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 652 Oct 2022 20:33One more brief note about the figures, which are again not entirely accurate:
The calculation is off because you shouldn’t use room temperature, but rather the surface temperature of the heating element. For underfloor heating, that’s about 32°C (90°F) versus 8°C (46°F), which equals 24 Kelvin (24°F difference), and for window heating, 43°C (109°F) versus -5°C (23°F), which equals 48 Kelvin (48°F difference), although at -5°C (23°F) outside temperature, you should probably assume around 50°C (122°F).
This shifts the result a bit more.
Regarding the system technology, I’d like to add my two cents.
To avoid having additional system technology for a window heating system, the only option is instantaneous water heaters.
If bathrooms are located on different floors, these should be electrically interlocked with each other.
Well, it’s no big deal, but something to consider.
Electric instantaneous water heaters are no longer worthwhile for large water volumes; I wouldn’t recommend equipping a household of four with long showers using this system.
No matter how cold it is outside, in Germany the heat pump achieves a minimum COP of 1.8 on 330 days per year.
Since a heat pump becomes less efficient the higher the heating water temperature, it makes sense to operate the heat pump continuously at a supply temperature of 35°C (95°F). Through the buffer tank with a primary/secondary loop, the domestic water is heated continuously in flow mode to exactly this 35°C (95°F) and, when needed, supplied to the instantaneous water heater, which then provides the marginal temperature increase to 45°C (113°F).
This keeps the power demand of the instantaneous water heater low, prevents issues with Legionella, and eliminates the need to maintain a storage water temperature of 60°C (140°F) as is typical for a hot water tank.
Why am I explaining this in such detail? Because for a heat pump, these components are already integrated through the heating technology.
Investing in a domestic hot water heat pump combined with a window heating system disproportionately increases upfront costs. And during winter, if it is supposed to produce hot water on its own, it becomes inefficient.
I would really appreciate a sober, mathematically accurate analysis including all side effects to be able to provide a genuine decision-making support for technically informed homebuyers.
There are certainly arguments that could make this technology attractive.
But please, only if they are understandable and without false promises.
I’m talking about: comfort, thermal curtains, lack of inertia, ease of maintenance, system technology, retrofit options, water sensitivity, delivery time, manufacturing process, etc.
Consumption simply isn’t one of them.
But there’s always something.
Regards, Christian
The calculation is off because you shouldn’t use room temperature, but rather the surface temperature of the heating element. For underfloor heating, that’s about 32°C (90°F) versus 8°C (46°F), which equals 24 Kelvin (24°F difference), and for window heating, 43°C (109°F) versus -5°C (23°F), which equals 48 Kelvin (48°F difference), although at -5°C (23°F) outside temperature, you should probably assume around 50°C (122°F).
This shifts the result a bit more.
Regarding the system technology, I’d like to add my two cents.
To avoid having additional system technology for a window heating system, the only option is instantaneous water heaters.
If bathrooms are located on different floors, these should be electrically interlocked with each other.
Well, it’s no big deal, but something to consider.
Electric instantaneous water heaters are no longer worthwhile for large water volumes; I wouldn’t recommend equipping a household of four with long showers using this system.
No matter how cold it is outside, in Germany the heat pump achieves a minimum COP of 1.8 on 330 days per year.
Since a heat pump becomes less efficient the higher the heating water temperature, it makes sense to operate the heat pump continuously at a supply temperature of 35°C (95°F). Through the buffer tank with a primary/secondary loop, the domestic water is heated continuously in flow mode to exactly this 35°C (95°F) and, when needed, supplied to the instantaneous water heater, which then provides the marginal temperature increase to 45°C (113°F).
This keeps the power demand of the instantaneous water heater low, prevents issues with Legionella, and eliminates the need to maintain a storage water temperature of 60°C (140°F) as is typical for a hot water tank.
Why am I explaining this in such detail? Because for a heat pump, these components are already integrated through the heating technology.
Investing in a domestic hot water heat pump combined with a window heating system disproportionately increases upfront costs. And during winter, if it is supposed to produce hot water on its own, it becomes inefficient.
I would really appreciate a sober, mathematically accurate analysis including all side effects to be able to provide a genuine decision-making support for technically informed homebuyers.
There are certainly arguments that could make this technology attractive.
But please, only if they are understandable and without false promises.
I’m talking about: comfort, thermal curtains, lack of inertia, ease of maintenance, system technology, retrofit options, water sensitivity, delivery time, manufacturing process, etc.
Consumption simply isn’t one of them.
But there’s always something.
Regards, Christian
S
stjoob_at3 Oct 2022 14:36A heat pump also offers the advantage of a cooling function (depending, of course, on the type of heat pump). Additionally, with a hydronic distribution system, it is relatively easy to change the generation system.
In general, I find it beneficial to view the entire house or building services as a system rather than considering each component separately. I am skeptical about using high-quality electricity directly for heating at a 1:1 ratio. Simply reducing the evaluation to economic efficiency alone is not the best approach nowadays.
Out of curiosity, what are the advantages compared to other direct electric heating systems? Infrared panels, embedded electric heating...
Even more interesting would be a comparison with an air conditioning system. It also costs just a few thousand and is at least a low-lift heat pump.
