Ancient Rome, building heating systems were used from the control of the flow of underground hot water and for this purpose, gates that opened and closed were used. However, it was not until the Industrial Revolution that the first versions of today's thermostats appeared. Steam boilers needed a device so that the temperature was always correct.

Current technology as we know it would not exist if thermostats had not been invented. In this sense, one of the most important advances in the history of mankind occurred with the appearance of the first refrigerators that allowed the temperature of food to be maintained.

Without refrigeration and without the intervention of the thermostats that produce it, we would not be able to consume fresh food normally. By 1880 there were already more than 3,000 patents for refrigerators. The simple fact of having a fridge at home has served to avoid having to go to the market every day and to keep food for much longer. All this would not have been possible without a thermostat system inside the refrigerator.