Jump to content

What to do with MVHR for final airtest


Recommended Posts

searched but couldn’t find an answer to this 
 

 

Got our final air test next week and just wondering what the best strategy is re MVHR.  For Earlier Test (0.42) it wasn’t installed so we just taped up the penetrations. 
 

For this test can we just seal the outside ducts with an airtight membrane and tape?    
 

 

Link to comment
Share on other sites

We had an air test done pre plasterboard, fixed all leaks, then on the final air test the guy just put tape on the room terminals, test was no better than the first test. So don't do that. Do as others have said and isolate the mvhr from the outside world.

Link to comment
Share on other sites

1 hour ago, Russdl said:

Can you not disconnect it inside the house and then cover the inlet and exhaust pipes with a plastic bag and a bit of tape?

That’s what I did.

Link to comment
Share on other sites

On 15/06/2024 at 08:22, JohnMo said:

We had an air test done pre plasterboard, fixed all leaks, then on the final air test the guy just put tape on the room terminals, test was no better than the first test. So don't do that. Do as others have said and isolate the mvhr from the outside world.

 

no ceilings ?

Link to comment
Share on other sites

43 minutes ago, Dave Jones said:

you said air test pre-plasterboard ?

 

Would be hard with ceilings open to trusses no ?

It was just ready to plasterboard, all insulation, vapour and airtightness done, but with access to fix stuff. So service void battens on walls and ceilings etc. Holes through wall for mvhr were blanked off at the wall.

Link to comment
Share on other sites

Thanks all. 

 

we also did a pre plasterboard (bare shell) 0.9, then a pre second fix test 0.42

 

We followed the advice re sealing the external MVHR ducts, it worked well enough, final result 0.47 ACPH.  Electrician had to re feed wires through a duct during second fix due to a fault so looks like we didn’t seal it as well as we’d previously.   
 

 

  • Like 1
Link to comment
Share on other sites

  • 1 month later...

Hi all - we have powder coated external MVHR vents in rendered walls. Did anyone find a good way to tape up the vents without pulling all the paint off? We've already had a bit of paint come off (mastic man on a ladder!). Thanks

Link to comment
Share on other sites

3 minutes ago, Meabh said:

powder coated external MVHR vents

If masking tape is pulling off the coating, they were badly done. I would strip the coating off and redo with a decent primer and top coat.

 

It may be easiest to take the inlet and outlet off the MVHR unit and bag and tape the ends there.

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...