ᐅ Heating System for New Construction – Which Is the Best Option?
Created on: 7 Oct 2017 20:33
F
FlohJoe
Hello,
starting next week, I will be building a single-family house of 180 m² (1,938 sq ft). Many details have already been finalized, but I keep changing my mind about the type of heating. Initially, I was convinced to go with a gas condensing boiler combined with tube collectors. Then I considered an air-to-water heat pump. Now I am leaning towards a pellet heating system. There is also the Vitovalor from Viessmann, which I find interesting—generating electricity myself..
Basically, I want to be as self-sufficient as possible regarding energy supply. So, perhaps an air-to-water heat pump with photovoltaic panels and a water-based fireplace? I’m a bit overwhelmed. Maybe someone here can give me some advice on what is feasible..
Best regards, Florian
starting next week, I will be building a single-family house of 180 m² (1,938 sq ft). Many details have already been finalized, but I keep changing my mind about the type of heating. Initially, I was convinced to go with a gas condensing boiler combined with tube collectors. Then I considered an air-to-water heat pump. Now I am leaning towards a pellet heating system. There is also the Vitovalor from Viessmann, which I find interesting—generating electricity myself..
Basically, I want to be as self-sufficient as possible regarding energy supply. So, perhaps an air-to-water heat pump with photovoltaic panels and a water-based fireplace? I’m a bit overwhelmed. Maybe someone here can give me some advice on what is feasible..
Best regards, Florian
Yes, I share the skepticism toward heating engineers and also regarding general statements made by planners. But as I said, he showed us a concrete offer, which I have here and would like to present briefly for transparency, to show what costs are involved. Maybe this will help someone with their personal assessment:
Location: Franconia, greater Nuremberg/Erlangen area
Offer for a ground probe system for a heat pump with 10.2 kW heating capacity, including connection and filling:
Total including VAT: 12,317 EUR – as mentioned, from 2012, so 5 years old. Assuming a price increase of 2% per year, that would be approximately 14,000 EUR in 2017/18.
Minus an effective government subsidy of 3,000 EUR (5,000 EUR for ground probe less 2,000 EUR for air-to-water heat pump subsidy) leaves around 10,000 EUR additional cost compared to an air-to-water heat pump. Assuming annual savings of 250 EUR for electricity compared to the air-to-water heat pump, this would pay off after 40 years (!) and with 500 EUR per year after 20 years. I would assume the lifespan of the probe and the air-to-water heat pump to be similar… this really makes you think about why you would choose a ground probe system…
Location: Franconia, greater Nuremberg/Erlangen area
Offer for a ground probe system for a heat pump with 10.2 kW heating capacity, including connection and filling:
- Probe site visit (preparation, assembling, traveling to the construction site, setting up the drilling location, departure after completion) 1 flat rate 350 EUR
- Probe drilling notification (preparation of drilling notification for local authority, excluding permit fees from authorities and any necessary expert evaluation by water management authority) 1 flat rate 65 EUR
- Probe expert service (water management expert, construction supervision, acceptance, final documentation) 1 flat rate 850 EUR
- Complete probe drilling (drilling of ground probes to a depth of 50 m (165 feet), total quantity 3 units, heat extraction rate per meter 50.00 watts, soil classes 2–7, double U-probes, casing of borehole annulus with cement, pressure and flow testing) 150 m (492 feet) at 42 EUR/m (1.60 ft) → 6300 EUR
- Auxiliary probe casing (installation and removal of auxiliary casing including re-drilling and additional cementing costs) 12 m (39 feet) at 22.25 EUR/m (0.33 ft) → 267 EUR
- Probe connection (connecting ground probes with supply and return lines, max distance 12 m (39 feet), Tichelmann arrangement, hydraulically balanced) 3 units at 235 EUR each → 705 EUR
- Excavation for probes (soil classes 2–5 with 3-ton (3.3 US ton) mini excavator to max depth 1.25 m (4.1 ft). Laying of pipes, sand bedding, backfilling and compaction of trenches, preparation of rough surface, material remains on site) 18 m (59 feet) at 25 EUR/m (0.33 ft) → 450 EUR
- Core drilling for house entry (for supply and return lines DN100) 40 cm (16 inches) at 2.10 EUR/cm (0.39 inch) → 84 EUR
- Doyma sealing (masonry sealing for wall penetrations) 2 units at 75 EUR each → 150 EUR
- Frost protection fluid (supply and installation of heat transfer fluid Terra Calidus N, 350 liters) 350 L (92 gallons) at 2 EUR/L (0.26 gal) → 700 EUR
- Container for drill waste (provision and rental of container for drill cuttings, disposal of uncontaminated material) 1 flat rate 245 EUR
- Wastewater disposal (removal of extracted water via discharge into local sewage system, permit fees, discharge fees, and related work) 1 flat rate 15 EUR
Total including VAT: 12,317 EUR – as mentioned, from 2012, so 5 years old. Assuming a price increase of 2% per year, that would be approximately 14,000 EUR in 2017/18.
