Building America Case Study: Field Performance of Inverter-Driven Heat Pumps in Cold Climates - Connecticut, Massachusetts, and Vermont

Program Document · Tue Sep 01 00:00:00 EDT 2015

OSTI ID:1225481

New inverter-driven ASHPs are gaining ground in colder climates. These systems operate at sub-zero temperatures without the use of electric resistance backup. There are still uncertainties, however, about cold-climate capacity and efficiency in cold weather and questions such as measuring: power consumption, supply, return, and outdoor air temperatures, and air flow through the indoor fan coil. CARB observed a wide range of operating efficiencies and outputs from site to site. Maximum capacities were found to be generally in line with manufacturer's claims as outdoor temperatures fell to -10 degrees F. The reasons for the wide range in heating performance likely include: low indoor air flow rates, poor placement of outdoor units, relatively high return air temperatures, thermostat set back, integration with existing heating systems, and occupants limiting indoor fan speed. Even with lower efficiencies than published in other studies, most of the heat pumps here still provide heat at lower cost than oil, propane, or certainly electric resistance systems.

• Research Organization: National Renewable Energy Lab. (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Energy Efficiency Office. Building Technologies Office
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 1225481
• Report Number(s): NREL/FS-5500-63914; DOE/GO-102015-4643
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
Residential
Residential Buildings
CARB
Building America
Inverter-driven
Air-source heat pumps
Steven Winter Associates
Inc.
Consortium for Advanced Residential Buildings
SWA
COPs
Cold climate
Northeast
Performance
Heating
Air flow measurement
Heat pump
ASHP