ᐅ Condensing Gas Boiler, Air-to-Water Heat Pump, Fuel Cells – Request for Advice
Created on: 9 Apr 2018 20:46
G
gmt94
Hello everyone,
We are currently in the planning phase for our new home. We are building an urban villa of about 157 m² (1,690 sq ft) according to energy-saving regulations.
My favorite option until this morning was a heat pump with deep geothermal drilling plus a conventional fireplace. However, the drilling company declined the order today due to too high a risk. So I need a new heating alternative.
We are three people: man, woman, and toddler, possibly a fourth child. The child usually takes a bath daily, so there will likely be a relatively high hot water consumption. A rain shower would be desirable.
1. Air-to-water heat pump – somehow I just can’t get comfortable with this option. On one hand, it bothers me that the system is very sensitive to outside temperature, and on the other hand, I’m concerned about the appearance on the house and the noise.
2. Gas condensing boiler with solar hot water support and central ventilation with heat recovery. Since this requires a relatively large water storage tank, I thought of installing a water-bearing (water-carrying) fireplace. This would reduce the risk of overheating the living room, among other things, and the remaining energy could be used for water heating. Woodworking is my hobby. I have a chainsaw license, saw, wood splitter, trailer, and relatively cheap wood is available.
3. My builder also suggested an alternative to the gas boiler: a fuel cell. I haven’t looked into this at all. Does anyone have experience with it?
I hope you can help me. Oh, and ground collectors are not an option due to insufficient space on the plot.
We are currently in the planning phase for our new home. We are building an urban villa of about 157 m² (1,690 sq ft) according to energy-saving regulations.
My favorite option until this morning was a heat pump with deep geothermal drilling plus a conventional fireplace. However, the drilling company declined the order today due to too high a risk. So I need a new heating alternative.
We are three people: man, woman, and toddler, possibly a fourth child. The child usually takes a bath daily, so there will likely be a relatively high hot water consumption. A rain shower would be desirable.
1. Air-to-water heat pump – somehow I just can’t get comfortable with this option. On one hand, it bothers me that the system is very sensitive to outside temperature, and on the other hand, I’m concerned about the appearance on the house and the noise.
2. Gas condensing boiler with solar hot water support and central ventilation with heat recovery. Since this requires a relatively large water storage tank, I thought of installing a water-bearing (water-carrying) fireplace. This would reduce the risk of overheating the living room, among other things, and the remaining energy could be used for water heating. Woodworking is my hobby. I have a chainsaw license, saw, wood splitter, trailer, and relatively cheap wood is available.
3. My builder also suggested an alternative to the gas boiler: a fuel cell. I haven’t looked into this at all. Does anyone have experience with it?
I hope you can help me. Oh, and ground collectors are not an option due to insufficient space on the plot.
C
Caspar202010 Apr 2018 11:43markus2703 schrieb:
Since I don’t like insulation boards on the house, the decision was quickly clear. And I have to spend the 5,000€ anywayIn that case, I would have opted for a controlled ventilation system with heat recovery. At least that provides a noticeable improvement in comfort.
markus270310 Apr 2018 11:46Caspar2020 schrieb:
Then I would have opted for a controlled residential ventilation system with heat recovery. At least that provides a noticeable increase in comfort.We do have one, but a decentralized system. I agree with you, in hindsight I would have invested more and chosen a central controlled residential ventilation system. Definitely for the second house :-)
Solar thermal systems for domestic hot water are a contentious topic here. Whether they are worthwhile, I don’t know. The fact is, even in March they provided a good amount of heat, and now in April, I have turned off the hot water function on our heating system, a Junkers. It works. However, hot water is supplied solely by solar. Whether it is cost-effective, I don’t know. Since we built without mechanical ventilation with heat recovery, we had no other option. Karsten
Nordlys schrieb:
Solar thermal systems for domestic hot water are a controversial topic here. Whether they are cost-effective, I don’t know. The fact is, even in March it provided a good amount of heat, and now in April I have completely turned off the hot water function on our heating system, a Junkers. It works. Still, hot water only through solar. Whether it’s worth it, I don’t know. We had no choice since we built without a mechanical ventilation system with heat recovery. KarstenAnd there is nothing wrong with that. However, there are people here who initially claim without any basis that questioning the economic viability of such a solar system (for hot water) is complete nonsense. But when you give them some numbers, their argument weakens.
From a purely economic point of view, the conclusion remains that such a system won’t pay off. Whether the bathtub is filled twice a day or only every few weeks. Due to the high upfront investment costs combined with the relatively low efficiency in winter, the rather small potential savings (hot water heating demand), and the gas price, in my opinion, no other conclusion is possible.
I am pretty indifferent about it now: we pay €50 per month for gas. That’s €600 per year. I’m not sure if that will be enough. If not, the budget will just be increased to €60-65 per month. What significant savings justify a four-figure investment?
The initial goal of KfW 55/40 shifted to complying with the Energy Saving Ordinance with gas heating (without solar) and a centralized mechanical ventilation system with heat recovery — and that’s that.
markus2703 schrieb:
So the decision often isn’t just about whether something makes sense or not, but rather which option offers more benefits despite being imperfect.That basically sums it up.
Especially with an all-in-one building shell package, I would take the standard thermal insulation (ST) immediately if it’s included in the package, since it usually doesn’t come with an additional cost—catalog homes are generally priced with that in mind. If you remove the ST and opt instead for more insulation, mechanical ventilation with heat recovery, or other compensatory measures, you might receive a credit of around 1000–1500 euros. However, you will then need to pay for those alternative measures.
Thank you for the many contributions.
I’ve clearly started a discussion here.
If I decide to install a solar thermal system, would a domestic hot water tank of about 300 liters (80 gallons) be practical, or would it be better to choose a combi storage tank that has significantly more capacity?
I’ve clearly started a discussion here.
If I decide to install a solar thermal system, would a domestic hot water tank of about 300 liters (80 gallons) be practical, or would it be better to choose a combi storage tank that has significantly more capacity?
Similar topics