Hello everyone,
My husband and I attended a home exhibition today featuring a local timber house builder (Schleswig-Holstein) and there we learned about the Vestaxx window heating system.
Is there anyone here who has experience with the Vestaxx window heating?
At first, it sounds unusual to have the heating integrated into the windows. For the triple-glazed windows, a nanotechnology-based, invisible layer is applied to the inner surface of the innermost pane, which warms the glass up to 40 degrees Celsius (104°F) via infrared and heats the room. The warmth actually felt very comfortable, and the windows were completely cold on the outside (today’s temperature was below 10 degrees Celsius (50°F)). Allegedly, the Vestaxx window heating transfers 92% of its heat to the room, and the Technical University of Berlin has tested this Vestaxx window heating system and rated it positively. It appears to have been on the market only recently.
Overall, I find this quite interesting. It is significantly cheaper than other heating systems, allows individual control of each room, and unlike underfloor heating, it is very responsive.
Of course, this only makes sense in a low-energy house (the timber builder mainly constructs 40+ standard homes), as the system runs on electricity. In that case, the Vestaxx window heating is said to consume very little power.
This is my impression from the expo; of course, they want to sell the system.
What are your experiences with Vestaxx? Have you heard of this system before? Could it be an alternative to conventional heating? Does it have a future?
My husband and I attended a home exhibition today featuring a local timber house builder (Schleswig-Holstein) and there we learned about the Vestaxx window heating system.
Is there anyone here who has experience with the Vestaxx window heating?
At first, it sounds unusual to have the heating integrated into the windows. For the triple-glazed windows, a nanotechnology-based, invisible layer is applied to the inner surface of the innermost pane, which warms the glass up to 40 degrees Celsius (104°F) via infrared and heats the room. The warmth actually felt very comfortable, and the windows were completely cold on the outside (today’s temperature was below 10 degrees Celsius (50°F)). Allegedly, the Vestaxx window heating transfers 92% of its heat to the room, and the Technical University of Berlin has tested this Vestaxx window heating system and rated it positively. It appears to have been on the market only recently.
Overall, I find this quite interesting. It is significantly cheaper than other heating systems, allows individual control of each room, and unlike underfloor heating, it is very responsive.
Of course, this only makes sense in a low-energy house (the timber builder mainly constructs 40+ standard homes), as the system runs on electricity. In that case, the Vestaxx window heating is said to consume very little power.
This is my impression from the expo; of course, they want to sell the system.
What are your experiences with Vestaxx? Have you heard of this system before? Could it be an alternative to conventional heating? Does it have a future?
C
Christian 6511 Oct 2022 01:51What’s annoying is that you all seem to think we’re idiots who wouldn’t act the way you consider correct. Completely unaware of the real reasons many homebuilders have, do you even skim through the forum sometimes? Check out the financing thread. It often boils down to: Can I even afford a house? Just like in real life. Why are so few electric cars sold? You definitely save on running costs. Absolutely. But they’re too expensive to buy. Yes, there are other reasons, but for most people, the initial purchase price is too high. Period. End of story. Long-term economic considerations don’t matter. Payback calculations are secondary.
Someone posted a table earlier showing that a 12 kWp (kilowatt peak) system generates around 700 kWh (kilowatt hours) on average in winter. That means over €800 in value in those four months, but to you: It’s worthless! Summer yield? Doesn’t matter. No one has ever disputed that the best way to do things is exactly the way you suggest: heat pump, underfloor heating, and rooftop photovoltaic system plus buffer battery. Ideal, great, I’d do it the same way. Undisputed. Any deviation from this ideal setup can only result in higher consumption. Correct, yes, that’s correct.
Electric heating without photovoltaics? Pointless. Electric heating without a sufficiently large photovoltaic system? Pointless. Electric heating without a buffer? Really pointless as well. Unfavorable roof area? Pointless. Poor orientation? Pointless. Enough buffer storage? Still pointless. Only a small niche remains where it actually makes sense. But that niche does exist. And those people aren’t necessarily idiots.
