Retrofit Insulation and vents - what to look out for

onrail

My mother currently lives in a very cold 1970s bungalow with some localised condensation issues. Next month she's due to have new windows fitted along with pumped insulation and new attic insulation under whatever grant scheme is going.

I've heard of some horror stories about such works and condensation afterwards. Is there anything to worry about here? The quote include €120 'vents' in each room.

Are the vents likely to be affective? Are they not just likely to let the cold in?!

con747

A relative had work done under the warmer homes scheme and the work done was sub standard but that was in 2015, they requested an inspection but the SEAI didn't do inspections on request so they got the company who done the work to inspect it, hello Ireland. They said they do random inspections only so make sure the work is up to standard and note any concerns on the feedback form.

onrail

https://www.boards.ie/discussion/comment/120797788#Comment_120797788

Doesn't fill me with confidence!

gooner99

My mother had hers done last year (external and attic insulation, new condensing heating system, dcv ventilation system following blower door test) and so far so good. Everything was carried out to a high standard and there was a check from the SEAI at the end. I believe all warmer homes houses are inspected now, unlike the other seai grants where a selection are inspected.

onrail

https://www.boards.ie/discussion/comment/120802893#Comment_120802893

Aye, all those works sound pretty comprehensive - especially the ventilation and heating systems.

I'd be worried with ours that these 'vents' won't provide enough ventilation for what we need.

I just see on the quote here that it's a 'SEAI Grant'

gooner99

https://www.boards.ie/discussion/comment/120804678#Comment_120804678

Yeah that's correct, it was the warmer homes scheme. I believe (could be wrong) that they are now doing blower door tests when external insulation is complete to determine what ventilation is required. Initially they had hole in the wall vents on the list. Aereco is what they went with.

onrail

I just visited the mother's after the work was carried out earlier this week and these 'vents' are just cheap plastic slotted covers over 4 inch open holes in the wall...wtf... Am I missing something, or does that completely negate the effect of the insulation???

They are a lot more careful now than they used to be, you need an independent BER assessment after the work is done to draw down the grant so if its substandard the contractor doesn't get paid.

Coring vents is likely to be the reason they are so expensive, but I would prefer to see a whole house ventilation system to control condensation without pissing it out of open vents. More expensive but a better approach. If they are not going to seal it to airtight standards then a Positive Pressure Ventilation system would be a better approach to ventilation and would probably be cheaper than vents in every room.

onrail

https://www.boards.ie/discussion/comment/120848355#Comment_120848355

Work is done now anyway, so there is little that can be done I supoose. Is there any reason why the house wouldn't be freezing in the winter with all those holes?

It certainly won't be as good as it could be. There are things that could be done but they would be pricey.

windowcills

A lot of cold will come in and heat will go out the vents on a windy days

She can use the heating to make up for the lost heat, this will use more fuel which is expensive

A more efficient method would have been to fit a heat recovery system, but this would be a lot expensive to fit, but saves on fuel

People love to invest big to (show off and also) save a bit over the years after, remeber the 30k diesel car was only e150 to tax, woop dee do

Sorry for ranting i had a busy day, and a customer just texted saying her sky box isnt working, and it was working when i left the house

onrail

https://www.boards.ie/discussion/comment/120848540#Comment_120848540

A really stupid question here, but what the hell is the point in having the insulation and windows done if heat just leaves through the vents anyway??

Alkers

I think you're being overly critical here.

There are 4" cores in the rooms now but its not the end of the world. See how the house is for a while and how much bills are during winter.

Was the house insulated internslly or externally? The house likely had lots of draughts beforehand and these will (hopefully) be reduced following the works so improved ventilation is required. Check whether there are trickle vents in the windows or not?

