ᐅ Which heating system would you choose for our planned new build?
Created on: 24 Jan 2016 11:25
F
FrenziHello everyone,
I have already read a lot in this great forum, but somehow I’m not making any progress.
Maybe you can help me...
We (a couple in our mid-50s) are planning, possibly, to sell our semi-detached house (prefabricated house with about 115 sqm (1235 sq ft) built in 1999) and build a detached single-family home.
Here are the basic details of the house:
- Prefabricated house with panel construction, approx. 125 sqm (1345 sq ft) on a slab foundation without a basement, exterior wall U-value about 0.14
- 2 people (kids have moved out)
- South-facing plot
- Fully developed new residential area (gas available)
- Targeting KfW 55 standard to potentially qualify for subsidies (but not mandatory)
We have spent several weeks researching and have some non-binding offers. According to these, such a house will cost us turnkey around 230,000 with a standard heating system.
We don’t want to spend too much, even though our current house is mortgage-free. But we’re not getting any younger. When selling our current home, we will have about two-thirds equity available, so we would need to take out a loan for at least one-third.
That’s why I’m paying particular attention to the cost-effectiveness of the heating system. Because what good are the claimed top values of different heating types if the extra costs only pay off after 25 years and I’m already six feet under on the plot?
So, here are the options I’m currently considering:
1. Standard gas boiler (condensing) with underfloor heating (cost about 2,500 in gas connection fees for the house)
2. Nibe exhaust air heat pump F730 at no extra cost (so saving the gas connection)
3. Air-to-water heat pump Elco S05 (COP value 4.0) surcharge 7,000 (net 4,500 after deducting no gas connection)
4. Stiebel Eltron LWZ 304 integral system surcharge 11,500 (net 9,000)
5. Ground-source heat pump Vaillant flexoCompact surcharge 10,900 (net 8,400)
For options 1, 3, and 5, we would like to use a controlled ventilation system with heat recovery (Zehnder 350D), which would cost us about 2,000 due to a promotion. For options 2 and 4, this would not be necessary. A solar system for domestic hot water for option 1 would cost about 3,500.
Some home builders recommend the Proxon system (Proxon Zimmermann ventilation). However, I quickly ruled this out after some research. I also have concerns about the Nibe system that I might end up paying more because I may need to use electric backup heating in winter.
Currently, our gas bill for two people in our house is about 70 per month (condensing boiler and underfloor heating).
I would prefer to avoid a gas connection to reduce dependence on one energy source. Photovoltaics interest me, but I think they are still too expensive right now. I would have a conduit installed for future preparation. A pellet heating system is not an option due to lack of storage space.
My current conclusion:
I’m leaning either toward
1. Gas boiler without solar hot water plus ventilation system (total additional cost with gas connection about 4,500) or
2. Elco air-to-water heat pump plus ventilation system (total cost about 6,500).
I am very unsure about option 2 (Nibe exhaust air pump), although the architect says it is sufficient and economical. It would cost us no extra money and no gas connection for the house.
Which type of heating would you choose?
What makes sense and what doesn’t? (Not considering environmental factors)
Thank you in advance for your opinions!
Regards,
Frenzi
I have already read a lot in this great forum, but somehow I’m not making any progress.
Maybe you can help me...
We (a couple in our mid-50s) are planning, possibly, to sell our semi-detached house (prefabricated house with about 115 sqm (1235 sq ft) built in 1999) and build a detached single-family home.
Here are the basic details of the house:
- Prefabricated house with panel construction, approx. 125 sqm (1345 sq ft) on a slab foundation without a basement, exterior wall U-value about 0.14
- 2 people (kids have moved out)
- South-facing plot
- Fully developed new residential area (gas available)
- Targeting KfW 55 standard to potentially qualify for subsidies (but not mandatory)
We have spent several weeks researching and have some non-binding offers. According to these, such a house will cost us turnkey around 230,000 with a standard heating system.
We don’t want to spend too much, even though our current house is mortgage-free. But we’re not getting any younger. When selling our current home, we will have about two-thirds equity available, so we would need to take out a loan for at least one-third.
