ᐅ Heating System for a KfW70 Multi-Family Residential Building – Complete Confusion
Created on: 11 Nov 2012 11:46
D
der_Micha
Hello Forum!
We are finally ready to build. The building plot is purchased, the architect’s plans are finished, and we are collecting quotes.
So far, so good – except for one issue that all five providers have answered very differently: Everyone has at least one opinion on the heating system. These opinions contradict each other so strongly that we – as uninformed laypeople – now have no idea what to decide. We might soon have to roll a dice to answer this question.
- The energy consultant says that in a well-insulated house with heat recovery ventilation, no room heating is needed, and a small boiler is sufficient for domestic hot water.
- Provider A says that an air-source heat pump for this huge house is expensive and not economical.
- Provider B recommends a pellet heating system.
- Provider C suggests a gas condensing boiler solution combined with solar thermal.
- Provider D recommends geothermal energy, which A and E advise against because the investment in the risky deep drilling would only pay off after 120 years.
- The idea of a small-scale power plant (micro combined heat and power) was mentioned once but was immediately dismissed elsewhere!
The house:
It will have 2.5 floors with approximately 130 m² (1,400 sq ft) each for living space,
plus 70 m² (750 sq ft) in the basement for practice/office rooms.
The ceiling height is effectively 2.75 m (9 ft).
A ventilation system with heat recovery is firmly planned, as well as underfloor heating.
We would like photovoltaic and solar thermal systems if they prove economically viable.
Regarding online calculators, I
a) don’t feel confident about them,
b) can’t include heat recovery in the calculations,
but the rough values are an annual heat demand of 7,000 kWh and a heating load of 17.84 kW.
What do you recommend? What experiences have you had?
Best regards,
der_Micha
We are finally ready to build. The building plot is purchased, the architect’s plans are finished, and we are collecting quotes.
So far, so good – except for one issue that all five providers have answered very differently: Everyone has at least one opinion on the heating system. These opinions contradict each other so strongly that we – as uninformed laypeople – now have no idea what to decide. We might soon have to roll a dice to answer this question.
- The energy consultant says that in a well-insulated house with heat recovery ventilation, no room heating is needed, and a small boiler is sufficient for domestic hot water.
- Provider A says that an air-source heat pump for this huge house is expensive and not economical.
- Provider B recommends a pellet heating system.
- Provider C suggests a gas condensing boiler solution combined with solar thermal.
- Provider D recommends geothermal energy, which A and E advise against because the investment in the risky deep drilling would only pay off after 120 years.
- The idea of a small-scale power plant (micro combined heat and power) was mentioned once but was immediately dismissed elsewhere!
The house:
It will have 2.5 floors with approximately 130 m² (1,400 sq ft) each for living space,
plus 70 m² (750 sq ft) in the basement for practice/office rooms.
The ceiling height is effectively 2.75 m (9 ft).
A ventilation system with heat recovery is firmly planned, as well as underfloor heating.
We would like photovoltaic and solar thermal systems if they prove economically viable.
Regarding online calculators, I
a) don’t feel confident about them,
b) can’t include heat recovery in the calculations,
but the rough values are an annual heat demand of 7,000 kWh and a heating load of 17.84 kW.
What do you recommend? What experiences have you had?
Best regards,
der_Micha
Hello Euro,
Micha has already mentioned that he will probably consult an energy advisor. So why are you warning?
What exactly do you find problematic with the online heating demand calculator I suggested? Are there systematic errors in the calculations that make it impossible to perform a first rough estimate? I am happy to be corrected.
In my opinion, the operator does not offer consulting services themselves... 😉
Just out of curiosity: What is the basis of your warning?
Micha has already mentioned that he will probably consult an energy advisor. So why are you warning?
What exactly do you find problematic with the online heating demand calculator I suggested? Are there systematic errors in the calculations that make it impossible to perform a first rough estimate? I am happy to be corrected.
In my opinion, the operator does not offer consulting services themselves... 😉
Just out of curiosity: What is the basis of your warning?
H
Häuslebauer4012 Nov 2012 11:03Euro warns everyone and everything. After all, he is a building services engineer himself. 😉
D
der_Micha12 Nov 2012 12:05However, he is unfortunately right about that. Only someone who is independent of sales has no financial personal interests. Their role is limited to the planning stage, unlike the consultant-seller-architect hybrid offered by full-service providers.
But I also understand what you are trying to say. After all, their financial interest lies in getting as many people as possible to seek their advice.
Fortunately, everyone can decide for themselves whom they want to trust. So far, it is just very clear to me that the previous "consultations" from providers have not been sufficient for me to make a lifelong investment with a clear conscience.
But I also understand what you are trying to say. After all, their financial interest lies in getting as many people as possible to seek their advice.
Fortunately, everyone can decide for themselves whom they want to trust. So far, it is just very clear to me that the previous "consultations" from providers have not been sufficient for me to make a lifelong investment with a clear conscience.
H
Häuslebauer4012 Nov 2012 12:21Then you are already on the right track. Get an independent expert, and you will be able to sleep well. 🙂
B
Bauexperte12 Nov 2012 13:52Hello Micha,
I probably didn’t express myself clearly enough ...
Best regards
I probably didn’t express myself clearly enough ...
der_Micha schrieb:
Since the house is not built yet and we have no points of comparison, we are exactly facing this problem—that we cannot evaluate these contradictory statements. Everyone talks nonsense and argues based on their own claim. As a layperson, you end up more confused after every consultation than before!
- I want to know why the energy consultant talks about a "well-insulated" house
- I want to know which KfW standard is being aimed for
- I want to know which brick/insulation is being used
- I want to know how the basement will be constructed.
der_Micha schrieb:MEP – mechanical, electrical, and plumbing planner. They invoice according to the HOAI (official scale of fees for services by architects and engineers); if you can’t find one, I can recommend my MEP planner, who has offices nationwide. However, I want to point out in advance that MEP services are not inexpensive.
Are these the MEP planners then?
Is there a directory of these sales-independent planners? Or a certificate/seal/association that can be trusted?
der_Micha schrieb:Even though I have been in this profession for 17 years, I’m losing faith in seriously advising salespeople. Due to the “penny-pinching is cool” campaign, they are all afraid to provide prices ... because that’s what it ultimately comes down to. And since the average builder prefers "cheap" rather than reasonable and thus valuable construction, one thing leads to another ...!
It’s simply shocking that in this free, public forum you get more sensible answers than from people who pretend to have swallowed the wisdom of housebuilding whole.
Best regards
der_Micha schrieb:
....Fortunately, everyone can decide for themselves whom they trust. For me, it has become very clear that the advice offered so far is not sufficient to confidently make a lifelong investment. Correct. In my opinion, it is completely sufficient in this "small" area to address only the most critical key points. A full technical building services planning according to HOAI is not necessary, which keeps the costs manageable. ;-)Best regards
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