Multifoil insulation *PIC*

[Anonymous]

Really interesting!

I'm not a maths wizard and totally failing to be any help at all to my daughter with maths homework. However, I wonder if its not possible to work out the equation for each curve and extrapolate these forward to estimate the heat loss for the domestic temperature range? I think I had some software that could have done this before my most recent hard-drive failure.

Or is my understanding of physics even worse than my maths?

 

[Anonymous]

Yes Worms, the data could be analysed in the way uou suggest, but, to be honest, the errors involved in my kitchen experiment are likely to be so great that it wouldn't be worthwhile trying to extract to much information from the dodgy data. I just did it out of a bit of curiosity, to spark a bit of debate, and to highlight the fact that serious science just has not been done on these materials. Countless millions are being spent of building materials whose performance is not agreed and problems such as those that Johneds highlighted are being experienced.

 

[Anonymous]

Biff, we used Frame Foil on our roof, difficult to see the difference between it and the actis one. We were very limited on build up depth so it was the only sensible option. We had to leave a 20mm gap between the insulation and ceiling and insulation and sarking felt/breather membrane. All the joints were taped both sides with 75mm alu tape.
Got some ofcuts if you would like to play with another.

 

[Anonymous]

Interesting results and as you say not scientific enough to be conclusive.

Just some food for thought: -

We used Kingspan in the Attic and if I had my time again I would have used TriIso9.

On the whole Kingspan has been OK but whenever the wind whips up the room drops temp quickly. Now I had my suspicions that it was because of the wind and it was not until I read the other site I realised it is what known as air leakage.

TriIso9 performs better in that situation as it would have been taped and sealed. I know from watching the Kingspan go in that it was an arse to put in and gaps were left.

Now again I could have jumped on the builders to do a better job but at that time I did not know the importance of tight fitting insulation.

So when the wind is whipping up and down the roof the room gets colder and I don't think TriIso9 would have given me this problem as it is a darn site easier to fix and seal.

Also we lost quite a bit of roof space to Kingspan, this would have been reduced if we had used TriIso9.

The final factor that swings me in favour of TriIso9 is that it is reflective. The roof is a massive expanse of black slate which just soaks up the heat in the summer. The room temp is bearable as we used the best Kingspan we could get. (I forget the tech spec.) I have a feeling that if we had used TriIso it would perform better due to the reflective nature of the surface where Kingspan just soaks it in.

Just my 2p worth based upon living with the two substances in two different parts of the house.

MJ

 

[Anonymous]

What I don't understand is why the manufacturers don't release the information needed to calculate heat loss for any given situation so it can be properly compared. I'm sure they must know how to do this. For all we know poorly installed PIR foam could be three times better than a full layer of TIS9 - there is just no way to tell.

One thing I do know about it is that contractors like it because it is very easy to install. It is also good for reducing air leakage - which will be a big factor now that we have air leakage testing in some buildings under the new Part L. I haven't noticed that it saves any space though. The cross battens and air gaps needed are about the same thickness as an inner layer of PIR in a normal design and possibly more.

 

[Anonymous]

I've asked Actis, in two e-mails over the past week, about the status of their TRADA certificate which apears to have expired on 23rd February but they have not yet replied. Hmmm.