Hello,
We are starting to get really frustrated... every builder tells us something different...
We want to build a 130sqm (1,399 sq ft) KfW 70 house with the living room facing south, and we are unsure whether to choose gas or an air source heat pump. Some providers, at almost the same price level, offer us air source heat pumps and claim that the annual costs are significantly (30%) lower compared to gas, while others doubt this.
We understand that insulation with gas/solar systems is usually better because an air source heat pump boosts efficiency more towards KfW 70 standards compared to gas/solar, which might argue in favor of gas. An air source heat pump might fail somewhat sooner, and in case of problems, you can usually get quick and competent local support with gas. With air source heat pumps, there could be more difficulties. Additionally, the noise of air source heat pumps (in our case about 3 meters (10 feet) from the neighbor) is not insignificant. Some say that sooner or later, everyone ends up having issues with neighbors for this reason.
We are interested in air source heat pumps with storage tanks from these providers: Vaillant, Mitsubishi Zubadan, and Rotex.
What we are really curious about is the annual cost for heating and hot water with both systems.
We live near Kassel.
What should we choose, and what would be cost-effective TODAY? What is your opinion on Vaillant?
Regards
Gigi
We are starting to get really frustrated... every builder tells us something different...
We want to build a 130sqm (1,399 sq ft) KfW 70 house with the living room facing south, and we are unsure whether to choose gas or an air source heat pump. Some providers, at almost the same price level, offer us air source heat pumps and claim that the annual costs are significantly (30%) lower compared to gas, while others doubt this.
We understand that insulation with gas/solar systems is usually better because an air source heat pump boosts efficiency more towards KfW 70 standards compared to gas/solar, which might argue in favor of gas. An air source heat pump might fail somewhat sooner, and in case of problems, you can usually get quick and competent local support with gas. With air source heat pumps, there could be more difficulties. Additionally, the noise of air source heat pumps (in our case about 3 meters (10 feet) from the neighbor) is not insignificant. Some say that sooner or later, everyone ends up having issues with neighbors for this reason.
We are interested in air source heat pumps with storage tanks from these providers: Vaillant, Mitsubishi Zubadan, and Rotex.
What we are really curious about is the annual cost for heating and hot water with both systems.
We live near Kassel.
What should we choose, and what would be cost-effective TODAY? What is your opinion on Vaillant?
Regards
Gigi
Gas costs are given as 7 cents per kWh – energy costs are stated as €833 --> 11,100 kWh of heat; electricity costs are given as 19 cents per kWh (which is quite cheap) and energy costs as €539 --> 2,836 kWh of electricity --> 11,100 / 2,836 --> 3.9... at least that’s the assumption made by the heating engineer.
We have a gas heating system with 10 sqm (108 sq ft) solar support.
Heated living area: 180 sqm (1,938 sq ft)
Annual gas bill: 650,-
When calculating costs, be sure to also consider the noise level of air-source heat pumps. In our neighborhood, someone installed an air-source heat pump. It can get very, very loud. This has caused quite a bit of conflict with the neighbors. I definitely wouldn’t want to deal with that.
Heated living area: 180 sqm (1,938 sq ft)
Annual gas bill: 650,-
When calculating costs, be sure to also consider the noise level of air-source heat pumps. In our neighborhood, someone installed an air-source heat pump. It can get very, very loud. This has caused quite a bit of conflict with the neighbors. I definitely wouldn’t want to deal with that.
R
R.Hotzenplotz6 Jan 2018 10:26An interesting thread that is currently relevant for us as well. Here is our new construction project.
Contrary to our initial expectations, a geothermal heat pump with deep boreholes is not possible.
Our options for consideration (each with additional costs compared to the initially planned Waterkotte AI 1 Geo, excluding the costs for deep drilling, which the general contractor initially estimated at €15,000, but which is not feasible):
First, it should be noted that the house will have a controlled residential ventilation system Vaillant Reco Vair with heat recovery.
