Dear community,
Our building specification includes a controlled ventilation system for our future KfW 70 house. Our developer now wants to sell it to us as having slots on the outside of the windows, where air is drawn into the window frame and then released back into the room through slots at the top of the frame. Although the slots can be opened and closed, this system is supposed to operate without any fans. The best part is that these slots are only cut after the blower door test.
1. Question: Is this sufficient to achieve KfW 70 standard?
2. Question: Is it allowed to cut the slots only after the blower door test?
Thank you very much for your feedback.
Best regards,
Michael
Our building specification includes a controlled ventilation system for our future KfW 70 house. Our developer now wants to sell it to us as having slots on the outside of the windows, where air is drawn into the window frame and then released back into the room through slots at the top of the frame. Although the slots can be opened and closed, this system is supposed to operate without any fans. The best part is that these slots are only cut after the blower door test.
1. Question: Is this sufficient to achieve KfW 70 standard?
2. Question: Is it allowed to cut the slots only after the blower door test?
Thank you very much for your feedback.
Best regards,
Michael
M
MüllerausKaarst21 May 2012 10:06€uro schrieb:
Unfortunately, full modulation is an unknown term here. An outdated "On/Off" technology.
Regards.Better to first ask which Tecalor model is installed before simply criticizing.
Tecalor THZ 303 Integral
...Supply/exhaust air volume flow 80-230 m3/h (47-135 CFM)...
"...Electronic outdoor temperature-controlled regulation for the heating circuit. Electronically stepless adjustment of the fans. Intelligent control with program presets for fans, heating, domestic hot water, and absence. Integrated control unit also usable as a remote control. Expansion tank 7.5 liters (1.98 gallons) / 0.75 bar (10.9 psi), circulation pump....
I believe linking is not allowed.
Best regards
MüllerausKaarst schrieb:
...better to ask first which Tecalor model is installed before simply criticizing The Tecalor is identical in construction to SE. Full modulation means that both the evaporator and the compressor are adjusted to the required heating output. Currently, neither SE nor Tecalor have a solution for this!
An on/off unit:
A fully modulating air source heat pump:
Hopefully, you have a very well-insulated building; otherwise, you might be overwhelmed by the later operating costs for heating and domestic hot water.
What is the calculated heating load according to DIN 12831?
These combi- (compromise) solutions are very often sold by general contractors because they are cheap
best regards
M
MüllerausKaarst21 May 2012 19:53€uro schrieb:
The Tecalor unit is identical to SE. Full modulation means that both the evaporator and the compressor adjust to the required heating output. Currently, neither SE nor Tecalor offer a solution for this!
An on/off unit:
A fully modulating air heat pump:
Hopefully, you have a very well-insulated building; otherwise, your future heating and hot water operating costs might be overwhelming.
What is the calculated heating load according to DIN 12831?
These combi- (compromise) solutions are often sold by general contractors because they are cheap.
Regards.Thank you for the explanation regarding air-to-water heat pumps and full modulation,
but I think that was off-topic.
The topic of the thread was about the ventilation system and someone suggesting slots in the window as a ventilation system.
In our case, the ventilation system is integrated into the Tecalor heating unit.
Additionally, our house has 17cm (7 inches) of thermal insulation on the upper floors and 12cm (5 inches) in the basement.
Best regards,
Ralf
T
Thomas46322 May 2012 11:59mik schrieb:
Dear community,
Our building specifications include a controlled ventilation system for our future KfW70 house.With windows that have ventilation slots, I cannot see how controllability is guaranteed. Also, when the word SYSTEM is mentioned, I expect a technical device and not a "leaky window" (exaggerating here).
mik schrieb:
The best part is that these slots are only cut after the blower door test.
1. Question: Will this still meet the KfW70 standard?
2. Question: Is it allowed to cut the slots only after the blower door test?
Thank you very much for your feedback.
Best regards, MichaelIn my opinion, the building must be tested exactly as it will be handed over. Therefore, the openings should already be present when the blower door test is carried out, just as you will receive the building.
You can apply the same test to a cardboard house, and then make some holes afterwards => this would completely distort the results.
After all, the house must meet the required airtightness level after handover. If testing with the openings is acceptable, then the test must be performed this way (and it should not pose a problem). But if the openings worsen the values (which is likely), this must also be taken into account.
Best regards, Thomas
Hi, we received an offer from our developer for the central controlled residential ventilation system with the Zehnder ComfortAir 350. However, the total cost is almost 12,000 € (approximately 13,000 USD). Could you please tell me if this price is similar to what you paid or if it seems rather high?
I would be very grateful for some reassurance.
Regards,
Patrick
I would be very grateful for some reassurance.
Regards,
Patrick
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