ᐅ Negative pressure monitor / chimney 4 Pa?

During the construction phase (before the screed/plaster), the cable is installed permanently and does not cost much. If necessary, you can lay the cable yourself and connect it to the electrician’s wiring. Once the cables are in place, they can be connected later.

The pressure difference is minimal. We have a chimney with DIBt approval (and a central ventilation system), and the pressure difference between inside the building and outside is nowhere near 1 Pa. If the pressure switch no longer works (after the screed is applied, the cable is difficult to install—maybe consider a wireless solution?!), you still have a chimney with DIBt approval as an option.

Payday schrieb:
you still need a chimney with DIBT approval.

Hi,

unfortunately, the DIBT approval alone is not the only criterion. The BSFM can still require a negative pressure monitor.

Best regards
Thorsten

Hello,

Just out of curiosity:

T21150 schrieb:
Hi,

unfortunately, the DIBt approval is not the only criterion. The BSFM can still require a negative pressure monitor.

I keep hearing this, but is there any reliable source for it?

Both the stove installer and the BSFM responsible for us clearly state that in our situation (central ventilation system and a recirculation hood in the kitchen), a DIBt-approved stove does not require a pressure monitor, and there is no legal basis to demand one.

There must be a legally _clear_ regulation somewhere, right?! It can’t be that someone has to pay around 1,000 euros for a pressure monitor (which probably contains measurement technology worth less than 20 euros…) just because the BSFM feels like requiring it, while the next person does not?

Yes, I have learned by now that building regulations are very, very full of absurdities, but this would ultimately be arbitrary.

Installing a pressure monitor as an additional safety measure is certainly a good idea, especially since it can be a matter of life and death in extreme cases. But as I said, where is this actually defined for sure?

Best regards,

Andreas

There are information sheets and optional regulations. Does your mechanical ventilation system with heat recovery automatically shut off, for example, if the supply air is faulty? Is there a certification for the ventilation system confirming that it cannot create negative pressure?

We also have a mechanical ventilation system with heat recovery, a recirculation hood, and a DiBT-approved stove, but still had to install a negative pressure monitor. The chimney sweep has the final say.
I no longer have the documents with the relevant requirements readily available.

Hi,

this will be a Helios ventilation system. So far, I have assumed that the ventilation unit would shut down and indicate a fault if individual components like motors (e.g., the supply air fan) fail, just like any proper device should. Otherwise, it probably wouldn’t be allowed. A washing machine, for example, also stops drawing water if the drain pump is broken.

I hope my assumption isn’t too naive.

Best regards,

Andreas

andimann schrieb:
Hi,

this will be a Helios ventilation system. So far, I have assumed that the ventilation unit would shut down and signal a fault if individual components like the motors (e.g., the supply air fan) fail, just like any proper device. Anything else should actually not be permissible. A washing machine also stops drawing water if, for example, the drain pump breaks.


I hope my assumption isn’t too naive.


Best regards,

Andreas

No, the assumption is too naive.
You have to provide the chimney sweep with everything in writing; basing things on assumptions won’t help you.
It’s possible that the ventilation still pushes out the full volume while no longer supplying enough air, which can cause negative pressure inside the house. Can Helios confirm in writing that under no circumstances whatsoever can a negative pressure exceeding 4 Pa (0.00058 psi) develop inside the house? If yes, you’re in a good position; if not, it could get expensive.