MVHR Location Dilemma

[Ryan Bazeley]

Hi,

 

I am having a dilemma as to where to install my MVHR.

 

Location 1 - in store / plant room.

This was the original plan but after needing some steels fitting the duct runs now have to be longer and there are many many holes I need to drill through I beams.

 

Location 2 - behind built in wardrobes in bedroom.

Perfect spot above all wet rooms, shorter duct runs, less drilling but although boxed in it will be in the bedroom area, will noise be an issue?

 

I have opted for an Airflow DV145 unit as I have been told it will be less noisy and a much better unit than a Vent Axia?

 

TIA

 

[joth]

I think you could build solid wardrobe that sufficiently sound proofs it. E.g. double up the thickness of the back wall.

The difficulty will be providing sufficient access (for filter changes, and to remove the whole device if larger maintenance needed), without compromising the sound insulation. Remember to remove the unit a lot of access space is needed, to get at and unhook ducts and drains etc. 

The main noise risk is vibration rather than airborne noise so be sure the unit is mounted on vibration proof suspension mounts, and no part of it or the ducts and manifolds touch anything in contact with the wardrobes.

 

Fwiw In my experience keeping ducts short wasn't a huge benefit as it meant those rooms had more vent noise (all supply side), and the solution was to lengthen those ducts. Extract rooms may not suffer vent noise so much, at least ours don't. 

[IanR]

Location 2 sounds the better location for the installation, but there are risks.

 

Would there be insulated stud work between the back of the built-in and the MVHR?

 

My DV1100 is within a storage area in the loft. There's 100mm of Rockwool above the ceilings and the unit is barely audible when running at a boost of 75% and you are right below it.

My unit is a little over-sized so in general it doesn't boost above 65%

 

Any ideas what sort of boost speed you will need to run at? Will you have any automation that would allow the boost to be turned down over night, just in case.

 

I've used some flexi-ducts on the inlet and exhaust, and to the plenums. Most of the air noise comes from these. I'd stick to rigid and semi-rigid on your location 2 scenario. I'd also have a back up plan to isolate the mountings for the floor (or wall) it's mounted to if it turns out there is a resonance issue.. Bolting through some rubber blocks should be enough.

Edited September 3, 2021 by IanR

[Ryan Bazeley]

19 minutes ago, IanR said:

Location 2 sounds the better location for the installation, but there are risks.

 

Would there be insulated stud work between the back of the built-in and the MVHR?

 

My DV1100 is within a storage area in the loft. There's 100mm of Rockwool above the ceilings and the unit is barely audible when running at a boost of 75% and you are right below it.

My unit is a little over-sized so in general it doesn't boost above 65%

 

Any ideas what sort of boost speed you will need to run at? Will you have any automation that would allow the boost to be turned down over night, just in case.

 

I've used some flexi-ducts on the inlet and exhaust, and to the plenums. Most of the air noise comes from these. I'd stick to rigid and semi-rigid on your location 2 scenario. I'd also have a back up plan to isolate the mountings for the floor (or wall) it's mounted to if it turns out there is a resonance issue.. Bolting through some rubber blocks should be enough.

My plan was to insulate the wall with some soundproofing material, I can pretty much build what will suit in front of the unit, I also want to make sure I have good access.

 

Didn’t think about rubber mounts, good idea.

 

Not sure about the boost speeds?? I did discuss with the supplier about turning it down at night which if there are noise issues will help.

 

 

[Conor]

Location 1. And instead of all flexi pipes coming from there, have a single 125 or 160mm vertical riser to the next ceiling so you have a manifold for each floor and fewer penetrations. That's what I'm doing.

Edited September 3, 2021 by Conor

[Iceverge]

+ 1 to the comments above. 

 

I would keep the unit itself away from the bedrooms. They do make noise. If you have to have it there I would consider hanging it with steel wires so it's suspended. Very good for decoupling.