Inside The Building Heated Envelope
SunPump shall be installed inside the building conditioned space. The Mechanical room must be located within the building envelope and be heated at all times.
BC says a garage is not conditioned space, even if heated.
Below is an excerpt from page 19 of the 2015 BC Building Code requirements for your review:
Get your own report free here: https://www.hpo.bc.ca/energy-efficiency-requirements