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

I have new information. The air source heat pump is expected to cost €8,000 more than the ground source heat pump. Therefore, a ground collector solution is now being recommended instead. This is supposed to be roughly the same price as the ground source heat pump and to include the same unit, if I understood correctly.

The air-to-water heat pump solution as a whole or just the device? At least the latter would be confusing in such clarity.

Joedreck schrieb:
People, in new buildings depending on the living area and insulation standard, you have between 5 and 8 kW heating load at your design temperature (-12 to -16 degrees Celsius (10 to 3 degrees Fahrenheit)). And you only have these temperatures for a maximum of 3-4 days per year.
If a heating technician comes along and says the heat pump is constantly running at full capacity, they don’t understand the subject.
Additionally, internal and solar gains are not included in the heating load calculation.

What is needed here is good, proper planning of the underfloor heating, then you can heat very efficiently with an air-to-water heat pump at a flow temperature of 30 degrees Celsius (86 degrees Fahrenheit). And it only costs a bit more planning.

These oversized heat pumps are then installed with buffer tanks, which completely destroy the efficiency. Unfortunately, this is common but wrong. Please inform yourselves extensively here and put pressure on the heating technician, otherwise you will end up with: my heat pump broke after 3 years or costs an immense amount of electricity.

To add, these incorrectly planned systems will not receive funding from BAFA because they will fail to meet the required annual performance factor (seasonal coefficient of performance) verification.

ruppsn schrieb:

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Let's be specific: what are the things a layperson should be cautious about when dealing with a home builder, and how can a layperson tell if the builder lacks expertise?

If they don’t carry out a room-by-room heating load calculation as a basis for planning, they have no clue. Without this, it’s impossible to properly size the heat pump. This leads to unnecessarily high investment costs and inefficient operation. Furthermore, the mentioned example exposes itself by claiming the system would constantly run at full load. joedreck has already written enough about this.

ruppsn schrieb:
It’s easy to say you should gather information beforehand, but what exactly about? Reading isolated cases where the conditions are unknown and perhaps not even comparable? Statements from partial laypersons who, apart from having a strong opinion, have neither long-term experience nor relevant training?

Of course, assumptions are made in forums. If the original poster doesn’t disclose that they have restrictions preventing deeper drilling, then the given price can be surprising. Otherwise, you need to ask yourself what you expect from forums and whether they are a suitable source of information for you. You are planning to purchase a heating system worth 25,000–35,000€ (probably closer to the higher figure in your case), but you have no personal knowledge about it and don’t want to rely on free sources like this forum. Then you will have to spend more money to have one contractor check another.

ruppsn schrieb:
Seriously, someone here claimed it’s nonsense and that home builders don’t know what they’re doing?

Then maybe look elsewhere. Buffer tanks for heat pumps are nonsense. First, there is already a huge buffer in the form of underfloor heating and the hot water storage tank. Second, heat pumps only operate efficiently at low temperatures; producing domestic hot water (45°C (113°F), sometimes higher, which is bad!) is not their strength. Keeping a large volume of hot water stored doesn’t make sense.

ruppsn schrieb:
And please be more specific than “all home builders” don’t know what they’re doing when buffer tanks are planned and “do your research.” And please include sources or statements from experts, otherwise it’s just the isolated opinion of a layperson who, at best, knows their own project but contradicts the views of professionals with experience from many other projects.

No comment. Where do you live?! Nobody owes you an explanation. You are here because you don’t know and are reluctant to research yourself. Take the free help or don’t, but drop your demands.

ruppsn schrieb:
although the latter must also guarantee that the building will actually be warm and stay warm

FEAR!! And how much is that guarantee actually worth? Do a quick poll here on how long it takes for a new homeowner to notice that their heating has failed. Maybe in a timber-frame house with low thermal mass they notice sooner, but for heavy construction, it takes many hours before it becomes apparent.

ruppsn schrieb:
Where do you get a heating load calculation from? Surely not from the home builder who disqualifies himself with his full-load statement? An MEP engineer? Many people (architects, home builders, building surveyors, and even MEP engineers themselves) say that’s like using a sledgehammer to crack a nut for a single-family house?

You can also buy these calculations separately online. It costs around 200€. Some people do it themselves.

ruppsn schrieb:
So how does a prospective homeowner get a “decent plan,” who performs it, and how can they tell that the proposed solution is sound? What are the criteria for a reasonable solution?

Reasonable plans are recognizable by clear, traceable planning approaches. Phrases like “it’s always been done this way,” “it’s good enough,” or “better a bit too big” reveal there was no real planning. A leads to B leads to C. If the builder can only name C without explaining the path, they guessed rather than planned. Just ask why the heat pump is supposed to be 12kW, like Hotzenplotz. If the only answer is “that’s what it needs to be for your house size,” they disqualify themselves.

R.Hotzenplotz schrieb:

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I have new information. The air source heat pump is supposed to cost €8,000 more than the ground source heat pump. Therefore, a ground collector solution is now recommended instead. That is supposed to be roughly the same price as the ground source heat pump and use the same unit, if I understand correctly.

It just gets better and better. An €8,000 price difference? Yes, an air-to-water heat pump, meaning just the unit, is more expensive because it includes the outdoor unit, costing 1,000–2,000€. Plus a bit for the base it sits on. Total €8,000? No way. That’s about the price of the entire heat pump system (online price, admittedly)!

Whether boreholes or ground collectors are used as the heat source doesn’t matter to the heat pump itself. It’s exactly the same unit, just with a different heat source.

ruppsn schrieb:
The air-to-water heat pump solution as a whole or just the device? At least the latter would be quite confusing.

Just the device. With the drilling no longer needed, that more than compensates, so overall I would be better off.

Alex85 schrieb:
Whether drilling or ground collector makes no difference at all for the heat pump. Exactly the same device, just a different heat source.

They now want to consider the ground collector solution. I said I’m skeptical since I plan to build a swimming pool in the garden later and also want to plant a large tree. She said they have already planned the front of the property in front of the house for that anyway. Apparently, that means digging about 1.50 m (5 feet) deep under the driveway to the garage.

But what’s the point if the soil itself is borderline for a geothermal heat system even at 100 m (330 feet) depth? They say the concept is different. But I don’t really understand that.

The surface collector lies just below the ground surface. It requires a really, really large area—don't let anyone tell you otherwise! It also has some other possible disadvantages; just look it up yourself.
Alternatively, there is the trench collector, which needs less space.
Both options are eligible for subsidies, although a bit less than drilling.

R.Hotzenplotz schrieb:
Only the device. By avoiding the drilling, it more than makes up for itself, so overall I would even be better off.

Besides the completely outrageous €30,000 for geothermal drilling, you should be glad that the air-to-water heat pump is offered at only twice the price. Unbelievable.

I just read your other thread about the mandatory expert costing €4,000.

When will your limit actually be reached?