ENERGY CONSUMPTION AND OPERATING COST OF A SOLAR/GAS POWERED ABSORPTION AIR CONDITIONING SYSTEM

Electrically powered vapour compression systems are usually employed in air conditioning of buildings. However, there are concerns over the high power consumption by these systems which lead to high electricity bills. Absorption cooling has the prospect to consume lower power. This study has carried out an assessment of the energy consumption and operating cost of a solar and gas powered absorption air conditioning system. The experimental plant has a prototype absorption chiller which operates on the lithium bromide/ water pair. The thermal energy requirement is supplied by solar energy via solar collector as well as an auxiliary gas burner powered by liquefied petroleum gas. The experimental plant was run under varying weather conditions in both solar and gas heating modes to cool a test room. Energy consumed as well as the cost of energy consumed were computed. Results showed the least gas consumption occurred on days with high solar fraction. Total daily energy consumption cost varied from $ 0.6 / day for a day with solar fraction of 0.6 to $ 1.21 /day for a day with solar fraction of 0. The cost of electric power consumption of the absorption system was lower in comparison to that of a conventional vapour compression chiller in the order of 44.4% to 64.2%. However, the cost per kWh of cooling for the conventional vapour compression chiller was lower than that of the absorption system.