ᐅ Use an Air Source Heat Pump or Gas and Solar?

R.Hotzenplotz schrieb:
I absolutely will not install an air-to-water heat pump. Why would I do that if a ground-source heat pump also works?

Because an air-to-water heat pump is about 10,000 - 15,000 euros cheaper depending on the location, and you would only recover that cost with a ground-source heat pump after many decades (if at all).

Alex85 schrieb:
Or, priced in between both solutions, pellets. You don’t need solar for that, and you also don’t need a flue when using gas.

Additionally: for pellets, you would need storage space. I don’t recall whether your house has a basement room available for that.

Alex85 schrieb:
Wasn't a ground-source heat pump insanely expensive for you?

No, I would save about €2,500 by using gas/solar compared to a ground-source heat pump. With the evacuated tube collectors, it might even be more expensive with gas/solar – I need to check the price difference.

Mycraft schrieb:
And why are the flat panels not an option? Just have them installed and the issue is solved.

I need to ask whether the company is willing to do it that way and whether it is even allowed. They have presented me these two options for now; I can clarify further on Monday. The question is whether the evacuated tubes are so much more expensive that the lower price for the less efficient flat collectors lying on the flat roof "pays off," or whether despite the higher cost, a better cost-benefit ratio is achieved by using evacuated tube collectors. Unfortunately, I have only received those two pictures. I would need to request calculations. Since that is always a slow process, I would need to specify exactly which data I require.

Bookstar schrieb:
Because an air-to-water heat pump is about €10,000 - 15,000 cheaper depending on location, and you would only recoup that with a ground-source heat pump after many decades (if at all).

I definitely do not want an outdoor unit like that, and if a heat pump, then only a ground-source heat pump with the highest efficiency rating.

Including drilling, the ground-source heat pump is about €2,000 more expensive than the air-to-water heat pump. I don’t have to think twice about that if those are the only two options.

What bothers me about heat pump topics is that I feel the numbers are often optimistic. I foresee higher maintenance costs than with established gas boilers, which have many service technicians available everywhere. If we had taken the offered Waterkotte AI1 Geo, there would also need to be one of the few Waterkotte service partners, which are not really nearby and who charge expensive hourly rates (due to less competition than with conventional heating engineers), plus hefty travel allowances. If such a heat pump is perfectly tuned, it may pay off and require few technician visits due to the system’s reliability. But with the slightest irregularities, my impression is that the additional costs (regardless of the often unachieved electricity consumption figures provided) will make it more expensive than gas/solar.

Currently, we have a Nibe system in a rental property. It is supposedly serviced once a year or every two years (I’m not sure because I don’t have the contract). There is a maintenance agreement. There are two heat pumps in the house. This costs the landlord around €500 every time, including everything, and the technician is there for less than 30 minutes. When someone comes for heating oil maintenance at my parents’, a regular servicing is about €120. At first, there was a huge fuss about the system’s inefficiency. Then the blame was passed around. The Nibe technician said the ventilation system’s dampers were not properly adjusted; the ventilation installer said he hadn’t received any instructions about it. Then the Nibe technician measured the entire ventilation system, adjusted the dampers correctly, and gave the landlord a hefty bill.

Pellets are not an option. This is now really just about choosing the solar collectors. But we won’t be able to finalize this here without knowing the price difference and whether they would even be willing to install the flat collectors without full functionality on the roof. For the evacuated tubes, it looks like fewer square meters are needed, which will likely offset the higher price somewhat.

R.Hotzenplotz schrieb:
Ground-source heat pump including drilling is about €2,000 more expensive than an air-to-water heat pump. I wouldn’t even hesitate for a second if those were the only two options.

Wow, I wouldn’t think twice either. For us, it’s a €14,000 (about $15,300) price difference compared to the air-to-water heat pump (which is almost exactly the drilling cost—how much does it cost for you?).
Please don’t forget when comparing to gas that, since it involves combustion, you need a chimney and a chimney sweep (ongoing costs).

I can’t share the concerns about maintenance. If the service network of that heat pump manufacturer is that poor, why are you even specifying that unit?! You’re working with an architect, right?

I mean, there’s not just one manufacturer. For example, solar thermal systems would be an absolute no-go for me, but building owners have very different preferences [emoji4]

ruppsn schrieb:
I don’t share the concerns about maintenance. If the service network of the heat pump manufacturer is that poor, why do you specify this unit?! You are working with an architect, right?

We are building with a general contractor, so the unit is predetermined. The contractor’s installer is an exclusive Waterkotte provider. Naturally, he’s not very happy about having to install a gas/solar system for us.

R.Hotzenplotz schrieb:
We are building with a central heating unit, so the device is predetermined. The installer of this central heating unit is the exclusive Waterkotte supplier. Accordingly, he is not very enthusiastic about installing a gas/solar system for us.

Ahh, ok, that does indeed make things more complicated.