ᐅ New Bungalow Construction – Air-to-Water Heat Pump, Photovoltaic System, and Solar Thermal?
Created on: 21 May 2017 11:44
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pelmenipeterP
pelmenipeter21 May 2017 11:44Hello,
I have a few questions regarding the planning of our new build. We are still quite inexperienced with all aspects of house construction, but the forum has already been very helpful.
A brief background: on Saturday, we visited a show bungalow by Town & Country. We have not yet seen any other model homes. Our goal is a bungalow with approximately 130m² (1400 sq ft) of living space. The model home featured solar thermal heating combined with an air-to-water heat pump, including a storage tank from Rotex. The entire house was equipped with underfloor heating.
We really liked the house overall. However, I have some questions about the heating system. After reading the Rotex brochure, I noticed the high electricity consumption.
My current idea: a bungalow with solar thermal heating, an air-to-water heat pump, plus a photovoltaic system with a battery storage unit. The photovoltaic system is intended to largely supply electricity to the air-to-water heat pump and to charge the battery storage. Since I have not yet experienced how noisy the outdoor unit really is, I also like the idea of having solar thermal panels on the roof.
My questions about this concept are:
1. Does this setup make sense for a build in Brandenburg, around Zossen/Königs Wusterhausen?
2. Or would the solar thermal system be unnecessary?
3. What are the approximate costs associated with each option?
The goal is to efficiently heat a KfW55 bungalow. Although, I am not sure if photovoltaic only combined with an air-to-water heat pump is sufficient for that.
Best regards,
Peter
I have a few questions regarding the planning of our new build. We are still quite inexperienced with all aspects of house construction, but the forum has already been very helpful.
A brief background: on Saturday, we visited a show bungalow by Town & Country. We have not yet seen any other model homes. Our goal is a bungalow with approximately 130m² (1400 sq ft) of living space. The model home featured solar thermal heating combined with an air-to-water heat pump, including a storage tank from Rotex. The entire house was equipped with underfloor heating.
We really liked the house overall. However, I have some questions about the heating system. After reading the Rotex brochure, I noticed the high electricity consumption.
My current idea: a bungalow with solar thermal heating, an air-to-water heat pump, plus a photovoltaic system with a battery storage unit. The photovoltaic system is intended to largely supply electricity to the air-to-water heat pump and to charge the battery storage. Since I have not yet experienced how noisy the outdoor unit really is, I also like the idea of having solar thermal panels on the roof.
My questions about this concept are:
1. Does this setup make sense for a build in Brandenburg, around Zossen/Königs Wusterhausen?
2. Or would the solar thermal system be unnecessary?
3. What are the approximate costs associated with each option?
The goal is to efficiently heat a KfW55 bungalow. Although, I am not sure if photovoltaic only combined with an air-to-water heat pump is sufficient for that.
Best regards,
Peter
P
pelmenipeter21 May 2017 11:53Oh yes, I almost forgot. A fireplace will also be used in the living room. It might help reduce the electricity demand for the air-to-water heat pump during the cold season with limited sunlight.
Hello first of all.
This cannot be explained in just one sentence.
Personally, I would avoid solar thermal systems because they require a buffer tank. Also, they are not that easy to integrate since heat pumps are designed to operate at as low a temperature as possible. Solar thermal systems usually produce higher temperatures, which then need to be tempered down to support the heating system.
I find a heat pump combined with photovoltaics to be a sensible choice. Photovoltaics provide electricity in the summer for heating domestic hot water.
With a KfW55 standard and your living area, assuming everything is properly designed, the energy demand of the heat pump should remain reasonable.
You will probably never save money with a fireplace. The installation cost is already quite high, and you also have ongoing expenses.
However, the heat is pleasant, so I would consider the fireplace more as a luxury item.
This cannot be explained in just one sentence.
Personally, I would avoid solar thermal systems because they require a buffer tank. Also, they are not that easy to integrate since heat pumps are designed to operate at as low a temperature as possible. Solar thermal systems usually produce higher temperatures, which then need to be tempered down to support the heating system.
I find a heat pump combined with photovoltaics to be a sensible choice. Photovoltaics provide electricity in the summer for heating domestic hot water.
With a KfW55 standard and your living area, assuming everything is properly designed, the energy demand of the heat pump should remain reasonable.
You will probably never save money with a fireplace. The installation cost is already quite high, and you also have ongoing expenses.
However, the heat is pleasant, so I would consider the fireplace more as a luxury item.
P
pelmenipeter21 May 2017 12:40Thank you for your opinion.
Yes, the fireplace is planned anyway, as a luxury feature.
Regarding the buffer tank, I thought it was necessary anyway because of the underfloor heating.
In the show home with the Rotex system, there was also a large water storage tank in the utility room. During our visit, the temperature on the roof was 125 degrees Celsius (257 degrees Fahrenheit), allowing the stratified storage tank to store a lot of heat.
I also recently saw a provider offering the house as a KfW 40 Plus standard home with an air-to-water heat pump, photovoltaic system, and lithium-ion battery storage.
Yes, the fireplace is planned anyway, as a luxury feature.
Regarding the buffer tank, I thought it was necessary anyway because of the underfloor heating.
In the show home with the Rotex system, there was also a large water storage tank in the utility room. During our visit, the temperature on the roof was 125 degrees Celsius (257 degrees Fahrenheit), allowing the stratified storage tank to store a lot of heat.
I also recently saw a provider offering the house as a KfW 40 Plus standard home with an air-to-water heat pump, photovoltaic system, and lithium-ion battery storage.
If your collector shows 125°C (257°F) during your visit, the system was not operating. This is a common issue with solar thermal systems, often caused by air in the system. Solar thermal combined with a heat pump is generally not practical; it is more effective to maximize the size of the photovoltaic system. If you can afford an air-to-water heat pump plus photovoltaic panels and energy storage, this is the best long-term solution for low energy costs.
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pelmenipeter21 May 2017 13:20Thank you, I have just been reading up a bit on energy storage systems. The costs involved are quite significant. Reports from the last three years show that the break-even point is reached after around 20 years. However, the batteries usually need to be replaced by then. The outlook might be better today, but I would probably need to talk to a solar installer specialist about that.
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