I know the reality out there. You don’t. Infrared heating users, all idiots. Electric underfloor heating? Complete idiots. Fan heaters, of course. No heat pump? Punishable. Wood chip heating? Probably just as crazy as gas with solar was 10 years ago. But systems like those have been installed thousands of times. To you, they’re all nuts. That’s how you come across.
And I stick to this: if I can have a large photovoltaic system installed for the same initial investment, I would do it. Properly insulate the house and generate enough electricity, even without a heat pump. But that’s what I would do. Who cares?!
Someone posted a table earlier showing that a 12 kWp (kilowatt peak) system generates around 700 kWh (kilowatt hours) on average in winter. That means over €800 in value in those four months, but to you: It’s worthless! Summer yield? Doesn’t matter. No one has ever disputed that the best way to do things is exactly the way you suggest: heat pump, underfloor heating, and rooftop photovoltaic system plus buffer battery. Ideal, great, I’d do it the same way. Undisputed. Any deviation from this ideal setup can only result in higher consumption. Correct, yes, that’s correct.
Electric heating without photovoltaics? Pointless. Electric heating without a sufficiently large photovoltaic system? Pointless. Electric heating without a buffer? Really pointless as well. Unfavorable roof area? Pointless. Poor orientation? Pointless. Enough buffer storage? Still pointless. Only a small niche remains where it actually makes sense. But that niche does exist. And those people aren’t necessarily idiots.
I know the reality out there. You don’t. Infrared heating users, all idiots. Electric underfloor heating? Complete idiots. Fan heaters, of course. No heat pump? Punishable. Wood chip heating? Probably just as crazy as gas with solar was 10 years ago. But systems like those have been installed thousands of times. To you, they’re all nuts. That’s how you come across.
And I stick to this: if I can have a large photovoltaic system installed for the same initial investment, I would do it. Properly insulate the house and generate enough electricity, even without a heat pump. But that’s what I would do. Who cares?!
C
Christian 6511 Oct 2022 02:01When the feed-in tariff was still at 20 cents, a guy installed an electric underfloor heating system himself and then put a 15 kWp system on the roof and garage for the rest. The whole setup cost him less than 30,000 euros.
The house was well insulated, of course. But he didn’t really care how much electricity he used. He didn’t have to buy any more.
He was probably a bit crazy, too.
The house was well insulated, of course. But he didn’t really care how much electricity he used. He didn’t have to buy any more.
He was probably a bit crazy, too.
C
Christian 6511 Oct 2022 02:15Just read: feed-in tariffs increase by 31% starting from 07/22. It’s only 1.7 cents per kWh, but still.
If the feed-in tariff continues to rise in the coming years and batteries become cheaper, any calculation made now will be outdated anyway.
If the feed-in tariff continues to rise in the coming years and batteries become cheaper, any calculation made now will be outdated anyway.
C
Christian 6511 Oct 2022 02:253. Are there other features to consider for 24 kW tankless water heaters according to online tests?
The best 24 kW (32,300 BTU) tankless water heaters also have a low power consumption. The annual electricity consumption is measured in kilowatt-hours (kWh) and ranges from 465 to 479 kWh for these units.
At that point, heat pump water heaters (HPWH) no longer make sense. They’re not suitable for long showers. But you can still save money.
Costs in Germany are about 300 €
Costs for a HPWH: around 5,000 €, which again seems unreasonable, right?
The best 24 kW (32,300 BTU) tankless water heaters also have a low power consumption. The annual electricity consumption is measured in kilowatt-hours (kWh) and ranges from 465 to 479 kWh for these units.
At that point, heat pump water heaters (HPWH) no longer make sense. They’re not suitable for long showers. But you can still save money.
Costs in Germany are about 300 €
Costs for a HPWH: around 5,000 €, which again seems unreasonable, right?
R
RotorMotor11 Oct 2022 08:30Christian 65 schrieb:
What’s annoying is that you all think anyone who wouldn’t behave the way you consider right must be an idiot. Dear Christian, what exactly don’t you understand about the calculations?
