- Project plans
- Project activities
- Legislation and standards
- Industry context
- Specialist wikis
Last edited 15 Nov 2021
Absorption refrigeration in buildings
Refrigerants are used in buildings:
- For heating, ventilation and air conditioning (HVAC) systems.
- To provide cooling for refrigeration.
- To provide cooling for industrial processes.
Absorption and compression refrigeration both work on a similar basis, in that a refrigerant boils at a low temperature and pressure, and is then is then pressurised, and condensed at a higher temperature and pressure. The process of condensing releases heat which is rejected.
In ‘conventional’ compression systems, a liquid refrigerant with a low boiling point absorbs heat from the body that is being cooled and boils in an evaporator to form a gas. The resulting gas is then compressed, which increases its temperature further. The gas is then condensed, releasing its latent heat which is rejected. The process then repeats.
However, whilst in compression refrigeration, the compression and refrigerant flow is achieved by an electrical compressor, in absorption refrigeration, compression is achieved by heating, and circulation is achieved absorbing the refrigerant into and absorber and by an electrical pump. This pump uses much less energy than a compressor.
The liquid refrigerant absorbs heat from the body that is to be cooled (in buildings this may be water that once cool is circulated back to the building) and the refrigerant evaporates at low pressure (in the ‘evaporator’). It is then absorbed into an absorber fluid and the refrigerant / absorber mixture is heated (in the ‘generator’). The refrigerant evaporates again, this time at higher temperature and pressure. The refrigerant is then condensed (in the ‘condenser’) and the heat rejected. The process is then repeated.
The heat in absorption refrigeration can be gas powered, but absorption refrigeration is particularly suited to situations where ‘waste’, or other low-cost heat supply is available, such as; surplus heat from combined heat and power plant (CHP), heat from industrial processes, district heating, geothermal or solar thermal energy and so on.
The most common combinations of refrigerant and absorbent fluid are:
- Absorption cooling.
- Absorption heat pump.
- Absorption refrigeration.
- Adsorption cooling.
- Air conditioning.
- Air handling unit.
- BREEAM Impact of refrigerants.
- Chilled beam.
- Chiller unit.
- Chilled water.
- Compression refrigeration.
- Constant air volume.
- Evaporative cooling.
- Fan coil unit.
- Heat pumps
- Passive building design.
- Variable air volume.
- Variable refrigerant flow.
 External references
Featured articles and news
And CIOB's response.
Presidential update from CIAT's Eddie Weir PCIAT.
Rates freeze, NI cuts, full expensing; early election?
Could this be a remedy for condensation, damp or mould?
Unlocking a Healthier Tomorrow
Call for ministerial group and National Retrofit Delivery Plan.
The Great Transformation 1860–1920. Book review.
Including the devolved governments, CIOB, ECA, APM and IHBC.
AT awards small to medium size project category winner.
Formal and informal adaptive re-use or new use of buildings.
Temperatures hit new highs, yet world fails to cut emissions (again).
No longer enforcing certain waste transfer documentation.
Winners reactions during the event at the Park Plaza Hotel.
An exciting opportunity for stakeholders to collaborate.
Report from the BSRIA Briefing 2023, Cleaner Air, Better Tomorrow.