Minus an effective government subsidy of 3,000 EUR (5,000 EUR for ground probe less 2,000 EUR for air-to-water heat pump subsidy) leaves around 10,000 EUR additional cost compared to an air-to-water heat pump. Assuming annual savings of 250 EUR for electricity compared to the air-to-water heat pump, this would pay off after 40 years (!) and with 500 EUR per year after 20 years. I would assume the lifespan of the probe and the air-to-water heat pump to be similar… this really makes you think about why you would choose a ground probe system…
In this specific case, I would look into a trench collector, which can be installed quite easily as a DIY project.
The prices being asked here are really outrageous.
And definitely have a room-by-room heating load calculation done. After that, the heating engineer must design the underfloor heating system.
The prices being asked here are really outrageous.
And definitely have a room-by-room heating load calculation done. After that, the heating engineer must design the underfloor heating system.
Joedreck schrieb:
In this specific case, I would take a closer look at a trench collector, which can be installed quite well as a DIY project.
The prices asked for here are outrageous. Unfortunately, a trench collector won’t work on our property, I’ve already considered that [emoji17]
It will probably come down to an Ochsner system... if it fits the heating load calculation. You can’t have everything [emoji6]
K
Karlstraße25 Oct 2017 20:42The offer above aligns with our current options for the new build. Therefore, we are leaning towards gas combined with solar. In principle, I find the concept of a solar house interesting, but since we have almost exclusively south-facing glazing, I hope that with good insulation and the solar gains, we won’t need much heating.
Gas fuel cells are currently subsidized with 11,000 euros, as Viessmann promoted at a recent trade fair. However, this is mainly beneficial for those with constant consumption, as the system only operates during the summer for hot water. For me, it seems more attractive on paper but only partly useful in real life.
I find this topic quite challenging, and currently, it is delaying the energy certificate required for our building permit/planning permission, as we have not yet made a decision.
Gas fuel cells are currently subsidized with 11,000 euros, as Viessmann promoted at a recent trade fair. However, this is mainly beneficial for those with constant consumption, as the system only operates during the summer for hot water. For me, it seems more attractive on paper but only partly useful in real life.
I find this topic quite challenging, and currently, it is delaying the energy certificate required for our building permit/planning permission, as we have not yet made a decision.
People, in new buildings depending on the living area and insulation standard, you have a heating load between 5 and 8 kW at your design temperature (-12 to -16°C (10 to 3°F)). And these temperatures occur for a maximum of 3-4 days per year.
If a heating technician comes and says the heat pump is constantly running at full capacity, they do not understand the subject.
Additionally, internal and solar gains are not considered in the heating load calculation.
What is needed here is a proper and accurate design of the underfloor heating system; then you can heat very efficiently with an air-to-water heat pump at a flow temperature of 30°C (86°F). It just requires a bit more planning.
These oversize heat pumps are then installed with buffer tanks, which completely destroy your efficiency. Unfortunately, this is common but incorrect. Please thoroughly inform yourselves and challenge the heating technician; otherwise, you will end up with: my heat pump broke after 3 years or uses an enormous amount of electricity.
If a heating technician comes and says the heat pump is constantly running at full capacity, they do not understand the subject.
Additionally, internal and solar gains are not considered in the heating load calculation.
What is needed here is a proper and accurate design of the underfloor heating system; then you can heat very efficiently with an air-to-water heat pump at a flow temperature of 30°C (86°F). It just requires a bit more planning.
These oversize heat pumps are then installed with buffer tanks, which completely destroy your efficiency. Unfortunately, this is common but incorrect. Please thoroughly inform yourselves and challenge the heating technician; otherwise, you will end up with: my heat pump broke after 3 years or uses an enormous amount of electricity.
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