Your entire list also misses the point of this thread by a wide margin.
We have always argued based on numbers and calculations.
Not with feelings, nor with a fundamental rejection of certain technologies.
We also didn’t use any shell game tricks like moving money from one pocket to another.
We have never said that deviations aren’t allowed or possible.
We only strongly disagreed when it was claimed that a different approach would be fundamentally more sensible.
Christian 65 schrieb:
Do you even skim through the forum sometimes? Of course, unfortunately I realize that I spend far too much time here. 😉
Christian 65 schrieb:
Just take a look at the financing thread.
It’s often about whether you can even afford a house at all. But this is exactly why a full cost calculation is so important.
If someone’s finances are already tight, they should all the more avoid installing the wrong technology in their home.
It’s, as explained multiple times, not only about the investment costs as V. presented it.
If I pay significantly more to the energy supplier instead of the bank, that doesn’t help anyone.
Neither the homeowner nor the environment!
The deciding factor is the total monthly burden!
Christian 65 schrieb:
When feed-in tariffs were still at 20 cents, someone installed an electric underfloor heating system themselves and added a 15 kWp solar array on the roof and garage. The whole thing cost less than 30,000 euros (around 25,500 USD).
The house was well insulated, of course. But actually, it didn’t matter how much electricity was consumed. Nothing had to be bought anymore.
Must have been crazy, too. Christian 65 schrieb:
Just read: Feed-in tariffs increased by 31% as of 07/22. That’s only 1.7 cents/kWh, but still something.
If the feed-in tariffs continue to rise in the coming years and batteries become cheaper, current calculations will soon be outdated anyway. There is a small misunderstanding here.
A high feed-in tariff is actually a disadvantage for the economic assessment of inefficient heating systems.
Because the more feed-in tariff you get, the more money you lose by consuming the electricity yourself.
Here, the heat pump actually allows me to consume less and thus feed more of the well-paid electricity back into the grid.
Christian 65 schrieb:
That means a domestic hot water heat pump is no longer worthwhile. Not for long showers. But you can save there, of course.
Costs in Germany about 300 euros (around 255 USD)
Cost for a domestic hot water heat pump about 5,000 euros (around 4,250 USD), also nonsense, right? You’re welcome to start a dedicated thread on this topic where we can discuss it in detail.
V
Vestaxx GmbH11 Oct 2022 09:18OWLer schrieb:
This is starting to get borderline. Wow.
So the much bigger leverage for homeowners with limited budgets is to forgo the Passive House standard. Building to KfW 55 or the Building Energy Act with an air-to-water heat pump, or at most an air-to-air heat pump, definitely offers a better price/performance ratio. Plus: Both systems can provide cooling in summer.
In your case, you need large window areas, which then require top shading during the summer.
I have provided numbers. What CO2 equivalents did you use for your calculation? Can we see them sometime? Professionally, I work with Life Cycle Assessment—oh, sorry, probably Lebenszykluserfassung or -analyse in German—in the context of sustainability projects.
I have presented my calculation method clearly—including manual/forklift handling, considering several hundred kilograms of material for the heat pump and underfloor heating pipes. And with that, you don’t get far beyond 1000 kg (2205 lbs) of CO2 emissions. Unfortunately, that is what your system emits additionally EVERY YEAR. So after 2-3 years at the latest, the carbon footprint of the house installation has paid off compared to Vestaxx.
What mistake did I make in my calculation other than rounding errors or omitted valves amounting to a total of 20 kg (44 lbs) of material?
The "argument" unfortunately becomes quite polemical and detached from facts. The anonymous users here have provided numbers, interest rates, factors, assumptions, and laid them out transparently. The response consists of statements that could be perceived as insults.Okay – now we have reached an accusation of insult, and a factual discussion is no longer possible.
I am now withdrawing from the dialogue with you. I am sure this will be interpreted differently, but I can live with that ;o).
I will now focus again on customers who contact us for professional advice and who later thank us for it.
Enjoy your heat pump!
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