ᐅ Energy Saving Regulation 2016 or KfW 55 Standard for a Bungalow with Air-to-Water Heat Pump and Controlled Mechanical Ventilation, Optional Photovoltaic System
Created on: 5 Jun 2019 08:25
M
micric3Good morning,
We are currently in the preliminary planning phase and are being flooded with information from various builders.
The topic of the "Energy Saving Ordinance 2016 or KfW 55 standard" especially leads to additional discussions.
The current concept for a household of four is as follows:
- Underfloor heating + air-to-water heat pump / controlled mechanical ventilation system combo, for example Vaillant recoCOMPACT (alternative: Nibe 730/750)
- Photovoltaic system ready for later retrofitting
- No gas connection possible/available
Opinions from some builders:
- KfW 55 was only attractive because of the low interest rates compared to traditional bank loans
- Currently, few are building to KfW 55 standard; the Energy Saving Ordinance 2016 is 'back in trend'
Calculation from another builder:
30 cm (12 inches) exterior masonry instead of 24 cm (9.5 inches) exterior masonry (both according to Energy Saving Ordinance 2016) = (costs €3,750)
(Additional costs for KfW 55 with 36.5 cm (14 inches) exterior masonry, floor slab insulation, increased roof insulation, and KfW 55 calculations and documentation were (costs €14,680))
I would like to hear some opinions on this:
Good luck
Michael
We are currently in the preliminary planning phase and are being flooded with information from various builders.
The topic of the "Energy Saving Ordinance 2016 or KfW 55 standard" especially leads to additional discussions.
The current concept for a household of four is as follows:
- Underfloor heating + air-to-water heat pump / controlled mechanical ventilation system combo, for example Vaillant recoCOMPACT (alternative: Nibe 730/750)
- Photovoltaic system ready for later retrofitting
- No gas connection possible/available
Opinions from some builders:
- KfW 55 was only attractive because of the low interest rates compared to traditional bank loans
- Currently, few are building to KfW 55 standard; the Energy Saving Ordinance 2016 is 'back in trend'
Calculation from another builder:
30 cm (12 inches) exterior masonry instead of 24 cm (9.5 inches) exterior masonry (both according to Energy Saving Ordinance 2016) = (costs €3,750)
(Additional costs for KfW 55 with 36.5 cm (14 inches) exterior masonry, floor slab insulation, increased roof insulation, and KfW 55 calculations and documentation were (costs €14,680))
I would like to hear some opinions on this:
Good luck
Michael
Similar to our situation: air-to-water heat pump, controlled residential ventilation, 36.5cm (14.5 inches) brickwork. Our energy consultant calculates two possible concepts to achieve KfW55 standards. The premise: no external thermal insulation composite system (ETICS) on the walls, no thicker bricks.
Afterwards, we review the additional costs with the architect and weigh the options.
General contractors here often request flat-rate fees, which are sometimes excessive.
Afterwards, we review the additional costs with the architect and weigh the options.
General contractors here often request flat-rate fees, which are sometimes excessive.
micric3 schrieb:
@fragg: I don’t quite understand why a horizontal ground heat exchanger is supposed to be better or more efficient than an air-to-water heat pump with controlled mechanical ventilation. But that might be off-topic since a ground-source heat pump is not an option for us.An air-to-water heat pump extracts heat from the outdoor air to warm the inside. In winter, temperatures can drop to -18°C (0°F). At that point, your heat pump will provide heat electrically, depending on the model, often already from about -12°C (10°F).Especially in winter, you need the heat pump running day and night because the sun isn’t shining, it’s cold outside, heat losses are high, the building is poorly insulated, and the ventilation system operates 24/7 (we have one with 95% heat recovery, yet 70% of our heat loss still comes from ventilation). If you build like that, ideally with room-by-room temperature control, 24°C (75°F) in the bathroom, 18°C (64°F) in the bedroom, and a 20 cm (8 inches) spacing for the underfloor heating pipes, we’ll be back next winter complaining about the electricity consumption.
The main difference is that a horizontal ground heat exchanger always deals with positive temperatures as the heat source.
If a ground-source heat pump really isn’t an option for you (legally prohibited, for example), do yourselves a favor and carefully calculate the performance of the air-to-water heat pump. Add external wall insulation, choose a good ventilation system, and then check your heating degree days (HDD) and ask the same questions there.
Subjective opinion:
If you are building to the 2016 Energy Saving Ordinance (EnEV 2016), you should seriously consider whether a heat pump even makes sense. It does not matter whether it is a ground-source or air-to-water heat pump. Heat pumps really show their advantages in well-insulated houses.
You should also distinguish between what you do to achieve good energy performance and whether you want to have it officially certified. To receive the KfW 55 label, you must invest a bit more money. However, there is nothing wrong with reaching similar energy standards without obtaining the certificate.
If you only base your decision on economic profitability, it is a very complex calculation because it depends greatly on individual factors and, especially, highly uncertain variables like future energy costs for gas and electricity. It is often the case that beyond a certain point, further improvements are not cost-effective (anything better than KfW 55 energy standard rarely or never pays off). Since you are excluding gas and have decided on a heat pump, I would consider going beyond just meeting the 2016 Energy Saving Ordinance. If you are unfortunate with a poorly planned system, it can backfire.
You should also remember in your calculations that somewhat better insulation often allows for a smaller heat pump.
In general, it is difficult to give a blanket answer. Subjectively, I would no longer build to the 2016 Energy Saving Ordinance today (especially not if you cannot use gas). I would skip the KfW 55 certification but build roughly to that standard.
...why the subjunctive mood...that is exactly how I do it :P
If you are building to the 2016 Energy Saving Ordinance (EnEV 2016), you should seriously consider whether a heat pump even makes sense. It does not matter whether it is a ground-source or air-to-water heat pump. Heat pumps really show their advantages in well-insulated houses.
You should also distinguish between what you do to achieve good energy performance and whether you want to have it officially certified. To receive the KfW 55 label, you must invest a bit more money. However, there is nothing wrong with reaching similar energy standards without obtaining the certificate.
If you only base your decision on economic profitability, it is a very complex calculation because it depends greatly on individual factors and, especially, highly uncertain variables like future energy costs for gas and electricity. It is often the case that beyond a certain point, further improvements are not cost-effective (anything better than KfW 55 energy standard rarely or never pays off). Since you are excluding gas and have decided on a heat pump, I would consider going beyond just meeting the 2016 Energy Saving Ordinance. If you are unfortunate with a poorly planned system, it can backfire.
You should also remember in your calculations that somewhat better insulation often allows for a smaller heat pump.
In general, it is difficult to give a blanket answer. Subjectively, I would no longer build to the 2016 Energy Saving Ordinance today (especially not if you cannot use gas). I would skip the KfW 55 certification but build roughly to that standard.
...why the subjunctive mood...that is exactly how I do it :P
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