Details methods of testing and rating gas-fired air-conditioning and heat pump appliances which utilize natural, manufactured and mixed gases, liquefied petroleum gases, and LP gas-air mixtures. This includes engine-driven heat pumps, absorption-cycle heat pumps, desiccant-type heat pumps, and other gas-fired heat pumps. The heat pumps may provide the functions of year-round space conditioning either by direct heating and cooling of air or indirectly by production of heated and chilled water.