New House What Insulation?

jasgrif11

Hi all,

I'm about to start building a new house. I'm going ahead with a Geothermal Boiler from Ashgrove Engineering, therefore the whole house will have UFH. What I would like to know is what insulation is best for UFH and also for the Block Cavity. My builder is recommending 105mm Aeroboard Platinum for the cavity (with the slots) and also a smaller size platinum for the Floor however I haven't heard much regarding the platimum. I was thinking more along the lines of Kingspan however my builder reckons that the kingspan loses some of its U value when you pierce the foil to clip down the UFH. Any thoughts on whats best for both? Also waht are the cost differences between the varies insulation products?

Cheers

construct06

Both Kingspan and Erobord provide a free advisory Technical service. Give them a call. Obviously they will be trying their best to convince you that each of their products are the best.

Kingspan is dearer (by a good bit) than aerobord but for about 1/2 the thickness you get the same u-value.

I'd be dubious about the Kingspan losing some of its thermal performance because of a few piercings in the foil, especially if it were thicker than 50mm.

My advice for walls and floor would be Kingspan. It is a very important decision (financially also) and even though it might cost a few bob more it is essential to get it right.

You cannot retrofit this insulation - eg. if you find out you have not insulated the house well enough well then your stuck with that fact and you will be forever trying to keep the house warm - spending collosal amounts on electricty/oil etccc to keep the house warm.

Air leakage is also a very important factor. Your expensive insulation is no good if even the tiniest gaps occur, so workmanship is very important.

construct06

construct06 wrote:

Air leakage is also a very important factor. Your expensive insulation is no good if even the tiniest gaps occur, so workmanship is very important.

This is one of the key areas to energy conservation, used in conjunction with a heat recovery ventillation.

No point in having a well insulated and draught proof house if it's stuffy all the time.

jasgrif11

Anyone know a company doing heat recovery ventillation systems in Ireland. As all my internal walls are block it may be difficult to run the ducting throughout the house.

On the insulation front I think I will go with the Kingspan.

sunnysoutheast

there's a few, hit Google. We're using proair from Galway

you'll have to plan your extracts quite carefully to minimise drilling, but we haven't found it insurmountable. the air supplies generally go in the far corners of rooms as far as possible away from the extracts in the bathrooms etc., if you see what I mean!

if you have concrete first floor you'll be drilling holes anyway for services, but upstairs (where the bulk of the extracts/inlets will be) it's not so much of an issue as ceilings are wood/plaster

you may also find that you'll have boxing on to do in a few places, so hide the ducting there

Viking House

On the insulation both Kingspan and Polysterene are less than 30kgs per m3 so their density is very low which means that your house will loose heat quickly when you use these materials.
We use Softboard which is 250kgs per m3 and Paroc Granitewool which is 220kgs per m3, these insulation materials hold onto the heat for nearly 10 times longer than Kingspan or Polysterene so your heating costs are greatly reduced. It is not only about U-value.
The system you are planning to use has loads of cold bridges which cannot be avoided around the foundations, the doors and windows and and where the roof meets the walls.
There is also the problem of Thermal Looping with the insulation in the cavities. This reduces the insulation values in the walls by 35%.
If you changed your building system you could eliminate the need for heating completly.

anon1

You should consider full fill insulation such as ecobead by polypearl. If you builder fits the aerobord correctly it is a good product, but it is hard to get if fixed tightly to the wall all the way round.

Reyman

Viking House wrote:

We use Softboard which is 250kgs per m3 and Paroc Granitewool which is 220kgs per m3, these insulation materials hold onto the heat for nearly 10 times longer than Kingspan or Polysterene so your heating costs are greatly reduced.

Sorry Viking - completely untrue! Heat capacity or heat storage has nothing to do with heating costs.

If you use a denser material the house will stay cold longer when the material gets cold and will stay warm longer if the material is warm. Heat capacity smooths out the rate at which you lose heat if it's cold outside but also raises the time it needs to heat a cool house.

It has no nett bearing on heat costs.

Having dense materials in the house just mean that you are "insulated" from rapid viariations in the external temperature. Having a heat recovery ventillation system helps as well

Even though I am building an ICF house, I am also installing UFH in a concrete slab plus fermacell on the internal walls. There should be enough density in the fabric to "ride-out" rapid temperature variations, here are the results so far (I have NOT yet insulated the loft, so doesn't look as good as I expect it to when completed).

Viking House

Reyman wrote:

Sorry Viking - completely untrue! Heat capacity or heat storage has nothing to do with heating costs.
If you use a denser material the house will stay cold longer when the material gets cold and will stay warm longer if the material is warm. Heat capacity smooths out the rate at which you lose heat if it's cold outside but also raises the time it needs to heat a cool house.
It has no nett bearing on heat costs.

Here are four links that support my posting and explain a lot about Decrement Delay and phase displacement.
U-value is only as important as the weight of the insulation.

http://www.viking-house.net/decrement-delay
http://www.beak.gr/en/products/bricks/features/insulation.htm
http://www.natural-building.co.uk/pdfs/why-build-appendicies.pdf page4
http://www.functionalpolymers.basf.com/portal/streamer?fid=290929

Reyman

Viking House wrote:

Here are four links that support my posting and explain a lot about Decrement Delay and phase displacement.
U-value is only as important as the weight of the insulation.

http://www.viking-house.net/decrement-delay
http://www.beak.gr/en/products/bricks/features/insulation.htm
http://www.natural-building.co.uk/pdfs/why-build-appendicies.pdf page4
http://www.functionalpolymers.basf.com/portal/streamer?fid=290929

Interesting references but all they say is that you get a more even temperature with a denser material, which is quite correct.

None of them say that you lose or gain more nett heat i.e. that your heating costs are changed one way or another by a denser material. The first law of thermodynamics applies here like everywhere else.

I'm afraid these manufacturers are just 'twisting' well known information to promote their own 'special' products