Installation Requirements for MVHR?

[Andehh]

We had a company out who designed & installed our 2 x MVHR. We had to have two due to an middle entrance hallway separating two ''wing'' of the house preventing pipework.

 

The smaller unit is a Vent Axial Kinetic B....the installer didn't install the inlet & outlet rigid ducts due to not knowing where we were going to punch through the flat roof above the units location. As a result I have been installing the inlet/outlet ducting myself having worked out where.

 

However, no where in the manual does it state dos/don'ts nor requirements for the inlet/outlet ducting, and due to the Christmas hols the installer is offline to guide me, but I need to get it all done due to the plaster boarding starting when we get back.

 

I have used 125mm rigid ducting, have installed the ducting so that the externals are 1.2m apart in the roof & done my best to ensure there are no 'low spots' for moisture to pool. I will double wrap them in insulation, just because I have that quantity.

 

I will wrap each joint in aluminium foil tape to ensure it is secure.

 

is there anything else I need to be aware of, before I secure it all together & wrap in insulation?

 

Thanks,

 

 

 

 

 

 

Unit:

Lo-Carbon Sentinel Kinetic BH | Vent-Axia#

Manual: 

https://www.vent-axia.com/file/196379/download?token=EZMXaPT-

[MikeSharp01]

52 minutes ago, Andehh said:

We had to have two due to an middle entrance hallway separating two ''wing'' of the house preventing pipework.

That will make for an interesting balancing and control scheme. Sounds like you have done all you could - have you checked the penetrations to the roof have all sealed & flashed correctly and that any moisture getting into the ducting  (condensation / wind blown rain) can get out / is otherwise dealt with safely?

[JohnMo]

4 minutes ago, MikeSharp01 said:

will make for an interesting balancing and control scheme.

No - it's easy, each unit looks after its self, as long as the air going in and out of each unit is balanced, they are happy (even if it's not they are still happy).  They don't care where the air comes from, it's just air it's compressible and it moves about easily, it's not the same as a hydraulic system. 

 

One of my units supplies air in to the bedroom and the other sucks it out from the ensuite.

[Andehh]

Yeah, I really wanted a single big unit for the power usage reduction, but house design just blocked it outright. Was a none starter unfortunately. 

 

I have done my best to ensure a gradiant through the pipework down into the MVHR, and the vents have large overhangs to help limit driving rain getting in. 

 

Is 1.2m separation OK on external vents? Manual doesn't recommend anything and I figure with the unit likely to stay on 20%, nearly 2x over sized, and an above average windy location will ensure no cross contamination! 

[MikeSharp01]

I think there is a recommendation on this 2m springs to mind: have a read here

 

 

[JohnMo]

2 hours ago, Andehh said:

, I really wanted a single big unit for the power usage reduction

Fans basically work on a watt per m3 basis, so 2 or 1 unit will use the same amount of watts for a given m3/h.  Downside is really 2x the amount of filters.