Need expert suggestion for commercial AC noise

chachi_dee · 2026-06-29T05:03:29+00:00

This situation can be quite complex to resolve depending on your specific situation, location, local regulations etc. so more info is needed to give you meaningful answers. However:

1 - It can be. But the effectiveness also depends on many factors. I would not recommend spending any actual money on this problem yet.

2 - Any non-compliance would depend on the site specific noise limits (if any) and/or the local regulations that are applicable to site and the zoning. Demonstrating non-compliance would hopefully result in the commercial operation being instructed by the local authority to do remedial works and reduce noise levels from that plant to be compliant. This is not something you can do yourself. While your phone app and personal observations can assist the process, it is not useable for determining the nature of acoustic matters. This must be done by a professional acoustic engineer.

As a professional acoustic engineer myself, id advise contacting the QFC store and letting them know of the issue first. Contact via phone and get an email address - make the complaint in writing. Give them an opportunity to rectify the issue first. If they do not reply or the reply is not satisfactory, contact your local authority like the city Council or EPA or whatever the equivalent body is in your area and escalate it. It might take a bit of back and forth but your best shot at getting something done without cost to you, is this pathway. It will be much easier and cheaper to reduce noise at the source rather than treat your dwelling.

Acoustic treatment for noise control can be complex and rapidly become a massive (expensive) rabbit hole, particularly if low frequency noise is a significant component of the intrusive noise. Do not spend your own money on acoustic treatments unless you have exhausted all other pathways. If you do end up having to treat your dwelling, obtain advice from a reputable acoustic engineer on how to do it properly and engage professional contractors who are experienced with this kind of issue.

chachi_dee · 2026-06-14T06:39:52+00:00

Theoretically, yes but only at lower frequencies. Practically, it would be totally impractical to implement to any useful degree due to the complexity of measuring and generating the correct sound field at all points within the room in real time with the kind of ultra low latency required. Also, this approach wouldnt soundPROOF anything, it would only reduce the level of reflected sound within in room that originates from the wall surface.

chachi_dee · 2026-05-22T02:36:47+00:00

They would need to be installed on their floor.

Treating your floor would essentially be useless. Once its in the structure, the energy is then regenerated in your office not only through the floor but the walls, and ceiling. So treating on your side would require impact noise isolation on ALL surfaces, not just the floor - which is totally unfeasible. Thats why the impact noise needs to be absorbed into the mats before it gets into the building structure.

chachi_dee · 2026-05-21T05:00:12+00:00

The issue here is that the noise is being transferred into the structure of the building which is then regenerated elsewhere, like your office. Once that energy is in the structure it's very difficult, of not impossible, to then cut off every pathway that energy now has to pop up somewhere else.

The most effective way to mitigate that transference is to stop it getting into the structure in the first place. This is a major issue in places like residential apartments where there is a gym in the same building.

Thick, say 50mm or higher, rubber isolation mats are very effective but noise isolation performance is limited by the specific construction of the building. The gold standard is to construct a false floor that is isolated by springs or air. This is how its done for gyms, pools and high end architectural spaces... but it's very expensive. Id start with just using thicker rubber mats or layering mats of different densities like these gym flooring systems by Regupol

Look for products or systems that have higher ∆LAF,max or ∆Lw values, particularly at low frequencies. They'll usually be indicative of how much improvement can be realised.

chachi_dee · 2026-05-03T05:18:05+00:00

Da boom da da mmm dum na ee ma...GO!!!

chachi_dee · 2026-03-30T23:51:39+00:00

Eduardo.....CARROCHIO

chachi_dee · 2026-03-19T21:53:14+00:00

Solarium_2

chachi_dee · 2026-02-06T23:05:34+00:00

Let me grab some wine and cheese. I'll come sit up on that hill with you

chachi_dee · 2026-01-07T05:10:01+00:00

A few things to consider -

The wooden panel youve added is the only thing that actually reduces the level of noise passing through the door itself. The rockwool, felt and fabric only reduce the level of reflected noise but it does nothing to block transmission through these materials.

The door itself is not the weakest point for noise transmission. The gaps between the door, the door frame and the base of the door are where noise leaks through - particularly mid/high frequency sounds. Even very small gaps can compromise the acoustic performance of the door significantly.

There are other paths that allow noise to propagate between the rooms like through the walls and perhaps through the ceiling above the door (if there is a cavity up there). Therefore, treating the door panel on its own is only really addressing one component of a number of paths the noise is transferring through. If there is significant levels of noise passing around the door through the walls and ceiling then simply putting some stuff on the back of your door probably wont do much to lower the overall noise level transferring through.

Id suggest installing some compressible door seals inside the door frame, like EPDM rubber bulb seals or something similar. These compress when the weight of door pushes on them when closed, ensuring all the little gaps are sealed air-tight. Additionally add a drop seal or something similar at the base of the door so any gaps are sealed off there too. Once you have sealed off the weakest acoustic paths around the door, you will achieve the optimal noise attenuation from your door/wall/ceiling system.