If you want to improve on the current setup, the aereco vents are about 130e each to buy, they fit the 4" cores and what they do is the gap in the vent expands or contracts to control the inflow of air dependent on the humidity in each room. You still need something to draw air out of the house, you can do with a centralised aereco unit with ducts back to kitchen and bathrooms but that's a big enough job to fit and IMO will never pay for itself in savings unless doing significant other internal works. What we did instead is installed humidity controlled extractors in bathrooms *2, which are always running at a low rpm to promote airflow, these then ramp up significantly when the bathroom light is on (for odours!) or if they detect humidity from baths or showers and then slow down when the humidity decreases again. You can barely hear them standing beside them when on low rpm. We didn't bother with an aereco vent in kitchen, just left as a standard and we tend to leave the back doors open a lot anyway.

Alkers

You also need to ensure there is a 2cm gap beneath internal doors so there is sufficient airflow internally

windowcills

https://www.boards.ie/discussion/comment/120848572#Comment_120848572

On a windy day, but not every day is windy

Air can hold water, the warmer air is the more water it can hold, if there is no ventilation the air in the house will be 100% saturated, by water from sinks, people, sweat from bed and couch

Some parts of the house are colder, the air touching colder parts will cool, so now it cant hold as much water ( i mentioned above the warmer air is the more water it can hold) so excess water is sprayed like a fine mist on the celings, walls and floor, as it cools it falls to the floor and warm air from other parts of the house is pulled into room to replace, and the cooled air rolls out along the floor (open the fridge in bare feet to prove this), the fresh supply of warm air releases more water, this happening 24x7 causes mould to start to grow

Also cleaning chemicles will give of gasses

radon can come up the floor, and can cause cancer

Buring fuel can give off CO

What I would consider is adding a positive pressure ventilation system and changing out the room vents for adjustable mushroom valves. This would allow you to set the ventilation for each room by need and would reduce cold vent drafts into each room.

lostinsuperfunk

I've just had a retrofit done (external insulation) and vents fitted were similar to those described by the OP. There's a lot of air coming through them (it's been windy the past few days) so I'm worried there's going to be a freezing cold draught in the winter which might cancel out all the effects of the insulation.

There's also a lot of street noise coming in which I'm disappointed about. I'm going to raise these issues at the snagging stage to see what they suggest.

A poster above suggested Aereco vents - something like these? https://www.aereco.com/products/air-inlets/eht2/

Alkers

I have the previous version of those, all good so far. Noise abation isn't amazing but we leave on a very busy road

Alkers

But as I mention previously, you need fans to accompany them to achieve sufficient air changes

lostinsuperfunk

Thanks Alkers, looks like you have a good solution there.

TimHorton

https://www.boards.ie/discussion/comment/120852029#Comment_120852029

@Alkers s "you need fans to accompany them to achieve sufficient air changes" By fans you mean extractor fans in Bathroom/Kitchen ?

Busman Paddy Lasty

https://www.boards.ie/discussion/comment/120848630#Comment_120848630

"What we did instead is installed humidity controlled extractors in bathrooms *2, which are always running at a low rpm to promote airflow, these then ramp up significantly when the bathroom light is on"

@Alkers could you throw up a link to that product or PM please.

Alkers

https://www.boards.ie/discussion/comment/120853402#Comment_120853402

Yes but they need to run constantly at a low rate so your job extractor isn't suitable and you'll need to change bathroom fan also

Alkers

This is the fan we used in each wetroom (kitchen, bathrooms)

'intellivent" is the brand but any humidity controlled fan with a cotinious operation setting will do same job

https://www.greentherm.ie/product/intellivent-intelligient-extract-technology/

Have this five years and it's great

onrail

Thanks all for the input, but I'm still a little unclear on my central point. Do these 4 inch standard (SEAI spec) vents not completely counteract the improved attic and cavity insulation? Or even make things worse? If so, why even bother??

I stayed at the house last week and found the bedroom relatively cool for the time of year. No shock really given that I could see straight through a great big hole in the wall!

10-10-20

https://www.boards.ie/discussion/comment/120918769#Comment_120918769

Do these 4 inch standard (SEAI spec) vents not completely counteract the improved attic and cavity insulation? Or even make things worse? If so, why even bother??

