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Air tight air vent

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    #32
    sydthebeat
    Subscribers Posts: 41,645 ✭✭✭✭sydthebeat


    metricspaces wrote: »
    You have lost me. I don't understand what you are referring to in the link or regards design build\mvhr. This is a house I bought?

    You asked about my ACH result. I understand this is air tightness figure? I managed to get XML file for my BER, see relevant section below:

    RdzyoGz.jpg

    thats a particularly poor ACH result


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    #33
    BryanF
    Moderators, Home & Garden Moderators Posts: 10,140 Mod ✭✭✭✭BryanF


    At least the 4’’ holes are ok


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    #34
    metricspaces
    Registered Users Posts: 793 ✭✭✭metricspaces


    sydthebeat wrote: »
    thats a particularly poor ACH result

    There are a few figures with ac/h referenced. Which figure is the overall air tightness figure? The 0.239 I'm guessing ?

    When you say it's particularly poor, any more context so I can understand how poor? What is typical ac/h figure for A3 rated house (semi-detached, timber frame, 110sqm, constructed before 2017)?

    A quick Google tells me Part L 2011 specifies infiltration due to structure to be 0.35 ac/h. Figure for my house is 0.239. How is my figure particularly poor?

    According to this link here http://2eva.ie/air-tightness-test/ my ac/h figure seems particularly good?

    Best practise in domestic dwellings calls for an ac/h rate of:

    3.0 ac/h – natural ventilation (i.e. with wall vents) – very easy to achieve
    1.5 ac/h – with mechanical ventilation
    0.6 ac/h – Passive House Standard


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    #35
    metricspaces
    Registered Users Posts: 793 ✭✭✭metricspaces


    BryanF wrote: »
    At least the 4’’ holes are ok

    What 4" holes are you referring to? And what makes you say they are ok?


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    #36
    sydthebeat
    Subscribers Posts: 41,645 ✭✭✭✭sydthebeat


    metricspaces wrote: »

    A quick Google tells me Part L 2011 specifies infiltration due to structure to be 0.35 ac/h. Figure for my house is 0.239. How is my figure particularly poor?

    The 0.35 is the absolute maximum allowed under building reg compliance.
    It equates to an air infiltration rate of 7m3/hr/m2... So picture that... For every square meter of the house.... 7 cubic meters of air is passing through the fabric every hour. That's a kin to a hole the size of a 5c coin being drilled into your walls and roof at every meter center...

    Your figure of 0.239 equates to an air inflation rate of 4.78m3/hr/m2..... Which to me shows a lack of any stragety to prevent air leakage and possibly poor workmanship or finishing practises.

    It just means you will be losing most of the heat in your house through air draughts....this costing you more to run the house


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    #37
    metricspaces
    Registered Users Posts: 793 ✭✭✭metricspaces


    Ok. So my ac/h figure more than satifies Part L.

    What is typical ac/h figure for A3 rated house (semi-detached, timber frame, 110sqm, constructed before 2017)?

    Every figure is relative. To say my ac/h is particularly bad it needs a reference with respect to which it is particularly bad in comparison to. With respect to Part L it is clearly not particularly bad as it is well under max allowed value. So what is your reference when you say 0.239 ac/h is particularly bad?

    We are talking about a standard semi-d built by a developer. Not a passive house.


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    #38
    sydthebeat
    Subscribers Posts: 41,645 ✭✭✭✭sydthebeat


    metricspaces wrote: »
    We are talking about a standard semi-d built by a developer.

    And thus why is a particularly poor result.
    Which is a pity because it's actually quite easy to make a timber frame house particularity air tight with not much extra cost.... But if course developers are only interested in maximising profit and not in maximising energy efficiency.

    All my tender contracts have a min target air tightness of 3, which is an air change rate of 0. 15. Generally easy enough to achieve with ceiling membrane, ope taping and attention to detail in the workmanship.

    I was once involved in a build of close to 3000 sq ft where the total air leakage was the size of an A5 sheet of paper.


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    #39
    metricspaces
    Registered Users Posts: 793 ✭✭✭metricspaces


    sydthebeat wrote: »
    And thus why is a particularly poor result.
    .

    Once again. In comparison to?

    And what is typical ac/h figure for A3 rated house (semi-detached, timber frame, 110sqm, constructed before 2017)?


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    #40
    LauraWestCork
    Registered Users Posts: 3 ✭LauraWestCork


    Hi all, probably totally wrong place to post so apologies if this is the case (feel free to move moderator). I'm looking for recommendations for air tightness testing in Cork.
    Thanks any recommendations and advice much appreciated, getting deep retrofit done on 1970s bungalow.


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    #41
    WorldIsFalling
    Registered Users Posts: 2 ✭WorldIsFalling


    I have almost the same problem right now and before fixing it I wanted my vents to be cleared, so maybe someone knows good services out there in Canada?



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    #42
    muffler
    Registered Users Posts: 46,129 ✭✭✭✭muffler


    https://www.boards.ie/discussion/comment/119633315#Comment_119633315

    You're on an Irish website



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    #43
    WorldIsFalling
    Registered Users Posts: 2 ✭WorldIsFalling


    https://www.boards.ie/discussion/comment/119633552#Comment_119633552

    oh, sorry, didn`t figured out ie stands for Ireland



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    #44
    Yellow_Fern
    Registered Users Posts: 2,603 ✭✭✭Yellow_Fern


    I know most of the comments here are old but there is a lot of shouting going on about the requirement for non closable vents but I have been told by leading ventilation firms that mechanical ventilation is an option in this situation. Is that untrue?



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    #45
    sydthebeat
    Subscribers Posts: 41,645 ✭✭✭✭sydthebeat


    https://www.boards.ie/discussion/comment/119687913#Comment_119687913

    In what situation?



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    #46
    Yellow_Fern
    Registered Users Posts: 2,603 ✭✭✭Yellow_Fern


    https://www.boards.ie/discussion/comment/119687944#Comment_119687944

    For a room with combustion. if mechanical ventilation is not permitted, as there any mechanical ventilation system that can detect carbon monoxide and open for it?



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    #47
    sydthebeat
    Subscribers Posts: 41,645 ✭✭✭✭sydthebeat


    https://www.boards.ie/discussion/comment/119840153#Comment_119840153

    Liked any building regulation, if you are doing something that isn't covered by the prima facia compliant TGDs, it's up to you to prove to the building control officer that your solution still complies with the regulation.


    So in regards to the ventilation building regulations, the actual regulation states

    "Adequate and effective means of ventilation shall be provided for people in buildings. This shall be achieved by:

    (a) limiting the moisture content of the air within the building so that it does not contribute to condensation and mould growth, and

    (b) limiting the concentration of harmful pollutants in the air within the building.


    so if you want to offer a solution which i snot "permanent non closable background ventilation" which the TGD offers as prima facia compliance, then its up to you to get this confirmed with your local BCO



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