Installation year



Nominal power


 300 kW

Cooling capacity


 100 ton

Thermal COP



Dehumidifying solution



Hot water temperature inlet


 70 oC



 Temperature and pressure sensors


In recent years, the consumption of electricity for the operation of air conditioning systems has increased dramatically. The solar air conditioning is a smart, alternative cooling technology, as the demand of the load coincides with the availability of solar energy. The environmental benefits are remarkable, given that the building sector is responsible for 1/3 of global CO2 emissions.

The most common solar air conditioning system is the single-stage absorption chiller. Worldwide, there are 9 companies manufacturing such systems, with cooling capacity ranging from 100kW to 2000kW.

Given the need to reduce air conditioning loads and the increasing penetration of RES to meet thermal loads, the Laboratory of Applied Thermodynamics has installed a single stage absorption chiller. Because the chiller is thermally driven, it is ideally combined with a solar thermal system or trigeneration system. This application serves research purposes and for this reason, there is a plate heat exchanger which consumes the cooling load. The absorption system uses 700kW cooling tower that is already installed on the roof of the building.











Operation principle 

The key components of this cooling system is:

  • evaporator,
  • absorber,
  • condenser and
  • steam generator.

The secondary components are:

  • solution / solution heat exchanger,
  • refrigerant pump,
  • desiccant pump and 
  • controls.

The refrigerant is water. Under vacuum conditions, the boiling point of water is low (about 4.5oC) and thus, the water circulating in the evaporator is cooled. During cooling, water vapor is removed to increase the yield. The LiBr used as a desiccant to absorb the water vapor produced by this process and lead it to the steam generator. There, the steam is released and fed to the condenser. After the condensation of steam into water, this water is led to the evaporator to begin a new cycle. The heat released during the evaporation is removed by the cooling tower.