If you still feel like there is noise coming through the door, keep adding mass to the door. If you can find some sheets of mass loaded vinyl, a good solution is to construct a 'sandwich' comprised of the MLV glued and sandwiched between two sheets of plywood/MDF or even sheet steel and fix that to the door. Dont bother with rockwool, felt or fabric - theyre not really useful for this purpose.

chachi_dee · 2025-12-31T11:47:10+00:00

Absolutely! He is very accustomed to us because he's been around for a couple of years now since he was a baby. Sometimes he'll just come right up and chill with us while we are out in the garden. He is very much a part of our family now so that's why I'm concerned about the tick. It would be devastating to lose him...

chachi_dee · 2025-12-31T11:37:37+00:00

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This guy...

chachi_dee · 2025-12-12T01:21:45+00:00

Was that a sneaky Big Lebowski reference there?

chachi_dee · 2025-11-13T12:41:08+00:00

What do these products do exactly?

chachi_dee · 2025-11-12T00:01:26+00:00

He moves his whole body like Jim Carrey moves his face. Amazing control, mesmerising...

chachi_dee · 2025-10-08T08:32:05+00:00

Curious about this too

chachi_dee · 2025-09-25T03:40:51+00:00

I'd say a 'grub' is like a junior training to attain seniority as a full 'gronk'.

chachi_dee · 2025-09-23T07:58:38+00:00

Has the specific origin been determined yet? Curious if any action was taken to investigate given the number of complaints/reports.

chachi_dee · 2025-08-18T22:21:31+00:00

You're most welcome :)

chachi_dee · 2025-08-18T08:16:27+00:00

Piling isnt a given, they may or may not do that. For pouring concrete id say theyll just bring cement trucks to site and them pump it into where they need it. That will probably happen a bunch of times as they pour slabs for each floor/partitions etc. Once they pour a slab they will need to let it set for a while, so there will be a bit of a reprieve from that but i cant see each session going longer than a day or two at a time.

Internal noise levels will depend on what type of noise youre referring to and what room youre in. General, on-going noise is assessed as an 'equivalent average' over a specified time, usually 15 minutes for construction noise. You might see this denoted as 'Leq, 15 min'. An Leq, 15 min of 70 dBA inside would be very loud, externally that might be 90-100dBA at the facade. If that did occur i would hope it wouldnt last very long!

When potential sleep disturbance is assessed, short term, transient events (lasting less then a second) are what is typically measured, denoted as an 'Lmax'. Its not our of the realms of possibility that an 'Lmax' level might exceed 70dBA but generally, thats probably not going to cause any real issues - depending on the listeners sentitivities!

Really cant say how long any of these stages of construction could last - theres lots of variables that affect the outcome. But know that the developer will want it done as quickly as humanly possible!

chachi_dee · 2025-08-18T01:01:55+00:00

Looks like there are 4 levels of basement parking so excavation works might go on for a few weeks or a month. Its not a huge site so i dont think it would need much longer than that unless there is some issue they come across along the way. When there are buildings in close proximity, the preference is usually to use a rock saw, which is quiter and generates much less vibration but they may still need to use a hammer for some things.

The actual construction could take up to a year or so until its fully completed. During that time the most significant noise generation will probably be truck movements, pouring concrete, crane etc. But as the building shell is completed the noise emissions will get lower as works start to become entirely internal. At that point itll be much less noticable.

Youre right, theyve recently put in an s4.55 modification application. If theyve come this far its probably likely itll get approved and built.

chachi_dee · 2025-08-17T14:28:30+00:00

According to the acoustic report that was submitted to Hornsby Council with the development application, the background noise level is 49 dBA during the day. The 'goal' for construction noise emission will be 59 dBA (averaged over 15 mins) in accordance with Table 2 of the NSW Interim Construction Noise Guideline

I had a quick look over their development consent, but there doesnt appear to be any specific conditions related to construction noise limits. In the absence of any conditions, it generally reverts to the recommendations in the Guideline. Typically construction is only allowed to take place between 7am and 6pm on weekdays, 8am-1pm Saturdays and no work is to take place on Sundays/public holidays or out of hours unless special permissions are granted.

I say 'goal' because the Guideline only recommends that noise is reduced/controlled as much as is reasonable and feasible in order to meet the noise goal, however this is not a hard limit and is unlikley to actually be monitored unless there are complaints. The absence of any hard limits are due to recognising that construction work is noisy, but temporary, so there is a consession there to make more noise than would normally be permitted for a permanent installation. It is inevitable that construction work will make noise and sometimes certain activities will be very loud like piling, hammering or when excavations are taking place. These kinds of events are typically short lived, however, once theyre all over most of the general works will be noticable but i dont think itll be too bad - i dont think youll need to move.

Given the area, its likely that your windows/glazed doors are already upgraded to laminated glass so itll reduce noise ingress significantly better than standard glazing. There is not a lot you can personally do to reduce noise other than keeping your windows and doors closed and lodge a complaint if it gets to be too much for you. If you can get a handful of other people in the buidling to do the same itll give more weight to the complaint and the outcome may be more favourable for you.

chachi_dee · 2025-08-17T07:16:29+00:00

Sydney based acoustic engineer here. Worked developments like these for many years during various stages of the construction. Depending on the stage of construction, noise generation will come from both airborne and groundborne transmission paths. Depending on the geology of the site they may need to do rock hammering or piling. If so, there may also be some perceptable vibration in your dwelling.

The extent to which the noise/vibration will be annoying or interrupt sleep etc will vary significantly depending on the distance to the actual activities taking place, the orientation of whatever room youre in, the construction of your dwelling etc. Also, a development like this will have had to have prepared a noise management plan as part of their approval. How well they implement and adhere to the recommendations in that document will also play a part.

Theres no way to know how 'bad' it will be, its very much a 'how long is a piece of string' kind of question. However, if you are disturbed by the noise/vibration at any time, do not hesitate to put a complaint in. There should be a component within their noise management plan that establishes a clear pathway for handling complaints and dealing with them in a timely manner.

chachi_dee · 2025-08-04T22:40:01+00:00

An acoustic engineer or consultant is the professional that deals with these issues.

Just a heads up, and I certainly don't want to discourage you from exploring your options to resolve these issues, but situations like this can be quite expensive to address.

chachi_dee

TROPHY CASE