'A' rated house but gaping vent holes

wolfyboy555

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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.

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.

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.

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

http://greenoakenergy.ie/ventilation/aereco-dcv/wall-window-inlets/

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

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

phelixoflaherty

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

Good luck wading through the ads

dathi

https://www.youtube.com/watch?v=0ofxAXPmwnM

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?

Outkast_IRE

https://www.boards.ie/discussion/comment/118077366#Comment_118077366

Believe it or not there are people who never open their windows , you have no guarantee they would be used correctly. You need to provide a fool proof way of ensuring ventilation . I honestly think there is a clear link to the houses built in the 60s-80s with no ventilation and increased in asthma and respiratory disease.

You would not believe how much the air quality can deteriorate overnight in a bedroom with 2 people sleeping if there is no dedicated ventilation

FitzElla

https://www.boards.ie/discussion/comment/118063546#Comment_118063546

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.

keno-daytrader

How on earth does a new A rated home in 2021 not have MVHR or DCV?

Del2005

https://www.boards.ie/discussion/comment/118077398#Comment_118077398

Its not fool proof ventilation by putting a massive hole in the wall. The people who don't open their windows will be the ones with expanding foam in the massive hole in their wall.

https://www.boards.ie/discussion/comment/118080283#Comment_118080283

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

Yellow_Fern

https://www.boards.ie/discussion/comment/118080283#Comment_118080283

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.

keno-daytrader

https://www.boards.ie/discussion/comment/118080329#Comment_118080329

Fools and their money...............

c.p.w.g.w

https://www.boards.ie/discussion/comment/118063616#Comment_118063616

https://www.partel.ie/product/44/7/lunos-aldr-160

was that the unit?

Flinty997

https://www.boards.ie/discussion/comment/118077398#Comment_118077398

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???

https://www.boards.ie/discussion/comment/118063529#Comment_118063529

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

phelixoflaherty

https://www.boards.ie/discussion/comment/118080829#Comment_118080829

Yep. That was it.

Outkast_IRE

https://www.boards.ie/discussion/comment/118080988#Comment_118080988

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.

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.

Yellow_Fern

https://www.boards.ie/discussion/comment/118080988#Comment_118080988

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.

Mickeroo

https://www.boards.ie/discussion/comment/118080829#Comment_118080829

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

https://www.partel.ie/product/39/8/lunos-e-

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.

Flinty997

https://www.boards.ie/discussion/comment/118083852#Comment_118083852

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.

10-10-20

https://www.boards.ie/discussion/comment/118083852#Comment_118083852

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

https://www.designingbuildings.co.uk/wiki/Defects_in_dot_and_dab

Standard Toaster

https://www.boards.ie/discussion/comment/118079055#Comment_118079055

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

Yellow_Fern

https://www.boards.ie/discussion/comment/118131030#Comment_118131030

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

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.

muffler

https://www.boards.ie/discussion/comment/118131134#Comment_118131134

Terrible advice not to mention the legality of it all.

c.p.w.g.w

https://www.boards.ie/discussion/comment/118131995#Comment_118131995

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

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

c.p.w.g.w

https://www.boards.ie/discussion/comment/118132026#Comment_118132026

Like the light bulbs you have in during the assessment affects your score(well it did when my mother was getting her gaff done)

Penn

https://www.boards.ie/discussion/comment/118132026#Comment_118132026

Because the vent holes are not related to heat retention, but ventilation. Without adequate ventilation, the humidity of the air within the house keeps increasing, and warmer air can hold greater levels of water content in the air. This then leads to condensation and mould within the house. You need ventilation to provide sufficient air changes.

That's why it's nonsense to suggest blocking them up or just "open a window every now and again". Air changes need to be constant to keep moisture levels in the air down. Houses nowadays are designed with both heat retention and sufficient ventilation in mind. Changing one affects the other.

When airtightness tests and BER assessments are done on houses, it's testing the airtightness through the building fabric itself. The wall vents are taped and sealed. The type and number of background ventilation such as wall vents are taken into consideration seperately.

The assessments aren't just a box ticking exercise, but are used as a design tool pre-construction as much as an analysis post-construction. You can over-specify some elements to compensate for some lower elements, however there's also still minimum specifications things have to achieve to comply with the building regulations (eg. minimum levels of ventilation, minimum airtightness, minimum insulation levels). In some regards, the BER results in some box-ticking, counting etc. But the design and specification first and foremost is done in accordance with achieving building regulations.

MicktheMan

https://www.boards.ie/discussion/comment/118132026#Comment_118132026

Correct, it is a box ticking exercise especially when it comes to existing housing and is not (nor was it designed to be) a reliable method of knowing how a house will actually perform with regards to heat loss and indoor air quality.

MicktheMan

https://www.boards.ie/discussion/comment/118131134#Comment_118131134

There is sooo much wrong with this post. Please do not heed.

https://www.boards.ie/discussion/comment/118131134#Comment_118131134

Do not do this under any circumstances. If you've a problem with the ventilation letting in cold, turn on the heat. It's an A rated house after all, it's not going to take long to warm up.

Chris_5339762

I'd block them immediately, awful stupidity. But only so long as you ventilate regularly by opening windows and it doesn't hurt to have a dehumidifier too. TBH everyone should get one of those anyway.

Yellow_Fern

Windows can provide adequate ventilation without any vents. I would for a landlord but for myself its ok. Even if you support vents, there is a optimal size of vents, direction of road noise and prevailing winds to consider. The minimum required air changes required under regulations option for natural ventilation are far too high IMO and local geography is not considered.

