Heat pumps in New Zealand houses (November 2010)

Presented at the 5th Australasian Housing Researchers’ Conference November 2010, Auckland, New Zealand, 17-19 November 2010

Author

LJ Burrough

Abstract

Heat pumps have grown rapidly in popularity – in 2009 approximately 21% of New Zealand houses had a heat pump compared to only 4% in 2005. It is important to understand how heat pumps are being used to ensure houses are heated in an effective and efficient way, and to update information on where electricity is being used in homes.

BRANZ is currently monitoring 85 homes with heat pumps throughout New Zealand. They are having their heat pump energy use, temperatures and humidity monitored, a house audit, and there is an extensive survey of heat pump users. Next year another 85 homes will be monitored.

This work allows us to understand how people are using them for both heating and cooling, if healthy conditions are being achieved, the future uptake of heat pumps, and the benefits, negatives and potential problems with them. Results are compared to the Household Energy End-Use Project (HEEP) data to see how heat pumps are changing the way we condition our houses and the expected increase in energy use.

Early results show extensive use of heat pumps during winter and warmer houses than in HEEP. There are health benefits to warmer houses, but electricity use from some of the houses is high. The potential exists for savings through thermal envelope improvements and improving the installation quality of the heat pumps.

Heat pump use is less during summer, but many houses are using them for cooling – a completely new energy use in New Zealand. Most heat pump users are very pleased and happy to recommend them to family and friends.

Early results of this work suggest heat pump usage in New Zealand will continue to grow in popularity as well as the energy use required to run them.