That’s why I’m paying particular attention to the cost-effectiveness of the heating system. Because what good are the claimed top values of different heating types if the extra costs only pay off after 25 years and I’m already six feet under on the plot?
So, here are the options I’m currently considering:
1. Standard gas boiler (condensing) with underfloor heating (cost about 2,500 in gas connection fees for the house)
2. Nibe exhaust air heat pump F730 at no extra cost (so saving the gas connection)
3. Air-to-water heat pump Elco S05 (COP value 4.0) surcharge 7,000 (net 4,500 after deducting no gas connection)
4. Stiebel Eltron LWZ 304 integral system surcharge 11,500 (net 9,000)
5. Ground-source heat pump Vaillant flexoCompact surcharge 10,900 (net 8,400)
For options 1, 3, and 5, we would like to use a controlled ventilation system with heat recovery (Zehnder 350D), which would cost us about 2,000 due to a promotion. For options 2 and 4, this would not be necessary. A solar system for domestic hot water for option 1 would cost about 3,500.
Some home builders recommend the Proxon system (Proxon Zimmermann ventilation). However, I quickly ruled this out after some research. I also have concerns about the Nibe system that I might end up paying more because I may need to use electric backup heating in winter.
Currently, our gas bill for two people in our house is about 70 per month (condensing boiler and underfloor heating).
I would prefer to avoid a gas connection to reduce dependence on one energy source. Photovoltaics interest me, but I think they are still too expensive right now. I would have a conduit installed for future preparation. A pellet heating system is not an option due to lack of storage space.
My current conclusion:
I’m leaning either toward
1. Gas boiler without solar hot water plus ventilation system (total additional cost with gas connection about 4,500) or
2. Elco air-to-water heat pump plus ventilation system (total cost about 6,500).
I am very unsure about option 2 (Nibe exhaust air pump), although the architect says it is sufficient and economical. It would cost us no extra money and no gas connection for the house.
Which type of heating would you choose?
What makes sense and what doesn’t? (Not considering environmental factors)
Thank you in advance for your opinions!
Regards,
Frenzi
Provider 1 is out because with Eff 55, it’s clear from the start that you can’t manage with just a gas stove. My favorite is number 4, although I would have a serious talk with the seller about their surcharge policy. I would strongly reject the promotional ventilation offer. You will never get a complete ventilation system for 2,000 (2,000) euros unless the price was heavily marked up somewhere before. It’s just an illusion. The Nibe device itself is a great unit, but it’s no longer state-of-the-art (only basic ventilation, essentially the "simple" type of system).
Rübe1 schrieb:
Provider 1 is out, because with Eff 55 it’s clear from the start that just using a gas stove won’t be enough. Hi Rübe,
I think that’s not entirely correct from a factual point of view. It’s true that just with a gas condensing boiler you won’t achieve it.
However:
You can indeed reach KfW55 under the 2014 energy saving regulation (EnEV 2014) with a gas condensing boiler if you implement additional measures.
The relevant values for EnEV 2014 are Q_p and H_t.
Calculations are always done individually for each building according to EnEV 2014. It’s the combination of insulation and system technology that determines the result.
You could calculate it precisely here. Since the original poster plans to install a mechanical ventilation system with heat recovery – I’m curious about the outcome.
For exhaust air heat pumps and other heat pump solutions, the heating load must also be calculated accurately, and the coefficient of performance (COP) estimated correctly according to the local conditions.
With today’s prices for gas and heating electricity, for example, an air-to-water heat pump is more or less a break-even option.
Gas kWh: 4.9 - 5.5 cents
Heating electricity kWh: 19 - 21 cents
(This clearly shows what COP you should achieve!)
In my opinion, having a gas connection in the house also offers advantages:
a) A gas stove is possible
b) Future heat and power generators can be retrofitted later (currently still in early stages)
For around 1,500-2,000 euros (about 1,500-2,000 USD) during new construction, I wouldn’t skip having a gas connection, even if I chose an air-to-water heat pump for my house.
The investment costs for a heat pump are generally higher than for a gas condensing boiler. The gas connection doesn’t cost 4,500 euros – it’s more around 2,000 euros, and some energy providers even offer special deals.
Best regards,
Thorsten
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