Penn

"Far too high" based on what, though? What types of hygrothermal assessments or analysis are you basing that comment on?

If local geography is determined to be a factor, the onus for that is on the designer to address, and to perhaps look at an MVHR system instead of natural ventilation. It doesn't mean the regs are wrong. And the issue with just opening windows or using a dehumidifier is that they're not always used right by the occupants. Windows are left closed, or dehumidifiers only in one or two rooms or not turned on enough. Hell I've been in plenty of houses where even the trickle vents are left closed by the occupants (who are complaining about condensation and mould at the windows). I've taken high Relative Humidity and Dew Point readings in houses where the occupant is complaining that it's too cold.

Many owners/occupiers/tenants etc don't understand the need for ventilation or the effects of improper ventilation. They will do whatever's most comfortable or easiest at the time, and the gradual effect of that ends up being mould/condensation which they don't understand because "Sure I'm constantly opening the windows!"

As houses become more airtight and better insulated, proper ventilation strategies are more important than ever, and can rarely be left just as the owner/occupant's discretion to implement because that's rarely going to be done right. If there's deemed to be an issue with background wall vents due to local geography, then an MVHR system should be installed, and it's the designer's responsibility to establish that.

SupplyandDemandZone

We just blocked ours up as the house was an ice box with them left open. We leave the vents on the windows open and we've no condensation. Might not work for everyone

Flinty997

https://www.boards.ie/discussion/comment/118133368#Comment_118133368

How could house be A rated with uncontrolled passive vents in the walls. It wouldn't pass an air tightness test.

Penn

https://www.boards.ie/discussion/comment/118134758#Comment_118134758

Wall vents are sealed and taped during the airtightness test. The airtightness test is testing air permeability through the building fabric itself (walls, wall/ceiling joints, wall/floor joints etc).

Anywhere that air is supposed to escape from (wall vents, opes) is sealed so as not to affect the results.

TGD Part F:

Air infiltration: The exchange of air between outside a building and inside other than through openings provided by design (for ventilation, access and other purposes). Infiltration is caused by pressure difference effects of wind and/or stack effect and occurs through cracks, porosity of building elements and other unintentional openings in the building fabric. 

Flinty997

I'd love to see the SEAI do another study to see how many houses are actually built to the standard they claim to be. There is almost no checking of how houses are built.

If you are self building you have to have eyes in the back of your head trying get tradesman and builders to do things to properly. I can only imagine what happens everywhere else.

Flinty997

https://www.boards.ie/discussion/comment/118134766#Comment_118134766

So they are untested in effect.

Penn

https://www.boards.ie/discussion/comment/118134785#Comment_118134785

But what are you testing in that case? You can't test the air permeability in the room with a wall vent open.

The airtightness test is required to determine the air permeability of the building fabric. It's seperate from how much ventilation is provided to achieve the required level of ventilation/air changes per hour, and there are different ways to achieve that (eg. wall vents, wall vents + trickle vents in windows, mechanical ventilation, mechanical ventilation & heat recovery).

One feeds the other. For example if you want to use an MVHR system, you need a better airtightness result because otherwise you're going to be losing too much through the building fabric and the MVHR system won't be able to operate efficiently.

But again, airtightness testing is measuring unintentional air infliltration through the building fabric. Background ventilation (wall vents, trickle vents) are sources of intentional air infiltration to provide the required air changes.

Flinty997

You are measuring the positive air pressure (or negative). Once you uncover the vents all your measurements are null and void. ( I get the fabric of the house has been tested). But if house was in an exposed location (in relation to the wind) vs sheltered location the pressure of air coming through the vents, would be entirely different vs the test. You could have a gale coming through those vents.

Penn

https://www.boards.ie/discussion/comment/118134875#Comment_118134875

The external louvres on most wall vents dissipate the effects of most strong gales. But yes, again a lot of that comes down to the designer and if they feel the external air or noise levels will be factors, alternatives to wall vents should be assessed.

But that's not an excuse to block up wall vents and just say "I'll open the window every now and again." That's the issue, and I've seen it in plenty of houses where it leads to mould & condensation because the required level of air changes aren't being achieved.

sydthebeat

https://www.boards.ie/discussion/comment/118133441#Comment_118133441

fcuk me..... but thats an ignorant statement

sydthebeat

https://www.boards.ie/discussion/comment/118134758#Comment_118134758

another ignorant statement.

dont post when you havent a clue

Flinty997

https://www.boards.ie/discussion/comment/118134892#Comment_118134892

Not an excuse no. Can also be a safety issue depending on the heating in the room.

But if people are doing things like that, or struggling with draughts it shows there's a problem with vents like this. Its too simplistic to dismiss it out of hand.

Bargain_Hound

https://www.boards.ie/discussion/comment/118134777#Comment_118134777

I have often thought the same (Based on my experience). Having previously owned a new build A3 rated home, I no longer have any confidence in the rating system actually meaning anything. It was no warmer then the current B3 15+ year old house we live in now. Nearly every skirting board had a draught coming in under it, air coming in around the front door and making its way under the skirting again, and the French doors into back garden were never fitted correctly either, again a visible hole at the bottom of the door frame to the outside with air leaking. And that was just what I uncovered. Corners were definitely cut and I'm sure behind the plasterboard/brickwork there were many shortcuts taken.

Oh, each room had 4" vents and they let in an awful draft along side road noise.

Our new (old) house is nearly just as bad, but at least I didn't buy this on the premise of it being super efficient (A3+) and built to a high standard.