This guidance provides important information on securely restraining heat pumps to minimise the risk of injury to people and to minimise damage to the systems themselves from earthquakes.
The information was confirmed as current in November 2017. It originally appeared in Codewords 59.
Damage to heat pump exterior (compressor) units and their connections during earthquakes has resulted in costly repairs in some cases, which could have been avoided.
To meet the performance requirements of the Building Code (Clause B1 structure), heat pump exterior units in both residential and commercial applications need to be restrained. Verification Method B1/VM1 cites NZS4219 as a means of meeting these requirements.
Typical condenser units have four base lugs which can be used to anchor the unit to a support system such as a concrete plinth or a timber deck, but sometimes these fixings are not installed.
Most of the units are lightweight and therefore only require small anchors or fixings. Some units come supplied with fixings which will cover all applications.
Building control inspections should check the restraint of heat pump exterior units as part of their audit for a code compliance certificate.