ᐅ New Bungalow Construction – Air-to-Water Heat Pump, Photovoltaic System, and Solar Thermal?
Created on: 21 May 2017 11:44
P
pelmenipeter
Hello,
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
pelmenipeter schrieb:
Yes, the fireplace is planned anyway, as a luxury feature. That doesn’t quite add up:
Town & Country house and a fireplace as a luxury?
I haven’t heard very positive feedback about that from people I know.
Before spending maybe €5,000 (about $5,400) on a fireplace and stove (+ annual chimney sweep), I would rather invest the money in geothermal heating or a better equipped house.
pelmenipeter schrieb:
I thought the buffer tank was necessary anyway because of the underfloor heating. No, it’s not necessary. A well-designed underfloor heating system has enough volume to store heat.
P
pelmenipeter21 May 2017 13:51You can find a lot of both positive and negative feedback 😕
It is not yet certain that Town & Country or the franchisee MBB GmbH will be our partner. This was just our first personal contact, and it was relatively pleasant. We have already scheduled a follow-up meeting to do some "calculations." I am trying to stay as objective as possible.
What I have read so far about geothermal energy involves quite high costs for earthworks and defective probes. And a chimney is definitely a luxury, that’s for sure 😉 Or do you think Town & Country generally does not represent "luxury"?
So far, I haven’t found any strong recommendations for construction companies in Berlin/Brandenburg.
It is not yet certain that Town & Country or the franchisee MBB GmbH will be our partner. This was just our first personal contact, and it was relatively pleasant. We have already scheduled a follow-up meeting to do some "calculations." I am trying to stay as objective as possible.
What I have read so far about geothermal energy involves quite high costs for earthworks and defective probes. And a chimney is definitely a luxury, that’s for sure 😉 Or do you think Town & Country generally does not represent "luxury"?
So far, I haven’t found any strong recommendations for construction companies in Berlin/Brandenburg.
Town & Country is budget-friendly. But that doesn’t matter—if it fits your needs, it fits.
Solar thermal systems are not effective without a buffer tank (no, underfloor heating is not suitable for this, otherwise you’d be overheated in summer – solar thermal is for domestic hot water!). Solar thermal and photovoltaic systems hardly support the heat pump in winter due to low solar radiation. Battery storage is generally uneconomical (you mention 20 years, while the manufacturer’s warranty is only 10 years); this is even more the case with a heat pump as a major power consumer. You will already achieve a high self-consumption rate with it.
Geothermal energy can be worthwhile, especially for KFW 55 standard homes and smaller floor areas, meaning low heating demand. In this case, subsidies (about 4,500–5,000 euros) from BAFA almost cover the drilling costs. Alternatively, surface collectors or trench collectors are very attractive, particularly for people who can do some of the work themselves (small excavator, etc.), since the subsidy then exceeds the construction costs, meaning you can even come out ahead.
Solar thermal systems are not effective without a buffer tank (no, underfloor heating is not suitable for this, otherwise you’d be overheated in summer – solar thermal is for domestic hot water!). Solar thermal and photovoltaic systems hardly support the heat pump in winter due to low solar radiation. Battery storage is generally uneconomical (you mention 20 years, while the manufacturer’s warranty is only 10 years); this is even more the case with a heat pump as a major power consumer. You will already achieve a high self-consumption rate with it.
Geothermal energy can be worthwhile, especially for KFW 55 standard homes and smaller floor areas, meaning low heating demand. In this case, subsidies (about 4,500–5,000 euros) from BAFA almost cover the drilling costs. Alternatively, surface collectors or trench collectors are very attractive, particularly for people who can do some of the work themselves (small excavator, etc.), since the subsidy then exceeds the construction costs, meaning you can even come out ahead.
If self-construction is possible, the trench collector is ideal. If not, drilling here costs around €12,000 with a local company.
Using underfloor heating as a buffer means that, through the water volume, the circulation flow rates required by the heat pump are achieved with correct design, eliminating the need for an additional buffer tank. This also removes the necessity for a bypass valve.
That is why solar thermal systems should be omitted, as they complicate control systems or cause the heat pump to operate very inefficiently.
In summer, domestic hot water is then supplied by the heat pump supported by photovoltaic panels, not by solar thermal.
An important aspect of the heating system is the correct calculation of the heating load, done room by room. The underfloor heating should be designed accordingly to allow for the lowest possible supply temperature. You can find information on how to do this online.
Using underfloor heating as a buffer means that, through the water volume, the circulation flow rates required by the heat pump are achieved with correct design, eliminating the need for an additional buffer tank. This also removes the necessity for a bypass valve.
That is why solar thermal systems should be omitted, as they complicate control systems or cause the heat pump to operate very inefficiently.
In summer, domestic hot water is then supplied by the heat pump supported by photovoltaic panels, not by solar thermal.
An important aspect of the heating system is the correct calculation of the heating load, done room by room. The underfloor heating should be designed accordingly to allow for the lowest possible supply temperature. You can find information on how to do this online.
P
pelmenipeter21 May 2017 18:26Doing work ourselves is hardly feasible. My partner works in an office and I’m in IT—basically, both of us lack hands-on skills 😀 Laying some parquet flooring or doing painting is fine, but nothing beyond that.
Since we don’t have extremely strong sunlight in our area, I hope to increase self-consumption with a solar storage system combined with the photovoltaic system. We’re usually at work during the sunshine hours anyway.
From what I’ve read so far, geothermal heat pumps are somewhat more efficient than air-to-water heat pumps. But how does that work with frozen ground? In a thread here, I saw something about a depth of 80cm (32 inches), which seems a bit shallow to me. Although I don’t really have much knowledge about that.
Since we don’t have extremely strong sunlight in our area, I hope to increase self-consumption with a solar storage system combined with the photovoltaic system. We’re usually at work during the sunshine hours anyway.
From what I’ve read so far, geothermal heat pumps are somewhat more efficient than air-to-water heat pumps. But how does that work with frozen ground? In a thread here, I saw something about a depth of 80cm (32 inches), which seems a bit shallow to me. Although I don’t really have much knowledge about that.
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