Residential Gas-Fired Cost-Effective Triple-State Sorption Heat Pump

Oak Ridge National Laboratory (ORNL), in partnership with ClimateWell and Rheem, will develop a residential, gas-fired split heat pump that will use an ammonia refrigerant, which is not a greenhouse gas and can convert chemical energy to heating and cooling without using any moving seals. The hydronic heat exchanger will heat the air in the central duct, and uses triple-state sorption, which attains unprecedented high energy density by crystallizing the salt in the reactor. By using an ammonia refrigerant, the system is able to maintain a high delivery temperature at a low ambient level.

Project Impact

In 2015, the federal standards for heat pumps became more stringent, requiring a minimum SEER of 14 and the minimum HSPF to be 8.2 in all regions. In order to meet and surpass these requirements technologies like ORNL's sorption heat pump are being commercialized and adopted into the market. This new heat pump innovation allows for high efficiency in a compact package with installation costs, reliability, and maintenance requirements that are competitive with conventional electric heat pump technologies. This residential gas-fired heat pump system offers a short, 3-4 year simple payback for climate zones 1-2, a technical potential of 942 TBtu/year and 44% energy savings compared with 2010 technologies.