ᐅ Neighbor’s ventilation system set too high and therefore too noisy?
Created on: 19 Jul 2021 16:43
T
Toja007
Hello dear forum members,
I am reaching out to you with a problem:
Our neighbors have a controlled central ventilation system (probably a Stiebel Eltron 280), which we find "too loud" and, in my opinion, incorrectly adjusted.
It produces about 60 dB(A) sound pressure level at the exhaust outlet, which faces our terrace. On our terrace, about 8m (26 feet) away, it sounds like a constant airplane flying overhead. The air velocity in the 160mm (6.3 inch) duct is 2.6–2.8 m/s (meters per second), which I calculate to be about 200 m³/h (cubic meters per hour) of air volume (see side question below regarding supply air vs. exhaust air).
This occurs between 7:30 a.m. and 9 p.m., although hardly anyone is home on weekdays during this time (also on weekends, even with open windows). In the evenings, they reduce the system. This is all happening now in summer (May to September); in autumn/winter, they generally turn the system down!?
Our neighbors refer us to the plumbing company that installed and maintains the system; according to them, the system is correctly set.
House data: approx. 450 m³ (cubic meters),
5 occupants
==> Therefore, I come to a required air exchange rate of about 130–150 m³ per hour (factor 0.3 or 25–30 m³ per person for “normal air”).
Side question: On the weekend, they were airing out for two whole days during the daytime at the highest supply air setting, with an air velocity of 3.6 m/s (meters per second) = 260 m³/h, but on the exhaust side, it was 4.5 m/s = 325 m³/h, with a sound pressure level of 70 dB(A). That is 25% higher. It seems to me that the exhaust air from the rooms is set too high? I once read about a maximum deviation of +5–10%.
What do the experts in this forum think? I have already tried talking to the neighbor and might have an independent plumbing company inspect it. So far, no success...
Kind regards, Toja
I am reaching out to you with a problem:
Our neighbors have a controlled central ventilation system (probably a Stiebel Eltron 280), which we find "too loud" and, in my opinion, incorrectly adjusted.
It produces about 60 dB(A) sound pressure level at the exhaust outlet, which faces our terrace. On our terrace, about 8m (26 feet) away, it sounds like a constant airplane flying overhead. The air velocity in the 160mm (6.3 inch) duct is 2.6–2.8 m/s (meters per second), which I calculate to be about 200 m³/h (cubic meters per hour) of air volume (see side question below regarding supply air vs. exhaust air).
This occurs between 7:30 a.m. and 9 p.m., although hardly anyone is home on weekdays during this time (also on weekends, even with open windows). In the evenings, they reduce the system. This is all happening now in summer (May to September); in autumn/winter, they generally turn the system down!?
Our neighbors refer us to the plumbing company that installed and maintains the system; according to them, the system is correctly set.
House data: approx. 450 m³ (cubic meters),
5 occupants
==> Therefore, I come to a required air exchange rate of about 130–150 m³ per hour (factor 0.3 or 25–30 m³ per person for “normal air”).
Side question: On the weekend, they were airing out for two whole days during the daytime at the highest supply air setting, with an air velocity of 3.6 m/s (meters per second) = 260 m³/h, but on the exhaust side, it was 4.5 m/s = 325 m³/h, with a sound pressure level of 70 dB(A). That is 25% higher. It seems to me that the exhaust air from the rooms is set too high? I once read about a maximum deviation of +5–10%.
What do the experts in this forum think? I have already tried talking to the neighbor and might have an independent plumbing company inspect it. So far, no success...
Kind regards, Toja
I would also be interested to know if the supply air/exhaust air ratio might indicate an incorrect setting on the exhaust side.
If that is the case, the problem could potentially be resolved by adjusting the exhaust airflow closer to the supply airflow in terms of volume flow.
If that is the case, the problem could potentially be resolved by adjusting the exhaust airflow closer to the supply airflow in terms of volume flow.
Toja007 schrieb:
According to the plumbing company, the existing hood is already the absolute best... It’s just a simple metal hood, for example available from Wolf. So claiming that it’s the ultimate solution is quite an exaggeration.
In my opinion, the Vallox hood is definitely a superior option. However, whether it would actually solve your problem or not would need to be tested.
Toja007 schrieb:
Maybe the problem is already solved if the exhaust air is closer to the supply air in terms of volume flow. The systems usually handle that automatically. You generally don’t have any influence over it. A pressure imbalance (in both directions) is only possible to a limited extent.
Very interesting problem and detailed conclusion based on your observations. Did you measure the airflow velocity together, or is this a covert project? One might suspect that your profession is a physics teacher.
I have the same duct collar on the wall, but the device is not yet in operation. I just quickly found the option for sound attenuators for supply and exhaust air with Wolf.
I have already bookmarked the sound attenuators for my system.
Search recommendation Wolf sound attenuators DN 180 for CWL-400
I have the same duct collar on the wall, but the device is not yet in operation. I just quickly found the option for sound attenuators for supply and exhaust air with Wolf.
I have already bookmarked the sound attenuators for my system.
Search recommendation Wolf sound attenuators DN 180 for CWL-400
Hello OWLer,
Physics teacher? I was just glad not to have a grade 5 😀 But I am good with numbers and interested in mathematics. However, I have no knowledge of the technical side.
Regarding the measurement: yes, I carried it out myself without involving neighbors; BUT: I did not enter any gardens or climb over fences. The exhaust vent is right in front of their front door, which faces our garden. I wouldn’t do that even if a hurricane came from the system 😉
Physics teacher? I was just glad not to have a grade 5 😀 But I am good with numbers and interested in mathematics. However, I have no knowledge of the technical side.
Regarding the measurement: yes, I carried it out myself without involving neighbors; BUT: I did not enter any gardens or climb over fences. The exhaust vent is right in front of their front door, which faces our garden. I wouldn’t do that even if a hurricane came from the system 😉
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