Hello everyone. My partner and I are planning to build a house. About 140-150 square meters (1507-1615 square feet), 1.5 stories. After initially considering building a KfW 40 house, I quickly moved away from that idea. The general opinion seems to be that it’s not cost-effective (considering only the costs). So now we want to build according to KfW 55 standards.
Underfloor heating is planned throughout the entire house. However, despite extensive research, we are still uncertain about other details. For the standard KfW 55, a heat pump or a gas connection (then with a share of renewable energy) is mandatory, right?
What do you think is the best combination for KfW 55? I had originally planned on a ground source heat pump / geothermal system. But this seems somewhat oversized for a new build, doesn’t it? What technology would you recommend for an air-source heat pump?
Does it make sense to install a photovoltaic system (because of the additional electricity costs of the heat pump and generally) or solar thermal collectors? Would solar thermal still be mandatory if using a heat pump? With gas, solar thermal would be mandatory, right?
I’m also interested in your opinions on a controlled mechanical ventilation system. If yes, with or without heat recovery? I know the cost of the system does not pay off financially. But it’s a gain in comfort (no need to ventilate manually and you have fresh air). Does it offer any additional benefits? The filters would also reduce dirt like pollen, dust, etc. inside the house, right? Maybe someone has current experiences with these systems. I have read a lot, but mostly reports from 3-4 years ago.
Am I forgetting any important systems or options?
Underfloor heating is planned throughout the entire house. However, despite extensive research, we are still uncertain about other details. For the standard KfW 55, a heat pump or a gas connection (then with a share of renewable energy) is mandatory, right?
What do you think is the best combination for KfW 55? I had originally planned on a ground source heat pump / geothermal system. But this seems somewhat oversized for a new build, doesn’t it? What technology would you recommend for an air-source heat pump?
Does it make sense to install a photovoltaic system (because of the additional electricity costs of the heat pump and generally) or solar thermal collectors? Would solar thermal still be mandatory if using a heat pump? With gas, solar thermal would be mandatory, right?
I’m also interested in your opinions on a controlled mechanical ventilation system. If yes, with or without heat recovery? I know the cost of the system does not pay off financially. But it’s a gain in comfort (no need to ventilate manually and you have fresh air). Does it offer any additional benefits? The filters would also reduce dirt like pollen, dust, etc. inside the house, right? Maybe someone has current experiences with these systems. I have read a lot, but mostly reports from 3-4 years ago.
Am I forgetting any important systems or options?
You can and should ventilate Nordlys in a passive house.
To the original poster
If it is only about costs, the Energy Saving Ordinance (EnEV) will suffice.
If you want to become relatively independent from energy suppliers in the future, the Energy Saving Ordinance is not enough. If you are interested, search for the blog "autark with passive house" to see monthly breakdowns of energy consumption.
Otherwise, the Energy Saving Ordinance or KfW standards apply.
I would decide between gas or heat pump once the plot and construction company are confirmed.
To the original poster
If it is only about costs, the Energy Saving Ordinance (EnEV) will suffice.
If you want to become relatively independent from energy suppliers in the future, the Energy Saving Ordinance is not enough. If you are interested, search for the blog "autark with passive house" to see monthly breakdowns of energy consumption.
Otherwise, the Energy Saving Ordinance or KfW standards apply.
I would decide between gas or heat pump once the plot and construction company are confirmed.
Haydee, why would anyone want that? Self-sufficiency. Am I self-sufficient from Aldi, Lidl, Edeka? No. Am I self-sufficient from C and A, Karstadt, Ikea, and so on? No. Am I self-sufficient from Esso, Shell, Orlen, Avia, etc.? No.
So why should I be self-sufficient from E.ON or the municipal utilities?
So why should I be self-sufficient from E.ON or the municipal utilities?
Autonomy means independence, that’s what the word implies. Not least from price fluctuations. I hardly drive, so I don’t really care if the price per liter is €1.20 or €1.60, because overall it doesn’t cost much. That’s why, for example.
You can directly apply this to heating. Gas prices? They have easily doubled several times within two years. Oil even more so. But it doesn’t really matter if €20 becomes €40. If €120, which is what I currently pay for gas, became €240, that would be tough on the household budget.
And for some, sustainability is also an important argument. I also accept that many people here plan on different time horizons than you have with your retirement home.
You can directly apply this to heating. Gas prices? They have easily doubled several times within two years. Oil even more so. But it doesn’t really matter if €20 becomes €40. If €120, which is what I currently pay for gas, became €240, that would be tough on the household budget.
And for some, sustainability is also an important argument. I also accept that many people here plan on different time horizons than you have with your retirement home.
I already understand what self-sufficiency means; I’m not stupid. Still, I think it’s a foolish idea in a connected society where everything is interlinked. But... if you choose to pursue it, please don’t forget that all the products enabling so-called self-sufficiency also need to be manufactured and transported. And please also remember that the most sustainable heating method is actually the least self-sufficient one: district heating from combined heat and power. Karsten
D
Deliverer7 Jun 2018 21:21Lumpi_LE schrieb:
The additional basic fee for the 2000 kWh that the heating requires is 8 euros per year.
That comes to 23.4 cents. That’s incredibly cheap. Unfortunately, I can’t get that here...
So, I pay a gross rate of 30.9 cents plus about 100 GG.
And yes, I know that an air-to-water heat pump operates with a COP of 1 to 4 (depending on outside temperature).
But I also know that a gas boiler costs €2,800 (current project) and an air-to-water heat pump €10,000 (quote for the same project).
For the gas boiler, there is an additional external chimney cost of about €900.
Annual costs:
€120 per year for the chimney sweep. This is not critical for gas since no soot is produced.
€179 per year rental fee for the gas tank (all-inclusive).
The rest of the installation is identical. When I hear that I spend the same on energy costs (optimistically calculated for the air-to-water heat pump), I can offset the annual costs of the gas heating for the next (6000/300) 20 years. Neither the gas boiler nor the air-to-water heat pump lasts that long.
And yes, the underfloor heating has a pipe spacing of 10cm (4 inches) in all rooms and 5cm (2 inches) in the bathroom, which is quite suitable for a heat pump. Additional costs for the closer pipe spacing are about €1,500 (for 320 m² (3,445 sq ft) of heated floor area and 29 heating circuits).
And yes, I know that an air-to-water heat pump operates with a COP of 1 to 4 (depending on outside temperature).
But I also know that a gas boiler costs €2,800 (current project) and an air-to-water heat pump €10,000 (quote for the same project).
For the gas boiler, there is an additional external chimney cost of about €900.
Annual costs:
€120 per year for the chimney sweep. This is not critical for gas since no soot is produced.
€179 per year rental fee for the gas tank (all-inclusive).
The rest of the installation is identical. When I hear that I spend the same on energy costs (optimistically calculated for the air-to-water heat pump), I can offset the annual costs of the gas heating for the next (6000/300) 20 years. Neither the gas boiler nor the air-to-water heat pump lasts that long.
And yes, the underfloor heating has a pipe spacing of 10cm (4 inches) in all rooms and 5cm (2 inches) in the bathroom, which is quite suitable for a heat pump. Additional costs for the closer pipe spacing are about €1,500 (for 320 m² (3,445 sq ft) of heated floor area and 29 heating circuits).
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