MVHR New Install advice - Ducting in cold loft space insulation requirements

[Olu]

We are having MVHR installed as part of a new selfbuild project. 

The designer is proposing Zehnder Comfoair Q600 MVHR as per attached.

The Zehnder Comfoair Q600 will be installed within the house as shown on the drawings

We are having a cold roof with insulations at ceiling with 100mm across then 400mm over. Our questions are around air tightness and also not compromise on insulation.

Do we need to run the ducts o the ceiling then run the 500mm insulation on top of the ducting?

Any advise would be appreciated.

 

Many thanks

[JohnMo]

There are a lot of inlet and outlet terminals going on, looks overkill. 4 extracts in a kitchen and 2 in most bathrooms is just daft. It's fine running multiple ducts to a single terminal to keep the pressure drops in check, but you just don't need all this terminal points littering your ceiling. You only need one extractor or supply to each room.

 

30 minutes ago, Olu said:

Do we need to run the ducts o the ceiling then run the 500mm insulation on top of the ducting?

Any advise would be appreciated.

I would. You will need to seal the terminal manifold to the plasterboard once it's complete. I would have a single supply thermal in your master bedroom and only one extract in each bathroom to reduce the number of points to make airtight.

[Chanmenie]

Totally agree with John, there are too many terminals 

[Marvin]

Hi @Olu

 

Mechanical Ventilation with Heat Recovery

 

Your ducting in your cold loft space will become ducting in your hot loft space in the summer months. I know! I have insulated my MVHR ducting to within an inch of its life to avoid this. 

 

Heat Recovery should be called Temperature Recovery

 

It really means either supplying the fresh air at the outside air temperature or trying to maintain the inside air temperature: be it hotter or cooler than the outside air temperature. 

 

Good luck

 

M

 

 

[Olu]

Thank you @JohnMo  for the kind advice, we will feed this to the designer to update accordingly.

[Olu]

Thank you @Chanmenie, appreciate you contribution

[Olu]

Thank you @Marvin, we will take note of your advice when putting in insulation.