Hello everyone,
I have a question regarding a heating system renovation. I am new here and hope this is the right place for my inquiry.
We are currently planning to modernize our heating system. Our house was built in 1995, conventional construction, Poroton bricks, underfloor heating, about 220m² (2,368 sq ft).
We are currently heating with oil (consumption about 4000 liters/year (1057 gallons)), without a condensing boiler.
We are refinancing at the moment and would like to remove the oil heating system to get rid of the oil tanks and later convert the gained space into living areas.
As options, gas or a geothermal heat pump have emerged. Air-to-water heat pumps are not an option since we do not want an outdoor unit. Gas could be connected to the house for under 2000 euros, the investment is manageable, but it would still mean relying on a fossil fuel. According to our quotes, converting to gas would cost around 16,000 euros.
Geothermal would be possible for us. Our neighbor has a borehole of about 100 meters (328 feet). I do not know the details. According to our quotes, we expect costs around 35,000 euros. The drilling company offered a borehole with 3 x 45 meters (3 x 148 feet), 3 x 15 kW.
Now, I have no idea how to evaluate this borehole or if it is sufficient. It confuses me that the neighbor only has the one borehole, which goes significantly deeper.
In principle, we are also unsure whether the considerably higher investment will ever pay off (apart from the gas dependency). Our neighbor uses about 50-60 euros of electricity per month for his heat pump but has a low-energy house with a ventilation system. We have generally left out subsidies for now. The region of Hesse offers discounted electricity tariffs for heat pumps.
Perhaps someone can give us an assessment to help us with our decision-making. We would really appreciate it.
Best regards
Christian Kumpf
I have a question regarding a heating system renovation. I am new here and hope this is the right place for my inquiry.
We are currently planning to modernize our heating system. Our house was built in 1995, conventional construction, Poroton bricks, underfloor heating, about 220m² (2,368 sq ft).
We are currently heating with oil (consumption about 4000 liters/year (1057 gallons)), without a condensing boiler.
We are refinancing at the moment and would like to remove the oil heating system to get rid of the oil tanks and later convert the gained space into living areas.
As options, gas or a geothermal heat pump have emerged. Air-to-water heat pumps are not an option since we do not want an outdoor unit. Gas could be connected to the house for under 2000 euros, the investment is manageable, but it would still mean relying on a fossil fuel. According to our quotes, converting to gas would cost around 16,000 euros.
Geothermal would be possible for us. Our neighbor has a borehole of about 100 meters (328 feet). I do not know the details. According to our quotes, we expect costs around 35,000 euros. The drilling company offered a borehole with 3 x 45 meters (3 x 148 feet), 3 x 15 kW.
Now, I have no idea how to evaluate this borehole or if it is sufficient. It confuses me that the neighbor only has the one borehole, which goes significantly deeper.
In principle, we are also unsure whether the considerably higher investment will ever pay off (apart from the gas dependency). Our neighbor uses about 50-60 euros of electricity per month for his heat pump but has a low-energy house with a ventilation system. We have generally left out subsidies for now. The region of Hesse offers discounted electricity tariffs for heat pumps.
Perhaps someone can give us an assessment to help us with our decision-making. We would really appreciate it.
Best regards
Christian Kumpf
B
boxandroof2 Apr 2019 12:22smurf26579 schrieb:
So the supply temperature is always around 30 degrees Celsius (86°F). If I were you, I would collect detailed data throughout the next winter and use it to plan the new heating system:
- Optimize/increase flow rates
- Install heat meters: record flow, supply and return temperatures, and heat quantity
- Measure heat energy on the coldest day or over several consecutive cold days (heating load)
- Determine the maximum supply temperature needed on the coldest day (I’m skeptical about the 30°C (86°F), but that would be great!)
This way, you can properly design the heating system and also determine if a heat pump can be operated efficiently at your location. You have the advantage that the old heating system is still working, so you can plan and decide wisely.
smurf26579 schrieb:
Is it really possible to do without passive cooling? Or is the effect in summer so pleasant that the extra 900 euros (plus tax) would be worth it in our case? You are already living in the house, right? If the house tends to overheat significantly, an air conditioning system would be more effective. If it’s manageable as it is, passive cooling is more of a nice-to-have feature.
Last summer, we tested cooling a few times with the heat pump (air-to-water heat pump). It’s quite nice but doesn’t perform miracles. I imagine the effect would be greater in timber-framed houses. The cooling was especially pleasant after the heat wave, helping to remove the stored heat from the massive structure more quickly.
For geothermal systems, I find cooling particularly interesting and useful from a technical perspective.
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