Underpressure monitor / Chimney 4 Pa

during the construction phase (before the screed/plaster) the cable is fixed in place and does not cost a lot. if necessary, lay a cable yourself and connect it to the electrician’s wiring. once the cables are there, you can connect them 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 not even close to 1Pa. if the pressure switch stops working (after the screed the cable is hard to lay - possibly a wireless solution?! ) you still have a chimney with dibt approval.

You still have a fireplace with dibt approval.

Hi,

unfortunately, it is the case that the DIBT approval is not the sole criterion. The BSFM can still require a negative pressure monitor.

Best regards
Thorsten

Hello,

Just out of interest:

Hi,

unfortunately, it is the case that the DIBT approval is not the sole criterion. The BSFM can still require a negative pressure monitor.

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

Both the stove builder and the BSFM responsible for us say clearly that in our configuration (central ventilation system and a recirculating hood in the kitchen) with a DIBT stove, no pressure monitor is needed anymore and there is also no legal basis to require one.

This must be legally _clearly_ regulated somewhere, right?!? It can’t be that someone has to drop 1,000 € on a pressure monitor (which probably contains measuring technology worth less than 20 €) just because the BSFM feels like it, and the next person doesn’t?

Yes, I have by now learned that building law is very, very full of absurdities, but this would be outright arbitrariness.

Installing a pressure monitor as an additional safety measure is certainly a good idea; after all, in extreme cases it’s about life and limb. But as I said, where is this really stipulated?

Many greetings,

Andreas

There are information sheets and optional regulations. Does your controlled residential ventilation system shut off automatically, for example, if the supply air is defective? Is there a confirmation regarding the controlled residential ventilation system that it cannot create negative pressure?

We are also equipped with controlled residential ventilation + recirculation hood + [DiBT-Ofen], but also had to install the negative pressure monitor. The chimney sweep has the final say. I no longer have the documents that contain the requirements readily available.

Hi,

this will be a Helios ventilation system. Until now, I have assumed that the ventilation system, in case of failure of individual components such as motors (e.g. supply air fan), like any decent device, goes into fault and thus shuts down. Anything else should actually not be permissible. A washing machine also does not draw more water if, for example, the wastewater pump is broken.

I hope my assumption was not too naive.

Best regards,

Andreas

Hi,

this will be a Helios ventilation system. So far, I have assumed that the ventilation system, in the event of failure of individual components such as motors (e.g. supply air fan), would fail and thus shut down like any decent device. Anything else should actually not be permissible. A washing machine also does not draw any more water if, for example, the wastewater pump is broken.


I hope my assumption was not too naive.


Best regards,

Andreas

No, the assumption is too naive
You have to prove everything to the chimney sweep in black and white; just assuming something does not help you.
It may be that the ventilation system, for example, no longer supplies enough air but still outputs the full volume. Then you get a negative pressure inside the house. Can Helios confirm to you in writing that under no, absolutely no circumstances, can a negative pressure of more than 4Pa arise inside the house? If yes, you have good chances; if not, it can get expensive.