ᐅ Gas Heating + Solar & Controlled Ventilation or Air-to-Water Heat Pump Energy Saving Regulation 2016
Created on: 21 Apr 2018 11:26
F
Filstal
Hello everyone,
Since I am quite new here, I would like to provide some background information about my situation. Please excuse any gaps in my knowledge in advance, and I am happy to provide further details if needed.
I own a fairly flat plot of land with 400 sqm (4,305 sq ft) (gas connection available), on which a KfW 70 energy-efficient solid brick single-family house with a slab foundation (no basement) is planned. The house will have approximately 134 sqm (1,442 sq ft) of living space and 144 sqm (1,550 sq ft) of total floor area, spread over 1.5 stories. It will have a gable roof with a 30° pitch and a knee wall height of 1.50 m (4.9 ft). Due to a nearby railway line, increased sound insulation is required, so the exterior walls must be constructed with a thickness of 36.5 cm (14.4 inches).
The build will be carried out by a local general contractor who has provided me with two offers as follows:
Offer 1: Thermo solid masonry blocks S9, 36.5 cm (14.4 inches) thick, enhanced insulation in the roof/attic, a gas condensing wall boiler type Viessmann VITODENS 200-W with a 500-liter (132-gallon) storage tank, and Viessmann VITOSOL 200-F flat plate solar collectors. Controlled ventilation with heat recovery is provided by four decentralized ventilation units, along with standard compact radiators throughout the house. Airtightness testing will be performed using a blower door test. This build will comply with the Energy Saving Ordinance 2014 including the 2016 tightening.
Offer 2: Thermo solid masonry blocks SX 10, 36.5 cm (14.4 inches) thick, Bartl air-to-water compact heat pump ECO 3-6 LCI for indoor installation with an 800-liter (211-gallon) storage tank. Underfloor heating throughout the entire house. Vento ventilation systems installed at all windows and patio doors in living areas. Prepared for a future photovoltaic system installation. This build will comply with the Energy Saving Ordinance 2016.
In terms of price, the second offer is exactly €3,000 more expensive, which is offset by the gas connection cost required for the first offer.
Since I am quite uncertain about which heating system would be the, let’s say carefully, "better" option for this house and more economical in the long run, I would like to ask for your recommendations here. My secondary question is whether the compact heat pump makes sense or if a split system from the same manufacturer would be a better choice?
I do not want to start a general debate about whether gas or air-to-water heat pumps are better and am specifically focusing only on the air-to-water heat pump.
My general contractor is clearly leaning towards the air-to-water heat pump. Here is a link to the technical data of the air-to-water heat pump.
Best regards,
Filstal
Since I am quite new here, I would like to provide some background information about my situation. Please excuse any gaps in my knowledge in advance, and I am happy to provide further details if needed.
I own a fairly flat plot of land with 400 sqm (4,305 sq ft) (gas connection available), on which a KfW 70 energy-efficient solid brick single-family house with a slab foundation (no basement) is planned. The house will have approximately 134 sqm (1,442 sq ft) of living space and 144 sqm (1,550 sq ft) of total floor area, spread over 1.5 stories. It will have a gable roof with a 30° pitch and a knee wall height of 1.50 m (4.9 ft). Due to a nearby railway line, increased sound insulation is required, so the exterior walls must be constructed with a thickness of 36.5 cm (14.4 inches).
The build will be carried out by a local general contractor who has provided me with two offers as follows:
Offer 1: Thermo solid masonry blocks S9, 36.5 cm (14.4 inches) thick, enhanced insulation in the roof/attic, a gas condensing wall boiler type Viessmann VITODENS 200-W with a 500-liter (132-gallon) storage tank, and Viessmann VITOSOL 200-F flat plate solar collectors. Controlled ventilation with heat recovery is provided by four decentralized ventilation units, along with standard compact radiators throughout the house. Airtightness testing will be performed using a blower door test. This build will comply with the Energy Saving Ordinance 2014 including the 2016 tightening.
Offer 2: Thermo solid masonry blocks SX 10, 36.5 cm (14.4 inches) thick, Bartl air-to-water compact heat pump ECO 3-6 LCI for indoor installation with an 800-liter (211-gallon) storage tank. Underfloor heating throughout the entire house. Vento ventilation systems installed at all windows and patio doors in living areas. Prepared for a future photovoltaic system installation. This build will comply with the Energy Saving Ordinance 2016.
In terms of price, the second offer is exactly €3,000 more expensive, which is offset by the gas connection cost required for the first offer.
Since I am quite uncertain about which heating system would be the, let’s say carefully, "better" option for this house and more economical in the long run, I would like to ask for your recommendations here. My secondary question is whether the compact heat pump makes sense or if a split system from the same manufacturer would be a better choice?
