Hello everyone,
for our new construction project aiming for KfW55 standard, we are planning to install a central ventilation system with heat recovery (yes, we discussed this extensively and decided on it). I have now received the initial plan from Zehnder, see attachment.
Some points have not been recorded correctly, for example the ceiling height on the upper floor, as we are planning an "open ceiling" here. The calculation is based on a ceiling height of 2.50m (8.2 feet), which is clearly too low. The other height references are also inconsistent; once the finished floor level of the ground floor is used, another time the top edge of the floor slab in the basement. I have already pointed this out.
Aside from that, I often read that these systems tend to be somewhat oversized to allow for reserves and partial load operation. Zehnder suggested the Q350TR model to us.
What also strikes me is the low number of supply air vents – or am I mistaken? For example, there are no vents in the hallway/wardrobe area. I would also have expected two vents per bedroom and children’s room (?).
It is important to us that no noises or drafts are noticeable, and that we do not regret a wrong decision afterwards that initially seemed like a cost-saving measure. We are not committed to a single manufacturer; Zehnder was chosen because I have only read good things so far.
Thanks for taking a look!
Best regards,
Jentopa
for our new construction project aiming for KfW55 standard, we are planning to install a central ventilation system with heat recovery (yes, we discussed this extensively and decided on it). I have now received the initial plan from Zehnder, see attachment.
Some points have not been recorded correctly, for example the ceiling height on the upper floor, as we are planning an "open ceiling" here. The calculation is based on a ceiling height of 2.50m (8.2 feet), which is clearly too low. The other height references are also inconsistent; once the finished floor level of the ground floor is used, another time the top edge of the floor slab in the basement. I have already pointed this out.
Aside from that, I often read that these systems tend to be somewhat oversized to allow for reserves and partial load operation. Zehnder suggested the Q350TR model to us.
What also strikes me is the low number of supply air vents – or am I mistaken? For example, there are no vents in the hallway/wardrobe area. I would also have expected two vents per bedroom and children’s room (?).
It is important to us that no noises or drafts are noticeable, and that we do not regret a wrong decision afterwards that initially seemed like a cost-saving measure. We are not committed to a single manufacturer; Zehnder was chosen because I have only read good things so far.
Thanks for taking a look!
Best regards,
Jentopa
Thank you @Mycraft
Do you mean an additional exhaust vent in the HVAC room? One is already planned.
Does the building volume not play a role in the design or calculation?
What is your opinion on the ventilation unit—is it sufficient, or would a larger model (Q450) be better?
A quick note on our specific requirements, if that’s what you meant: as quiet as possible, especially in the bedrooms. That’s why I was thinking of two supply air vents, each with half the air volume—if that makes sense.
Sorry for all the questions.
Do you mean an additional exhaust vent in the HVAC room? One is already planned.
Does the building volume not play a role in the design or calculation?
What is your opinion on the ventilation unit—is it sufficient, or would a larger model (Q450) be better?
A quick note on our specific requirements, if that’s what you meant: as quiet as possible, especially in the bedrooms. That’s why I was thinking of two supply air vents, each with half the air volume—if that makes sense.
Sorry for all the questions.
Jentopa schrieb:
Do you mean an additional exhaust vent in the HVAC room? One is already planned. I must have overlooked that.
Jentopa schrieb:
Does the building volume not play a role in the design or calculation? Of course it does. But everything is well within the limits for your case.
Jentopa schrieb:
What is your opinion on the ventilation unit? Is it sufficient, or would a larger one (Q450) be better? The 350 model is sufficient. However, you can of course go with the 450 if you prefer.
Jentopa schrieb:
A quick note about our special requirements, in case you mean that: as quiet as possible, especially in the bedrooms. That’s why I was thinking of two supply air vents each at half airflow – if that makes sense. You can simply have a larger vent installed; this will reduce the outlet noise even further. For example, I only hear my system when it’s running at full capacity, and I am a very light sleeper.