A2 Rate house is so cold at night

A BER cert isn't worth the paper it's written on.

What temperature do you get each room up to during the day?

Is your house timber frame? If you have warm day and cold nights timber frame may not hold the heat and do feel cold relatively quickly when the heating is off. On the plus side timber frame heat up quicker than block built as you don't have all the cement blocks to warm.

Personally I would put on the heating a bit at night and ensure if you have thermostatic valves on the radiators they are set to keep the rooms not too cold nor too warm. If you have zones for upstairs only heat upstairs at night.

Buying cheap temperature displays is a good start, bedrooms should be really 16-18 Celsius at night as in cooler than living rooms although many people like them warmer.

If it's cold you need to put energy in to heat the place, if it's 5 degrees outside even an A rated house will cool and need lots of heating. Modern houses may have very small radiators and lower temperature boilers so cooler radiator temperatures for efficiency reasons.

The problem is that an A2 rated house is designed to be airtight in its fabric, overnight a room will get very high levels of moisture and carbon dioxide, hence the insistance on permanent ventilation.

The issue is that this sort of ventilation, though essential, is totally uncontrollable and it over specified for most situations. The reality is that any A rated house should have MHRV as standard but for some reason the Irish building code cheaped out and went for permanent vents.

Basically it makes all your expensive airtightness building fabric redundant. The solution is to install MVHR and block up your vents. Your house is probably performing down at a D rating with the vents.

Stupid situation, but retrofitting MVHR is both expensive and disruptive (just done it myself).

We've e got the exact same problem as you. We find 18-18.5 is comfortable for us for sleeping, but one bedroom in particular is much colder than this.

We replaced the vents with these, https://www.amazon.co.uk/gp/aw/d/B077CKKBBQ/ref=ox_sc_saved_image_2?smid=AJ8Q5SD9MLKTW&psc=1

They're closed during the winter and open in summer. But even when they're closed they still allow enough air to pass through and we haven't seen any condensation on windows. They've improved the situation a bit, but haven't solved it.

Does your heating system run on zonal stats placed on the walls of the landing and hallway? You might need to move the one upstairs if its temperature reading is consistently higher than the bedrooms.

He already said, theres gusts of cold air coming in through the vents.

Get your part l report and dwelling report from SEAI. That'll tell you airtightness of the house.

Also look at something like these. I'm assuming there's no wall stat in the kids bedroom.

Also, these hoods can prevent wind gusts into vents but leaves them open

Probably better versions of that available, but you get the point

Any recommendations on 5 inch humidity vents? A lot of places seem to only do 4 inch.

Do builders test every house in a development now? I thought that only a few where tested and the results used for the development.

The house can't be very air tight with massive vents in all the rooms.

Just a generic portable display, it helps you decide on which rooms are colder, if they are unusually cold, at this time of year with 3 degrees outside you will need to heat multiple hours a day. Houses with heat pumps typically run on and off all night long.

It’s got nothing to do with extract vents or anything I think.

its more for carbon monoxide build up ?

if you have a gas boiler inside your house then they put in those big vents, I think they are even required larger than an oil burner? ( I could be wrong) just going from memory from when I was reading about it.

you’ll see on the likes of screwfix that some wall vents are suitable for gas and some are not, the ones suitable for gas , don’t have screens and have larger openings.

we had the same issue, it’s not really heat loss, in the bedroom you could actually feel the cold air blowing in when lying in bed. You could feel the draft, even worse when windy and in winter.

i just took the old ones off and put something similar to this.

yea they might not be suitable for gas, but I was damned if I was sitting in the house feeling the draft. They will help until/ or if you want a better solution.

The vents are blocked up for the air pressure test. Vents are needed for part f compliance.

Your boiler is likely a room sealed boiler so no vent required for that. If the flue has an outlet with a pipe inside a pipe there's no extra vent required for it.

My house is new and very leaky. Air tightness test result of 6.5 . My son's room is always cold as it faces the prevailing wind. The stat is in our room which is always warm so the heating system doesn't know his room is cold so it doesn't turn on the heating.

Those reports can be sourced from SEAI and they will tell you the airtightness result. You multiply the figure from the part l report by 20 to get the test figure. If the result is above 3, then I'm likely right in what I'm saying.

You need ventilation though so make sure that is part of your retrofit. Best of luck with it

Yes it MVHR

Perfect.

Ventilation and window upgrade only?

Vents.

You need to block the vents.

They're probably the two warmest rooms and the worst places to have stats located. It might be worth having the upstairs stat moved to the colder bedroom.

Use strips of draft excluder foam wrapped around the vent to make up the 50mm gap and it'll fit snug.

Put in a 4 inch pipe and foam around the edges both sides.

Everything is 110mm you'll find. No point in square shape round hole so to speak.

This is it