Gas Absorption Heat Pumps



Natural gas is the primary fuel for space and water heating in both Canada and the United States. Although electrification of heating combined with the decarbonisation of electricity generation is an important climate strategy, natural gas will continue to be used to heat buildings and water systems for the foreseeable future.

For this reason, it is critical that gas is used as efficiently as possible. This paper provides an overview of high-efficiency gas absorption heat pump (GAHP) technology, and presents The Atmospheric Fund’s (TAF’s) energy and emission findings from a detailed study of two GAHPs installed as part of a domestic hot water system in a multi-unit residential building in Toronto, Ontario. This paper also explores the cost and carbon effectiveness of GAHPs compared to alternative technologies such as electric heat pumps and condensing boilers. Performance of the GAHPs met TAF’s expectations and was in-line with the manufacturer’s performance curves. TAF observed a mean Coefficient of Performance (COP) of 1.14 and Gas Utilization Efficiency (GUE) of 1.16 during cold weather operation, between November 1st 2017 through May 31st 2018.

Low-Cost Gas Heat Pump for Building Space Heating


Gas-fired residential space heating in the U.S is predominantly supplied by furnaces and boilers. These technologies have been approaching their thermodynamic limit over the past 30 years and improvements for high efficiency units have approached a point of diminishing return. Electric heat pumps are growing in popularity but their heating performance at low ambient temperatures is poor. The development of a low-cost gas absorption heat pump would offer a significant improvement to current furnaces and boilers, and in heating dominated climate zones when compared to electric heat pumps. Gas absorption heat pumps (GAHP) exceed the traditional limit of thermal efficiency encountered by typical furnaces and boilers, and maintain high levels of performance at low ambient temperatures. The project team designed and demonstrated two low-cost packaged prototype GAHP space heating systems during the course of this investigation.  

Gas Absorption Heat Pumps: Carbon, Energy and Cost Reductions for Heating Applications in a Cold Climate


The Sustainable Technologies Evaluation Program (STEP) is a collaborative non-profit research initiative within the Toronto and Region Conservation Authority (TRCA). Among other priorities, STEP leverages partnerships with municipalities, provincial and federal government bodies, utilities, non-profits, academic institutions, and private companies, to pilot and evaluate emerging low-carbon technologies with the aim of providing real-world data that informs effective technological responses to climate change. STEP team members are scientific monitoring and M & V experts, particularly as it pertains to renewable energy, HVAC and smart-grid. Research projects are conducted either in STEP’s own state-of-the-art Living Labs or off-site in real-world buildings.