We are planning our 40+ single-family house with a ground source heat pump and a ventilation system with heat recovery.
Some time ago, we visited a show home from a company that starts with "Finger" and ends with "Haus" (I'm not sure if the name can be mentioned). This show home also had a ground source heat pump with a ventilation system equipped. The air ducts for it were located on the floor, both on the ground floor and the upper floor. We already noticed the relatively loud noise from the ventilation downstairs, but when we were upstairs in a closed meeting room, it was really disturbingly loud.
I can’t quite describe it properly; it sounded like metal blowing air. Really hard to explain, but it was definitely noticeable and unpleasant.
On another occasion, we visited a show home by a company with "Streif Haus" in the name, but no extra suffix at the end. Here, however, there was a ground source heat pump with integrated ventilation. We absolutely couldn’t hear anything, not even with the door closed and my head (almost) right at the air outlet on the wall.
Actually, we have never heard the air in any of the houses; it was only noticeable in the first house mentioned.
Since we are considering the same system principle, albeit with different brands, I’m now a bit worried that it might be the same with us, and then this system would be turned off 100%, permanently! That’s simply not an option, not only when sleeping but in general.
Are there general things to consider in advance to reduce the "noise"?
Is the brand decisive?
Are the ducts included with the brand of the ventilation system, or do they generally come from somewhere else, so that one can be lucky or unlucky depending on what the builder installs?
I would appreciate your answers…
Best regards Dany250
Some time ago, we visited a show home from a company that starts with "Finger" and ends with "Haus" (I'm not sure if the name can be mentioned). This show home also had a ground source heat pump with a ventilation system equipped. The air ducts for it were located on the floor, both on the ground floor and the upper floor. We already noticed the relatively loud noise from the ventilation downstairs, but when we were upstairs in a closed meeting room, it was really disturbingly loud.
I can’t quite describe it properly; it sounded like metal blowing air. Really hard to explain, but it was definitely noticeable and unpleasant.
On another occasion, we visited a show home by a company with "Streif Haus" in the name, but no extra suffix at the end. Here, however, there was a ground source heat pump with integrated ventilation. We absolutely couldn’t hear anything, not even with the door closed and my head (almost) right at the air outlet on the wall.
Actually, we have never heard the air in any of the houses; it was only noticeable in the first house mentioned.
Since we are considering the same system principle, albeit with different brands, I’m now a bit worried that it might be the same with us, and then this system would be turned off 100%, permanently! That’s simply not an option, not only when sleeping but in general.
Are there general things to consider in advance to reduce the "noise"?
Is the brand decisive?
Are the ducts included with the brand of the ventilation system, or do they generally come from somewhere else, so that one can be lucky or unlucky depending on what the builder installs?
I would appreciate your answers…
Best regards Dany250
Speculation ON:
When sheet metal air ducts are connected, air turbulence (possibly including vibrations) can occur at the joints (organ pipe effect), causing noise disturbances.
However, it would be very unlikely for the exact same effect to happen in another building using the same technique.
I wouldn’t be fundamentally concerned if that were the case.
A firm hit on the joint can sometimes eliminate the “defect.”
Even if fans and ducts are sold under the same brand, they usually come from different manufacturers.
When sheet metal air ducts are connected, air turbulence (possibly including vibrations) can occur at the joints (organ pipe effect), causing noise disturbances.
However, it would be very unlikely for the exact same effect to happen in another building using the same technique.
I wouldn’t be fundamentally concerned if that were the case.
A firm hit on the joint can sometimes eliminate the “defect.”
Even if fans and ducts are sold under the same brand, they usually come from different manufacturers.
I’m not sure, it sounded the same throughout the entire house. I would support your theory if it were happening in individual rooms, but it was the case both downstairs and upstairs. It wasn’t a whistle, just a constant noise like metallic wind in a duct (I wish I could explain it better).
Since there isn’t much feedback here, I hope it’s because the problems rarely occur, which is a bit reassuring 🙂.
Since there isn’t much feedback here, I hope it’s because the problems rarely occur, which is a bit reassuring 🙂.
O
Oetzberger16 Oct 2021 15:32Well, if noise levels are important, first you need to choose a high-quality ventilation unit and second, design the air ducts generously. Use sufficiently large duct cross-sections or several ducts for supply and exhaust openings with high airflow volume. Avoid excessively long duct runs, and very importantly, perform proper balancing where at least one of the dampers remains fully open. If you cut corners from the start, it’s difficult to fix later on.
For those who are particularly sensitive, install two silencers in series after the unit. It’s also important that the main ventilation ducts to the outside air and exhaust air from the mechanical ventilation with heat recovery system are kept as short as possible. Additionally, consider planning for an enthalpy exchanger (or at least the option to switch to one later), which makes the system much more comfortable.
For those who are particularly sensitive, install two silencers in series after the unit. It’s also important that the main ventilation ducts to the outside air and exhaust air from the mechanical ventilation with heat recovery system are kept as short as possible. Additionally, consider planning for an enthalpy exchanger (or at least the option to switch to one later), which makes the system much more comfortable.
Maybe the system in that one house was just "loud" because it was either undersized and/or set to a very high level. In dense new developments with closely built houses, it shouldn’t feel stuffy, and a great indoor climate is often advertised everywhere – so thorough ventilation isn’t a bad thing.
Otherwise, dampers (of any design) should not be rejected in the system. Centralized systems are significantly better than decentralized ones. Systems with a tree/star topology are preferred; nothing that distributes air in series (which can cause sound transmission like telephone noise through rooms).
The airflow at nominal ventilation should be max. 50% of the device’s possible capacity. This way, the fan runs slower and is quieter—manufacturers usually publish helpful charts on this.
Duct diameters must not be undersized.
The system should be planned according to where which airflow is required. In rooms with higher demands, it is preferable to install two valves instead of one valve with increased airflow. If that’s not possible, then this single valve should at least be connected with two ducts rather than forcing increased airflow through one duct.
Otherwise, dampers (of any design) should not be rejected in the system. Centralized systems are significantly better than decentralized ones. Systems with a tree/star topology are preferred; nothing that distributes air in series (which can cause sound transmission like telephone noise through rooms).
The airflow at nominal ventilation should be max. 50% of the device’s possible capacity. This way, the fan runs slower and is quieter—manufacturers usually publish helpful charts on this.
Duct diameters must not be undersized.
The system should be planned according to where which airflow is required. In rooms with higher demands, it is preferable to install two valves instead of one valve with increased airflow. If that’s not possible, then this single valve should at least be connected with two ducts rather than forcing increased airflow through one duct.