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I replaced an old condenser and furnace with a 21 seer 5 head mini split system last summer. It’s much quieter and allows everyone to have their preferred temp.

I replaced an old condenser and furnace with a 21 seer 5 head mini split system last summer. It’s much quieter and allows everyone to have their preferred temp. My biggest surprise was the efficiency. I have amp meters on my mains, and I thought something was wrong when we first turned it on. The old condenser was 32k btu and the new one was ~40k, but it consumes 30% the energy compared to the old unit on average. This is all for AC. As for heating, my electricity bill is higher as I replaced natural gas… but I have solar. Anyways, heat pumps are pretty awesome IMO. On a new build I’d look at geo thermal heat pumps. Still a lot of theoretical efficiency to gain with improvements.

twothamendment 4y ago
I have a ground source heat pump to heat and cool my home. If you can do it, it is the best system I've ever had. You've got to have enough room for the horizonal loop, or drill some wells. It is a bit expensive to put in, so I wouldn't do it unless you plan to live there long enough to recoup the costs. If I were to sell my house nobody would give me a dime extra for it.
- OJFord 4y ago
  Well, I would! But I get the point, it's just chance of who's otherwise interested, and to actually get the amount extra they think it's worth you probably need two of them anyway.
  - twothamendment 4y ago
    The first house I built (designed, generaled and did a lot of the work) was super insulated. Selling it taught me that people just look at square footage and price. They aren't likely to know or care if is built better. It was eye opening. I got a taste of exactly why builders build crap homes. Building code is the minimum and they build to it for a reason. We are now friends with the people who bought it and several times they have thanked us for building it well. They didn't know what they were getting, but it is nice to see they appreciate it now - especially when the power is out and neighbors are crying about their cold houses and these lucky people are staying warm. My third and final build I built for me. I never plan to sell. Even when my kids are gone and I only need half the house it would be very hard to find something to downsize to that would cost me less per month than I pay now. Ground source is that good.
    - ulrikrasmussen 4y ago
      It is crazy how cheap it is to heat modern houses compared to old ones, and this really ought to be factored into the price! The money you spend on energy is gone forever whereas your down payments go right into your equity, so most people should be happy to pay a lot more for well-insulated square footage. Do you think this is really an information asymmetry problem? What if there was a standardized way to compare the cost of maintenance per M2?
      - CalRobert 4y ago
        Maybe it's cultural? We built a house in Ireland and our neighbours freaked out at the idea you could build a house without radiators, or heat a house without burning something (oil, gas, etc). It's been nice and warm (affordably) with just two air source heat pumps.
        raffraffraff 4y ago
        Interesting. I live in Dublin, we have a terrace house so it's not that large. When we bought it 12 years ago we did a complete renovation (decent insulation, new gas boiler). Since everything works, I don't want to rip everything out and junk it. But I was think about filling the south-facing roof with PV solar and installing two air-source heat pumps. I was hoping to cool the house in summer and heat it from March to October for free. Plus in the sunniest months, divert extra electricity from PV to the hot water tank. But I intended to leave the gas boiler in place as a backup. Maybe I shouldn't. Anyways, if it ever breaks down I'll just have it removed.
        CalRobert 4y ago
        Nice! Maybe it's just Offaly.
      - voidee 4y ago
        A standard to compare costs would be ideal. Right now in the US, your best bet is to repeatedly mention energy efficiency in the listing and use a realtor who understands how to market it. Provide monthly bills to show actual usage and use the analytics which most energy companies and smart thermostats provide. Being able to show 50% energy usage compared to average homes in your area helps homebuyers understand the benefits.
- JumpCrisscross 4y ago
  Do heat pumps make sense if you don’t have central air?
  - hn_go_brrrrr 4y ago
    Absolutely. A mini split system is perfect for this use case.
    - IanCal 4y ago
      You can also use them to heat water and pump to radiators or underfloor heating.
- foxyv 4y ago
  I think I would pay at least $5-10k more for a ground source heat pump on a house. The energy cost savings are insane. I think I would even prefer that over a solar installation.
leohart 4y ago
Which model of indoor and outdoor did you go with? My research into multi split suggest that going with multiple mini splits is more efficient. There is also a concern that multi split is not eligible for IRA tax credit
- simpsond 4y ago
  I went with the Daikin 5MXS48TVJU for the condenser and 3 models of the head units. All Daikin. I didn’t want a bunch of condensers around the house, and I didn’t want to run power everywhere. I’m not sure about efficiency compared to multiple condensers or the IRA stuff.

