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Technology Development and Field Monitoring in nZEB



Vance (Wm.) Payne, Brian P. Dougherty


The International Energy Agency (IEA) Heat Pumping Technologies (HPT) Annex 49, "Design and Integration of Heat Pumps for Nearly Zero Energy Buildings," deals with the application of heat pumps as a core component of the HVAC system for nearly or net-zero energy buildings. This report covers Task 3 activities of the US team. Three institutions are involved on the US team and have worked on the following projects: • Oak Ridge National Laboratory summarized development activities since the conclusion of IEA HPT Annex 40 for several integrated heat pump (IHP) systems—electric ground-source (GS)-IHP and air-source (AS)-IHP versions and an engine-driven AS-IHP version. • The University of Maryland partnered with ORNL and Blue Bear Management and developed a personal cooling device, RoCo, that can provide personalized conditioned air to occupants in inadequately or even un-conditioned environments. With RoCo, building facility management can elevate the HVAC thermostat settings without compromising occupants' thermal comfort. Researchers have found that a 4F increase in thermostat settings can save 12 to 30% energy savings and therefore RoCo is a promising technology that can help reduce building energy consumption and facilitate achievement of nZEB performance. • The National Institute of Standards and Technology (NIST) is working on a field study effort on the NIST Net-Zero Energy Residential Test Facility (NZERTF). Two air-source, split system heat pumps were installed in a residential, net-zero energy home that was constructed as a laboratory on the campus of the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland USA. The first heat pump was a two-stage, 7 kW (2 ton), 15.8 seasonal energy efficiency ratio (SEER), 9.05 heating seasonal performance ratio (HSPF) conventionally ducted system, and the second heat pump was a variable-speed, 10.6 kW (3 ton), 14 SEER, 8.35 HSPF, high velocity ducted system.
IEA HPT Annex 49: Design and Integration of heat pumps for nearly Zero Energy Buildings


Payne, V. and Dougherty, B. (2020), Technology Development and Field Monitoring in nZEB, IEA HPT Annex 49: Design and Integration of heat pumps for nearly Zero Energy Buildings, [online],, (Accessed June 12, 2024)


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Created July 1, 2020, Updated February 23, 2022