Hello,
we built a KfW 70 house with 140 sqm (1,507 sq ft) of living space. We have now lived here for half a year. It seems to me that our gas consumption is too high. We have two solar collectors on the roof. So far, we have used about 1,400 cubic meters (49,400 cubic feet). The entire house has underfloor heating. It is mostly off upstairs. The heating is set to level one. The flow temperature is 35 degrees Celsius (95 degrees Fahrenheit). Is this normal?
we built a KfW 70 house with 140 sqm (1,507 sq ft) of living space. We have now lived here for half a year. It seems to me that our gas consumption is too high. We have two solar collectors on the roof. So far, we have used about 1,400 cubic meters (49,400 cubic feet). The entire house has underfloor heating. It is mostly off upstairs. The heating is set to level one. The flow temperature is 35 degrees Celsius (95 degrees Fahrenheit). Is this normal?
Switching off the underfloor heating on the upper floor is already a mistake... unless it is thermally separated from the ground floor, which is probably not the case...
Your solar collectors will only be effective in summer...
Also, the heating-up phase for the 1400m³ (49,239 ft³) is probably included as well...
Has a hydraulic balancing been performed?
Your solar collectors will only be effective in summer...
Also, the heating-up phase for the 1400m³ (49,239 ft³) is probably included as well...
Has a hydraulic balancing been performed?
We have a KFW 55 house and have used just under 750 m³ (26,500 cubic feet) of gas since March 2013, excluding the warm-up phase. We have 5 m² (54 square feet) of solar collectors on the roof (west side), live in the sunny Südpfalz region, and cook with gas.
The warm-up phase (radiators) alone accounted for 790 m³ (28,000 cubic feet).
If you convert this to calorific value, we have used:
750 * 11.1106 = 8,332 kWh.
What is your calorific value for heating?
It makes a difference whether you burned
1400 * 11 = 15,400 kWh or 1400 * 8.5 = 11,900 kWh.
However, if this is really your heating demand without the warm-up phase, you will probably end up around 2,000 m³ (70,600 cubic feet) per year, which is far too high—at least for a new build.
Are the heating circuits on the first and ground floors separated? Do you have an unheated bathroom upstairs?
If I read “heating off upstairs,” I have to ask: Is there only one occupied bedroom upstairs? Or are the children’s rooms unheated?
We have set our heating so that all rooms are at 21 degrees Celsius (70°F). All radiators are turned fully on all the time.
At 8:30 p.m., the heating switches off. In the mornings, our bedroom temperature drops to just above 18 degrees Celsius (64°F) due to the ventilation system blowing cold air into the bedroom. The heating switches back on at 6:30 a.m.
What heating curve have you set? And in which region do you live?
More information is needed to estimate your consumption.
The warm-up phase (radiators) alone accounted for 790 m³ (28,000 cubic feet).
If you convert this to calorific value, we have used:
750 * 11.1106 = 8,332 kWh.
What is your calorific value for heating?
It makes a difference whether you burned
1400 * 11 = 15,400 kWh or 1400 * 8.5 = 11,900 kWh.
However, if this is really your heating demand without the warm-up phase, you will probably end up around 2,000 m³ (70,600 cubic feet) per year, which is far too high—at least for a new build.
Are the heating circuits on the first and ground floors separated? Do you have an unheated bathroom upstairs?
If I read “heating off upstairs,” I have to ask: Is there only one occupied bedroom upstairs? Or are the children’s rooms unheated?
We have set our heating so that all rooms are at 21 degrees Celsius (70°F). All radiators are turned fully on all the time.
At 8:30 p.m., the heating switches off. In the mornings, our bedroom temperature drops to just above 18 degrees Celsius (64°F) due to the ventilation system blowing cold air into the bedroom. The heating switches back on at 6:30 a.m.
What heating curve have you set? And in which region do you live?
More information is needed to estimate your consumption.
haus22 schrieb:
.....So far, we have used about 1,400 cubic meters (49,400 cubic feet). Is that normal? That can be significantly too much or too little. In other words, it cannot be assessed at all. This is most likely because the actual demand for heating and hot water is not known. => no baseline determination. Therefore, there is no reference point for comparison, and any evaluation is purely subjective!
It is also unadvisable to consider short periods, as these need to be adjusted accordingly.
Best regards
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