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    • CommentAuthorDarylP
    • CommentTimeMar 2nd 2017
     
    .... let's see how unbiased/factual the article turns out to be...?:cry:
    • CommentAuthorDarylP
    • CommentTimeMar 2nd 2017
     
    ah ha, that's it ....... blame the EU!:devil:
  1.  
    And the 'live' example they used was a whole-wall, un-shaded window causing severe overheating! Hmm, that will be down to high levels of air-tightness and insulation, then... (although, yes, I do understand the inter-linking of many different factors. I just think they let themselves stray). The headline was something to the effect of: 'Super-insuated, air-tight homes may cause a health time-bomb'. So they could have cited failure to change MVHR filters, flexi-ducts caausing slimy condensation sumps, mould of course. So much to choose from.
    •  
      CommentAuthorSteamyTea
    • CommentTimeMar 2nd 2017
     
    Not listened to it yet, but could they have said 'cold, damp and mildew infested places may cause a health time-bomb'.
  2.  
    A tad off topic, but I just saw a Grand Designs episode on a KLM flight from Amsterdam to Montreal where a "code 6" house was built in some environmentally sensitive area ... so they had to go to great lengths etc. They stressed airtightness, but didn't install any kind of ventilation system whatsoever, apart from opening windows (which were all triple glazed). Over here, HRVs are mandatory for all new construction with a full-time electrical supply and they have to be used during the heating season. I'm surprised that a proper ventilation and heat recovery strategy wouldn't be required on a construction that's supposedly at the highest code level. Can anyone shed any light on this?

    Paul in Montreal.
    • CommentAuthorDarylP
    • CommentTimeMar 2nd 2017
     
    Nope, CfSH (the Level 6 nomenclature) is Part L Building Regs plus PV and some paperwork....... no need for MVHR, but of course it would be sensible!
    • CommentAuthorcjard
    • CommentTimeMar 2nd 2017
     
    And by that Daryl means it was binned, and some bits o ti may have made their way into the building regs, which in themselves are a real mix of adequate (Part L) and laughable (Part F)
    • CommentAuthorringi
    • CommentTimeMar 2nd 2017
     
    The issue is the the summer output from PV is used to offset the winter energy needs of the home in the calcs, but the UK has peek energy usage in winter....
    • CommentAuthorDarylP
    • CommentTimeMar 2nd 2017
     
    yep, PV enabled some very 'average' designs to look very good on paper....
    •  
      CommentAuthordjh
    • CommentTimeMar 2nd 2017
     
    Posted By: Paul in MontrealCan anyone shed any light on this?

    There are four different versions of building regs - England, Wales, Scotland and Norther Ireland - and they change over time, so you would need to tell us where it was built and when it submitted its building regs info before we could start.

    IIRC, current English regs do require mechanical ventilation if the design airtightness is less than 5 or so. No requirement to use it and no requirement for heat recovery. There are European countries that do require sensible ventilation strategies, but the UK isn't one of them.
    • CommentAuthorEd Davies
    • CommentTimeMar 2nd 2017
     
    AIUI, Scottish are as DJH says for English. It's all a bit vague, says “should” not “must” for example.

    http://www.gov.scot/resource/buildingstandards/2013Domestic/chunks/ch04s15.html#d5e9860

    “Simpler and more efficient systems are steadily being introduced that augment, complement and/or improve the natural ventilation of dwellings.Where infiltration rates of less than 5m3/h/m2@50 Pa are intended, such a system should be used. The following are examples of mechanical systems that will aid ventilation in a dwelling:”
    • CommentAuthorSimon Still
    • CommentTimeMar 5th 2017 edited
     
    Posted By: Paul in MontrealCan anyone shed any light on this?


    This one, in Norfolk?
    http://www.walesonline.co.uk/whats-on/film-news/grand-designs-eco-home-puts-7903485

    Building regs
    https://www.planningportal.co.uk/info/200130/common_projects/34/kitchens_and_bathrooms/6

    "alternative approaches to ventilation may also be acceptable, subject to agreement with the Building Control Body."

    I've met the architect - he's designed an house for some friends of ours which they're currently building. He's managed to convince the local buildings inspector that neither trickle vents nor mech vent are needed and ventilation will be achieved by 'purging' European style. I've not been to see the build for a while but pretty sure they're fitting bathroom and kitchen extractors as well.

