How cold a climate will heat pumps work?

I want to install a heat pump in Melbourne Australia, which has a similar climate to northern California, or southern France. Will it work on its own, or does it need some sort of backup? And if so, what sort of backup works best?

Hello Marty,

There has been a lot of bad history concerning heat pump technology in Victoria, and to be honest a lot of people have the misconception that it is technology that wont work for us in the southern states.
Perhaps the biggest contributor to this ideology is the Heat Pump scheme that went in a few years where thousands of those “Quantum” Heat Pumps were installed across the state, and failed to deliver the savings promised.

Quality Heat Pumps are incredibly efficient, there are studies and tests that actually show them being more efficient than actual Solar Hot Water Systems. Units such as SANDEN and Stiebel Eltron have units that will use less than 3kWh per day to heat 300L of Water around say Sydneys Latitude, but having said that, they are still very efficient down here(Victoria).
We actually install them nowadays in Off Grid Situations as we are that happy with there performance. You can get Units which have an electric element Backup, but with the top end units having sub-zero operating temperatures as low as minus 5 and the ability to program them to run in the middle of the Day when you are producing Excess Solar Power and the ambient air is a lot warmer, they are extremely efficient.
The only downside really, is the fact there is more to breakdown, but if you buy quality you get quality and the service on the top end units is great.
All in all, they are a great unit to use for Hot Water Heating, Especially as an accompaniment to a good quality Solar System.

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Thanks @BHekman that’s very reassuring to know, I was certainly under the impression that they wouldn’t work very well in that climate. Do you have any manufacturers that you recommend for heat pumps?

Hey @Marty, I use two main Brands which are centered around quality and efficiency. Stiebel Eltron which is an all in one unit and very efficient, and SANDEN which is a tank with separate heat pump, and also very efficient and handy if you need to locate the tank separate to the Heat Pump unit.

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Thanks for that information, I’ve been looking at getting a heat pump & couldn’t make up my mind between the chromogen & stiebel etltron system, the incentive for the chromogen system at the moment as with the govt rebates you actually get the 170lt system for $0! but just because its cheap or free doesn’t mean it’s of good quality & reliable.

Certainly! Although heat pumps can operate well in a variety of settings, temperature extremes have an impact on their efficiency.

Air-source heat pumps work effectively when temperatures are above freezing and are ideally suited for moderate to cool climes. To keep indoor temperatures at a tolerable level in extremely cold areas, more heating may be required.

Ground-source (geothermal) heat pumps excel in a wide range of climates, including very cold regions, as they use the consistent temperature of the earth for heating and cooling.

Ductless mini-split heat pumps, similar to air-source heat pumps, can operate in colder conditions, typically around 5°F to -15°F (-15°C to -26°C), making them suitable for areas with colder winters.

Hybrid heat pumps combine a heat pump with a secondary heating source and automatically switch to the secondary source in extremely cold weather, ensuring warmth in very cold climates.

Refer to the manufacturer’s specifications for the most precise details regarding a particular heat pump’s working range.