Advice on insulation please

Easter Sunday

Hi
We’re building a new house....spec is
Block,
150 mm cavity filled with bonded bead, block
internal insulation.

We will have a MHRV system with air source heat pump.

My question is...is internal insulation ok as I have heard of issues with condensation / mould on the block side of the internal insulation.
Does a vapour barrier or MHRV system solve that?

Also any opinion on MHRV system-counter flow or thermal wheel best for Ireland’s humid climate?

sydthebeat

Who specified it like that, and why?

funnyname

Sorry for to be jumping in here but why would you have a cavity wall only to fill it in?

Easter Sunday

Just noticed mistake.. a comma missing!
I meant
-block,
-150 mm cavity with bonded bead,
-block,
- and then internal insulation.

Specified by engineer, approved by builder friend, and builder agreed it was the right way to go

Easter Sunday wrote: »

Hi
We’re building a new house....spec is
Block,
150 mm cavity filled with bonded bead, block
internal insulation.

We will have a MHRV system with air source heat pump.

My question is...is internal insulation ok as I have heard of issues with condensation / mould on the block side of the internal insulation.
Does a vapour barrier or MHRV system solve that?

Also any opinion on MHRV system-counter flow or thermal wheel best for Ireland’s humid climate?

Calahonda52

funnyname wrote: »

Sorry for to be jumping in here but why would you have a cavity wall only to fill it in?

I suggest you read through a few of the 1,000 or so threads in here on that topic.

B-D-P--

As above, Discussed to death on this forum,

Sorry to say people probably wont reply because its a discussion thats been had over and over.

Besides, what makes you think strangers on the net are more qualified than your engineer?

Some are, but a lot arent.

Calahonda52

Easter Sunday wrote: »

..
Also any opinion on MHRV system-counter flow or thermal wheel best for Ireland’s humid climate?

IIRC the thermal wheel performs better when there are higher level of RH in The EXHAUST air.

Humidity problems with domestic MHRV in Ireland are normally in the SUPPLY air so are normally dealt with using a chilling coil.

This make sense when you look at the science:
the exhaust air is being chilled, hence the RH will soon reach saturation point.
The reverse happens on the supply side.
http://www.dpcalc.org/
https://en.wikipedia.org/wiki/Thermal_wheel