    Having lived with MVHR for a year or so now I'm really happy with it. Noisy, drafty extractor fans seem archaic in a modern airtight house. Personally I don't think "purge" works well in the UK - fine in a cold dry climate but it's often too damp here.
    •  
      CommentAuthordjh
    • CommentTimeMar 6th 2017
     
    Posted By: Simon StillHaving lived with MVHR for a year or so now I'm really happy with it. Noisy, drafty extractor fans seem archaic in a modern airtight house. Personally I don't think "purge" works well in the UK - fine in a cold dry climate but it's often too damp here.

    I agree. All our previous houses have had neither trickle vents nor mechanical ventilation, oh, except for the last ten months we spent in rented accomodation. In all of them we controlled the IAQ by opening windows wide, and all of them had gas heating that dealt with the resultant chill. Some also had extractor fans.

    As you say, MVHR is much more pleasant. Today the only reason for opening doors or windows for any length of time is because the cats have trained us that having to go through the cat flap to get a smell of outside is an unreasonable imposition on them by us :shocked: :sad:
  3.  
    In a modern house which is struggling for air circulation I quite like the facility on roof lights to be cracked open if they have 2 positions, if there is nothing else available or if all the other facilities may be not used or blocked.

    I have occasionally been known to leave it like this as a default in a cathedral ceiling.

    Ferdinand
    •  
      CommentAuthordjh
    • CommentTimeMar 11th 2017
     
    Posted By: ferdinand2000In a modern house which is struggling for air circulation I quite like the facility on roof lights to be cracked open if they have 2 positions, if there is nothing else available or if all the other facilities may be not used or blocked.

    I agree that roof lights are quite effective for ventilation and also for lighting but they're not very efficient thermally. It sounds like there are other problems if opening them is the best option.
    • CommentAuthortony
    • CommentTimeMar 11th 2017
     
    It will be very different on windy days and also dependant on wind direction.

    I don't like letting warmed air out of my house.
  4.  
    Posted By: Simon Stillhttp://www.walesonline.co.uk/whats-on/film-news/grand-designs-eco-home-puts-7903485


    yes, that was it. They mentioned it was airtight - but I bet they didn't do a blower door test and I doubt it is that tight otherwise it would need mechanical ventilation IMHO.

    Paul in Montreal.
    •  
      CommentAuthordjh
    • CommentTimeMar 11th 2017
     
    Posted By: Paul in MontrealI bet they didn't do a blower door test

    It's required by building regs, unless Wales is different.
  5.  
    Posted By: djhIt's required by building regs, unless Wales is different.


    The house is in Norfolk (despite the URL of the article).

    I wonder what the results of the test were ... I know 5ACH@50Pa is considered "airtight" in the UK ... but it's really not. Still, you don't need mechanical ventilation until 3ACH@50Pa or better

    Paul in Montreal.
    • CommentAuthorDarylP
    • CommentTimeMar 12th 2017
     
    @djh and others, a single dweling does NOT need an air-permeability test (ATT) to meet Part L Building Regs in England and Wales.
    The DER < TER calc can use air permeability 15m3/mh2 which negates the need for an ATT.
    In effect, you can build a cardboard sieve, with PV, and it will meet Part L.. :cry:
    • CommentAuthorgravelld
    • CommentTimeMar 13th 2017
     
    What is the "DER < TER calc"?
    • CommentAuthorDarylP
    • CommentTimeMar 13th 2017
     
    sorry.. :shamed:
    Part L Building Regulations compliance for new dwellings;

    Dwelling Emission Rate less than Target Emission Rate,
    along with DFEE < TFEE (Dwelling Fabric Energy Efficiency less than Target Fabric Energy Efficiency in England).
    •  
      CommentAuthordjh
    • CommentTimeMar 13th 2017
     
    Posted By: DarylP@djh and others, a single dweling does NOT need an air-permeability test (ATT) to meet Part L Building Regs in England and Wales.

    I think it is a requirement, but there is an exception to use a penalty default, and I doubt it would be practicable on a code 6 project. And yes, there should be no exceptions!
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