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'A' rated house but gaping vent holes

  • 23-10-2021 5:41pm
    Registered Users Posts: 1,404 ✭✭✭

    Recently moved into a new build. Everything is good but what's annoying me are the massive 6 inch diameter vents in every room of the house. I'm mostly annoying at the fact and can hear everything that is happening outside. I can even hear the baby crying next door in my house even though it's detached. Now the winter is setting in I'm noticing the house doesnt stay warm for that long even though is is supposed to be this fantastic A rated out. The heat obviously just goes out the vent.

    Is there anything to be done with these? I've asked around and most people say you can't block them as could lead to damp which is fair enough I guess. I was thinking about shoving in some insulation and I also have small vents on the windows I could leave open instead. Any other suggestions? I don't want to seal up with expanding foam.

    I've attached picture of the vent and the cover which slides over but makes feck all difference.



  • Registered Users Posts: 31,778 ✭✭✭✭listermint

    You can put baffles in them to prevent wind pushing in and some noise. But do not block them up. Your house needs to breathe. Ultimate solution is to install MHRV or DCV system in the house in replacement of the fixed vents.

    Fixed vents are very rudimentary but they do a job.

  • Registered Users Posts: 31,778 ✭✭✭✭listermint

    Oh one thing I will say is those slide vent covers are crap. Replace them with circle ones design for the hole. They are infinitely more controllable.

  • Registered Users Posts: 32,624 ✭✭✭✭Penn

    The wall vents are to provide background ventilation and air changes to reduce moisture in the air in prevent damp/condensation. All houses require ventilation, even A rated houses. In fact especially A rated houses, as they're generally more insulated and airtight (with regards the building fabric) and therefore need some form of ventilation. The trickle vents in the windows likely wouldn't be enough to provide this, so by insulating or blocking up the vents, you're increasing the risk of damp/mould.

    Your best bet is to install something like these at the existing wall vents

    They'll reduce noise/heat loss, and open/close depending on built-in humidity sensors.

  • Registered Users Posts: 1,412 ✭✭✭phelixoflaherty

    There was a device featured on Duncan's eco prog on Rte.

    It was designed to fit in the vent pipe and act as a heat recovery unit

  • Registered Users Posts: 1,412 ✭✭✭phelixoflaherty

    Retrofitting Ireland. It's in 2nd half of programme.

    Good luck wading through the ads

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  • Registered Users Posts: 1,344 ✭✭✭dathi

  • Registered Users Posts: 2,526 ✭✭✭Yellow_Fern

    The building regulations insist on these holes when there is not mechanical ventilation. It is a terrible rule as windows are a far better way of providing ventilation an ventilation needs vary by household size. Why not let windows ventilate, it is their purpose. Id really encourage you going down the mechanical ventilation route. I have it and its wonderful. You could also get your BER report which will be in the SEAI database, done by the builders and see what your houses airtightness is.

    Does anyone here have experience fitting decentralised heat recovery in hole in the wall houses? Do you need one in every room where there is a vent?

  • Registered Users Posts: 126 ✭✭FitzElla

    The Aereco vents you linked to can only be installed as part of their full DCV ventilation system. I've yet to come across a similar product that can be easily retrofitted into existing vents. Like the OP I have first hand experience with these A rated homes and the hole in the wall vents. They are especially prone to over ventilation when it is anyway windy. It is even worse when paired with a heat pump (so typically low intensity constant heat which struggles with sudden cold bursts) and it often means the room feels a lot colder than it should be.

    A MHRV is the obvious solution but a retrofit is a big job to get the ducting in place and not likely feasibly for someone who has just moved into a new build.

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  • Posts: 864 [Deleted User]

    Because you can achieve A3 (at least) without them and they cost feck all.

  • Registered Users Posts: 2,526 ✭✭✭Yellow_Fern

    It is foolish way to cut costs but when I am driving around new suburbs of Dublin I get the impression that it is common. I can't always tell from outside if they have hole in the wall vents or decentralised mechanical ventilation but sometimes you can.

    Someone should do a study of energy bills of post 2011 homes with hole in the wall vents and heat pumps.

  • Registered Users Posts: 762 ✭✭✭keno-daytrader

  • Registered Users Posts: 10,138 ✭✭✭✭Flinty997

    House built in the 60s-80s are not airtight.

    If there is an associated increase in respiratory problems, I can't see how it would be lack of ventilation???

