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 GmbH11 Oct 2022 09:28RotorMotor schrieb:
This is quite something. The gentleman doesn’t even realize that a ground-water heat pump and an air-to-water heat pump basically use the same technology.
An air-to-water heat pump is just as much a refrigerator as a ground-water heat pump is.
The maintenance effort is therefore identical.
The only possible argument might be that replacement parts for a full-scale air-to-water heat pump could be somewhat more expensive because they are sometimes larger and more powerful.
We have all checked this multiple times and supported it with figures and sources.
The output in winter is low. Therefore, it is not sufficient to operate a heating system.
Instead of rambling, making claims, and insulting, a rebuttal would be appropriate. First, RotorMotor writes that the solar system produces nothing in winter, then claims the output is rather low.
And I have already confirmed several times that the output is not enough to operate electric direct heating.
Here old – sometimes incorrect – arguments keep being repeated. For readers who are looking for guidance, these posts must be frustrating to read.
I cannot convince RotorMotor, and I will not try further.
That would mean admitting that they chose the uneconomical system.
We will be successful, and this is reflected in conversations with experts and home builders. At the moment, a lot is happening, and you will hear more from us.
Enjoy your heat pump! ;o)
V
Vestaxx GmbH11 Oct 2022 09:45Fuchur schrieb:
@Vestaxx GmbH
Why compare systems that are not comparable? If you clearly have an issue with electric heating cables embedded in screed (either because of the cost or due to the water), then the correct comparison for your window heater is a classic air-to-air heat pump. It has been tested for ages, especially in prefabricated houses when it comes to saving heating costs.
Please run a comparison based on that—I would really be interested! Since the costs of an air-to-air heat pump are lower, you could calculate both heating options with or without photovoltaic, and then you would get a comparable result. What systems are comparable then? Am I not allowed to compare a window heater (electric direct heating) including a domestic hot water heat pump and photovoltaic to a heat pump at the same price? But if there's an air-to-air heat pump on the other side, then the comparison is allowed again. What sense does that make? And it's not ME who has problems with heating cables in screed—I don’t have any—but maybe those who will eventually encounter real problems with them.
I have never argued against or compared air-to-air heat pumps here; I explicitly referred to water-based systems. The air-to-air heat pump uses air as a heat transfer medium, is less expensive than an air-to-water heat pump, and therefore has advantages over water-based systems.
One could—and please understand this only hypothetically—also buy two hot air blowers with 2000 W power each for a total of 40 € at a hardware store and use those for heating. Nobody would do that, but it would be possible in a well-insulated house. The investment compared to a heat pump would then be a factor of 1000 lower, leaving plenty of money for a photovoltaic system that produces completely CO2-free electricity.
This is just an example to show that you don’t have to spend 40,000 € on complex, highly engineered technology just to extract about 2,000 to 3,000 kWh/year of heating energy from the air: a truckload of equipment for a shot glass of energy. But if that’s how people want it… we live in a free country… then by all means.
R
RotorMotor11 Oct 2022 09:48I will now add the required maintenance costs to my calculation, as well as a version without photovoltaic panels, to have all options clearly compared:
150m² (1600 sq ft) with 40kWh/m²a -> 6000kWh/year heating energy demand
10kWp photovoltaic + 5kWh storage -> approx. 15kWh/day in Nov, Dec, Jan, Feb. With 10kWh per day for household electricity including hot water, 5kWh/day remains available for heating
The costs of the photovoltaic system are not included in this example, as the system pays for itself through feed-in tariffs and savings on household electricity.
Hot water costs are omitted since both systems provide it with a seasonal performance factor (SPF) of 4, resulting in no difference; electricity for hot water is included in the household electricity calculation.
Electricity purchase price: 35¢/kWh
Feed-in tariff price: 8.2¢/kWh
Interest rate 3.5% (current rate for 10-year fixed)
Electricity price increase 6% (average of the last 20 years)
Vestaxx + Photovoltaic:
Additional cost compared to standard windows: €10,000 (€)
Purchase and installation of BWWP (brine-water heat pump): €5,000 (€)
Interest on purchase over 18 years: €5,239 (€)
Maintenance BWWP: €200/year (€)
4 months * 30 days * 5 kWh/day = 600 kWh from photovoltaic electricity
Remaining 5400 kWh to be purchased
Total cost (averaged, due to rising electricity prices) 5400 * (35 + 35 * 1.06^18) / 2 + 600 * 8.2 = €3,691/year (€)
After 18 years, this amounts to: €90,286 (€)
Heat Pump + Photovoltaic:
Hydraulics: €80/m² * 150m² = €12,000 (€)
Purchase and installation of air-to-water monoblock heat pump: €20,000 (€)
Interest on purchase over 18 years: €11,176 (€)
Maintenance air-to-water heat pump: €250/year (€)
Electricity demand: 6000 / 4 = 1500 kWh
Remaining to be purchased: 900 kWh
Total cost (averaged, due to rising electricity prices) 900 * (35 + 35 * 1.06^18) / 2 + 600 * 8.2 = €656/year (€)
After 18 years, this amounts to: €59,488 (€)
Vestaxx without Photovoltaic:
Additional cost compared to standard windows: €10,000 (€)
Purchase and installation of BWWP: €5,000 (€)
Interest on purchase over 18 years: €5,239 (€)
Maintenance BWWP: €200/year (€)
Total cost (averaged, due to rising electricity prices) 6000 * (35 + 35 * 1.06^18) / 2 + 600 * 8.2 = €3,691/year (€)
After 18 years, this amounts to: €94,558 (€)
Heat Pump without Photovoltaic:
Hydraulics: €80/m² * 150m² = €12,000 (€)
Purchase and installation of air-to-water monoblock heat pump: €20,000 (€)
Interest on purchase over 18 years: €11,176 (€)
Maintenance air-to-water heat pump: €250/year (€)
Electricity demand: 6000 / 4 = 1500 kWh
Total cost (averaged, due to rising electricity prices) 1500 * (35 + 35 * 1.06^18) / 2 = €1,011/year (€)
After 18 years, this amounts to: €65,878 (€)
This example shows additional costs for Vestaxx of €30,798 compared to the heat pump.