In general, I find it beneficial to view the entire house or building services as a system rather than considering each component separately. I am skeptical about using high-quality electricity directly for heating at a 1:1 ratio. Simply reducing the evaluation to economic efficiency alone is not the best approach nowadays.
Out of curiosity, what are the advantages compared to other direct electric heating systems? Infrared panels, embedded electric heating...
Even more interesting would be a comparison with an air conditioning system. It also costs just a few thousand and is at least a low-lift heat pump.
W
WilderSueden4 Oct 2022 00:39stjoob_at schrieb:
It is also relatively easy for me to change the generation system in a water-based distribution system.And for me, that was the decisive factor to always include underfloor heating in the offer, despite the often offered air heating systems. In this case, by the way, we don’t just have a heating element in the ventilation system that can probably be replaced in other ways, but a special system that apparently comes from only one manufacturer. Whether that manufacturer will still exist in 10, 20, or 30 years...?I still maintain that if you follow the argument of low investment, you might as well buy electric fan heaters and spend the money saved every week on a nice bottle of wine with your dream partner. That probably provides more comfort than a heating window 😉
C
Christian 654 Oct 2022 06:51In terms of the resulting responsibilities, you are actually far behind when it comes to ongoing costs. It’s better to go with a window heating system, which is significantly more cost-effective over time.
Christian 65 schrieb:
When it comes to the resulting responsibilities, you are definitely not at the forefront of ongoing costs.
Better to go with a window heating system, which is considerably cheaper over time. Colleague from management with a locked profile? 🙂
V
Vestaxx GmbH4 Oct 2022 08:34Yes, I know from multiple discussions that it can be really hard for some to understand, so here it is again, and gladly in a shorter version as well.
Yes – a heat pump has an annual performance factor, let’s say around 3 or even 4 (without losses), and our panel heating including losses to the outside is about 0.95. However, anyone who stops thinking or calculating here makes a crucial mistake.
What concerns users right now – especially at this time? -> What will I pay for the kWh of energy over the next 20 years?
Here, one must consider the energy flows in a house that actually need to be PAID for!
And again, yes – of course, a direct electric heating system consumes about 3-4 times as much as a heat pump – yes and again yes!
But the heat pump only needs to cover heating and hot water demand and requires electrical energy for this.
In addition, the house still needs regular electricity, but unfortunately, the heat pump doesn’t provide anything for that.
So now, let’s look at another system that is AVAILABLE for THE SAME PRICE as a heat pump.
The homeowner receives panel heating, a hot water heat pump, a large photovoltaic (solar) system, and possibly a battery – all for the same cost!!! This results in a net energy surplus over the year – a plus-energy house. In winter, electricity is purchased, while in summer surplus electricity is fed into the grid and credited. This credit can then be used to buy electricity again.
In the overall balance, they pay much less annually than with a water-based system (heat pump or pellet heating).
This is called a full cost calculation.
If you buy a car for €40,000 and boast that it only consumes one-quarter of the fuel of another car, you ignore that the other car only costs one-quarter as much and with the remaining €30,000 you could buy a "gas station."
And now again – but this will be the last time here – it is hard for some to understand why our system has not yet become established, but since the energy crisis, people calculate what they pay and consume. Everyone can tell me what they currently pay for oil, gas, or electricity. Before February 2022, those costs were very, very low. And every end customer to whom I explain the full cost calculation understands me.
Among energy consultants, I am slowly also meeting approving people. However, there has not yet been anyone who could calculate the opposite for me.
You are welcome to publish this here publicly. Go ahead, give it a try!
Yes – a heat pump has an annual performance factor, let’s say around 3 or even 4 (without losses), and our panel heating including losses to the outside is about 0.95. However, anyone who stops thinking or calculating here makes a crucial mistake.
What concerns users right now – especially at this time? -> What will I pay for the kWh of energy over the next 20 years?
Here, one must consider the energy flows in a house that actually need to be PAID for!
And again, yes – of course, a direct electric heating system consumes about 3-4 times as much as a heat pump – yes and again yes!
But the heat pump only needs to cover heating and hot water demand and requires electrical energy for this.
In addition, the house still needs regular electricity, but unfortunately, the heat pump doesn’t provide anything for that.
So now, let’s look at another system that is AVAILABLE for THE SAME PRICE as a heat pump.
The homeowner receives panel heating, a hot water heat pump, a large photovoltaic (solar) system, and possibly a battery – all for the same cost!!! This results in a net energy surplus over the year – a plus-energy house. In winter, electricity is purchased, while in summer surplus electricity is fed into the grid and credited. This credit can then be used to buy electricity again.
In the overall balance, they pay much less annually than with a water-based system (heat pump or pellet heating).
This is called a full cost calculation.
If you buy a car for €40,000 and boast that it only consumes one-quarter of the fuel of another car, you ignore that the other car only costs one-quarter as much and with the remaining €30,000 you could buy a "gas station."
And now again – but this will be the last time here – it is hard for some to understand why our system has not yet become established, but since the energy crisis, people calculate what they pay and consume. Everyone can tell me what they currently pay for oil, gas, or electricity. Before February 2022, those costs were very, very low. And every end customer to whom I explain the full cost calculation understands me.
Among energy consultants, I am slowly also meeting approving people. However, there has not yet been anyone who could calculate the opposite for me.
You are welcome to publish this here publicly. Go ahead, give it a try!
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