An adsorption Activated Carbon/Methanol air conditioning system was developed by Wang in 2001 to be powered by heat sources with temperatures close to 100 °C. Evacuated tube collectors could be used to supply hot water at this level of temperature. The system, had two adsorbers with 26 kg of carbon inside each one and used methanol as refrigerant. The COP and the SCP of this system were significantly influenced by the cycle time. The operation of the system with a cycle time of 30 minutes leads to a COP of 0.15 and a cooling power of 3.84 kW while operation with a cycle time of 60 minutes leads to a COP of 0.21 and cooling power of 3.03 kW.
In both situations, the evaporation temperature was close to 6 °C. To improve the performance of the system, the authors changed the adsorbers, keeping the same charge of carbon, and used a tube and plate heat exchanger being the carbon placed outside the tubes, between the plates. With this new design, the COP obtained was 0.4 and the cooling power was 3.80 kW.
The experimental conditions in this case were: a heat source temperature of 100 °C, an evaporation temperature of 10 °C, a condensing temperature of 24 °C and a cycle time of 50 minutes.