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?
V
Vestaxx GmbH10 Oct 2022 16:39RotorMotor schrieb:
Ah, it was obvious that only things that move break, I can't believe no one else has thought of that yet!
I should definitely explain that to my SSD, which failed a few days ago!
Yes, exactly, comparing heating systems only makes sense if you add photovoltaic to one and not the other. It would be so unfair if the heating systems had to be efficient on their own in the comparison.
Yes, that totally makes sense now that I read it for the hundredth time, because banks and loans have unfortunately not been invented yet, so photovoltaic plus heat pump is absolutely impossible.
Scroll up and read.
What was it again, not everything that stumbles is a comparison?!
Show our arguments and calculations to the energy consultants and professors. Even if it’s not their field, hopefully they’ll be able to understand it.
Also, just scroll up a bit or go back a few pages and read/recalculate.
Spoiler: in that example Vestaxx was over €30,000 (about $33,000) more expensive. An SSD – a highly complex electronic component – compared to a simple coating is....
I give up on you! If you want to compare a Porsche with a Golf, go ahead – but that’s hardly fair.
And yes – of course loans exist (they are actually very attractive right now) but they still have to be repaid.
Loan amount plus interest -> every bank is happy, and eventually the building family will have to leave if they can no longer afford their loans.
So show your arguments to the energy consultants and professors yourself. What would I gain from doing that?
Sorry – I can’t make any further progress with you – let’s just leave it at that.
V
Vestaxx GmbH10 Oct 2022 16:54i_b_n_a_n schrieb:
I did some googling on this topic. The "inventor" of the system apparently comes from the thin-film photovoltaic module development sector and has experience with sputtering and heating float glass (yes, exactly, not tempered glass) with metal without causing the expected stress cracks.
But despite the embedded (if I sputter a surface, is that then embedded?) metals, glass can still break or the only few micrometer thick layer can develop interruptions due to expansion/contraction (this was also the argument for a possible defect in underfloor heating pipes). Reliable data has so far been withheld from me. Whether due to lack or intent, I don’t know? But it may still come 😉 Well – first of all, I’m not the inventor, but never mind. Also, the experience is not mine but that of the glass industry, which has been producing this coating for decades.
And yes, it is a sputtered layer, like all thin-film glasses (by the way WITHOUT tempered glass). Now comes our experience, because we have about 2,000,000 m² (2,150,000 sq ft) of thin-film modules without any stress cracks. Even in cases where a chimney has cast a severe shadow on the modules.
Well Kati, and if you are reading this, you are looking through exactly such a layer, and if it had stress cracks, it would be dark. Then consider all the thin-film modules out there that have been generating energy for over 50 years...
What kind of reliable data do you want from me – open your eyes.
If you have no real knowledge and have only googled dangerous half-truths, it’s better to keep quiet.
I am slowly reaching a point where I wonder whether I should continue to struggle with people who have dangerous half-knowledge. For those who are truly interested, it must be a nightmare to read such posts from anonymous people. Who knows what interests are behind it. My interests are open and well known, since I am not anonymous.
If anyone here wants to hear real experience, we are happy to connect them with our customers all over Germany. THOSE answers are also not anonymous and come firsthand.
Finally, things are moving forward here. Fortunately for you, I’m not allowed to leave the house for at least the next 5 days, so I’m on standby for more calculations and discussions.
Oh, what happened there? Has our house shrunk? We were starting from 4,500 kWh, right?
Also include the domestic hot water heat pump in the calculation. The €200 seems about right, but most homeowners probably won’t continue maintenance after the warranty period. The heat pump reports errors itself, and otherwise maintenance mostly consists of just checking the heat pump and giving an approving nod. Possibly also reading the seasonal performance factor.
Sometimes I get the feeling you don’t have a photovoltaic system yourself that is supposed to make you independent in winter. With my 9.5 kWp system, I get less than 100 kWh per month from November to January. There’s basically no solar power in winter, so you have to buy electricity to operate. My “plus energy house” and the 6–8 cents (per kWh) I get in summer don’t help with that! That’s precisely why all the discussions about dark doldrums (periods of low renewable energy production) happen in politics.
Go ahead and say that you don’t understand greenhouse gas emissions and their accounting according to the GHG Protocol.
Sorry, but that is the worldwide (industry) standard for assessing sustainability. That doesn’t change my assessment of window heating as a significant environmental offender. It’s really time for your master’s thesis, because doing your own calculations is indeed very enlightening and, in your case, unfortunately disastrous.
And it doesn’t help that you can hold your coating elements in your hand. Heating usage unfortunately pulls the CO2 footprint of our model house down by at least 16–20 tons of CO2 over time. Meanwhile, heat pump owners can comfortably fly a few times to New York for a hot dog.