twothamendment 4y ago

I have a ground source heat pump to heat and cool my home. If you can do it, it is the best system I've ever had. You've got to have enough room for the horizonal loop, or drill some wells. It is a bit expensive to put in, so I wouldn't do it unless you plan to live there long enough to recoup the costs. If I were to sell my house nobody would give me a dime extra for it.

OJFord 4y ago
Well, I would! But I get the point, it's just chance of who's otherwise interested, and to actually get the amount extra they think it's worth you probably need two of them anyway.
- twothamendment 4y ago
  The first house I built (designed, generaled and did a lot of the work) was super insulated. Selling it taught me that people just look at square footage and price. They aren't likely to know or care if is built better. It was eye opening. I got a taste of exactly why builders build crap homes. Building code is the minimum and they build to it for a reason. We are now friends with the people who bought it and several times they have thanked us for building it well. They didn't know what they were getting, but it is nice to see they appreciate it now - especially when the power is out and neighbors are crying about their cold houses and these lucky people are staying warm. My third and final build I built for me. I never plan to sell. Even when my kids are gone and I only need half the house it would be very hard to find something to downsize to that would cost me less per month than I pay now. Ground source is that good.
  - ulrikrasmussen 4y ago
    It is crazy how cheap it is to heat modern houses compared to old ones, and this really ought to be factored into the price! The money you spend on energy is gone forever whereas your down payments go right into your equity, so most people should be happy to pay a lot more for well-insulated square footage. Do you think this is really an information asymmetry problem? What if there was a standardized way to compare the cost of maintenance per M2?
    - CalRobert 4y ago
      Maybe it's cultural? We built a house in Ireland and our neighbours freaked out at the idea you could build a house without radiators, or heat a house without burning something (oil, gas, etc). It's been nice and warm (affordably) with just two air source heat pumps.
      - raffraffraff 4y ago
        Interesting. I live in Dublin, we have a terrace house so it's not that large. When we bought it 12 years ago we did a complete renovation (decent insulation, new gas boiler). Since everything works, I don't want to rip everything out and junk it. But I was think about filling the south-facing roof with PV solar and installing two air-source heat pumps. I was hoping to cool the house in summer and heat it from March to October for free. Plus in the sunniest months, divert extra electricity from PV to the hot water tank. But I intended to leave the gas boiler in place as a backup. Maybe I shouldn't. Anyways, if it ever breaks down I'll just have it removed.
        CalRobert 4y ago
        Nice! Maybe it's just Offaly.
    - voidee 4y ago
      A standard to compare costs would be ideal. Right now in the US, your best bet is to repeatedly mention energy efficiency in the listing and use a realtor who understands how to market it. Provide monthly bills to show actual usage and use the analytics which most energy companies and smart thermostats provide. Being able to show 50% energy usage compared to average homes in your area helps homebuyers understand the benefits.
JumpCrisscross 4y ago
Do heat pumps make sense if you don’t have central air?
- hn_go_brrrrr 4y ago
  Absolutely. A mini split system is perfect for this use case.
  - IanCal 4y ago
    You can also use them to heat water and pump to radiators or underfloor heating.
foxyv 4y ago
I think I would pay at least $5-10k more for a ground source heat pump on a house. The energy cost savings are insane. I think I would even prefer that over a solar installation.

leohart 4y ago

Which model of indoor and outdoor did you go with? My research into multi split suggest that going with multiple mini splits is more efficient. There is also a concern that multi split is not eligible for IRA tax credit

simpsond 4y ago
I went with the Daikin 5MXS48TVJU for the condenser and 3 models of the head units. All Daikin. I didn’t want a bunch of condensers around the house, and I didn’t want to run power everywhere. I’m not sure about efficiency compared to multiple condensers or the IRA stuff.