Heat recovery system in new build - where's the vents?

Have you seen the A1 BER Cert for a house with trickle vents.

I am a BER assessor so have my doubts

Also these systems need sign off now so ask for that

EA's play fast and loose with this stuff as nothing on their websites is binding

Yes they could, which is an issue for me as substituting ESB elec with PV elec to get a better rating does not reflect the true fabric related energy performance.

However, we are where we are.

Ps just read your first post, house not finished means its desktop New build BER, which won't be accessible on the SEAI site

There should be at least one vent in the ceiling in every room.

furthermore there should 2 vents on the wall outside or on the roof in the tiles.

These perhaps would be for supply and extract. But they should be hooded to prevent water ingress from showers.

So, if the MHVR was never fitted but it’s airtight walk away.

Will be full of mold if you start living in it. Retro fitting the system would cost a fortune and rip the place apart.

Not necessarily. The upstairs would be easy with ceiling access from the attic.

The downstairs would be a challenge, but you could get smart depending on the layout of the house and maybe open up only one or two stud walls to run piping to the downstairs ceiling.

For instance, my living room, downstairs bathroom and utility share a wall. It would definitely be a few thousand

Not exactly the experience you’d want in a home purchase that says it’s included.

I’d also be cautious considering buying a property where such a critical system was omitted for some unknown reason.

Trickle vents in a modern house claiming to be airtight? This screams huge winter energy bills to me. What else will they be pulling a fast one on? Insulation..... I would be very concerned that they will be loose with the truth as to what's actually buried in the walls and floor.

No vents in every room = no MVHR.

A1 Ber is horseshite because of the massive boost of a 22 panel PV system.

BER ratings are mostly shite because people assume high ratings mean warm comfortable home. When the system doesn't really account for that well. Low energy is a cop out if your brand new house is cold and uncomfortable.

You would remediate existing ventilation like all mhrv installs. Unless you think mhrv is only ever installed in brand new airtight builds?

My comment about being horseshite was in relation to the whole BER system and not the 22 panels of PV. I'm a big believer in PV power.

You will find A1/2/3 rated houses with 6inch vents (holes) in the rooms. Loads of nightmare stories on boards with these houses hemmeraging money for winter heating.

Yes it renders the whole BER system a joke. No A rated house should have any room vents that aren't attached to a MVHR unit.

My house has mechanical ventilation. Trickle vents in the windows that can be manually closed, and extractor fans in all the bathrooms, kitchen and utility.

Yep, I had considered retrofitting it, but the cost outweighs the benefit. The heat pump is a steady COP of 4 and the electricity bills for whole house are generally under 130 euro a month.

BER is a crock of **** for warm and comfortable homes.

It's not my fault the system doesn't cater for that well. You only have to look at the ample threads opened with I just moved into my A2 rated home and it's cold and with high winds it's freezing and noisey.

Etc etc etc.

BER has it's uses, but it's easily manipulated.

Nobody said it was your fault. I asked why you think it doesn’t cater to that well. You haven’t really explained that part.

If people are falsifying the numbers. The issue there is false numbers (and I agree that’s an issue). But on a fundamental level the concept of energy use is sound.

A lot of complaints I see, are often based in a misunderstanding of how it works. Eg solar panels being a perfect example.

A2 with 22 PV panels, and A2 with Uber-insulation are different systems. Assume they both required the same heating is misunderstanding the meaning.

They should of course required the same total energy to be purchased.

How is it ignoring the thermal performance? The rating is based the total energy performance of the building. That includes the thermal performance.

Take a hypothetical building that requires 100MWh annually (choosing a round number).

Say upgrading the heating system, airtightness, and insulation reduces that need to 50MWh.

Alternatively adding a huge PV array to the roof generates 50MWh annually, would reduce the need for additional energy to 50MWh.

Those building are very different thermally. But the net energy is the same. Energy rating is not a thermal/heating rating.

Energy Efficiency is quantifiable, A rated (by definition), is the most efficient.

Comfort is subjective. It’s highly likely that A rated will be most comfortable on average. But they should stress the generalisation part, as otherwise it contributes to the misunderstanding.

Definitely. The worse performing thermally will be all over the place.

Swings come down to the sensitivity of the system. How accurately it can measure the temperature, and adjust the heating.

With perfect tracking, there would be no swings. Manually turning it on and off, would be the most swingy. The total energy might be the same. Which also Illustrates that BER is ultimately a measure of energy, not comfort.

The BER system is like an elasticated measuring tape..... useless.

The A/T test is designed to find uncontrolled ventilation so leaving vents open will prevent the house from pressurising.