Heat pump generates audible structure-borne noise (with photos of the system)

  • Erstellt am 2021-02-01 15:16:14

vaderle

2021-02-01 15:16:14
  • #1
Hello everyone,

we moved into our house in the summer (150m² townhouse made of 16cm aerated concrete prefabricated parts + ETICS insulation). For hot water generation (heating + domestic water) we have an air-to-water heat pump from Vaillant. It is the VWL 55/5 AS 230V S2 with outdoor and indoor units. Outside, the fan with the compressor is located.

On cold days - when the system runs more frequently - we have now noticed that we can hear the system (when the compressor is running) in all rooms (a humming). It makes no difference whether I open or close doors/windows. Therefore, I assume that this humming is transmitted through the walls (structure-borne sound). In the utility room (where the indoor unit is located) and outside, I have noticed the strongest vibrations in the pipes of the cooling circuit. All other components apparently generate hardly any vibrations. When you touch these pipes, you can feel the vibration. When the fluid is not flowing or the compressor is not running, of course you don’t feel anything. Then it is quiet in the house.

The outdoor unit is mounted on the facade (see photos). It stands on dampers. The mentioned pipes run from inside through the house wall to the outside (see photos). I noticed that the holes where the pipes were pulled through were simply closed with concrete (see photos). I see no special channel to prevent contact between pipe and concrete. Therefore, I assume that the vibrations from the pipe are transmitted directly to the wall.

Would you also consider this the cause?

Finding a solution: I was thinking about placing the indoor unit on a mat and additionally wrapping the already white-insulated coolant pipes (see photos) with soundproofing material. Do you think that would help? Or is the core of the problem the passage from inside to outside? I also thought about whether placing the outdoor unit on a concrete base would help. But as long as these white pipes have direct contact with the concrete elements, the problem will remain.

How do your coolant hoses run from inside to outside?
 

andimann

2021-02-01 16:23:28
  • #2
Hi,

my first suspicion would be the console of the outdoor unit. If something is vibrating there, it goes directly into the load-bearing outer wall. And you can really hear that throughout the entire house.

The routing of the cables is also not in order, it’s not sealed at all? And that strange, flying cable in the picture is hopefully just a temperature sensor that you’ve just laid there, right? That’s not part of the heating system?

But in general: You only moved in during the summer, so have the heating engineer come by for adjustments!

Best regards,

Andreas
 

seat88

2021-02-01 17:16:25
  • #3
Even the pipes on the outside are completely wrong for me. They should hang down as a sack and then go up to enter the house. Simply so that rain, condensation, or similar can collect at the lowest point and drip off. Instead, it collects and flows to the lowest point almost directly into the wall, which apparently has not been sealed at all.
 

Bookstar

2021-02-01 17:28:04
  • #4
Everything that could possibly be done wrong was really done wrong there.
 

vaderle

2021-02-01 19:12:52
  • #5


Can you be a bit more specific? That doesn't help me much. What exactly is still wrong?

So far I have understood that the white pipe should actually go from bottom to top into the house so that no water flows in.

What exactly do you mean by compacting? The insulation is still there after all.

And what about the point that the pipe is in contact with concrete?
 

seat88

2021-02-01 19:38:53
  • #6
It's not about compressing but sealing. Moisture travels along the pipe, through your hole in the plaster to your insulation, possibly even behind the insulation, because no one knows how big the hole is there. Suitable sealing material must definitely be placed in the gap from the outside.
 

Similar topics
05.06.2010Basement made of high perforated bricks or concrete?11
14.06.2011New building: Which insulation is appropriate?14
30.04.2015KFW70 with gas-solar heating65
12.08.2015Is insulation worth it beyond the new construction standard?34
09.05.2016Compliance with the 2016 Energy Saving Ordinance with the following heating14
09.02.2016Should concrete be waterproofed or allow water to pass through?14
20.02.2016Basement made of watertight concrete - switch problem12
10.06.2016Possible defects in installed controlled residential ventilation pipes - concreting will be done today19
11.10.2017Sealing on Styrodur insulation?14
31.07.2019Filling and compacting the ground for the house155
14.04.2017House construction from concrete vs Energy Saving Ordinance 201631
10.07.2017WU concrete + flush-mounted boxes in the residential basement - how can this be solved?35
02.12.2017Insulation of the top floor ceiling17
06.02.2018Solar for hot water/heating or better photovoltaic for electricity?21
24.03.2018Compact gravel layer of about 25 cm - Experiences11
27.11.2018Change heating "after" building permit?13
29.12.2020Y-Tong vs Concrete without extra insulation in practice (heating costs)38
09.03.2021Reinforce floor slab insulation, reduce heat entry into the upper floor13
26.03.2022Which is more sensible: heat pump or insulation?33

Oben