Good day,
My newly built semi-detached house (about 150 sqm (1600 sq ft) without basement, KfW55 standard) is now nearly 10 months old. The air-to-water heat pump is working well. However, I recently noticed that a couple of friends also built a new semi-detached house (same builder, without basement, KfW55 standard) and they have the same heating system but with 50% less heating capacity, even though their house is 250 sqm (2700 sq ft)!
I would prefer not to operate my heating system inefficiently, and I also paid more for the heating system!
Who should I contact about this? The builder remains silent on this matter.
My newly built semi-detached house (about 150 sqm (1600 sq ft) without basement, KfW55 standard) is now nearly 10 months old. The air-to-water heat pump is working well. However, I recently noticed that a couple of friends also built a new semi-detached house (same builder, without basement, KfW55 standard) and they have the same heating system but with 50% less heating capacity, even though their house is 250 sqm (2700 sq ft)!
I would prefer not to operate my heating system inefficiently, and I also paid more for the heating system!
Who should I contact about this? The builder remains silent on this matter.
H
HilfeHilfe12 Sep 2018 11:21Hello, could you please specify the consumption? Is it really comparable, or do the friends, for example, have collectors?
The houses are almost identical, just with a larger floor area and roof. Both use an air-to-water heat pump with a ventilation system. Neither has solar collectors or similar equipment. The heating capacities are around 4 kW (small model) and 6 kW (large model, which I have). The larger model was also specified in the building contract / planning permission. After all, I am commissioning housebuilding professionals to install a properly calculated heating system. That is my standpoint.
O
Obstlerbaum12 Sep 2018 16:066 kW is generally sufficient for a single-family house, allowing the heating element to activate only at lower temperatures. Energy consumption can typically be reduced by better adjusting the time control to the actual needs. If an unnecessarily large hot water tank is kept at 55°C (131°F) continuously, significant electricity will of course be used. Heating habits also have a strong impact. Anyone who keeps their home at a cozy 23°C (73°F) during winter will naturally pay more...
H
HilfeHilfe12 Sep 2018 17:06Well, the matter is settled now. No one will replace the system, it will only be adjusted as described. What is your energy consumption in kWh? Also, how high is your water consumption (due to hot water)? Anyone who takes a warm shower every day will also heat up
B
boxandroof13 Sep 2018 21:44You are only describing the maximum capacity of the heat pump here. That initially has little to do with actual consumption. You haven’t provided other data yet, such as heat output in kWh and electricity consumption in kWh. Also, KFW 55 is not the same as KfW 55.
A 4kW heating load for KfW55 on 250m² (2700 sq ft) is quite good. 6kW for 150m² (1600 sq ft) is also acceptable. More important would be, among other things, that the underfloor heating is optimized for heat pumps or designed for low supply temperatures, and that you have not installed a buffer tank or bypass valves.
Take some time to learn how to operate a heat pump optimally, then (hopefully) consumption will improve:
- Set the thermostats fully open, or remove them entirely
- Perform hydraulic balancing
- Set the supply temperature as low as possible using the heating curve
And once everything is optimally adjusted, you can go further by, for example, turning off the heating at night for 12 hours, since it runs more efficiently during the day. Then it will typically deliver only 3kW of heat on average and cycle less often.
A 4kW heating load for KfW55 on 250m² (2700 sq ft) is quite good. 6kW for 150m² (1600 sq ft) is also acceptable. More important would be, among other things, that the underfloor heating is optimized for heat pumps or designed for low supply temperatures, and that you have not installed a buffer tank or bypass valves.
Take some time to learn how to operate a heat pump optimally, then (hopefully) consumption will improve:
- Set the thermostats fully open, or remove them entirely
- Perform hydraulic balancing
- Set the supply temperature as low as possible using the heating curve
And once everything is optimally adjusted, you can go further by, for example, turning off the heating at night for 12 hours, since it runs more efficiently during the day. Then it will typically deliver only 3kW of heat on average and cycle less often.
Additionally, hot water should be heated to a maximum of 45°C (113°F). 42°C (108°F) is also possible, but I still find it quite hot when showering.
Do you have a buffer tank for hot water? If so, which one?
And set restriction times for hot water between 7 PM and 10 AM. At night, with low outside temperatures, there is no need to preheat the water.
The circulation pump should not run continuously.
Do you have a buffer tank for hot water? If so, which one?
And set restriction times for hot water between 7 PM and 10 AM. At night, with low outside temperatures, there is no need to preheat the water.
The circulation pump should not run continuously.
Similar topics