ᐅ Heating System for New Construction – Which Is the Best Option?

ruppsn schrieb:
So, I just called and requested a price estimate. The drilling alone for an 8kW heat extraction capacity will cost between 12,000 and 15,000 EUR... You really have very builder-friendly conditions where you are. Here, the limit is usually 100 meters (330 feet) at the latest, sometimes even 60 meters (200 feet). Deeper than 100 meters (330 feet) requires a special permit from the mining authority, which involves considerable effort – according to the information I received. It will probably end up being an air-to-water heat pump after all...

Who is offering this price?

Regarding the special permit: it’s just an application form! Who claims it’s a big effort? I suspect a general contractor and/or their installer. Ask a drilling contractor! It’s just a phone call away. Then you can have the drilling done by the builder’s side, and the installer only connects the heat pump afterwards.

R.Hotzenplotz schrieb:
A vicious circle. Unfortunately, that only happens once the construction contract is signed, because only then does phase 4 of the project start, which includes the calculation of the heat demand. And anything that isn't included in the contract beforehand and is changed later can be expected to come at a high additional cost.

Just as a clarification, thermal insulation certification is not the same as heat load calculation.

You can also have a heat load calculation done externally. It’s not very expensive. There are even a few (more or less reliable) calculators available online, for example at u-wert.net, just to get a rough idea.

Otherwise, consider agreeing on options with a price per meter of drilling. Or request a quote from a drilling company and arrange the drilling yourself on site.

Alex85 schrieb:
Alternatively, arrange options with a price per meter drilled. Or request a drilling company and have the drilling done by the builder.

That’s already the builder’s responsibility anyway. My concern was more about the technical aspect. If I want to change the equipment after signing the contract, they won’t offer me a good price.

Then consider it as an option. Should it accommodate both an air-to-water heat pump and a ground-source heat pump? The choice of which one to use is entirely up to you.

Just for your information, a KFW 55 standard, 192 square meters (2065 square feet), with controlled residential ventilation, results in a maximum heating capacity of 4.85 kW (kilowatts) based on our actual transmission heat losses (calculator using U-values). Of course, this is just an online calculator estimate.

To emphasize again, that is the maximum heating capacity... which is only needed in exceptional cases and not continuously. Oversizing the system "just to be safe" is absolutely pointless. If necessary, there is always an auxiliary electric heater.

Alex85 schrieb:
Who offers this price?
Keyword special permit. That is an application form! Who claims this is a major effort? I suspect a general contractor and/or their installer. Ask a drilling company! It’s just one phone call away. Then just do the drilling on site and have the installer only connect to the heat pump.

Hi Alex,
first of all, we are building with an architect in a direct contract model, so no design-build, general contractor, or construction manager at risk.

The price comes from three independent sources:
1. The refrigeration specialist company contacted 2 hours ago, just one call away
2. The drilling company, also just one call away
3. Our architect, who has already installed several ground source heat pump systems in the region and provided us with a drilling company’s offer from late 2012 for one of his projects

Regarding the deep drilling:
Quote from the development plan: “Ground source probes at the location are generally allowed. The maximum permitted drilling depth varies between 60 and 65 meters (197 to 213 feet) depending on the elevation at the drilling starting point. The Estherian layers in the deeper subsurface must not be completely penetrated. According to the Water Management Office of Nuremberg, no drilling risks are known or expected.”

It seems that your conditions differ significantly from ours here. It may be that for you it is just a form, but here it is not. If three independent sources assure me that this is not simply done with an application form, should I seriously respond that someone in a forum reports a different experience and therefore things must be different here too?

If, however, you yourself are a drilling contractor, I look forward to your offer for my project. Otherwise, I don’t have much choice but to accept it as it is, even though I would very much like to have your conditions here...

I said myself, there can be exclusions. If you need x short drillings, that’s understandable.

Aside from that, I don’t trust heating engineers (too much new territory), and even my own architects gave a crazy estimate until a real offer was available. It has to be modern and therefore expensive.

I wouldn’t do it for €15,000.