Enclosure or longer piping run for split ASHP system

[sharpener]

38 minutes ago, DanDee said:

a lucky random find

 

Well done, you are on a roll today @DanDee

 

Looks well constructed and the attenuation is quite impressive.

 

With 16 pages of documentation and all the custom sized individual panels and seals no wonder they cost £4k and are a foot bigger than the HP on all sides.

 

I would have thought you could copy the basic layout (which is very similar to the thing I once built round a motor-generator set) and make one yourself out of chipboard lined with the self-adhesive acoustic mat from Amazon. With a roofing felt cover it should last quite a few years. The Arotherm + come with AV mounts as a standard accessory.

 

Looks as though if I get the 12kW model I will need a plain full screen hence my interest but a fence panel should suffice. As a two-fan unit it is a lot higher and one of these total enclosures would look truly massive.

 

BTW do you have a link to the specimen Planning Application someone kindly posted here? Or maybe it was on another site.

 

EDIT: Snap!

 

The Stratocell Whisper FR looks like the basic material which is made into the acoustic fence panels listed upthread. Would be useful to put on the wall behind the HP. Can you then count it as one reflecting surface (the ground) and not two for MCS calcs do you think?

 

 

Edited June 12, 2023 by sharpener

[JamesPa]

The solfex https://solflex.eu/en/ range seems to be one of the most comprehensive, don't know yet if the deliver to UK.  I'm also now wondering about a DIY job, the prices are crazy and surely must come down.  Extremely heavy too!

[sharpener]

48 minutes ago, JamesPa said:

Extremely heavy too!

 

Mass is your friend in the world of soundproofing!

 

Edited June 13, 2023 by sharpener

[sharpener]

12 hours ago, sharpener said:

BTW do you have a link to the specimen Planning Application someone kindly posted here? Or maybe it was on another site.

 

Found it here, thanks to @RichardL for posting it!

[RichardL]

@sharpener It turned out my planners - informally and formally didn't seem to test the MCS calcs in anger (unless behind closed doors) -  both times I described what I wanted to do and, I guess, lucked out there was no issue.

Sound & visibility certainly priorities in discussions and approval.

1. My initial informal query to planning emphasised location & size, referencing local planning policy of unit asking for a view on PD.

I'm lucky enough to have space to neighbours, and on friendly terms, so less criticality on sound levels - but was not asked for detail TBH (notwithstanding the units are virtually silent ~1m away from them)


2. The second full planning (text linked in the forum),
Referenced the PD.
I was advised to be specific about units to be installed. So again - sound was important, I think I mentioned using qualified installers - but no ask for MCS calcs etc.

I picked locations which are basically invisible from outside the property, discrete trunking and inaudible ~2m away - I know that's not always possible.

Also offered to answer any questions to neighbours as soon as the planning notice went on the gate.


Recommendation - if you can find local planning policy which says heat pumps are good idea - reference it. Ultimately the tone of the application needs to align with that policy.

+Don't elaborate where you don't need to.

[JamesPa]

13 hours ago, sharpener said:

 

Looks as though if I get the 12kW model I will need a plain full screen hence my interest but a fence panel should suffice.

How does the above stack up with the below?  My real question is, does a fence panel really give the 5-10db attenuation that the MCS calculation method would have you believe, and if so whats the advantage of high mass soundproofing - unless its to stop reflections'? 

5 hours ago, sharpener said:

 

Mass is your friend in the world of soundproofing!

 

[JohnMo]

MCS calc is a blunt pen approach, it's a wall so adds to the reflection factor, so I creases noise. No amendment for it being absorbing. Same as MVHR really, is not heat recovery just ventilation.

 

Whole system thought by office bods with no sense.

[sharpener]

 

2 hours ago, JamesPa said:

How does the above stack up with the below?  My real question is, does a fence panel really give the 5-10db attenuation that the MCS calculation method would have you believe, and if so whats the advantage of high mass soundproofing - unless its to stop reflections'? 

 

It doesn't really stack up at all. AFAIR the MCS text just calls for a "fence or wall". The only test is visual:

 

 

A brick or block wall would probably give 10dB but I doubt a fence would in reality. Depends a bit on construction but a fence made of thin strips of wood for visual screening is light enough to vibrate with the incident sound and re-radiate it from the back. Like a drumskin. But it is still a "fence".

 

OTOH any reasonably constructed wall will be sufficiently massive and rigid so it will neither be excited by the incident sound nor flexible enough to re-radiate it.

 

Neither will stop reflections. Walls are good reflectors precisely because they are rigid and have no internal friction. Ditto springy materials with low damping like hardwood and sheet metal. So the ideal materials are a combination of e.g. rockwool or fibreboard type materials which use their internal friction to turn the incident sound into heat, and rigid masses which don't conduct or radiate. Hance my past success with chipboard lined with fibreglass insulation. Cf also construction of loudspeaker cabinets.

 

IIRC there was a noise consultant on here but can't remember his handle, it would be good if he could join this discussion. I am only an amateur now but I did work in the recording studio equipment business for a few years and have done a lot of sound in theatres.

 

Edited June 13, 2023 by sharpener

[JamesPa]

3 hours ago, JohnMo said:

MCS calc is a blunt pen approach, it's a wall so adds to the reflection factor, so I creases noise. No amendment for it being absorbing. Same as MVHR really, is not heat recovery just ventilation.

 

Whole system thought by office bods with no sense.

I sort of thought that. 

 

But the only current alternative is a full noise impact assessment according to BS whatever (I have the number somewhere), which is well over the top for a replacement boiler. 

 

Possibly as a consequence of my own application, my (Green party controlled) LPA is now demanding the latter for any new applications involving ashps. That should kill off any attempts to install ashp other than under PD 

Edited June 13, 2023 by JamesPa

[JohnMo]

It's all bs, we want ASHP to save the planet, says the national government (here have a load of Dosh), local government say no we don't want them, so make it difficult.

[JamesPa]

45 minutes ago, JohnMo said:

It's all bs, we want ASHP to save the planet, says the national government (here have a load of Dosh), local government say no we don't want them, so make it difficult.

In fairness to local government, it can only do what the law and funding allows it to do.  Both are, in practice, controlled by national government. 

 

The cynic would say that, so far as National government is concerned, the principal reason for local government, is to take the blame for difficult decisions which, in reality, are so heavily constrained by national government, that the 'local' discretion is tiny.

Edited June 13, 2023 by JamesPa