Radial vs Branch MVHR

[Mr PC]

Hi all, I have a newbie question which I can’t find the answer to anywhere. We’re just starting to plan the MVHR for our new build house, and of the quotes we have received some propose a radial system and others a branch. I’ve searched high and low online but to no avail. Please could someone put me out of my misery ?.

Thanks very much.

PC

[JFDIY]

Radial is lots of small flexible pipes distributed off a common manifold.

 

Branch is typically a large run through the building with small branches to the rooms.

 

Radial takes up more space (at the manifold in particular) but gets rid of the potential 'cross-talk' of noise from one room to another. 

 

Radial is more DIY friendly in my opinion. 

 

 

 

[Moonshine]

https://www.heatspaceandlight.com/difference-between-branch-radial-duct-which-better/

[Mr PC]

Many thanks JFDIY and Moonshine - really helpful and I understand it so much better now.
Looks like radial is the cheaper, easier option, so I am still slightly confused why one of the companies who’ve quoted for us have proposed a branch system for those reasons ie they say it’s easier to install and lower cost (at least for our new-build - a simple rectangular SIP dormer bungalow with 3 bathrooms across the two floors).

Cheers.

PC

[JOE187]

https://www.heatspaceandlight.com/difference-between-branch-radial-duct-which-better/

My thoughts the above compares radial with a steel  branch system which is a lot harder to self install!

 If solid plastic duct and fittings used DIY components considerably cheaper than radial.

It all depends on how complex the duct layout and access!

[Gone West]

@Mr PC We designed our MVHR system ourselves and used a branched layout with plastic ducting. It was straightforward and has worked well. It doesn't require space for manifolds but does need space for straight runs of ducting so works well with metal web joists.

 

 

 

 

 

[Stones]

I've fitted both types of duct systems in various houses we have built.  I found radial systems much easier and quicker to install compared to branch systems, BUT I have found the radial system to be nosier (even having installed silencers which helped).

[Mr PC]

Thank you so much, everyone, for all your advice and comments - really helpful. PC

[gc100]

On 14/04/2020 at 09:00, PeterStarck said:

@Mr PC We designed our MVHR system ourselves and used a branched layout with plastic ducting. It was straightforward and has worked well. It doesn't require space for manifolds but does need space for straight runs of ducting so works well with metal web joists.

 

 

 

 

 

 

 

It looks like you don't have any sound attenuators - won't you get cross talk from room to room?

 

I'm looking at this now, and due to space and length of my build a branch layout would be better, however my gut is telling me a radial would be more easy and less prone to noise.

 

@Stones comment about noise is surprising though

 

[Gone West]

6 hours ago, gc100 said:

It looks like you don't have any sound attenuators - won't you get cross talk from room to room?

The only attenuator we have is on the supply side as shown in the first picture. There is a very small amount of fan noise on the extract side if you are near an extract vent. I didn't think it was worth fitting an attenuator on the extract side but if I was doing it again I probably would fit one. We haven't experienced any cross talk from room to room.