The design limits of a hot water fired absorption chiller in a cycle simulation were examined. The first report described how to determine the lowest limiting value of the smaller of the two temperature differences to get a logarithmic mean temperature difference when designing each element. This new algorithm was applied, based on the trend toward the super hot water fired absorption chiller that employs a two-stage absorption system. After performing a cycle simulation, the lowest temperature for hot water that could be used in air conditioning was found and the conditions for determining this lowest temperature were clarified. As a result, it was found that two-stage absorption could be used to decrease the usable hot water temperature from 21 to 16℃, compared with single-stage absorption. It was also found that it would even be possible to use hot water below 50℃.
