Multi Layer foil insulation

[MdB]

Sorry Biff. Completely wrong.

Er, actually no, but life's to short to go through it all again. It's all in the Green Building Forum thread that I started over a year ago, mostly on the old site. The first 148 pages are at http://www.greenbuildingforum.co.uk/forum/index2.php?DATEIN=tpc_wlpssdlpg_1142805843
and then it continues with another 62 pages (so far) on the new site at: http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=125&page=1

I've read through some of what has been said so far and some of the reasoning used so far to explain why it doesn't work very well is completely wrong and I stand by that. The basic IR physics is wrong. However, I do agree that this isn't the place to argue. I will add to the other green building forum thread when I get a moment. What does matter though is the practical perfomance which is where your experiments and Ceedeepics experiments come in. These show that foil doesn't work very well so multifoils should be treated with caution.

 

[Penners]

When I cook salmon, I wrap it in foil.

It still seems to cook.

(The above scientific treatise complies with the Penners Principle of Thinking-Of-His-Stomach-First)

 

[skier-hughes]

Could you quantify that please by cooking two identical fresh pieces next time and record the time difference in cooking one foil wrapped and the other open, so that we may extrapulate an insualtion factor :wink:

 

[Geoff Flegg]

That spacetherm stuff looks good - I wonder why Proctor group don't carry it on their main website?

Biff, any idea roughly what thickness of phenolic foam insulation Spacetherm is equivant to?

I was going to use Kingspan / Celotex and just put up with bashing my head occasionally, but if this stuff works and doesn't cost way over the odds then it could be a possible.

 

[biffvernon]

Spacetherm has a thermal resistance of 0.013W/mK so you can do the arithmetic. It comes in various thicknesses.

 

[Flyfisher]

When I cook salmon, I wrap it in foil.

It still seems to cook.

Funny you should say that . . . I've just got back from the river with a very nice 2lb brown trout, which will be subjected to the foil treatment tomorrow lunchtime.

Excellent hatch of mayfly this evening. If the other fish hadn't broken my line I could have carried out Graham's suggested experiment

 

[Gervase]

Shame there isn't an emoticon for 'Green with Envy'!!!

 

[biffvernon]

My neighbour cooks salmon in her dishwaher - just the right temperature but remember to leave the detergent out. We haven't got a dishwaher.

 

[Howard Ogden]

Having never cooked a salmon in a dishwasher nor used multifoil insulation I cannot offer any comments borne from experience. However on the Celotex website you will find the following articles:-

http://www.celotex.co.uk/news_story.php?id=6
http://www.celotex.co.uk/news_story.php?id=25

http://www.just-insulation.com/thinsulex.html

I guess any manufacturer of solid board insulation is justifiably going to expect a rival offering a different product to back up their claims. :?

 

[biffvernon]

Thinsulex uses layers of infra-red reflecting film to reflect heat back into insulation containment cells. Thinsulex boosts the thermal value of glass wool...

"insulation containment cells", "thermal value". Give me strength. No O'-level physics for their copywriter then. Not even a mention of salmon cooking.

 

[citizensmith]

We have a large roof, slated, with three large rooms and a landing which are half in the "Loftspace" as it would be.
The roof is currently being refurbished, slates stripped, timber checked and... insulated.
We had no insulation whatever and have cone for a hybrid approach - conventional fibre on flat areas above ceilings and the tri iso foil over the whole roof.
The original tiles are going back on shortly - we will need about 2-300 24 x 12 welsh slates to replace the broken/poor ones.
I understand the reticence about the foils "science", but even now we are much cosier than when we had a "roof" and we wanted to keep the top floor a bit cooler in summer when it turns into an oven.
There has been one drawback so far - we seem to have become a target for the RAF! we have been "bombed" on several occaisions in the last few weeks and have had some very close flybys - are they locking on to my foil roof?

I will let the forum know how my oil bills change when the oil burning season restarts.

 

[Penners]

The pilot clearly moonlights as a building inspector.

 

[citizensmith]

Is that why the pilot was waving a clipboard at me?

 

[biffvernon]

now we are much cosier

and poorer.

 

[citizensmith]

Not really - It seems expensive at first - but goes a hell of a long way. The roof had to be done - no nails left holding up the slates, no effective gutters so it has been part of a bigger job. It would have been nigh on impossible to insulate this place without the roof off as there is so little access and its 3 floors high.
We found a halfpenny rolled ni the lead around a chimney - 1862 and in near unworn condition, so the current roof lasted 150 years. What should we put in the lead to mark this refurb?

 

[Penners]

What should we put in the lead to mark this refurb?

A copy of Tony Blair's resignation speech? At least it would give future generations a good laugh.

 

[chuckey]

A computer magazine?
Frank

 

[Mark]

I've had a quick read of the spacetherm stuff - one question that I have is that if it is a gas (presumably an inert gas?) in a foam then over time the gas will escape and you will be left with a semi-collapsed air filled foam. What performance does that give?

 

[Penners]

I wonder why an inert gas gives better insulation than air.

Experts...?

 

[biffvernon]

The gas in aerogels is air. The clue is in the name. Mostly nitrogen, about a fifth oxygen, and a very small but unfortunately increasing amount of carbon dioxide, 384ppm at the last count. When it leaks out it will be replaced by something rather similar.

The PUR and PIR foam boards are inflated with something other than air, such as pentane. This insulates better than air but it is unclear how much of it will have leaked out and been replaced by air after a few decades.