Split heat pump hot water

A split has the compressor outside and the tank separate, so the tank can be any size and any material and the compressor can go where it has air. An all-in-one is a single shell — simpler to place, fewer options, and the compressor sits on top of the tank. If you have room for both parts, a split is usually the better system.

CO₂ (R744) is a natural refrigerant with zero global-warming potential, and it holds heating capacity further down the temperature range. On a Melbourne winter morning that's the difference between making hot water and falling back on an element. It's also the reason Reclaim costs more than a budget unit.

Stainless has no sacrificial anode to replace and nothing to rust, so it's the one to pick if you'd rather not think about it again. Glass-lined is cheaper up front and needs the anode checked. On hard or bore water, stainless — and the 2205 duplex tank for the worst of it.

Roughly: 160–250 L for one or two people, 250–315 L for a family of three or four, 315–400 L for five or more. Recovery rate matters as much as volume though, which is where the Panasonic 6 kW pairing earns its place — a smaller tank that refills fast can beat a bigger one that doesn't.

Yes, and it's the best pairing on this site. The PV-diverter kit fires the compressor on solar surplus, so the water gets heated on power you'd otherwise export for a few cents. Without the kit you can still just time it for the middle of the day.

37 dBA at one metre on the Reclaim compressor — quieter than a fridge. It can sit near a bedroom window without being the reason somebody rings us in February.

It varies by tank: the stainless tanks carry the longest cover and the glass-lined ones less. We put the exact figure for the model you're quoted in writing rather than quoting a headline number that only applies to the flagship.