Retrofit Insulation and vents - what to look out for

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.

Shoog

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.

Shoog

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

Shoog

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.