In my opinion, yes they do as they allow over-ventilation during windy days. But they are there out of necessity as the insulation upgrades and modifications to the house make it more difficult for moisture to pass through the new layers, so hence trap it within, requiring this ventilation be installed to counteract the effect. Otherwise you'll end up with interstitial condensation at every wall and mold at thermal bridge points.

The only workaround which I can suggest is to fit closable vents in bedrooms etc (but not in rooms where there is a heating appliance fitted), but only close them off during windy periods.

maxamillius

Would DCV not be a good alternative to those standard vents?

onrail

https://www.boards.ie/discussion/comment/120923458#Comment_120923458

From what I read here, it seems good - but presumably we'd have no chance of getting a grant on something like that if the insulation grant work with vents has already been done?

Why would SEAI approve an piece of work such as ours, paying out a few grand in grants when it's quite possibly not making things any better? Seems insane

con747

https://www.boards.ie/discussion/comment/120923558#Comment_120923558

They just tick the boxes, the fact you pay a lot more to heat the house most likely doesn't compute with them. I think it negates the fact they are trying to get you more green when you use more energy to heat your home. That's just my 2 cents and I'm sure people will explain how I'm wrong.

Busman Paddy Lasty

https://www.boards.ie/discussion/comment/120918769#Comment_120918769

Ball up old socks and cotton t shirts into a 4" sausage shape and stuff the hole. Still lets in fresh air and even a breeze in without freezing the place.

TheDoc

https://www.boards.ie/discussion/comment/120918769#Comment_120918769

From my understanding (currently having works quoted on an old house, was my grandparents)

Room vents are essential because a) Your house needs to breathe and b) It helps tackle mould

Having a house fully insulated with no ventilation is, to my understanding, a dreadful idea.

This is information I've received from someone in the building industry and a surveyor. For both of them top of the list was get the vents sorted. It looks like they had been plastered over. One in the kids room was open a little but is a horror show. Took the cover of the wall and it was done dreadfully.

I have someone coming out next week who can hopefully do a ton of work for me, but I am assuming it will just be the Plastic white vents in, and that's fine by me.

A lot of new builds arn't coming with wall vents, instead having vents in windows. But it was explained to me that's just for newer builds, the older styled houses need wall vents.

I've found the entire insulating conversation and discussion a head melt. The only agreement I've found amongst loads of people in the business is that the external wall wrap is dreadful, has no basis in building and to be avoided at all costs.

Your mothers house is newer than the one I'm finalising building. And like I said top of everyones checklist for us is to get wall vents sorted. You can get ones that slide closed, but it seems an essential thing.

Like compared to mine it's just a hole in the wall to an external vent that looks like was put into the house in the 60's :D So we will be getting the modern setup of PVC pipe, expanding foam (probably) and then an internal white plastic vent cover.

listermint

https://www.boards.ie/discussion/comment/120923962#Comment_120923962

Don't do this. It will sure fire cause mould.

Yes DCV/ MHRV would be a better option, there are cheaper PCV options available that work with the vents in situ.

At a low cost I would probably change the vent covers to circular ones with closer controls on them and put a central PCV into the attic to provide positive ventilation. You can close over each vent to a certain degree which would provide the airflow but diminish the noise and wind factors.

The whole hog would be a MHRV which are fantastic but come with an associated fantastic price tag.

Busman Paddy Lasty

*stuff. They are very gently stuffed into the hole. Made sure there was still a good breeze coming through the hole afterwards. It dampens down the breeze. They are in no way blocked.

https://www.boards.ie/discussion/comment/120935319#Comment_120935319

Mechanical Whole House Ventilation is the solution to venting an old house which has been upgraded. It is forced ventilation with heat recovery on the exhausted air through a matrix. relatively cheap to run and should solve all air quality issues without cooling the house. Costs about €3K to do it yourself on a 100m2 house or double that to get it done for you.

Positive Pressure Ventilation is a cheaper option which will keep down condensation but it will lose heat. PPV allows you to close up most of your vents and rely on the leakyness of the house fabric to change the internal air.

Just about to do it myself.

