Anywhere I can go for advice about MVHR?

EmRayMarRhys

I am incredibly fortunate to live in a housing association Passivhaus. It has an MVHR system and I was told in winter to keep my windows shut as the MVHR sucks up the heat and condensation then re distributes it. That way I'd need the heating less.

First winter all fine. This year I'm experiencing massive problems in condensation in two rooms in particular - the downstairs loo which for some reason is a really cold room and my son's bedroom on the top floor (it's a townhouse).

No change in lifestyle or occupancy whatsoever.

Is there anywhere I can go for advice? I am of course airing the rooms now but obviously this means I'm having to use the backup heating which negates the entire Passivhaus concept.

As our house is part of the only development our housing association has of these kinds of house nobody has a clue what to do, lots of head scratching. Google only produces results about MVHR improving condensation problems.

Any ideas anyone?

poppysarah

First winter there?

The weather has got colder, so humidty is condensing...

Does the MVHR need servicing? Does it have a name on it you can contact the company for info?

EmRayMarRhys

Second winter. Last winter was far colder and we didn't have this problem at all. Been here 19 months so far.

Nothing on the system box at all. No servicing has been undertaken and nobody at housing association knows whether it needs servicing or not. We were just told to vacum the filters.

daisygirlmac

My first thought was do your filters need checking/cleaning? I'm assuming the system will need some sort of a service every so often to check it is working properly and not clogged up?

Maybe ask HA if they can contact the installers and see if they need servicing? Have you any neighbours you could ask to see if they have had similar problems?

EmRayMarRhys

Will have a chat to neighbours. Have asked HA about where to get new filters as I'm aware they should be changed - they don't know!

Actually think I have the builders' phone number somewhere - might try going that way.

daisygirlmac

EmRayMarRhys wrote: »

Will have a chat to neighbours. Have asked HA about where to get new filters as I'm aware they should be changed - they don't know!

Actually think I have the builders' phone number somewhere - might try going that way.

Your HA sound wonderfully well informed! Definitely would try builders or the company that installed the system.

vectistim

Did you turn it off in the summer, and have you turned it back on again?
(OK, I know this seems like a stupid question, but I've had people tell me their boiler was broken in the past when they hadn't turned it on)

EmRayMarRhys

No it's designed to run all the time.

poppysarah

Nothing changed outside the house? No damp walls or drippy gutters?

What have the HA and/or builder said?

xylophone

http://www.greenwood.co.uk/content/1/40/mvhr-filter-replacement.html
Anything here?

Johnandabby

You mention Passivhaus, so there are probably a few things that could have caused this.

1. That the balance of the MVHR air flows has been altered somehow, so that the heat delivery is affected. Might be extracting more from the downstairs loo (why it's colder), and not putting enough supply air into the upstairs bedroom. They should recommission the MVHR system to check this.

2. That something has changed in those rooms to increase heat losses, as this is finely balanced in a Passivhaus. This could be a problem with the window seals, or a new penetration in the air barrier in the wall (picture hooks in the walls?) that increases air leakage. As Passivhaus only works in extremely airtight buildings, even a small leakage could make it colder. This can be checked by undertaking an air test to identify areas of leakage, as these are probably still too small to identify with a candle flame.

Either way, because it's a complicated Passivhaus system, your HA needs to get some professionals in to review it. Obviously frustrating that you're having to pay out more money in energy bills than you should have to.