Advertisement
Help Keep Boards Alive. Support us by going ad free today. See here: https://subscriptions.boards.ie/.
https://www.boards.ie/group/1878-subscribers-forum

Private Group for paid up members of Boards.ie. Join the club.
Hi all, please see this major site announcement: https://www.boards.ie/discussion/2058427594/boards-ie-2026

MHRV for old houses

  • 04-11-2008 04:31PM
    #1
    Enaghan01
    Closed Accounts Posts: 12 ✭


    I'm having a bit of trouble with condensation in my house. It's a dormer, has insulation in the cavity walls, not much insulation in the attic though. I was thinking of putting in more insulation and some kind of ventilation. It was recommended on another thread to investigate using a MHRV unit. I was under the impression that these were only for new builds or airtight houses. Does anyone have any experience using these in non-airtight houses? Theoretically it would solve my ventilation problems but will it drive up my heating costs?
    Tagged:


Comments

  • #2
    sinnerboy
    Closed Accounts Posts: 5,433 ✭✭✭sinnerboy


    Enaghan01 wrote: »
    I'm having a bit of trouble with condensation in my house. It's a dormer, has insulation in the cavity walls, not much insulation in the attic though. I was thinking of putting in more insulation and some kind of ventilation. It was recommended on another thread to investigate using a MHRV unit. I was under the impression that these were only for new builds or airtight houses. Does anyone have any experience using these in non-airtight houses? Theoretically it would solve my ventilation problems but will it drive up my heating costs?

    It would solve your ventilation problems . It may drive your energy cost up .

    An air tightness test will cost about €1k . Money well spent . It will highlight your problem areas .

    Others WILL differ with me here - i would install HRV even if a house was not super air tight - for the quality of your internal environment and health .

    Q50 / 10 - is building regs min for air tightness . If you get a worse reading than this your energy bills will rise - no question . But you enter a "neutral area at around Q50 8-9 . Your bills will neither fall or rise . The lower the Q50 number the better from an energy perspective

    But energy is not the ONLY perspective .....


  • #3
    Enaghan01
    Closed Accounts Posts: 12 ✭Enaghan01


    Yeah, that's what I'm thinking. There are other benefits to using a MHRV that make it worthwhile to look at. Any recommendations for what MHRV to use?

    From looking at other boards, some of the prices seem crazy. I found a company Brookvent that published their price on the internet http://www.brookvent.co.uk/airchanger/downloads/heatharvesterprices.pdf. This looks a bit more reasonable so I can use this as a baseline. I know a crowd called ATC supply a MHRV also. Any other recommendations?


  • #4
    sinnerboy
    Closed Accounts Posts: 5,433 ✭✭✭sinnerboy


    http://www.sap-appendixq.org.uk/search.jsp?parentID=1&categoryID=3


  • #5
    Enaghan01
    Closed Accounts Posts: 12 ✭Enaghan01


    Excellent Sinnerboy, that's exactly what I needed


  • #6
    Carlow52
    Closed Accounts Posts: 2,389 ✭✭✭Carlow52


    While not wishing to cross swords with any one here, I was at PLEA 2008 in Dublin a week or so ago and I can across the idea of demand driven ventilation as an alternative to MHRV ( which, if I understand it properly is an 'always on' system ) The demand driven system seems to be just that, it is driven by things such as humidity levels.

    The notion won a prize at PLAN EXPO today for the exhibitor at stand P14

    A useful list of the expo exhibitors can be found here: most have web links so a useful way to collect them
    http://www.expo-events.com/planexpo/plan_expo_exhibitor_list.htm


  • Advertisement
Advertisement
Advertisement