This article suggests a numerical study of a biogas fired Ammonia-Water absorption refrigeration system. The hot biogas coming from the biogas furnace having a temperature range of 50-75 o C is used as an energy input to the generator of absorption system. A computational model has been developed for the parametric investigation of this system and the thermodynamic properties of the fluids have been used from the computer code. The analysis involves the determination of effects of generator temperature on various performance parameters. The performance parameters studied are exergy losses in the different components, COP cooling, COP heating and the exergy efficiency. The results indicate that COP cooling as well as COP heating lies in the range of 0.20-0.93 and 1.20-1.93 respectively for same variation in generator temperature ranging from 50-75 o C. The exergetic efficiency of the system lies in the range of 0.092-0.1275. The maximum exergy loss is found to be in case of generator and the lowest in case of condenser. It is also found that with an increase in the evaporator as well as absorber and condenser temperature, the COP increases as well as decreases respectively. The effect of ambient temperature on exergy loss in different components is also studied.