I do not want to start a general debate about whether gas or air-to-water heat pumps are better and am specifically focusing only on the air-to-water heat pump.
My general contractor is clearly leaning towards the air-to-water heat pump. Here is a link to the technical data of the air-to-water heat pump.
Best regards,
Filstal
Then just do it the way I did. I have an appointment next week with a local energy agency in the district. Yes, such a thing exists, and it’s non-binding, free of charge, and you get a competent and neutral energy advisor who can definitely answer questions like these.
Because collecting thousands of opinions and preferences from the forum and reading everything in detail didn’t get me any further, especially since no one has even roughly said which offer would be the more reasonable one!
However, here are some facts I can definitely share with you:
- In recent years, electricity prices have continued to rise, while gas prices have remained almost at the same level. No one knows if that will ever change, especially not here in Germany!
- The annual performance factor of an air-to-water heat pump depends heavily on the weather, and no one knows how the next 5/10/15 winters will be. On average, the actual annual performance factor of air-to-water heat pumps is about 3, but most are advertised with COP (Coefficient of Performance) values of 3.4–3.6. It’s like with cars—these are all laboratory figures.
- But thanks to the lovely (irony intended) 2016 Energy Saving Ordinance, gas heating systems must not only include solar thermal systems, but if you want to build with solid construction, they also require a ventilation system with heat recovery. That means an air-to-water heat pump with underfloor heating is already as expensive, if not cheaper, than a gas heating system with everything included.
These are my current thoughts. Let’s see what comes out of the consultation next week.
Because collecting thousands of opinions and preferences from the forum and reading everything in detail didn’t get me any further, especially since no one has even roughly said which offer would be the more reasonable one!
However, here are some facts I can definitely share with you:
- In recent years, electricity prices have continued to rise, while gas prices have remained almost at the same level. No one knows if that will ever change, especially not here in Germany!
- The annual performance factor of an air-to-water heat pump depends heavily on the weather, and no one knows how the next 5/10/15 winters will be. On average, the actual annual performance factor of air-to-water heat pumps is about 3, but most are advertised with COP (Coefficient of Performance) values of 3.4–3.6. It’s like with cars—these are all laboratory figures.
- But thanks to the lovely (irony intended) 2016 Energy Saving Ordinance, gas heating systems must not only include solar thermal systems, but if you want to build with solid construction, they also require a ventilation system with heat recovery. That means an air-to-water heat pump with underfloor heating is already as expensive, if not cheaper, than a gas heating system with everything included.
These are my current thoughts. Let’s see what comes out of the consultation next week.
I agree with you on everything and have also sought individual advice. “Individual” here especially means considering my specific property, soil conditions, and floor plan.
In this forum, you quickly run the risk of overlooking certain framework conditions. For example, we also considered gas versus air-to-water or ground-source heat pumps. Some forum members get their boreholes done very cheaply, manage with just one borehole, and may have well-regenerating soil. For us, you can only go down 40m (130 feet), so around 4 to 6 boreholes are needed, totaling about 15,000 just for drilling. The soil is quite clayey, meaning limited regeneration capacity is to be expected. A problem here in NBG affects 2 to 3 people now: the probe extracts too much energy from the soil, meaning rainfall is insufficient to recharge the soil with energy. Poor infiltration of water further worsens this issue. Consequently, the coefficient of performance (COP) decreases.
Then there is gas versus air-to-water heat pump. The gas connection was already paid for with the property, so that would be attractive. However, it doesn’t really pay off because the replacement measures (more insulation, even better windows) would be impractical and expensive. Photovoltaics are still too costly and would be an aesthetic disaster or compromise efficiency on a monopitch roof with a 7-degree pitch. Also, with gas, you have to consider flue gas routing. Our technical room is in the basement (southeast) and the living room chimney is on the west side, somewhat far apart. The flue gas cannot vent through the existing chimney—although it might partially be possible. Therefore, another “chimney” would be needed, which is hardly or only with major restrictions feasible in the floor plan. That leaves the air-to-water heat pump, with an outdoor unit, sadly in the front garden. Indoor installation is not possible due to clay soil, rising seepage water, and corner placement being impossible because the sun deck is on the south side. Proper sealing is simply only partly achievable. What I want to say is: very often these calculations are done too loosely “on a napkin” and they “prove” that xyz is much cheaper (especially often the case with gas). That may be true for some, but in my opinion, the individual circumstances have too much influence for general statements to make much sense. At least that is my conclusion [emoji6]
Regarding gas prices and temperatures, here are my thoughts. Gas means dependence on the Russian czar, which I certainly do not want—though that is more an emotional issue than a numerical one. Yes, the air-to-water heat pump is an electrical heating system, that’s true. As bad as that is from a global climate perspective, winters here tend to be getting warmer, so the use of the electric booster heater should decrease. That’s at least how I rationalize it [emoji6]
The biggest risk is still the installer; the economics stand or fall with that. We try to reduce the risk by having the HLB carry out the installation and fine-tuning, and the manufacturer handle the preliminary planning and acceptance. But a residual risk remains...
