Household of two and a dog · 1910s villa, ~130 m², four bedrooms. Replaced an LPG burner in the lounge with a heat pump.
I underestimated the benefits, it's made life a lot easier. We're in a very cold city and we can be in a comfortable temperature inside without worrying about how much this is going to cost me.
Upgrade: heat pump climate control
Upfront cost: $3,400
Gas use: from ~2 LPG bottles a month to ~1 every 6 weeks
Payback: on track for ~10 months (Anuraag's estimate; originally modelled at 14)
Power bill: ~$850–900 a month to ~$400–450 a month
Anuraag's home is a classic Dunedin villa: built in the 1910s, with high ceilings and single-glazed windows. It has been rewired and insulated underfloor, in the roof and in the walls, but it's still hard to heat.
All the windows are single glazed, which is a major thing, and our ceilings are quite high, as you'd expect from an old villa. So heating is difficult. We live in Dunedin, so it gets quite cold.
The lounge was heated by an LPG burner, and the household was getting through about two gas bottles a month at around $160 each. An older heat pump in the hallway couldn't push warm air into the lounge, and a plug-in space heater used too much power to be worth it. The household rationed heating and showers to keep costs down.
Anuraag works in sustainability consulting, so getting off gas was always the plan.
On an everyday basis I keep telling clients you should move away from gas and look into electrifying, it's going to be cheaper for your wallet and better for the environment. That was something I wanted to do before we even moved in.
Then other renovation costs ate the upgrade budget, putting plans on hold for a year and a half. The nudge to go ahead came from a free home energy assessment by the local council. The assessor helped Anuraag run the numbers on heating, and also found that inefficient showerheads were behind almost a quarter of the household's utility bill. With money set aside, heat pump prices down a little and an installer available that week, the timing finally worked.
Anuraag still wasn't sure it would pay off. The household expected to move within two and a half years.
I'm the sort of person to make spreadsheets. I was a little bit nervous on if I'll actually see a return.
His rule was simple: if the numbers were roughly break-even, go ahead anyway, because it's lower emissions.
Anuraag contacted four or five heat pump companies one morning, a couple of weeks before Christmas. Three visited the same day to measure the lounge, with its high ceilings in mind, and the rest followed within days. Each gave a rough figure on the spot and emailed a proper quote afterwards. Quotes ranged from about $2,900 to $3,800, depending on the make, model and size.
Anuraag compared them on three things: the model's efficiency rating (its COP, or how much heat you get for each unit of power), the company's reliability, and price. The chosen quote wasn't the cheapest, but it was the best on balance. The heat pump was installed within about ten days, and there was no other work needed.
Seven months on, the lounge is warm. Anuraag says the heat feels different too. The gas burner was hot up close but left the rest of the room cold, while the heat pump warms the whole space. It also has a mode where it turns itself on and off whether there's someone in the room.
That's the mode the heat pump uses when the dog is home alone, and Anuraag is glad to be away from breathing LPG fumes. There's peace of mind too:
There's two things: the mental comfort that I'm not being as horrible to the planet as I was before, and the heat pump has this setting called comfort mode. It basically senses where you're sitting and doesn't throw air directly at you. It heats up the room and makes the room temperature a lot more comfortable than, you know, heat being straight at you.
The biggest change is no longer thinking twice before turning the heating on.
Previously we were like 'we can't switch the heating on because it's costing us a lot of money'. But now we're living comfortably at a lower bill.
The heat pump cost about $3,400 installed. LPG use has dropped from around two bottles a month to about one every six weeks. Power bills were around $850–900 a month last winter and are now around $400–450.
Anuraag points out that the household is smaller now and the new showerheads help too, so not all of that is the heat pump. Even so, the bill is significantly lower per person. Anuraag had modelled a 14-month payback and now expects it closer to 10.
Definitely go for it. I would have told myself to go for it as soon as we moved in.
He also suggests doing your research to get the right system for your home. And when you run the numbers, remember the things a spreadsheet misses:
I underestimated the benefits, it's made life a lot easier... I don't need to put on five layers when I'm inside.
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