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How a heat pump works


How a heat pump works.We have already wondered about theoperation of a heat pumpfor air conditioning and hot water production, on this page we will further investigate the subject trying to explain theoperating principle of the heat pump.

How the heat pump works, In summary
Inheat pumpthere is a closed circuit in which a refrigerant fluid cyclically passes from the liquid phase to the vapor phase and vice versa. During these changes of state there is a change in temperature and pressure: in the evaporator, the refrigerant fluid passes from liquid to vapor, absorbing heat from the environment. Thereheat pumptakes the heat contained in the environment: in the air, water or ground, managing to exploit it even if the heat taken from the medium (air, water or ground) is inferior to that contained in the environment to be heated.

There heat pumpuses a fair amount of electricity at the level of the compressor which increases the energy contained in the fluid and prepares it for condensation. Moving back from the liquid phase to the vapor state, the refrigerant releases useful heat to the heating system. The cycle of state changes (from liquid to vapor and vice versa) closes by the hand of the expansion valve which brings the fluid back to its initial conditions.

Thereheat pumpsees a very positive energy balance: generally the thermal energy yielded by aheat pumpit is worth four times the electrical absorption of the machine. Thereheat pumpit is even more convenient when the electricity needed to produce heat is supplied by a photovoltaic system.

The cycle described above can be reversed, thus, the same apparatus, if suitably prepared, can be used for both heating and cooling.

Air-water heat pump

In this case, theheat pumptake thethermal energyfrom the air outside the home and transfers it to the air conditioning system. There air-water heat pump it must be installed outside the building, it connects to the home network without problems but must have an automatic defrosting system.

Water-to-water heat pump

With thewater-water heat pump, the thermal energy necessary for the air conditioning of an environment is taken from groundwater, a lake or a river and is transferred to the internal air conditioning system of the town. Therewater-water heat pumpit presents a higher initial expense for the supply and treatment system, but has the advantage of being completely independent of climatic conditions.

Ground-water heat pump

This kind of heat pump uses geothermal energy. The heat contained in the subsoil has a constant temperature throughout the year, this heat is conveyed to thepumpby special probes inserted into the ground horizontally at a depth of 1 - 1.5 meters, or vertically which descend for tens of meters.

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Video: HVAC Heat Pump Basics (October 2021).