  • Posts: 864 [Deleted User]

    Got a link to any such baffles? Preferably ones that can fit into the existing pipe without having to rip out what's there already

  • Registered Users Posts: 1,412 ✭✭✭phelixoflaherty

  • Registered Users Posts: 7,515 ✭✭✭Outkast_IRE

    No building is air tight . There is always some level of infiltration, you can't as a blanket statement say that buildings built across 2 decades have enough infiltration to allow for sufficent ventilation.

    Monitor the CO2 in an average bedroom built in any decade with windows closed and no dedicated ventilation and you will quickly find the level of infiltration is completely insufficient to maintain co2 or moisture levels at an ideal level.

  • Registered Users Posts: 10,138 ✭✭✭✭Flinty997

    You could fly a flag in most of those old houses with all the windows and doors closed.

    In the winter you'd be breaking the ice on the inside of the glass. If you could feel your hands.

    But you are right I've never tested them for airtightness or CO2. I'm just making assumptions based on my own experience which may be an outlier.

    So you could be could be entirely right. I'd love to see any studies on it.

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  • Registered Users Posts: 2,526 ✭✭✭Yellow_Fern

    Very good point but it is possible to have a reasonable airtightness value (and thus poor ventilation) but also also have a freezing house, due to the plasterboard tent effect. The risk of this is particularly high in windy areas like Ireland. I dont know if 60-80s houses have the plasterboard tent issue but in the 1990's you would. I don't have any data on this but I have experienced this.

  • Administrators, Computer Games Moderators, Sports Moderators Posts: 31,840 Admin ✭✭✭✭✭Mickeroo

    That's not the heat recovery one, this is:

    We put the non heat recovery version which you linked in our vents (90s house) and they are an improvement in terms of noise and wind getting in. They still over ventilate when it's windy though, but not as bad as it used to be.

    Seems crazy to me a brand new house would have hole in the wall vents like the pics in the OP, personally if it was me I would close them up and get MHRV installed.

  • Registered Users Posts: 10,138 ✭✭✭✭Flinty997

    In my limited experience I've only seen dot and dab on party walls. Everywhere else I've only every seen plasterboard on timber studs. That's from the late 70s onwards. Might have just been the people I worked with. Might be more common in apartments and one offs. I have experienced that tent effect on those walls with studs and plasterboard on houses built in the 2000s. You might feel a draft under a skiting board or closed vents. You might also see dust blown away from the skirting board. But thats probably due to poor construction and patchy insulation.

    There was a study from the SEAI about poor construction standards in the 90's, 2000s, (I think) where it showed the poor insulation and draughts of those houses, about 90% weren't up to the standard. But I can't find it now. I would say peak Celtic tiger, there was a lot of poor quality building going on. Things were just thrown up.

    Other people will more experience would have a more informed and experienced viewpoint.

  • Registered Users Posts: 5,677 ✭✭✭10-10-20

    Thanks for the reference to "plasterboard tents" which I had never heard of; this is well worth a read:

  • Registered Users Posts: 10,243 ✭✭✭✭Standard Toaster

    Is it possible, or should I say legal, to DIY a MHRV install or does it need to be certified etc?

    Any recommendations? (brands etc)

    2000+ sq/ft dormer

  • Registered Users Posts: 2,526 ✭✭✭Yellow_Fern

    Not sure about first question. For the second, Id generally avoid a well known UK brand beginning with A.

  • Registered Users Posts: 34,660 ✭✭✭✭BorneTobyWilde

    Block those vents up, it's all bull. There is enough ventilation with the coming and going of people, the opening and shutting of windows and doors, Geez.

    It's easy vent your home on a warm day, just open the windows, having vents like that open on a frosty night is bull.

  • Moderators, Regional North West Moderators Posts: 45,345 Mod ✭✭✭✭muffler

    Terrible advice not to mention the legality of it all.

  • Registered Users Posts: 4,986 ✭✭✭c.p.w.g.w

    Totally again it's awful advice, I have an older house, currently looking vat getting vents installed due to ventilation and damp issues...

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  • Registered Users Posts: 641 ✭✭✭techman1

    Makes you wonder about the energy rating system in the first place, it seems to be a box ticking exercise rather than a scientific measurement of heat loss etc. Surely if a house that doesn't have all the boxes ticked but still is sound with regards to heat retention etc , that house should still get a high rating. In the current system it seems to be "is so and so installed" tick