Which pressure switch do you recommend? Any experiences? We want to operate a fireplace (room air-independent) that requires a pressure switch. We will have decentralized ventilation from Inwert.
The chimney sweep said the fireplace must be tested at 4 Pa (0.016 inch water column) and the pressure switch must activate at 4 Pa (0.016 inch water column).
Wouldn’t the ventilation system keep shutting off constantly then?
The chimney sweep said the fireplace must be tested at 4 Pa (0.016 inch water column) and the pressure switch must activate at 4 Pa (0.016 inch water column).
Wouldn’t the ventilation system keep shutting off constantly then?
Hey everyone,
please don’t argue so strongly.
The points from both sides are valid and understandable. You both are very knowledgeable.
However – we live in Germany and have BSFW (building supervisory authority). They have discretionary power, and that discretion cost me quite a bit of money regarding the heating system. I even had to give up part of my garden for it.
A DIBt-certified chimney (stove) alone is definitely not enough.
If there is a controlled ventilation system, it must also have DIBt certification.
Exhaust hoods and similar equipment are included. This is where it starts to become critical.
The BSFW can still insist on an underpressure monitor, even if only DIBt-certified devices are installed in the house.
In my case, after a *very* thorough demonstration of expertise and a review of all documentation of the existing technology, they initially waived this requirement. We monitor the situation by mutual agreement, though.
I have made all the preparations to install an underpressure monitor if any slight indications require it. However, my stove is serviced annually by my chimney specialist, seals are regularly replaced, and the chimney is swept four times a year. I also never leave the stove door open.
Anyone building a new house with a chimney (stove) should definitely install wiring for an underpressure monitor and coordinate with the BSFW. Ultimately, it’s a matter of about 1000 euros (approximately 1100 US dollars).
So let’s calm down, continue celebrating Easter, and accept that an underpressure monitor is generally sensible, and that BSFW does not always operate strictly following scientific measures—and that they are allowed to do so.
Best regards,
Thorsten
please don’t argue so strongly.
The points from both sides are valid and understandable. You both are very knowledgeable.
However – we live in Germany and have BSFW (building supervisory authority). They have discretionary power, and that discretion cost me quite a bit of money regarding the heating system. I even had to give up part of my garden for it.
A DIBt-certified chimney (stove) alone is definitely not enough.
If there is a controlled ventilation system, it must also have DIBt certification.
Exhaust hoods and similar equipment are included. This is where it starts to become critical.
The BSFW can still insist on an underpressure monitor, even if only DIBt-certified devices are installed in the house.
In my case, after a *very* thorough demonstration of expertise and a review of all documentation of the existing technology, they initially waived this requirement. We monitor the situation by mutual agreement, though.
I have made all the preparations to install an underpressure monitor if any slight indications require it. However, my stove is serviced annually by my chimney specialist, seals are regularly replaced, and the chimney is swept four times a year. I also never leave the stove door open.
Anyone building a new house with a chimney (stove) should definitely install wiring for an underpressure monitor and coordinate with the BSFW. Ultimately, it’s a matter of about 1000 euros (approximately 1100 US dollars).
So let’s calm down, continue celebrating Easter, and accept that an underpressure monitor is generally sensible, and that BSFW does not always operate strictly following scientific measures—and that they are allowed to do so.
Best regards,
Thorsten
B
bierkuh8329 Mar 2016 13:43Since I want to install a fireplace and an exhaust hood at my home, I have looked into the topic and did not find any arbitrary rules.
Room-air-independent fireplaces are approved according to DIBt certification (all) for a negative pressure of up to 8 Pa (0.03 inches water column). Compliance must be demonstrated to the chimney sweep through calculation or measurement. The latter can be done by the chimney sweep himself.
For room-air-dependent fireplaces, a negative pressure of less than 4 Pa (0.016 inches water column) must be proven, see the options mentioned above. Alternatively, without proof, a safety device (such as a ventilation control device, window contact switch) can be installed.
Since my exhaust hood can extract about 750 m³/h (441 cubic feet per minute), I am not considering proof. I will have a window contact switch and a temperature sensor installed in the flue pipe. The former costs 100 coins, and the latter is worth about 250 € to me for the comfort of not having to open the window wide at around -10°C (14°F).
Room-air-independent fireplaces are approved according to DIBt certification (all) for a negative pressure of up to 8 Pa (0.03 inches water column). Compliance must be demonstrated to the chimney sweep through calculation or measurement. The latter can be done by the chimney sweep himself.
For room-air-dependent fireplaces, a negative pressure of less than 4 Pa (0.016 inches water column) must be proven, see the options mentioned above. Alternatively, without proof, a safety device (such as a ventilation control device, window contact switch) can be installed.
Since my exhaust hood can extract about 750 m³/h (441 cubic feet per minute), I am not considering proof. I will have a window contact switch and a temperature sensor installed in the flue pipe. The former costs 100 coins, and the latter is worth about 250 € to me for the comfort of not having to open the window wide at around -10°C (14°F).
Hello everyone,
I need to make a general mea culpa here...
Indeed, my assumption that a controlled residential ventilation system in 2016 would at least meet the basic safety requirements of the Machinery Directive was obviously too naive.
