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
Toja007 schrieb:
The system has been off since this morning 🙄 So it doesn’t seem to be completely indifferent to them after all. Now seriously. If my neighbor gave me a strange look when I switched off my mechanical ventilation system and then wrote me a letter asking me to ventilate but with a lower airflow rate... I’m not sure I’d be able to stay as calm as your neighbor apparently did.
Schimi179120 Jul 2021 10:02Toja007 schrieb:
...
But yes, I agree with you, on our terrace it’s naturally quieter, about 35-40 dB(A). Still, that constant low-level noise is really annoying 🙁 I’ll do some research and I have a contact for an acoustics expert through a colleague. I’ll give them a call.As we know from the garden thread, sounds and their volume levels are perceived very subjectively. However, 35 to 40 dB is roughly in the range of a refrigerator or dishwasher.
35 dB is roughly the noise level you experience when sitting in a room with closed windows—that is, the wind rustling through the leaves is louder. I believe if you couldn't see the ventilation duct at all, you would never have noticed it. It's all a matter of perception.
Tolentino schrieb:
35 dB is roughly the level of quietness you experience sitting in a room with the windows closed. That means wind rustling through leaves is actually louder.
I believe that if you couldn’t even see the ventilation duct, you probably wouldn’t have noticed it at all. It’s mostly psychological. Noise is not just noise. Some sounds are perceived as more annoying than others. I think the rustling of leaves evokes a different feeling than the sound of a ventilation system.
And yes: the mind definitely plays a role. Because drawing conclusions about perceived annoyance solely from sound pressure levels is only possible to a limited extent. Some people are more sensitive to noise than others. Some tolerate cold better, while others handle heat better. Nevertheless, I believe I should be able to talk to my neighbor. After all, we are all reasonably civilized.
And no: I didn’t see the duct and then search for a noise 😉
I kindly ask for constructive contributions on the topic. Thank you!
I just took a rough measurement with my phone and got around 58-59 dB right at the grille with a nominal airflow of 200 m³/h (120 CFM). When I step back 5-6 meters (16-20 feet), the noise is no longer audible. How did you measure the 35 dB, at what distance, and how do you attribute that value? During the specified daytime hours, almost everything in your environment is louder than 35 dB.
Disclaimer, now comes my personal opinion. I find it, let’s say cautiously, difficult when someone tries to turn their own issues into problems for others.
Disclaimer, now comes my personal opinion. I find it, let’s say cautiously, difficult when someone tries to turn their own issues into problems for others.
Thank you for the shift away from technical solutions like mufflers toward statements such as "it's not that bad," "I can't hear anything from 6 meters (20 feet) away," or "it's just in your head"; in reality, the noise is gone. I saved a lot of money. 😉
I’m planning to let my robotic lawn mower run at night soon, too; it’s not that loud—only 59 dB(A) at the mower. The sound is less noticeable further away. And I actually like the noise. It doesn’t matter how my neighbors perceive it... NO, after one neighbor asked me to run it a bit less or at different times, I reprogrammed it in agreement with them.
I’m planning to let my robotic lawn mower run at night soon, too; it’s not that loud—only 59 dB(A) at the mower. The sound is less noticeable further away. And I actually like the noise. It doesn’t matter how my neighbors perceive it... NO, after one neighbor asked me to run it a bit less or at different times, I reprogrammed it in agreement with them.