AF_IM01_Refrigeration and air conditioning installation
Unit 2 Heating machines
A heat pump is a machine that
transfers thermal energy from a cold
source (low thermal level or low
temperature) to another hotter
source (higher thermal level or
higher temperature).
TO KNOW MORE
Here you have a link to know more about these Systems and Energy Efficiency.
https://www.youtube.com/watch?v=KH47xAXEEe0
1.1 Operation
The operation in four steps:
1.
In the first step a coolant fluid is compressed with a compressor.
2. The hot fluid goes to a heat exchanger, called condenser, where the fluid transfers his
heat and partially condensed, it goes from gaseous to liquid state.
3. After the fluid, still under pressure, is passed an expansion valve where the fluid losses
pressure and also gets cold abruptly.
4. Finally passes through a second heat exchanger located in the cold source, called
evaporator, absorbs heat again, to restart the cycle in the compressor again.
The following image shows a home circuit:
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1.2 Heat sources
Considering only the heat pump for heating, there are different heat sources:
 Outside air
 Water source, well or river
 Geothermal
1.3 Types of heating pump
Depending if the fit is a cold or a hot source, the heating pumps can be:
 Air to Air: the heat taken from the outside air is directly transferred to the space to be
heated.
 Air to Water: the heat is taken from the air rand it is transferred to a water circuit that will
fill a floor/ roof heat/cold, radiators o convectors.
 Water to Water: the System takes heat from a water circuit in Touch with an element
that provides heat to transfer it to another water circuit. This is normally used in
geothermic heat pumps.
 Water to Air: Heat is taken from the water and transferred directly to the room air.
1.4 Heating external machines
In the following video you will find some examples about home under floor heating machines.
https://www.youtube.com/watch?v=1BBqXQEIMNM
The following image shows the machines working in this kind of system:
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