Adiabatic means that a process takes place without exchanging heat with the surroundings. In construction and building services, the term is mainly used for cooling and ventilation, where adiabatic processes offer an energy-efficient way to cool air.
How does adiabatic cooling work?
In adiabatic cooling, water is sprayed into an air stream. The water evaporates and draws heat from the air — the air temperature drops. No external cooling energy is supplied; the energy comes from the phase change of water to water vapour.
The principle is similar to the cooling effect of sweat on your skin.
Application
Adiabatic cooling is used in construction for:
- Air handling units — water is sprayed into the exhaust air to indirectly cool the supply air via a heat exchanger
- Data centres — adiabatic cooling replaces energy-hungry compression cooling
- Greenhouses — misting systems cool the air without mechanical refrigeration
- Outdoor areas — terrace cooling with misting systems works on the same principle
Advantages
- Energy efficient — significantly lower energy consumption than conventional air conditioning
- Sustainable — no refrigerants required
- Simple — the installation is relatively straightforward
Note
Adiabatic cooling works best in dry air. In high humidity, the cooling capacity decreases because the air can absorb less water.
Related terms
- Indoor climate
- Ventilation
- Heat pump
- Insulation
- Building physics
Want to learn more about construction terms? Visit our knowledge base at fredsdiyplans.com.