Dear forum members,
I am planning to build a single-family house with a heat pump and want to carry out a deep drilling for this purpose.
Problems in my view – possible legacy issues from mining (Ore Mountains).
In another post, I also read that the local water authority has objected:
“Now the local water authority has thrown a wrench in the plans and does not allow deep drilling.”
Therefore, I would like to know where problems generally arise and how these can be identified early and avoided.
Best regards,
Florian
PS: The construction company believes that deep drilling would not be problematic.
PPS: I would prefer not to be surprised by insurmountable problems after the planning process.
I am planning to build a single-family house with a heat pump and want to carry out a deep drilling for this purpose.
Problems in my view – possible legacy issues from mining (Ore Mountains).
In another post, I also read that the local water authority has objected:
“Now the local water authority has thrown a wrench in the plans and does not allow deep drilling.”
Therefore, I would like to know where problems generally arise and how these can be identified early and avoided.
Best regards,
Florian
PS: The construction company believes that deep drilling would not be problematic.
PPS: I would prefer not to be surprised by insurmountable problems after the planning process.
S
Sebastian7916 Nov 2015 09:30No, referring to the trench collector.
Oh, and ironically, the upper layers have significantly higher extraction capacity than the lower ones (starting from 10 m (33 feet))... There is also space available, but we really didn’t find anyone knowledgeable about it (at least no professional company – geothermal energy was already difficult to impossible).
As I mentioned before – if I were starting from scratch now, I would probably choose a gas condensing boiler (but now we don’t have a chimney, and I no longer want to deal with draft through the children’s room).
As I mentioned before – if I were starting from scratch now, I would probably choose a gas condensing boiler (but now we don’t have a chimney, and I no longer want to deal with draft through the children’s room).
Good evening dear forum members,
The construction and deep drilling projects have now progressed further, and we need to decide how deep to drill.
Basic information:
Living area based on the living space calculation according to the Wohnflächenverordnung: 126.45 m² (1361 sq ft)
Living area based on the execution drawings:
Upper floor: 65.05 m² (700 sq ft)
Ground floor: 67.05 m² (722 sq ft)
Basement: 69.62 m² (749 sq ft) (with underfloor heating: 23.17 m² (249 sq ft), underfloor heating + radiators: 59.94 m² (645 sq ft))
Totals: 201.72 m² (2171 sq ft), 155.27 m² (1671 sq ft), 192.04 m² (2067 sq ft)
The question now is – which heat pump to choose. Since we have not yet received the thermal insulation certificate, we spoke with the heating engineer who said they definitely need a 10 kW heat pump.
The choice is therefore a Viessmann Vitocal 300-G (BWC 301.B10):
Nominal heating capacity: 10.36 kW
Cooling capacity: 8.43 kW
Electrical power input: 2.07 kW
Coefficient of performance (COP) in heating mode: 5.01
Maximum flow temperature: 65°C (149°F)
Our first offer from the deep drilling company included a down-the-hole hammer drilling for 125 m (410 ft), a geothermal probe Raugeo PE-RC 32 x 3.0 mm, as well as grouting of the borehole with GeoSolid 235 – presumably sufficient for a “standard” single-family home.
With the specification for a 10 kW heat pump, we requested a concrete offer and received a quote for two down-the-hole hammer drillings of 90 m (295 ft) each (all other conditions the same). Since the price of a manifold shaft is added here, we also requested an offer for a single borehole.
With the probe adjusted to 40 x 37 mm, a depth of 152 m (499 ft) was offered. This might just be enough with the larger probe...
Our own estimation using formulas found online leads to the following values:
Heating capacity (50 W/m²): 9.602 kW (192.04 m² (2067 sq ft))
Heat extraction capacity: 7.685 kW
Borehole depth (1800 hours with 55 W/m): 139.7 m (458 ft)
Borehole depth (2400 hours with 50 W/m): 153.7 m (504 ft)
Since only the 155.27 m² (1671 sq ft) from the living area calculation will be continuously heated, the 152 m (499 ft) should more than suffice.
Still, we are very uncertain about how many meters are actually necessary and whether it would be better in the long run to have one or two boreholes. Do you happen to have any advice?
The construction and deep drilling projects have now progressed further, and we need to decide how deep to drill.
Basic information:
Living area based on the living space calculation according to the Wohnflächenverordnung: 126.45 m² (1361 sq ft)
Living area based on the execution drawings:
Upper floor: 65.05 m² (700 sq ft)
Ground floor: 67.05 m² (722 sq ft)
Basement: 69.62 m² (749 sq ft) (with underfloor heating: 23.17 m² (249 sq ft), underfloor heating + radiators: 59.94 m² (645 sq ft))
Totals: 201.72 m² (2171 sq ft), 155.27 m² (1671 sq ft), 192.04 m² (2067 sq ft)
The question now is – which heat pump to choose. Since we have not yet received the thermal insulation certificate, we spoke with the heating engineer who said they definitely need a 10 kW heat pump.
The choice is therefore a Viessmann Vitocal 300-G (BWC 301.B10):
Nominal heating capacity: 10.36 kW
Cooling capacity: 8.43 kW
Electrical power input: 2.07 kW
Coefficient of performance (COP) in heating mode: 5.01
Maximum flow temperature: 65°C (149°F)
Our first offer from the deep drilling company included a down-the-hole hammer drilling for 125 m (410 ft), a geothermal probe Raugeo PE-RC 32 x 3.0 mm, as well as grouting of the borehole with GeoSolid 235 – presumably sufficient for a “standard” single-family home.
With the specification for a 10 kW heat pump, we requested a concrete offer and received a quote for two down-the-hole hammer drillings of 90 m (295 ft) each (all other conditions the same). Since the price of a manifold shaft is added here, we also requested an offer for a single borehole.
With the probe adjusted to 40 x 37 mm, a depth of 152 m (499 ft) was offered. This might just be enough with the larger probe...
Our own estimation using formulas found online leads to the following values:
Heating capacity (50 W/m²): 9.602 kW (192.04 m² (2067 sq ft))
Heat extraction capacity: 7.685 kW
Borehole depth (1800 hours with 55 W/m): 139.7 m (458 ft)
Borehole depth (2400 hours with 50 W/m): 153.7 m (504 ft)
Since only the 155.27 m² (1671 sq ft) from the living area calculation will be continuously heated, the 152 m (499 ft) should more than suffice.
Still, we are very uncertain about how many meters are actually necessary and whether it would be better in the long run to have one or two boreholes. Do you happen to have any advice?
S
Sebastian7916 Mar 2016 21:38Since you are building according to the 2016 Energy Saving Ordinance, the 10kW (kilowatt) pump is definitely oversized for the living area.
And the drilling depth as well – a reputable drilling company will determine the correct depth based on the heat extraction capacity of the heat pump and the soil conditions.
Without a heating load calculation, all the calculations are pointless and will not lead to a useful result.
And the drilling depth as well – a reputable drilling company will determine the correct depth based on the heat extraction capacity of the heat pump and the soil conditions.
Without a heating load calculation, all the calculations are pointless and will not lead to a useful result.
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