ᐅ Experiences with Water Source Heat Pumps vs. Condensing Gas Boilers?

Hello everyone,

since most of the discussions here are about air source heat pumps, I would like to hear your opinions on water source heat pumps versus gas condensing boilers.

I might be able to handle the drilling of the wells myself, and according to the home builder, the initial cost of the heat pump should not be much higher.

What is your opinion, which option is better? And which company would be a good supplier?

Thank you
insgruene

Hello,

insgruene schrieb:
.... I would like to hear your opinion on water-source heat pumps versus gas condensing boilers.

The same applies here as with air-source heat pumps! Comparing to gas condensing boilers is somewhat misleading because these often include an uneconomical solar thermal system as part of the package.
Water-source heat pumps have the advantage of a higher source temperature compared to ground-source systems. This results theoretically in a higher seasonal performance factor. Additionally, the physical properties of water are more favorable for heat transfer and circulation. However, only a few wells meet the requirements for adequate water quality. Problems tend to occur especially with infiltration wells. It should not be forgotten that the usually higher energy consumption of the source pump can cause an initially good seasonal performance factor to deteriorate quickly compared to a ground-source system. (Open loop system)

insgruene schrieb:
.... What is your opinion, which one is better? And which company would be a good provider?

Without calculating the boundary conditions, this question cannot be reliably answered unless you trust a crystal ball for such a significant investment 😉

Best regards.

An independent energy consultant can probably tell me that as well, I think—I have already planned for one.

Can a soil report determine if the groundwater is suitable? I want to have that done anyway before signing the contract. I assume I will have to pay for it? At least the builder said that this is the case, but that I would get reimbursed by them during construction. Is that common practice?

And then I would have the groundwater tested at the same time, right?

Best regards
insgruene

insgruene schrieb:
...An independent energy consultant can probably tell me that as well, I think I have already planned for one.

Unfortunately, “energy consultant” is not a protected professional title. Therefore, it is quite important that this person is also an MEP (mechanical, electrical, and plumbing) planner and has completed additional technical training in building construction!

insgruene schrieb:
...Can a soil survey report tell me if the groundwater is suitable?

No, a separate investigation is required for that. Soil survey reports focus on load-bearing capacity as a basis for building foundation design.

Best regards.

Hello,

insgruene schrieb:
...Why do I have to buy a solar thermal system together with the groundwater heat pump? The collectors are already included in the house price anyway, but can’t I operate a heat pump without it, or what would be the most economical option?

A solar thermal system is usually not necessary as a heat source when using a heat pump. The fact that the collectors are included in the price is due to the general contractor’s concept, which probably uses a gas condensing boiler as the standard. Moreover, it’s less about what is technically possible and more about what is required in terms of primary energy.
What is actually economical can be determined with a cost-effectiveness analysis. However, at least a heating load calculation is needed beforehand. I would question whether your architect friend is really well-versed in building services engineering. 😉
Best regards

Dear €uro,

you brought up the solar thermal system, but that wasn’t the question.

My question was simply whether a groundwater heat pump is worth it compared to a gas boiler.

I also didn’t say that my architect is knowledgeable about building services. I said he will arrange for one for me, and that’s a difference.