Noisy return air

Hi there,

I recently got Brivis 2PW 15 installed in a 1st floor apartment. The return air grill is on the ceiling and makes noise similar to a plane taking off, you can hear it in all rooms, I suspect neighbours maybe hearing it too. Could anyone suggest if anything can be done to fix this?

Thanks in advance.

There are a few options for a noisy return air grille:

1) Give it a clean - the dirtier it is the noisier it is.

2) Add another return air grille - If one is noisy, you can add a second grille to decrease noise

3) Get a thinner filter - If for instance the filter is 3 layer, you can usually get a thinner 2 layer filter which will be quieter.

4) Reduce the airflow of the unit - try set the fan to low instead of high

5) Play around with grille & fittings - sometimes a nudge or adjustment can reduce a hissing or high pitch squealing noise.

6) Warranty - This should come under warranty if it less than 5 years old.

If you just had it put in call back installer it's under warranty for 6 years

Check to see that the return air duct is of full lenght (6mt) My brother in law had a similar problem and was fixed by using a full six metres of ducting. If it was recently installed I would question them if the the return air duct is alot shorter than 6m. The grill being on the ceiling I would guess they would of done this. I am no expert on heating this is only what I have experience and could be one option to look at.

Mick01

Great Point Mick01.

The return air duct should be minimum 6M in length.

This helps to minimize noise.

Thanks very much for your replies, yes the duct was too short. They made it about 7m as well as doing few other things and it's a lot better now.

Good to hear its all sorted out.......h8dk97

Hi, I didn't want to pinch this thread until h8dk97 got sorted

I moved my intake from just above the floor (going through a cupboard) to overhead, but put in a 600x400 grill in (from 700x400).

Inlet Filter now whistles!! I have a mr slim PEH4 A/C

Ducting is fairly long but basically U-turns on itself
Std 400mm ducting

I shifted the intake in the ceiling about 600mm closer to the unit

What are my choices?
A - bigger inlet duct
B - ? bigger inlet duct
C???

I took the filter out atm to stop the noise

A thinner filter may help if you can find one.

It doesn't really matter if the duct curls around and does u turns, as long as the duct is at least 6M in length.

You can upsize the ducts, but you would also need to upsize the necks on the return air grille box to do this. Or add a second return air grille.

boat man why is it important to have 6meters of duct. Doesn't this just simply fix the problem by increasing resistance and thus reducing the airflow before it comes to the return air grill??

Wouldn't it be a more efficient design to keep return air as close as possible to grill but then slow down the speed of the fan?