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?
WilderSueden schrieb:
The niche exists, but it doesn’t fit into 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. But for such a high-end house, I can’t argue anymore that the homeowners can’t afford photovoltaics. The group of budget-conscious homeowners is definitely better served by the building energy code combined with underfloor heating and a Daikin heat pump. This is the core issue for me.
In Baden-Württemberg, the argument about photovoltaics is already outdated since photovoltaics are mandatory for new buildings.
Yes, it’s no secret that underfloor heating doesn’t make sense in houses close to the passive house standard. But those aren’t the budget-oriented homeowners, and I would argue that in 80% (or even more) of cases, a new building planned from today that is close to passive house will also be planned with photovoltaics outside of Baden-Württemberg as well. So that factor has to be excluded from the comparison calculation.
The target group must be those houses with such a low heating demand. Then the comparison must not be made with a heat pump plus photovoltaics, because that wasn’t even an option for those houses.
Then I compare with low-temperature radiators or comparable systems.
But by all means, @Vestaxx GmbH, keep focusing on the comparison with the budget-oriented KfW55 homeowner... I don’t think you’re doing yourself any favors here.
V
Vestaxx GmbH11 Oct 2022 10:32RotorMotor schrieb:
I will now add the required maintenance costs to my calculation and include a version without photovoltaic to have all options clearly compared:
150m² (1,615 sq ft) with 40kWh/m²a (40kWh per square meter per year) → 6000kWh/year heating energy demand
10kWp photovoltaic + 5kWh storage → approximately 15kWh/day in Nov, Dec, Jan, Feb. With 10kWh for household electricity including hot water, 5kWh/day remain for heating
The costs of the photovoltaic system are not included in this example since the system pays for itself through feed-in tariffs and savings on household electricity.
Hot water costs are omitted because both systems can provide it with a seasonal performance factor (SPF) of 4, so it makes no difference; electricity for hot water is included in household electricity costs.
Electricity purchase price: $0.35/kWh
Feed-in tariff price: $0.082/kWh
Interest rate: 3.5% (current rate for a 10-year fixed term)
Electricity price increase: 6% (average over the last 20 years)
Vestaxx + Photovoltaic:
Additional cost compared to standard windows: €10,000
Purchase and installation of the underfloor heating heat pump (UFH HP): €5,000
Interest on purchase over 18 years: €5,239
Maintenance UFH HP: €200/year
4 months * 30 days * 5kWh/day = 600kWh from photovoltaic electricity
Remaining 5400kWh purchased
Total cost (average, considering rising electricity prices) 5400 * (0.35 + 0.35 * 1.06^18) / 2 + 600 * 0.082 = €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 = 1500kWh
Remaining 900kWh purchased
Total cost (average, considering rising electricity prices) 900 * (0.35 + 0.35 * 1.06^18) / 2 + 600 * 0.082 = €656/year
After 18 years, this amounts to: €59,488
Vestaxx without Photovoltaic:
Additional cost compared to standard windows: €10,000
Purchase and installation UFH HP: €5,000
Interest on purchase over 18 years: €5,239
Maintenance UFH HP: €200/year
Total cost (average, considering rising electricity prices) 6000 * (0.35 + 0.35 * 1.06^18) / 2 + 600 * 0.082 = €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 = 1500kWh
Total cost (average, considering rising electricity prices) 1500 * (0.35 + 0.35 * 1.06^18) / 2 = €1,011/year
After 18 years, this amounts to: €65,878
In this example, the additional cost for Vestaxx compared to the heat pump is €30,798.
That means paying €142/month more every month for 18 years without even keeping underfloor heating at the end of the term!
All that money is gone to the energy supplier and mostly converted into CO2. Incorrect!!! Important factors are left out here (costs for underfloor heating), prices for the heat pump are understated, maintenance costs are listed that do not occur, household electricity is left out again, photovoltaic yields are calculated at 30 days with 5kWh/day and 4 months, etc., etc., very unfortunate.
Please trust independent institutes instead of anonymous users here.
For example
Dr.-Ing. Peter Kosack
PEKOHAUS®
Research Institute for Building Energy Technology
who has conducted many studies and measurement series comparing infrared heating with heat pumps.
He states, among other things:
For new builds: → If you say infrared heating, you must also say photovoltaic!
For renovations: → If you say infrared heating, you must also say photovoltaic plus heat pump!
What I have written here several times: For renovations, heat pumps make sense again – for new builds, they do not. Period!
R
RotorMotor11 Oct 2022 10:54Oh, this is the first time “he addresses my calculation.” If numbers and sources follow now, I’ll be happy to repost the calculation with different values. Otherwise, I’ll repost it as it is.
In technical terms, underfloor heating is also called hydraulics and is, of course, included:
.
20,000€ for a heat pump including installation is already quite high and can be found by many experts at this level or even lower.
It concerns maintenance and repair costs.
Air-to-water heat pumps and domestic ventilation heat pumps (BWWP) are basically maintenance-free.
However, over their lifetime, pumps, valves, etc. can fail on both, which is accounted for by maintenance costs.
Otherwise, please provide a reason or source why air-to-water heat pumps have maintenance costs, but BWWP do not. 😉
I have already explained that. Household electricity does not affect the heating systems, only the photovoltaic system.
