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
It’s enough for me to know what the additional costs are for a house of the same size that is not KfW 70 certified.
We are currently searching for a construction company. One offers heat pumps at a good price, while the other insists on gas. If I choose the builder who prefers selling gas systems, he definitely won’t be able to offer me the heat pump as cheaply as the other company that sells those units in large quantities. How am I supposed to determine the heating demand beforehand? Everyone will probably tell me something different, if anything at all.
As mentioned, the house is supposed to be KfW 70 certified.
I can already see that only a few people here will really be able to help me… apparently, there isn’t much experience with this topic yet.
What helps me are statements like those from Cascanda. At least I can work with that.
We are currently searching for a construction company. One offers heat pumps at a good price, while the other insists on gas. If I choose the builder who prefers selling gas systems, he definitely won’t be able to offer me the heat pump as cheaply as the other company that sells those units in large quantities. How am I supposed to determine the heating demand beforehand? Everyone will probably tell me something different, if anything at all.
As mentioned, the house is supposed to be KfW 70 certified.
I can already see that only a few people here will really be able to help me… apparently, there isn’t much experience with this topic yet.
What helps me are statements like those from Cascanda. At least I can work with that.
gigi schrieb:
..How am I supposed to determine the heating demand in advance? .. This is also overwhelming for a layperson. To ensure consistent information, this should be done by an independent MEP engineer. Best regards
Hello,
You really shouldn’t try to do that yourself. It’s better to get a professional planner who can assist you with that......
Best regards
gigi schrieb:
How am I supposed to determine the heating demand in advance?
You really shouldn’t try to do that yourself. It’s better to get a professional planner who can assist you with that......
Best regards
H
Häuslebauer4015 Jul 2012 17:32€uro schrieb:
How can anyone want to build a house without first knowing what running costs for heating, hot water, and possibly ventilation to expect later on?Quite simple. If you already paid that much before, then the costs can only be lower in the new house, regardless of the type of heating system.
That was the case for me. Previously, we were paying 475 USD per month for electricity and gas in a semi-detached house of 120 m² (1,292 sq ft). It can’t get any more expensive than that...
M
Micha&Dany17 Jul 2012 05:40Hello Euro!
Nice to see that I’m not the only one “professionally obsessed” with these topics
What’s the point of knowing the consumption beforehand?
Besides, of course, properly sizing the heating system.
And with a gas condensing boiler, apparently you can’t go too wrong with the sizing, right?
Whether I have $50 or $500 per month, I have to live with it (as long as I’ve done everything necessary to optimize the heating system). I’m not going to give up on building the house because of that...
I can’t draw conclusions about my house from a small rental apartment. It already starts with not knowing if I will run the controlled mechanical ventilation system in summer or not – that alone causes a 50% variation in the ventilation’s electricity consumption...
When I finally have a proper bathroom with a decent bathtub – how often will I (and especially my wife) bathe in winter? Probably more often than now – but how often??
Will we really use the wood stove as often as I imagine now? And if so, how much will it heat the upper floors? Or will I be completely relying on the gas boiler there?
These are all small questions I don’t have answers to beforehand – but which can significantly affect my consumption costs overall...
Best regards!
Micha
€uro schrieb:
How can someone want to build a house without first knowing what consumption costs to expect later for heating, hot water, and possibly ventilation? I would never consider that.
Nice to see that I’m not the only one “professionally obsessed” with these topics
What’s the point of knowing the consumption beforehand?
Besides, of course, properly sizing the heating system.
And with a gas condensing boiler, apparently you can’t go too wrong with the sizing, right?
Whether I have $50 or $500 per month, I have to live with it (as long as I’ve done everything necessary to optimize the heating system). I’m not going to give up on building the house because of that...
I can’t draw conclusions about my house from a small rental apartment. It already starts with not knowing if I will run the controlled mechanical ventilation system in summer or not – that alone causes a 50% variation in the ventilation’s electricity consumption...
When I finally have a proper bathroom with a decent bathtub – how often will I (and especially my wife) bathe in winter? Probably more often than now – but how often??
Will we really use the wood stove as often as I imagine now? And if so, how much will it heat the upper floors? Or will I be completely relying on the gas boiler there?
These are all small questions I don’t have answers to beforehand – but which can significantly affect my consumption costs overall...
Best regards!
Micha
Micha&Dany schrieb:
...What’s the point of knowing the consumption beforehand? How else can you find an economical system or evaluate an investment? Micha&Dany schrieb:
...Whether I have 50 euros or 500 per month, I have to live with it (as I said: if I have done everything necessary to optimize the heating system). But I won’t give up building the house because of that... I would personally prefer the option with 50 euros Also, you do not have to accept an undefined consumption later, but can influence it yourself during the planning phase. Low consumption means investment. But how much, and what is economical and sensible? Micha&Dany schrieb:
...I cannot draw conclusions about my house from a small rental apartment. Correct, that is why an exact demand calculation is carried out for the specific building, taking into account the particular conditions. Micha&Dany schrieb:
...When I finally have a proper bathroom with a decent bathtub – how often will I (and especially my wife) take baths in winter? Probably more often than now – but how often?? Higher demand always leads to higher consumption. 25°C (77°F) room temperature requires more energy than 20°C (68°F). It is not without reason that, for example, heating load calculations are based on the desired indoor temperatures. Micha&Dany schrieb:
...These are all small questions to which I have no answer beforehand – .. But you can answer them beforehand by defining a general comfort scenario for yourself. Any deviation from that later means a change in consumption. A worst-case scenario can also be easily represented. Any increase means automatic additional consumption. Comfort and luxury always come at a cost. With efficient technology, this "extra" consumption is always lower. Best regards
P.S.: The comparisons might be imperfect, but still: Who buys a car without knowing in advance the fuel consumption data? Someone who drives little might accept a gas guzzler, while someone who drives a lot will have to pay attention to low consumption values and thus prefer the somewhat more expensive vehicle.
Energy prices for all sources are expected to rise sharply. It is relatively easy to get rid of an uneconomical car, but much more difficult with a building.
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