Hello everyone,
we are planning a prefabricated house using timber frame construction. It will have 180 sqm (1,937 sq ft) of living space with underfloor heating, and about 230 sqm (2,475 sq ft) of usable area.
So far, the offer included an air-to-water heat pump from Daikin (Altherma 3R, formerly Rotex HPSU compact Ultra).
Now it seems that this unit might not have enough capacity (?) and as an alternative (additional cost around 4,000) we have been offered a "Wolf heat pump CHC Monoblock 10/300-35".
The Daikin is available in the 4-9 kW version—would that really be insufficient for this size? And what do you think about this offer?
I have the energy-saving regulation heat protection certification and a renewable energy heat law document available, if any information from those is needed.
Thank you very much!
Best regards
we are planning a prefabricated house using timber frame construction. It will have 180 sqm (1,937 sq ft) of living space with underfloor heating, and about 230 sqm (2,475 sq ft) of usable area.
So far, the offer included an air-to-water heat pump from Daikin (Altherma 3R, formerly Rotex HPSU compact Ultra).
Now it seems that this unit might not have enough capacity (?) and as an alternative (additional cost around 4,000) we have been offered a "Wolf heat pump CHC Monoblock 10/300-35".
The Daikin is available in the 4-9 kW version—would that really be insufficient for this size? And what do you think about this offer?
I have the energy-saving regulation heat protection certification and a renewable energy heat law document available, if any information from those is needed.
Thank you very much!
Best regards
S
Smirnoff19833 Nov 2021 08:58OWLer schrieb:
In the upstairs bathroom, in my opinion, the small area has been used quite well. Unfortunately, even after long discussions, the general contractor (GC) did not want to fully adjust the shower layout or the area under the bathtub. Still, the 5cm (2 inches) spacing up there is quite accurate.
For the downstairs toilet, I roughly estimated about 7cm (3 inches) spacing (specification is 5cm (2 inches)). Except for the corridors and bathrooms, everything else now has a full 10cm (4 inches) spacing and, in my opinion, looks really good. How did you convince your GC to agree on the pipe spacing? My GCs always tell me that the spacing is calculated and designed individually for each room.
I’m always worried that the GC just wants to save on material costs and will end up installing larger pipe spacings (including higher supply temperatures), simply because that’s how they’ve always done it.
Did you have to consider anything specific regarding cooling with the air-to-water heat pump? For example, when laying the pipes or installing the associated technology?
Does anyone know if it’s possible to simply apply a 5cm (2 inches) pipe spacing in the bathroom/guest toilet and 10cm (4 inches) spacing in the other rooms? Or is it better to use and implement the room-specific calculations? Can specific values be preset in the calculation?
Smirnoff1983 schrieb:
How did you convince your general contractor (GC) about the installation spacing? The GCs keep telling me that the spacing is calculated and designed individually for each room. I had the installation spacing calculated myself based on my target specifications. The result looks like this, for example: #123
After that, you have to be persistent.
S
Smirnoff19833 Nov 2021 09:13OWLer schrieb:
I had the installation spacing calculated myself based on my target specifications. The result looks like this, for example: #123
Then you have to be persistent. Did you specify values for the calculation? Like supply/return/room temperature? Or how were the values determined?
Desired room temperature and U-values of the house + postal code for NAT.
Then instruction to the calculator: I want to lower the supply temperature as much as possible and the expected heat pump used for the maximum flow rate.
It turned out that, according to the standard, we built a less favorable house, so we can only operate with a supply temperature of 34.5°C (94.1°F) and a 5 K temperature difference.
Then instruction to the calculator: I want to lower the supply temperature as much as possible and the expected heat pump used for the maximum flow rate.
It turned out that, according to the standard, we built a less favorable house, so we can only operate with a supply temperature of 34.5°C (94.1°F) and a 5 K temperature difference.
B
Benutzer2003 Nov 2021 09:47Smirnoff1983 schrieb:
Did you specify values for the calculation? Like supply temperature/return temperature/room temperature??? Or how did you arrive at these values? That’s exactly how it should be done. There are many ways to achieve the same goal. First, the heating load for each room must be known or calculated.
Then, you can achieve the same result (a warm home) with, for example, 30/26/22 or 40/34/22 (these are just example numbers). The first case would use pipe spacing between 5 and 10cm (2 and 4 inches), the second with spacing between 10 and 15cm (4 and 6 inches). So it’s either proper planning with some extra effort (and cost) or a quick and easy solution. With a high supply temperature, you can heat any building, but it’s less efficient.
S
Smirnoff19833 Nov 2021 11:42Benutzer200 schrieb:
That's exactly how it’s done. There are many ways to achieve the same result. First, the heating load for each room must be known or calculated.
Then you can reach the same result (= a warm apartment) with pipe spacing of 30/26/22 or 40/34/22 (just example figures). The first option uses spacing between 5 and 10cm (2 and 4 inches), the second uses spacing of 10-15cm (4 to 6 inches). So either proper planning and a bit more effort (costs), or a standard approach. With a high flow temperature, any building can be heated. Wouldn't it then be simpler to contractually specify: "all rooms 10cm (4 inches) & bathroom 5cm (2 inches)"???
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