Busman Paddy Lasty

https://www.boards.ie/discussion/comment/120935363#Comment_120935363

"Yes DCV/ MHRV would be a better option, there are cheaper PCV options available that work with the vents in situ"

Would you have a link to a passive product?

Have been searching but found nothing with good reviews. No budget for running power to wall vents, don't have wall voids or budget for whole house ventilation.

https://www.boards.ie/discussion/comment/120935446#Comment_120935446

I don't know of any passive products that would be retrofit. The mushroom vents are probably the best bet since you can adjust them to meet your individual room ventilation needs. They are what are used to balance a whole house ventilation system.

dbas

Could go with a couple of these lads either

https://www.vent-axia.com/range/lo-carbon-tempraselv

There are more expensive options available with decentralised mvhr.

It won't do anything for noise in the house and they need a power supply cable routed to them.

Noise attenuating wall vents are available.

https://buildstore.ie/fresh-90-db-acoustic-wall-vent.html

They could be available cheaper somewhere else. Links above are for info only

Busman Paddy Lasty

That's great. I'll look for a 4" with damper/regulator. On a windy site so need protection from wind more so than noise, although both are ideal.

dbas

https://www.boards.ie/discussion/comment/120935545#Comment_120935545

I've heard those vents with wind flaps make noise themselves in the wind. That one there has an adjuster. Just close it over slightly on a windy night, and remember to open it the next day

Once you factor in an electrician at around €100 + per vent it starts to make a whole house system look attractive.

dbas

https://www.boards.ie/discussion/comment/120936810#Comment_120936810

Whole house system would cost me a fortune.

2.5 storey 4 bed house. Fire lines etc.

A bungalow with open attic could have mvhr very cheaply. (Insulated ductwork etc)

All depends on the house type.

The decentralised option suits a lot of house types.

Yellow_Fern

https://www.boards.ie/discussion/comment/120918769#Comment_120918769

Of course they do. I cant stand them. They are not necessary in normal households where people are willing to open the windows. I have MVHR instead and I am very evangelical about it. Id encourage it for everyone. I also spend a lot of time in houses with neither hole in the wall vents or mechanical ventilation. I use humidity and C02 sensors and I open the window as needed. It works fine. Hole in the vents are such a retrograde nanny state option. They are written by people who dont understand buildings.

BTW they are required in all buildings, even very old ones with breathable materials.

con747

A friend just had a contractor out to inspect for the warmer homes scheme due to a disability and he was told because he had window vents he didn't need the wall vents. I found that a bit strange considering his house is riddled with mould and the window vents don't seem to be helping much. He was told the bedrooms and other rooms didn't need them, only the kitchen and bathroom needed to be vented out.

He was also told only half his house would be wrapped externally because there was some insulation in the other half's walls were there's an extension so he will have a step back halfway down the house. Sounds a bit mad but he's getting it done free so I suppose it's better than nothing.

Yellow_Fern

https://www.boards.ie/discussion/comment/120941183#Comment_120941183

I am not a professional but that information isnt correct. Are the trickle vents blocked? I don't think trickle vents provide same volume of ventilation as hole in the wall. I think half insulating a house is foolish, as older insulation was often done very poorly with thermal looping.

dbas

He likely needs a second opinion

con747

https://www.boards.ie/discussion/comment/120942085#Comment_120942085

Trickle vents in the windows are clear, I think half insulating is ridiculous as well. I'll tell him to ask when the project manager calls out why they don't think vents are needed in the other rooms.

Yellow_Fern

https://www.boards.ie/discussion/comment/120943191#Comment_120943191

I agree.

There is a lot of talk of investing in new tech, like electric vehicles, heat pumps and solar panels. Far less on ventilation. But I think that is wrong. Id urge people to use mechanical ventilation above electric vehicles, heat pumps and solar panels, for one simple reason, it is the only one that makes your life just easier and better. It is really the key tech for having a cosy house with good (not damp) air.

listermint

https://www.boards.ie/discussion/comment/120946195#Comment_120946195

Highly underrated and unknown.

But also it's really hard to notice unless it's in your own home and you've lived with it for a few weeks.