Heat Pump Performance Monitoring
Project Lead: Tom Johnson
Heat pumps are a promising technology that can provide heat at substantially reduced cost when compared to conventional boilers. Traditionally, heat pumps have been installed in moderate climates, often in buildings that would otherwise use electric resistance heating. However, several varieties of heat pumps are now available for use in colder climates and may be suitable for widespread use in Alaska. There are approximately 50,000 earth source heat pumps installed in the United States each year, and over 500,000 total systems currently in place. In Alaska, there are heat pumps installed in Southcentral, Kodiak, and Southeast, however actual operating data and costs are sparse or non-existent.
The Alaska Center for Energy and Power (ACEP) has partnered with Fairbanks Engineer, Andrew Roe, and provided data logging equipment to help quantify the performance of a residential earth source heat pump. By precisely measuring electricity and heat flow, ACEP can determine the real cost of energy delivered by the system, and make a direct comparison to other forms of heating. Because heat pumps are electrically operated, the cost of electric power as well as the alternative heating fuel is important in making an economic assessment of their value.
ACEP’s instrumentation was installed in early 2009 and preliminary results are very encouraging. The data indicate that the heat pump system is providing heat for approximately half the cost of heating oil at current (2008-09) prices. Additionally, these data have revealed that there is still significant room for system optimization. That is, the system is only running at 75% of it’s expected efficiency. ACEP is working with the owner to explain this discrepancy, and is also assessing other opportunities for heat pumps throughout the State.
Heat pumps work on the same principle as refrigerators and air conditioners, and remove heat from a cold temperature source (such as the ground or a body of water) and transfer it to a higher temperature ‘sink’, such as the inside of a building.