A basic question: how were the 92/95% efficiencies determined? Is that the efficiency of the heating glass? What I didn’t understand is how the heating power from the 230 V mains voltage is regulated. That requires a transformer or something similar, right?
Vestaxx GmbH schrieb:
The heat pump saves about 2,000 kWh annually in a new build house with around 3,000 kWh heating demand.
Oh, what happened there? Has our house shrunk? We were starting from 4,500 kWh, right?
Vestaxx GmbH schrieb:
Your table is great – thanks for that. It clearly shows that the seasonal performance factor matters, and with a seasonal performance factor of 5, after 15 years we’re roughly breaking even. Unfortunately, maintenance costs are missing – zero for us, but for the heat pump? Maybe around €200 annually? I’m not sure right now.
Also include the domestic hot water heat pump in the calculation. The €200 seems about right, but most homeowners probably won’t continue maintenance after the warranty period. The heat pump reports errors itself, and otherwise maintenance mostly consists of just checking the heat pump and giving an approving nod. Possibly also reading the seasonal performance factor.
Vestaxx GmbH schrieb:
And now again—sorry to be repetitive—the consideration that the customer is smart and chooses security. By investing the saved costs into a photovoltaic system, that’s exactly what they do. Photovoltaics are good—that’s something we all agree on here. But then we have to forget about your table and create a new one that takes this into account. The customer becomes largely independent of the likely rising electricity prices with a large photovoltaic system. That’s what motivates people.
Sometimes I get the feeling you don’t have a photovoltaic system yourself that is supposed to make you independent in winter. With my 9.5 kWp system, I get less than 100 kWh per month from November to January. There’s basically no solar power in winter, so you have to buy electricity to operate. My “plus energy house” and the 6–8 cents (per kWh) I get in summer don’t help with that! That’s precisely why all the discussions about dark doldrums (periods of low renewable energy production) happen in politics.
Vestaxx GmbH schrieb:
Put differently: I can easily hold the materials for the entire house’s heating system in one hand. For water-based systems, you’d need a strong forklift. Does that make sense?
“… Of course, you also have to consider Scope 3 downstream emissions, not just cradle to gate…” Who among the average people, who want to learn about window heating here, understands a sentence like that? Write understandable English or just leave it out.
Go ahead and say that you don’t understand greenhouse gas emissions and their accounting according to the GHG Protocol.
Sorry, but that is the worldwide (industry) standard for assessing sustainability. That doesn’t change my assessment of window heating as a significant environmental offender. It’s really time for your master’s thesis, because doing your own calculations is indeed very enlightening and, in your case, unfortunately disastrous.
And it doesn’t help that you can hold your coating elements in your hand. Heating usage unfortunately pulls the CO2 footprint of our model house down by at least 16–20 tons of CO2 over time. Meanwhile, heat pump owners can comfortably fly a few times to New York for a hot dog.
A basic question: how were the 92/95% efficiencies determined? Is that the efficiency of the heating glass? What I didn’t understand is how the heating power from the 230 V mains voltage is regulated. That requires a transformer or something similar, right?
A
alterego13410 Oct 2022 17:02I am still waiting for a calculation that does not come from a user. I appreciate the effort involved – but in my opinion, the obligation to provide this clearly lies with the other side...
No offense intended, but shouldn’t this be presented in a table? Maybe I just missed it.
No offense intended, but shouldn’t this be presented in a table? Maybe I just missed it.
alterego134 schrieb:
I am still waiting for a calculation that doesn’t come from a user. I respect the effort involved, but in my opinion, the responsibility clearly lies with the other side here...
No offense intended, but shouldn’t this be presentable in a table? Maybe I just missed it. That won’t happen. The startup founder doesn’t want to confuse customers with too many numbers. It would only confuse them. The customer wouldn’t be able to make use of it anyway.
W
WilderSueden10 Oct 2022 17:08Vestaxx GmbH schrieb:
When it comes to photovoltaics, I know exactly what the output will be over the system’s lifetime. -> Certainty No, you don’t. You can only have a rough idea if you are feeding all electricity into the grid. In that case, the feed-in tariff is fixed for 20 years, and after that, only the energy fed in matters. How long the system ultimately lasts and the availability of spare parts like inverters remain unknown.
Your calculation also always includes a significant amount of self-consumption, which means you are highly dependent on electricity prices. So, the actual outcome is far from certain.
OWLer schrieb:
Oh, what happened here? Has our house shrunk? We started from 4500 kWh, didn’t we? Actually, we don’t have much money and can only build according to the Building Energy Act. Because the extra cost of, say, 20,000 € for KfW55 standard now has to be paid without subsidies and would easily cover the photovoltaics for a heat pump. Thanks to photovoltaics, though, the extra energy consumption is no longer an issue 😉
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