Heat recovery manifold

Mrs Doyle

Just wondering how people with HRV systems are getting on with regard to noise transfer between rooms?i spoke to a guy at an exhibition that said noise travels between rooms with one supply duct and one extract duct, and to prevent that, a manifold system should be installed, and each room be supplied separately-I get the theory, but in practice is it noisy?most suppliers seem to just go with one duct and tee offs.
Need to start deciding on which system to go with, there seems to be lots of options, so anyone can recommend one, much appreciated!

blast06

Well Mrs Doyle ..... if you're kids know about the birds and the bees then you'd be well advised to bite on a stick to avoid shouting when Mr Doyle is doing the dirty deed
Go with a manifold if you can afford it

fclauson

Ignoring Blast06 comments - noise is all about design :rolleyes:

I suspect the person you spoke to at the show was selling a manifold system !!

You need first of all to look at air speeds - this is what creates noise - the narrow duct system tend to have higher air speeds as the ducts are narrow and hence tend to be more noisy.

The large duct system have slower air speed=less noise - but the design needs to consider and silencers need to be include. Using acoustic duct (for short lengths at the end of each run just prior to the grills can work very well

Mrs Doyle

Thanks Fclauson, that is helpful, but is the noise you are talking about from the system itself? I was originally referring to being able to hear people talking in the next room through the duct (But will take the above into account also!). and yes, he was of course selling a manifold system!

fclauson

Mrs Doyle wrote: »

Thanks Fclauson, that is helpful, but is the noise you are talking about from the system itself? I was originally referring to being able to hear people talking in the next room through the duct (But will take the above into account also!). and yes, he was of course selling a manifold system!

So noise comes from a number of places
1 - cross talk (noise from other rooms)
2 - the fans
3 - air in duct

Manifolds help to resolve (1) but not necessary 2 and 3

1 - can also be resolved by using attenuators/silencers on the feed lines close to the vent in the each room

Additionally you building fabric will help/hinder (1) - noise travels both through and over (if you have a service duct) walls - so wall make up is also important