Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Hi there,
There is an issue with role permissions that is being worked on at the moment.
If you are having trouble with access or permissions on regional forums please post here to get access: https://www.boards.ie/discussion/2058365403/you-do-not-have-permission-for-that#latest

Expected Airtightness in New Timber Frame

  • 17-06-2009 1:22pm
    #1
    cabol
    Registered Users, Registered Users 2 Posts: 2 ✭


    I'm building a new timber frame house and would like to go for a HRV system. What puts me off is the extra costs associated with providing service cavity, airtightness membrane, possibly eco joists etc.

    If I was to go ahead with current build method (timber frame with insulated plasterboard on inside) and maybe pay extra care to sealing around windows and doors does anyone know;

    (1) What level of airtightness could I expect to achieve? and
    (2) Would this be sufficient to get some benefit from a HRV system?


Comments

  • #2
    sydthebeat
    Subscribers Posts: 42,171 ✭✭✭✭sydthebeat


    cabol wrote: »

    (1) What level of airtightness could I expect to achieve? and
    (2) Would this be sufficient to get some benefit from a HRV system?

    (1) impossible to tell... all based on quality of workmanship.... and quality of system

    (2) in my opinion, no.. you should be aiming at an airtightness result of minimum of Q50 = 5 in order to get benefit from the HRV system....


  • #3
    cabol
    Registered Users, Registered Users 2 Posts: 2 ✭cabol


    Syd,

    Thanks for the quick reply.

    My question was partly prompted by this article which states that "73% of timber frame homes tested achieve a score of 5 q50 or less". Unfortunately it doesn't go into detail about construction standards (e.g. airtightness membrane present or not).

    If you try and ignore the heat recovery aspect of a HRV system do you think there is any benefit to purely using one as a ventilation system (I'd rather not put in wall vents or trickle vents) - even at airtightness levels of 5 to 10 ach?


  • #4
    sydthebeat
    Subscribers Posts: 42,171 ✭✭✭✭sydthebeat


    cabol wrote: »
    Syd,

    Thanks for the quick reply.

    My question was partly prompted by this article which states that "73% of timber frame homes tested achieve a score of 5 q50 or less". Unfortunately it doesn't go into detail about construction standards (e.g. airtightness membrane present or not).

    If you try and ignore the heat recovery aspect of a HRV system do you think there is any benefit to purely using one as a ventilation system (I'd rather not put in wall vents or trickle vents) - even at airtightness levels of 5 to 10 ach?

    without knowing anything further, i would expect these tests were carried out on dwellings which were built in accordance with the uks 'accrediate details'... we also have accrediated details.. .and if you build TF in accordance with these details you must included tapes and membranes.

    interesting to note wet plastered block houses had results comparable to TF houses.. .it was the internally drylined houses that had bad results...


Advertisement