In this forum, you quickly run the risk of overlooking certain framework conditions. For example, we also considered gas versus air-to-water or ground-source heat pumps. Some forum members get their boreholes done very cheaply, manage with just one borehole, and may have well-regenerating soil. For us, you can only go down 40m (130 feet), so around 4 to 6 boreholes are needed, totaling about 15,000 just for drilling. The soil is quite clayey, meaning limited regeneration capacity is to be expected. A problem here in NBG affects 2 to 3 people now: the probe extracts too much energy from the soil, meaning rainfall is insufficient to recharge the soil with energy. Poor infiltration of water further worsens this issue. Consequently, the coefficient of performance (COP) decreases.
Then there is gas versus air-to-water heat pump. The gas connection was already paid for with the property, so that would be attractive. However, it doesn’t really pay off because the replacement measures (more insulation, even better windows) would be impractical and expensive. Photovoltaics are still too costly and would be an aesthetic disaster or compromise efficiency on a monopitch roof with a 7-degree pitch. Also, with gas, you have to consider flue gas routing. Our technical room is in the basement (southeast) and the living room chimney is on the west side, somewhat far apart. The flue gas cannot vent through the existing chimney—although it might partially be possible. Therefore, another “chimney” would be needed, which is hardly or only with major restrictions feasible in the floor plan. That leaves the air-to-water heat pump, with an outdoor unit, sadly in the front garden. Indoor installation is not possible due to clay soil, rising seepage water, and corner placement being impossible because the sun deck is on the south side. Proper sealing is simply only partly achievable. What I want to say is: very often these calculations are done too loosely “on a napkin” and they “prove” that xyz is much cheaper (especially often the case with gas). That may be true for some, but in my opinion, the individual circumstances have too much influence for general statements to make much sense. At least that is my conclusion [emoji6]
Regarding gas prices and temperatures, here are my thoughts. Gas means dependence on the Russian czar, which I certainly do not want—though that is more an emotional issue than a numerical one. Yes, the air-to-water heat pump is an electrical heating system, that’s true. As bad as that is from a global climate perspective, winters here tend to be getting warmer, so the use of the electric booster heater should decrease. That’s at least how I rationalize it [emoji6]
The biggest risk is still the installer; the economics stand or fall with that. We try to reduce the risk by having the HLB carry out the installation and fine-tuning, and the manufacturer handle the preliminary planning and acceptance. But a residual risk remains...
ruppsn schrieb:
As unfortunate as it is for the global climate, winters in our area tend to be warmer, so the use of the heating element is likely to decrease. At least, that’s how I try to see it. In reality, the heating element hardly plays any role. The big concern about it is quite unfounded. In our case, it only activated at temperatures below -10°C (14°F) and was only on for a few hours. At such temperatures, the difference between having it or not isn’t very significant anyway. But how often do such temperatures actually occur? This winter, we had at least six nights that cold, which was colder than usual for us.
ruppsn schrieb:
What I mean is: here people quickly do their “tax returns on a beer coaster” and “calculate” that xyz is so much cheaper (especially often the case with gas). This might be true for some cases, but in my opinion the individual circumstances have too much influence for general statements to make any sense. In a few years, you will be able to buy nice houses cheaply, simply because a technically still new and flawless heating and climate system would have to be scrapped for economic reasons – just because the gap between theory and practical costs ends up painfully real for your wallet. My principle in such matters is "when in doubt, go against trendy gimmicks."
On paper, every new technology initially seems to fly to the moon, but in reality, it sometimes turns out to be just like the Berlin airport.
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
Heat Pump Consumption Database… Real values, not calculated. It doesn’t get more objective than this. Publicly accessible, anyone can take a look.
Heat pump technology has existed for many decades; it is not new technology. Will many of the current cars soon become unsellable because they use continually updated technology? Hardly.
But I can only agree: it always depends on the individual circumstances. If you can get a ground collector cheaply, geothermal energy is usually unbeatable. If a gas connection is already included in the price… gas is unbeatable…, etc.
Heat pump technology has existed for many decades; it is not new technology. Will many of the current cars soon become unsellable because they use continually updated technology? Hardly.
But I can only agree: it always depends on the individual circumstances. If you can get a ground collector cheaply, geothermal energy is usually unbeatable. If a gas connection is already included in the price… gas is unbeatable…, etc.
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