I have now been informed by Helios that these units have no internal monitoring or safety features. That means if the supply air fan fails, the device does not shut down (as is actually required by the Machinery Directive; I honestly don’t understand why these units are still allowed to be sold) but the exhaust air fan keeps running. Also, in the case of heat exchanger icing, only the supply air is restricted, not the exhaust air!
In other words, the design concept of these systems clearly did not intend for operation together with a wood-burning stove (whether room air-dependent or room air-independent).
Monitoring the motor speeds would only cost a few cents to euros. Every cheap car has several differential pressure sensors—that’s just trivial.
This means, as I understand it:
When installing a wood-burning stove without DIBt (German Institute for Construction Technology) certification, a pressure monitor is definitely required, no question.
When installing a DIBt-certified wood stove, it might work without a pressure monitor. No one can reliably predict this (so the statements made to me by the stove builder and BSFM were not correct). You can only measure in the installed state what happens if, at the highest ventilation level, the supply air fan fails or intake is blocked. If the underpressure remains above 8 Pa (0.03 inches water gauge), that’s acceptable. But this will always depend on the airtightness of the building and therefore cannot be generally guaranteed. And the catch: Strictly speaking, the measurement is only valid for the current weather and especially wind conditions! No one can tell you whether more or less wind will make the chimney draft better or worse, or if wind vortices from neighboring buildings or trees will affect the chimney draft behavior.
At this point, it becomes a lottery… the odds are low, but if something goes wrong, the consequences are really serious.
For my personal safety requirements, this means:
It does not matter at all if someone would approve it without a pressure monitor. Installing a controlled residential ventilation system together with a wood stove (even a DIBt-certified one) REQUIRES the installation of a pressure monitor. Anything else is playing Russian roulette with your own life.
Since equipping the stove with the DIBt option would cost me an additional €185, I can basically save that and instead install the pressure monitor directly for €380. This limits the extra cost to just under €200.
Best regards,
Andreas
I need to make a general mea culpa here...
nordanney schrieb:
No, the assumption is too naive.
You have to prove everything to the chimney sweep in black and white; just assuming something doesn’t help you.
Indeed, my assumption that a controlled residential ventilation system in 2016 would at least meet the basic safety requirements of the Machinery Directive was obviously too naive.
I have now been informed by Helios that these units have no internal monitoring or safety features. That means if the supply air fan fails, the device does not shut down (as is actually required by the Machinery Directive; I honestly don’t understand why these units are still allowed to be sold) but the exhaust air fan keeps running. Also, in the case of heat exchanger icing, only the supply air is restricted, not the exhaust air!
In other words, the design concept of these systems clearly did not intend for operation together with a wood-burning stove (whether room air-dependent or room air-independent).
Monitoring the motor speeds would only cost a few cents to euros. Every cheap car has several differential pressure sensors—that’s just trivial.
This means, as I understand it:
When installing a wood-burning stove without DIBt (German Institute for Construction Technology) certification, a pressure monitor is definitely required, no question.
When installing a DIBt-certified wood stove, it might work without a pressure monitor. No one can reliably predict this (so the statements made to me by the stove builder and BSFM were not correct). You can only measure in the installed state what happens if, at the highest ventilation level, the supply air fan fails or intake is blocked. If the underpressure remains above 8 Pa (0.03 inches water gauge), that’s acceptable. But this will always depend on the airtightness of the building and therefore cannot be generally guaranteed. And the catch: Strictly speaking, the measurement is only valid for the current weather and especially wind conditions! No one can tell you whether more or less wind will make the chimney draft better or worse, or if wind vortices from neighboring buildings or trees will affect the chimney draft behavior.
At this point, it becomes a lottery… the odds are low, but if something goes wrong, the consequences are really serious.
For my personal safety requirements, this means:
It does not matter at all if someone would approve it without a pressure monitor. Installing a controlled residential ventilation system together with a wood stove (even a DIBt-certified one) REQUIRES the installation of a pressure monitor. Anything else is playing Russian roulette with your own life.
Since equipping the stove with the DIBt option would cost me an additional €185, I can basically save that and instead install the pressure monitor directly for €380. This limits the extra cost to just under €200.
Best regards,
Andreas
S
Sebastian7930 Mar 2016 11:23You can also use a controlled residential ventilation system from Zehnder, which includes monitoring. However, I personally preferred Helios...
N
nordanney30 Mar 2016 11:32The ones from Vallox also do not switch off.
S
SteffenBank30 Mar 2016 13:34I would like to briefly join in with what might be a "silly" question.
Is a U-value also required for a decentralized ventilation system?
The supply air in the rooms is provided via Lunos ALD-R 160 units, so without fans or heat recovery. For exhaust air, we are using Lunos RA 15-60.
This is just a theoretical question. A chimney is present, but a fireplace is still something for the future.
Is a U-value also required for a decentralized ventilation system?
The supply air in the rooms is provided via Lunos ALD-R 160 units, so without fans or heat recovery. For exhaust air, we are using Lunos RA 15-60.
This is just a theoretical question. A chimney is present, but a fireplace is still something for the future.
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