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I'm curious how much this affects the price. I'm not a homeowner any more, but when I was, I longed to replace my furnace with a ground-source heat pump. It is

I'm curious how much this affects the price. I'm not a homeowner any more, but when I was, I longed to replace my furnace with a ground-source heat pump. It is not too much of an efficiency win over gas for heating, especially since we used little heat, but it's great for cooling. But I was really put off by the price. There was no way to justify it even under the most pessimistic assumptions about energy prices, except perhaps if my furnace and AC were to break at the same time.

Retric 8y ago
I think cost is the biggest issue. If you want to reduce heating and cooling costs via investments then insulation + solar can cheaply make a huge difference. Ground source scales well if you have a large building and a large body of water near by then the payback time is short. But at single family home level it's just not that useful.
- sdhgaiojfsa 8y ago
  That's not what my analysis showed. It has a payback period of 5-10 years depending on your assumptions, assuming new construction. Shorter period the more extreme the climate, longer in places like Norcal. Retrofitting though is a different story (higher cost -> longer payback).
  - Retric 8y ago
    If your further north compare it to solar hot water heater systems which cost ~3.5k self installed about double for someone else to add it to new construction. Further south solar systems have below your 5-10 year payback period.
- schiffern 8y ago
  > Ground source scales well if you have a large building and a large body of water near by then the payback time is short. But at single family home level it's just not that useful. There is a way: open-loop systems. A few years ago we installed an open-loop ground source heat pump (ClimateMaster brand) for under $6k. Water at 50F is drawn from a preexisting 15 gpm/50 foot well, through the heat pump unit, then dumped in a dry well at around 40F. It uses half a million gallons of water a year (costing <$30 in electricity), but of course there's no aquifer depletion, and closed-loop systems also use energy to pump water. This unit also pre-warms hot water at its coefficient of performance (about "600%"), reducing electric DHW costs. We homeowner installed, so we weren't eligible for NYS incentives. But it cut our annual bill in half vs. the previous heating oil furnace, with a payback period of 5-8 years.
  - Retric 8y ago
    The comparison for NYC is a solar hot water heater system which provides ~100f hot water and cost around 3k. You don't directly save on cooling costs, but as heating costs dominate and you get much warmer hot water that's worth it. Relative net savings depend on getting a system sized for your use, and how much cooling you use in the summer. But, you can also add solar panels for summer use with the overall value balancing over the year.
    - schiffern 8y ago
      Unfortunately my site is much too shaded for solar. Already tried that. For clarity, my system provides both water heating and space heating/cooling.
DannyBee 8y ago
Drilling is about half the cost. It's fairly cost efficient if they do it when building the house, much less so otherwise. It's basically "free" if your house needs a well anyway. (this assumes a lot about the ground under your house but it's relatively true ;P) If you live in a mild climate, you are just not going see a lot of payback because as you said, you don't spend a lot. Note: Most of them also provide hot water, not just heating and cooling But all told, the path to making it popular would be to make it part of new construction. I understand why they want to try to make retrofitting cheap, but it's just not even close right now.

Retric 8y ago

I think cost is the biggest issue. If you want to reduce heating and cooling costs via investments then insulation + solar can cheaply make a huge difference. Ground source scales well if you have a large building and a large body of water near by then the payback time is short. But at single family home level it's just not that useful.

sdhgaiojfsa 8y ago
That's not what my analysis showed. It has a payback period of 5-10 years depending on your assumptions, assuming new construction. Shorter period the more extreme the climate, longer in places like Norcal. Retrofitting though is a different story (higher cost -> longer payback).
- Retric 8y ago
  If your further north compare it to solar hot water heater systems which cost ~3.5k self installed about double for someone else to add it to new construction. Further south solar systems have below your 5-10 year payback period.
schiffern 8y ago
> Ground source scales well if you have a large building and a large body of water near by then the payback time is short. But at single family home level it's just not that useful. There is a way: open-loop systems. A few years ago we installed an open-loop ground source heat pump (ClimateMaster brand) for under $6k. Water at 50F is drawn from a preexisting 15 gpm/50 foot well, through the heat pump unit, then dumped in a dry well at around 40F. It uses half a million gallons of water a year (costing <$30 in electricity), but of course there's no aquifer depletion, and closed-loop systems also use energy to pump water. This unit also pre-warms hot water at its coefficient of performance (about "600%"), reducing electric DHW costs. We homeowner installed, so we weren't eligible for NYS incentives. But it cut our annual bill in half vs. the previous heating oil furnace, with a payback period of 5-8 years.
- Retric 8y ago
  The comparison for NYC is a solar hot water heater system which provides ~100f hot water and cost around 3k. You don't directly save on cooling costs, but as heating costs dominate and you get much warmer hot water that's worth it. Relative net savings depend on getting a system sized for your use, and how much cooling you use in the summer. But, you can also add solar panels for summer use with the overall value balancing over the year.
  - schiffern 8y ago
    Unfortunately my site is much too shaded for solar. Already tried that. For clarity, my system provides both water heating and space heating/cooling.

DannyBee 8y ago

Drilling is about half the cost. It's fairly cost efficient if they do it when building the house, much less so otherwise. It's basically "free" if your house needs a well anyway. (this assumes a lot about the ground under your house but it's relatively true ;P) If you live in a mild climate, you are just not going see a lot of payback because as you said, you don't spend a lot. Note: Most of them also provide hot water, not just heating and cooling But all told, the path to making it popular would be to make it part of new construction. I understand why they want to try to make retrofitting cheap, but it's just not even close right now.