So, for 18 years, you pay €142 more per month without ending up with underfloor heating at the end of the period!
All that money is gone to the energy supplier and largely converted into CO2.
150m² (1600 sq ft) with 40kWh/m²a -> 6000kWh/year heating energy demand
10kWp photovoltaic + 5kWh storage -> approx. 15kWh/day in Nov, Dec, Jan, Feb. With 10kWh per day for household electricity including hot water, 5kWh/day remains available for heating
The costs of the photovoltaic system are not included in this example, as the system pays for itself through feed-in tariffs and savings on household electricity.
Hot water costs are omitted since both systems provide it with a seasonal performance factor (SPF) of 4, resulting in no difference; electricity for hot water is included in the household electricity calculation.
Electricity purchase price: 35¢/kWh
Feed-in tariff price: 8.2¢/kWh
Interest rate 3.5% (current rate for 10-year fixed)
Electricity price increase 6% (average of the last 20 years)
Vestaxx + Photovoltaic:
Additional cost compared to standard windows: €10,000 (€)
Purchase and installation of BWWP (brine-water heat pump): €5,000 (€)
Interest on purchase over 18 years: €5,239 (€)
Maintenance BWWP: €200/year (€)
4 months * 30 days * 5 kWh/day = 600 kWh from photovoltaic electricity
Remaining 5400 kWh to be purchased
Total cost (averaged, due to rising electricity prices) 5400 * (35 + 35 * 1.06^18) / 2 + 600 * 8.2 = €3,691/year (€)
After 18 years, this amounts to: €90,286 (€)
Heat Pump + Photovoltaic:
Hydraulics: €80/m² * 150m² = €12,000 (€)
Purchase and installation of air-to-water monoblock heat pump: €20,000 (€)
Interest on purchase over 18 years: €11,176 (€)
Maintenance air-to-water heat pump: €250/year (€)
Electricity demand: 6000 / 4 = 1500 kWh
Remaining to be purchased: 900 kWh
Total cost (averaged, due to rising electricity prices) 900 * (35 + 35 * 1.06^18) / 2 + 600 * 8.2 = €656/year (€)
After 18 years, this amounts to: €59,488 (€)
Vestaxx without Photovoltaic:
Additional cost compared to standard windows: €10,000 (€)
Purchase and installation of BWWP: €5,000 (€)
Interest on purchase over 18 years: €5,239 (€)
Maintenance BWWP: €200/year (€)
Total cost (averaged, due to rising electricity prices) 6000 * (35 + 35 * 1.06^18) / 2 + 600 * 8.2 = €3,691/year (€)
After 18 years, this amounts to: €94,558 (€)
Heat Pump without Photovoltaic:
Hydraulics: €80/m² * 150m² = €12,000 (€)
Purchase and installation of air-to-water monoblock heat pump: €20,000 (€)
Interest on purchase over 18 years: €11,176 (€)
Maintenance air-to-water heat pump: €250/year (€)
Electricity demand: 6000 / 4 = 1500 kWh
Total cost (averaged, due to rising electricity prices) 1500 * (35 + 35 * 1.06^18) / 2 = €1,011/year (€)
After 18 years, this amounts to: €65,878 (€)
This example shows additional costs for Vestaxx of €30,798 compared to the heat pump.
So, for 18 years, you pay €142 more per month without ending up with underfloor heating at the end of the period!
All that money is gone to the energy supplier and largely converted into CO2.
W
WilderSueden11 Oct 2022 09:49Christian 65 schrieb:
There’s only a small niche left where it even makes sense. But that niche does exist. The niche does exist, but it doesn’t fit into the marketing. The niche for window heating—like for infrared, air heating, etc.—is a house close to the passive house standard that hardly needs any heating at all. However, for a house in the highest price category, I can no longer argue that the builders cannot afford photovoltaics. The segment of builders with limited budgets is more efficiently served by the Building Energy Act combined with underfloor heating and a Daikin heat pump.
Vestaxx GmbH schrieb:
I can’t convince RotorMotor, and I won’t try any further.That’s an understatement; otherwise, you wouldn’t have been able to convince anyone. 🙂
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