and how it changes under pressure and makes a heat pump work.
R-22 or Freon has its chemical name Chlorodifluoromethane, and it belongs to hydrochlorofluorocarbon family. It is a colorless gas which is better known for its work as the refrigerant. It's a highly regulated chemical, regulated in the USA by the Environmental Protection Agency (EPA).
On a large scale, industrial and domestic heat pumps employ this gas as their refrigerant. The major factor behind its usage as the refrigerant is its low boiling temperature, which is -40.8 degrees Celsius. This refrigerant can absorb more water than the earlier refrigerants. It is an essential requirement in the heat pumps for its prolong functioning. R-22 provides equal cooling, but consumes much lower power than R12. It is because the depression required to build the compression is significantly low, and the power consumed in this case is also low. This makes it cost-effective and efficient choice over the earlier refrigerants.
Also, R-22 has other properties such as it is a non-toxic and non-flammable gas, apart from its good thermodynamic properties. All this makes it safe and environment-friendly for the refrigerant purpose. R-22 causes less ozone depletion when it is compared to other refrigerants such as CFC11 and CFC12. The refrigerant is the main reason behind the functioning of heat pumps such as refrigerators and air-conditioners. Simple thermodynamics laws of transferring energy govern the inside working of heat pumps. Heat pumps are heat energy shifting device which absorbs the heat energy from the cold region and releases it to the warmer place.
Mechanism of the heat pumps using R-22 as refrigerant
Heat pumps functions throughout the year and alternates its functioning mode according to the season. During summers, these heat pumps work as an air-conditioner. It absorbs the heat present inside the room and releases it to the outside surroundings. In this way, it helps in maintaining a low temperature. During winter, this process just gets reversed. The heat present in the outside surrounding even after the chilling weather gets absorbed and transferred inside the room. This work takes place in the series compression and evaporation cycle inside the heat pump.
The main source through which this heat exchange takes place is the refrigerant. There are two coils within the heat pump in which the refrigerant circulates- evaporator and condenser. With the help of compressor pump, the refrigerant flows in both the coils. Both evaporator and the condenser are joined through an insulating pipe. This insulating pipe assures that there is no loss of energy in the movement of refrigerant. The refrigerants evaporate in the first coil due to the low pressure of the coil. The absorption of heat from the surrounding environment happens with this evaporation process. The heat absorbed refrigerant is, then channelled to another coil. Due to the presence of high pressure in this coil, the refrigerant condenses here. It releases the heat which it acquired in the initial stage. This cycle continues as a result of this the heat energy absorbed from one surrounding gets transferred to another.
These heat pumps are installed in two parts; the indoor and the outdoor part, within these two the refrigerant rotates. When the heat pump function as air-conditioner, the condensation occurs in the outdoor coil and the evaporation in the indoor coil. This process reverses when it acts as a heater.