4" Room Vent

Put humidity vent into eBay. Check your size and look for passive ones not electrical. They open themselves based on humidity

listermint wrote: »

Put humidity vent into eBay. Check your size and look for passive ones not electrical. They open themselves based on humidity

like below? are they battery operated?

https://www.ebay.ie/itm/Fresh-99H-Condensation-Damp-Control-Passive-Wall-Intake-Vent-Grille-Kit-Vent/264339513310?hash=item3d8bdcdfde:g:Ye0AAOSwI2Vc67N5

Outkast_IRE wrote: »

Honestly i think improper ventilation of homes in this country is partly responsible for the high levels of asthma, sinus issues and other breathing difficulties we have in this country.

You are far better to keep the room well ventilated and well heated vs poorly ventilated and well heated - That 4 inch room vent in many cases is actually too little its the minimum. ( For a baby its fine but for more than a single adult in a room its not enough).

We live in a humid maritime climate , we add humidity to it in the home, cooking cleaning, breathing, showering.

This is not a DIY opinion by the way, i am an engineer dealing with ventilation design every day of the week and do some CO2 and air quality monitoring as part of my work.

Don't forget the sexin too. All counts.

loyatemu wrote: »

you do need ventilation but a lot of houses just a have a big hole in the wall in each room, which creates draughts and encourages people to block them up with newspaper or whatever.

Maybe something like this OP
https://www.goodwins.ie/products/anti-draught-black-hole-ventilator-bm725-brown-outer-cowl.html

TGD F recommends a minimum of 7000mm2 equivalent area for a habitable room, even the device linked has 6000mm2 "Free Area" so doesn't comply with the 2019 regs.

If looking up devices remember the equivalent area of devices is always less than the free area.

Equivalent area takes into account the air path through the vent . Which is more realistic .

loyatemu wrote: »

so what's a better alternative? I notice my neighbours have had external insulation installed, and now have an open vent for each room, so whilst they've reduced heat loss through the wall those rooms are presumably draughtier than they were. What would be best practice - ducted MHRV?

Your neighbours now have a well insulated correctly ventilated house.

Best practice is MHRV once you are well insulated and have tackled any infiltration / airtightness issues as best you can. Obviously retrofitting MHRV is invasive and extensive works unless you are in a bungalow with adequate attic space.

cheif kaiser wrote: »

I had external insulation fitted and vents holes bored into each room. I am now raging that I ever did it. The rooms are constantly freezing with cold air blasting in all the time, not to mention to street noise. I now have to have the heating on more often than I used to.

Many others that I have spoken to are also not impressed and have the same issues.

why dont you partially block the holes then?

cheif kaiser wrote: »

I had external insulation fitted and vents holes bored into each room. I am now raging that I ever did it. The rooms are constantly freezing with cold air blasting in all the time, not to mention to street noise. I now have to have the heating on more often than I used to.

Many others that I have spoken to are also not impressed and have the same issues.

You would not have qualified for the grant if the vents were not bored.


If the rooms freezing then you have an airflow problem and it's not from the 4inch vents it's elsewhere. Windows doors coming from behind plasterboard.



How were you planning on providing adequate ventilation to the room sans vents ?

Outkast_IRE wrote: »

I have a circa 2000 semi d build with minimal cavity insulation and wall vents in each room. I would never say i have freezing cold air blasting in all the time. I would find leakage from a poorly sealed window more noticeable than the wall vents.

There is more than one type of wall vent out there, some are better than others.

What was your ventilation in each room before the insulation ? Nothing ? Having a poorly ventilated warm room is a health disaster waiting to happen.

House is an ex Corporation house and is concrete throughout. The back bedrooms always had vents but not 4 inch holes and they had metal hoods on the inside which seemed to take away some of the draught. They now have flimsy plastic covers and I can feel the breeze on my face when trying to sleep.

I also discovered that the holes bored downstairs in the sitting room and kitchen were 5 inch holes but with 4 inch inserts. I have since foam filled around the inserts and this helped somewhat but am still finding it draughty. I have not had time to check upstairs as yet

Windows are fairly new and I also draught proofed all of the doors in the house with foam tape and created an attic ladder cover from a cold water lagging jacket which now sits over the ladder and eliminated the draught from the attic hatch.

It still seems to need the heating turned on more often, although once heated it does seem to retain the heat better but once it looses it's heat it seems to get really cold, really quickly.

The outside of the vent holes have cowls but behind the cowl is just a big hole. Should there be a further cover behind the cowl?

How old is your ex-corpo house ? Is it one that had a central air heating instead of a fireplace ? Might make it easier/ less disruptive to install a heat recovery unit ?

Markcheese wrote: »

How old is your ex-corpo house ? Is it one that had a central air heating instead of a fireplace ? Might make it easier/ less disruptive to install a heat recovery unit ?

1940s and has a fireplace which is still in use.

cheif kaiser wrote: »

Also, 2 doors away is a house owned by DCC, It also had external insulation installed about 6 months after mine.

They have no vent in the sitting room.

Their hallway or any open plan room would have the vent in it. This can be sufficient enough for inspectors and there are inspectors.

That's to say if they applied for the grant at all.

cheif kaiser wrote: »

The work was contracted out by DCC and was inspected. There is no vent in their sitting room or hallway.

Ok well there should be it wouldn't have qualified if an inspector saw it. Because I highly doubt there's ventilation sufficient for the space on your description.

I've had inspector out to mine. They are quite annoyingly detailed.

loyatemu wrote: »

If you're doing MHRV, do you need a duct to every room?

Generally yes you will but the designer of the system will specify with you exactly whats needed. dont design yourself. It should be done by a provider of equipment. Many do that for free.

[Deleted User] wrote: »

Friend of a friend had 4" holes/pipes in her house. Apparently she got some 2" wavin pipe and cut it to the correct depth, put it in the vent, and then expanding foamed around it.


Idea being that her 4" hole was now only a 2" hole. She was making similar complaints to you - freezing all the time and lots of outdoor noise.


I've genuinely no idea how she got on with his, or what difference it made (if any) but it seemed a reasonable compromise to me.

Don't do this. That's not enough ventilation she will get condensation and probably mould issues.