1) Gas and solar:
Viessmann Vitodens 200-W with Vitosol 200F and 400 liter (105 gallons) water storage Vitocell 100B
---> €4,899 additional cost plus gas connection costs of around €2,000 to €2,500
2) Air source heat pump:
Waterkotte Eco Touch DA Air 5018.5 Ai with 390 liter (103 gallons) Waterkotte EcoStock storage
---> €9,487 additional cost, effectively €2,100 to €2,600 more expensive than the gas/solar solution
3) Ground source heat with surface collectors:
Probably the least attractive option. The Waterkotte AI1 Geo would remain. Additionally, about €10,000 for surface collectors and, according to the general contractor’s estimate, €6,000 to €8,000 (!!) for earthworks
Based on my current – unfortunately still subjective – assessment, I am leaning more towards gas plus solar, or just gas if we can qualify under the exceptions that are available here.
I have spoken with several installers who believe that for the underlying project and a calculated heating load of 7,548 W, an air source heat pump is not a sensible alternative to the gas/solar combination. Can this be stated so generally? The situation will change slightly since we had to reduce the building height somewhat to obtain the building permit/planning permission. A new calculation will be done, but it probably will not completely overturn the basis for the decision. About 41 cubic meters (1,447 cubic feet) less enclosed space will be involved.
I have a detailed heating load calculation available. Which values from this might still be relevant for evaluating this question?
The heating load calculation was commissioned by our general contractor from this company here.
Is it worth going deeper into this, commissioning further calculations, and weighing options? Or is gas or gas/solar really the most practical solution here? I don’t have an aversion to the idea. It is rather subjective. I consider gas boilers to be the more mature technology and believe that electricity prices will rise more sharply than gas prices. If we were to have a situation like in Denmark, where no new buildings are allowed to have oil or gas heating anymore, there might even be a significant oversupply of gas. These are all speculations, of course. Under no circumstances do I believe that gas prices will increase significantly more than electricity prices.
Contrary to our initial expectations, a geothermal heat pump with deep boreholes is not possible.
Our options for consideration (each with additional costs compared to the initially planned Waterkotte AI 1 Geo, excluding the costs for deep drilling, which the general contractor initially estimated at €15,000, but which is not feasible):
First, it should be noted that the house will have a controlled residential ventilation system Vaillant Reco Vair with heat recovery.
1) Gas and solar:
Viessmann Vitodens 200-W with Vitosol 200F and 400 liter (105 gallons) water storage Vitocell 100B
---> €4,899 additional cost plus gas connection costs of around €2,000 to €2,500
2) Air source heat pump:
Waterkotte Eco Touch DA Air 5018.5 Ai with 390 liter (103 gallons) Waterkotte EcoStock storage
---> €9,487 additional cost, effectively €2,100 to €2,600 more expensive than the gas/solar solution
3) Ground source heat with surface collectors:
Probably the least attractive option. The Waterkotte AI1 Geo would remain. Additionally, about €10,000 for surface collectors and, according to the general contractor’s estimate, €6,000 to €8,000 (!!) for earthworks
Based on my current – unfortunately still subjective – assessment, I am leaning more towards gas plus solar, or just gas if we can qualify under the exceptions that are available here.
I have spoken with several installers who believe that for the underlying project and a calculated heating load of 7,548 W, an air source heat pump is not a sensible alternative to the gas/solar combination. Can this be stated so generally? The situation will change slightly since we had to reduce the building height somewhat to obtain the building permit/planning permission. A new calculation will be done, but it probably will not completely overturn the basis for the decision. About 41 cubic meters (1,447 cubic feet) less enclosed space will be involved.
I have a detailed heating load calculation available. Which values from this might still be relevant for evaluating this question?
The heating load calculation was commissioned by our general contractor from this company here.
Is it worth going deeper into this, commissioning further calculations, and weighing options? Or is gas or gas/solar really the most practical solution here? I don’t have an aversion to the idea. It is rather subjective. I consider gas boilers to be the more mature technology and believe that electricity prices will rise more sharply than gas prices. If we were to have a situation like in Denmark, where no new buildings are allowed to have oil or gas heating anymore, there might even be a significant oversupply of gas. These are all speculations, of course. Under no circumstances do I believe that gas prices will increase significantly more than electricity prices.
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