Experimental Study of Solar Powered Air Conditioning Unit Using Drop – in Hydro Carbon Mixture to Replace R-22

In this study the performance of a one ton split air conditioning unit (a/c) was experimentally investigated. the unit was originally designed to use r-22 as refrigerant. liquefied petroleum gas mixture (lpgm) of 30 % propane, r-290 and 70 % butane, r-600, (weight ratio) was evaluated as a drop in replacement for the r-22. this work is part of the worldwide efforts to explore replacements for the chlorofluorocarbons and hydrochlorofluorocarbons. ozone depletion and climate changes warranted such efforts. it is a well-known fact that air conditioners (a/c) power consumption has a large share from the total building sector energy consumption. as a result of that, solar electricity was attempted in powering this unit. a photo voltaic array of twelve modules was used as an electrical generator. the performance of the unit was studied for both refrigerants used and then compared with each other. experiments of day-long runs were carried out. performance parameters were studied as dependent variables such as: coefficient of performance (cop); capacity; power consumption of the compressor; heat rejection and mass flow rate of refrigerant. in addition, changes of independent variables such as: evaporation temperature (te); and condensing temperature (tc) were evaluated. it was found experimentally that the cop of the system using lpgm as refrigerant and the capacity are lower than that using the r-22. both the cop and the capacity are 25% lower at optimum working conditions. in spite of that lpgm has other advantages such as: higher refrigeration effect; lower mass rate of flow; lower compressor exit temperature and lower power consumption. the power consumption of the compressor when using lpgm was found to be 35% lower than that when using r-22. this gives an advantage of using lpgm as a refrigerant to replace r-22 especially when the a/c system is powered by solar energy.