Priya Nathan

A heat pump's advertised COP is measured at one lab condition, not your climate. Here's why the real-world number is almost always lower, and what to check instead.

Multi-split heat pumps get sized right but zoned wrong. Here's why running every indoor head at once quietly wrecks efficiency and comfort.

Most sizing arguments focus on square metres, but the wrong design temperature is the number that actually wrecks a heat pump quote.

A heat pump that hums quietly all summer can suddenly sound rough in winter. Here's the actual mechanical reason, and when it does signal a problem.

The claim that heat pumps quit in the cold is mostly outdated. Here's what actually happens to output and efficiency as temperatures drop, and why.

Most heat pump quotes skip a proper room-by-room load calculation. Here's what a real Manual J or AS/NZS 3251 assessment actually checks, and why it matters.

Refrigerant handling licences are the one heat pump credential homeowners rarely ask about. Here's what to check, and why it matters for warranty and safety.

Bigger isn't better with heat pumps. An oversized unit short-cycles, dehumidifies poorly, and costs more to run than a correctly sized one.

A heat pump hot water system typically uses a third to a quarter of the electricity of a resistance tank for the same hot water. Against gas the comparison depends entirely on your gas tariff, which is the part most calculators skip.

Cold-climate heat pumps use vapour injection and smarter defrost logic to hold output as it gets colder outside. The rating tells you the equipment can keep working, not that it'll be cheap to run at minus fifteen.

Ducted systems heat and cool a whole home from one hidden unit; splits do it room by room. The right call depends on your ceiling space, your budget and how you actually use your rooms.

The honest answer is "it depends on your local gas and electricity prices" — but here's the framework for working it out for your own home, instead of trusting a marketing brochure's number.

A heat pump doesn't create heat from electricity the way a bar heater does — it moves existing heat from one place to another. That distinction is why it can deliver 3–5x more heating energy than the electricity it consumes.

A correctly sized heat pump and an oversized one can look identical on the invoice. The difference shows up in your running costs for the next fifteen years, so the sizing method the installer uses matters more than the brand.

Most households can't (or don't want to) electrify everything at once. If you're prioritising, here's a sensible order based on payback, comfort and the size of the load you're replacing.