Development of a Monitoring System for a Gas-Fired Absorption Heat Pump and Results for Testing in Heating and Cooling Mode

Abstract

A monitoring system was developed and implemented in the Archetype Sustainable House (ASH) of the Toronto and Region Conservation Authority (TRCA) for testing the performance of a gas-fired absorption heat pump various inlet temperatures at three different flowrates of glycol-water mixture, containing 50% propylene glycol. Results show that at 50% concentration of propylene glycol the output capacity of the GAHP is approximately 12–13 % lower than the specified capacity. Furthermore, at nominal flowrates in heating mode, the gas utilization efficiency (GUE), which is the ratio of heating (or cooling) output to the thermal energy input, stays above ‘1’ for outdoor temperatures down to –5 oC, implying that GAHP is more efficient than conventional heating equipment up to that point. Below –5 oC the GUE drops below ‘1’ and the GAHP acts like a conventional high efficiency boiler which means that GAHP is either better than or just as efficient as conventional heating equipment depending on the outdoor temperatures. However, the magnitude of energy savings achieved greatly depends on how frequently temperatures below –5 oC are encountered in a given heating season.