The photovoltaic system is listed in one case and omitted in the other.
This is an invalid conclusion.
Just because A implies B, it does not mean that B implies A.
Just because photovoltaic is always mentioned, it does not mean infrared heating is always mentioned as well.
Several calculations have shown exactly the opposite.
Vestaxx GmbH schrieb:
Some items are left out here (costs for underfloor heating)
In technical terms, underfloor heating is also called hydraulics and is, of course, included:
RotorMotor schrieb:
Heat pump + photovoltaic:
Hydraulics: 80€/m² * 150m² = 12,000€
Heat pump without photovoltaic:
Hydraulics: 80€/m² * 150m² = 12,000€
.
Vestaxx GmbH schrieb:
- Prices for heat pump are inflated
RotorMotor schrieb:
Purchase of air-to-water monoblock heat pump and installation: 20,000€
20,000€ for a heat pump including installation is already quite high and can be found by many experts at this level or even lower.
Vestaxx GmbH schrieb:
- Maintenance costs listed that do not occur
It concerns maintenance and repair costs.
Air-to-water heat pumps and domestic ventilation heat pumps (BWWP) are basically maintenance-free.
However, over their lifetime, pumps, valves, etc. can fail on both, which is accounted for by maintenance costs.
Otherwise, please provide a reason or source why air-to-water heat pumps have maintenance costs, but BWWP do not. 😉
Vestaxx GmbH schrieb:
- The household electricity was left out again -
I have already explained that. Household electricity does not affect the heating systems, only the photovoltaic system.
The photovoltaic system is listed in one case and omitted in the other.
Vestaxx GmbH schrieb:
Photovoltaic yields calculated over 30 days with 5 kWh/day and 4 months, etc.
Vestaxx GmbH schrieb:
Studies and measurements compared infrared heating with heat pumps.
They say among other things:
In new buildings: -> Anyone who says infrared heating must also say photovoltaic!
In existing buildings: -> Anyone who says infrared heating must also say photovoltaic plus heat pump!
This is an invalid conclusion.
Just because A implies B, it does not mean that B implies A.
Just because photovoltaic is always mentioned, it does not mean infrared heating is always mentioned as well.
Vestaxx GmbH schrieb:
What I have written here several times: In existing buildings heat pumps make sense again – not in new buildings. Period!
Several calculations have shown exactly the opposite.
Vestaxx GmbH schrieb:
Some items are left out here (costs for underfloor heating) I assume those are the 12,000 EUR under "Hydraulics." It’s expressed unclearly, but the costs roughly match.
Vestaxx GmbH schrieb:
Prices for the heat pump are made to look better than they are No, why? That is almost exactly what I paid including everything, considering my prices were from a year and a half ago (so plus price increases of about 30%).
Vestaxx GmbH schrieb:
Maintenance costs are listed that don’t occur Why? They do occur for the heat pump in all versions. Same technology means the same maintenance. But even if you leave out the 200 EUR/year for Vestaxx, the difference is so large that we could gladly leave it out and still see no greater cost-effectiveness.
Vestaxx GmbH schrieb:
Household electricity is left out again It’s included in all versions. Or do you mean that Vestaxx assumes lower household electricity consumption? The savings from the photovoltaic system are included in both photovoltaic options (namely as the missing costs for the photovoltaic system) and can therefore be excluded in the comparative analysis. The higher initial investment is offset by the higher interest costs.
Vestaxx GmbH schrieb:
Photovoltaic yields calculated over 30 days at 5 kWh/day and 4 months In winter, there are often days with lower yields, and those days are usually particularly cold. So assuming such an average is actually favorable for the self-consumption rate—which works in Vestaxx’s favor. Because on days with high yield, you won’t have higher self-consumption (for heating electricity) since solar heat gains mean you hardly need to heat at all.
kati1337 schrieb:
That is an understatement; otherwise, you wouldn’t have been able to convince anyone. 🙂 Are you sure? Can you provide evidence for that?
V
Vestaxx GmbH11 Oct 2022 11:25RotorMotor schrieb:
Oh, this is the first time "he addresses my calculation." If numbers and sources follow now, I’m happy to repost the calculation with different values. Otherwise, I’ll repost it as it is.
In professional circles, underfloor heating is also called hydraulics and is of course included:
.
€20,000 (about $22,000) for a heat pump including installation is already quite a lot and can be found at this level (or lower) by many experts.
This is about maintenance costs.
Air-to-water heat pumps and groundwater heat pumps are basically maintenance-free.
However, over their lifespan, pumps, valves, etc. may fail on both systems, which is accounted for in the maintenance costs.
Otherwise, please provide a reason or source why an air-to-water heat pump has maintenance costs but a groundwater heat pump does not. 😉
I already explained this. Household electricity does not affect the heating systems, only the photovoltaic system.
The photovoltaic system is listed once in both cases and omitted once.
This is an invalid conclusion.
Just because A implies B does not mean B implies A.
Just because photovoltaic is always mentioned does not mean infrared heating is always mentioned.
Various calculations have already shown the opposite. As already stated -> The discussion with RotorMotor leads nowhere because he does not include photovoltaic or household electricity, so the comparison cannot work. End of discussion!
Enjoy your heat pump—I’m going back to focusing on my clients. They understand me ;o)
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