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Comment by mono442 | Hacker News Reader

It's usually so much more expensive than an air source heat pump that makes it completely not worth it.

That depends on climate. The longer and colder your winters are, the more you benefit from the reliable efficiency of a ground source. Ground source heat pumps have been the most common choice for heating new single-family homes in Finland for the last ~20 years.

Installation is probably relatively cheaper there due to volume too. In areas where it is less common, there is less competition and fewer options for competent installers.

True but even then there are other criteria too: as I plan to sell the house in 10 years, the extra cost for drilling simply didn't make economical sense (to me). So the "regular" pump had to do, and does it fine.

There is barely any people living in those latitudes. In Lithuania last 10 years air to water pumps completely took over.

Now you also need consent to drill making it much too difficult.

Yeah, recently saw some numbers for air-to-air vs air-to-groundwater, and it break even after more than 25 years, with more than twice the initial cost

> more than twice the initial cost

Here in Norway you can get a decent air-to-air minisplit installed for $2k. I've not heard of anyone who paid less than 10x that for an air-to-ground or water-to-ground system, drilling 500-1000 feet is expensive.

Sorry, I actually meant air-water vs. water-water for my comment, makes less sense this way...

What were the figures and where are you?

There’s no way the system is designed to last 25 years though?

The well that you drill will last a 100 years if you don't have bad luck. That is half the cost of installation.

The water/water heatpump unit in my house is 20 years old and has not had any major failures yet. I hope it will run for another ten years before the compressor gives up, but it is indeed approaching its calculated technical lifespan. I estimate it will set me back €10k to have it replaced.

Air/air is the cheaper option over time, even in most of Scandinavia with coldish winters. The main drawback of air/air systems are that they are loud and ugly and therefore annoy both yourself and your neighbours.

Yeah, not worth it in most cases, but when things line up, it is the best.

I've built 3 houses and got a bid on ground source heat for each one. I finally pulled the trigger on the 3rd house because we:

1) Moved where it was quite a bit colder, -20F for a week is common. 2) We have enough land to trench only 6'/2m deep to bury the loops instead of drilling like we would have needed to do on the first 2 houses. 3) There was a tax credit on it 4) No equipment exposed outside

Absolutely love it and it will make it difficult to move away when we want to down size b/c we'll pay more in utilities for half the space.

We also have some air-source on an addition I built, I'd use it anywhere that was slightly warmer than where I'm at.

Air-source heat pumps give their worst performance when you need heat the most. Ground source doesn't vary year-round.

Bingo. Literally abandonded in Lithuania, air to air is so much cheaper. Some builders even ditch hp altogheter - basic electric underfloor heating + solar panels is so much cheaper.

I'm in New Zealand and my bedroom heater is $20 electric + $20 smart plug + $10 temperature sensor. Winter bill is ~$100 NZD. It would take ~20 years for heat pump to recover install cost alone.

I find that surprising - I'm only slightly north of Lithuania, and the seasonality of solar panels makes them pretty ineffective in the winter, and especially in the pre-dawn when you want to bring the house back up to temperature.

(when I had the instrumentation hooked up for a year: https://flatline.org.uk/daystats.html )

You can sell power to grid and get it back at a reasonable spread. Although I'm sure that's not going to be so lucrative in future.

As a Kiwi (now in UK) NZ doesn't get that cold for that long...mostly just wet, unless you're pretty far south.

In UK/other parts of Europe winter gets colder, lasts much longer, humid the entire time (so heat just escapes all over the place). Plus, the buildings here are a lot older - I think upgrading insulation would make a huge difference this side of the world.

I couldn't even imagine Canada. Almost moved there...decided to stay here. No -20c winters for me ty very much.

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