Actually it means that the insulation can have an insulation value up to the max of X because, like fibreglas, we all know that R20 in perfect conditions is not R20 in reality when in situ. Most people here don't know that a wall with R20 batts is not really R20.

PIR is Polyurethane Foam which is used extensively over in Europe. I have imported it in the past and it can be bought in many different densities some of which can be a lot more insulation/in than ISO foam.

I use polyurethane foam also and its great stuff. Better than iso in many applications. I assume you posted before you saw my latest post to AC. I think you might be using the wrong analogy about insulation ratings just being about in-situ. That's letting people off the hook just too easily.

It was basic physics that I was bringing up about application of radiant barriers in space vs on Earth. AC is always telling people that they do not know physics and they should get on the ball. But the comparison of multilayer spacesuits insulation ability in an air free environment and expecting that on Earth is crazy. Not even in the same ballpark as saying insulation in a wall and insulation that ignores framing factors, or batts bending around wires is the same basic thing.

I would not be so hard on AC except that I've seen how hard he is on other people. He actually told Xringer that he has a junk mind and Xringer hasn't been back. Don't know if that was the reason but I wouldn't be surprised. AC is very condescending to many people but this subject exposes very clearly how thin his knowledge of physics really is. This is really elementary stuff.
I certainly don't expect everyone to have the knowledge of physics I do but when a person presents himself as an expert, as AC does, then he should expect to reap the consequences.

We are vectoring off of the thread topic, but I would like to know more about PIR being higher in R-value than poly-iso

-AC

Here is the website of the company that makes it.

CONSTRUCTION: puren gmbh

How about the super thin foam material used to wrap/package fragile items in as separator material? I has some that is less than 1/16" thick that I use to tie fishing flies with. Very light, strong, stretchy and affordable. Usually comes in rolls.

10 layers seems like a lot of layers for diminishing returns. Just 6 tin foil/foam laters won me the "ice cube in the box" contest in junior high science.

Any updates?

Yes, some modest progress.

I had become a bit dispirited after the mini-troll vomited, but even the most distasteful moments eventually fade...



What got me re-interested, was that I was walking around the house with the first 10" x 10" ten-layer mylar & bridal veil sample in my hands and I walked past my espresso machine, and I realized that I had left it on for six hours... it does have a thermostat, but it gets uncomfortably hot to the touch after that amount of time...

So I put the MLI sample on top of the espresso pot, and put my hand on the sample, and was completely amazed at how well it held back the heat. My sample was maybe 50/thousandths thick, and for that thickness, the insulating ability was very surprising, to say the least.

So I went to a very large fabric store looking for some very thin micro-fiber batting that was not thinsulate-branded, in order to avoid the marketing burden.

I was not able to find exactly what I wanted, but I did buy some very thin lambs wool batting material. I bought enough to make an 18" x 18", 10-layer lambs wool & mylar test sample.

So far I have made an 8-layer sample piece and I have enough to go the full 10-layers.


This stuff is very slippery, and hard to keep in position. I have a sewing machine (it's even a walking-foot machine), but I think I'm going to need help to run stitching around the edges. There's a gal down the street with plenty of sewing savvy, so I'm waiting to set up a meeting with her.

I'm doing an outside wall insulation project (more later) and if the DIY multi-layer insulation works out well, it would be perfect, because the wall size isn't very large, I'm looking to insulate the innermost 2", so costs would be acceptably low.

-AC

Another fibered fabric that comes in several thicknesses and stiffness is pellon. I have used it in several different projects.

I checked out Pellon.

I have worked with fusible interfacing before, and I'm afraid it is not exactly the kind of material I need.

What I'm looking for is microfiber, because microfibers will be less thermally conductive because of the fiber diameter.

The material should also have some 'loft' like down, but it doesn't need to be very thick... just enough to keep the mylar layers from touching.

NASA used stuff called 'bridal veil'. I tried some actual bridal veil, and it worked pretty well, but the price is a bit much, and it was maybe a bit too sheer.

-AC

Not all Pellon is heat fusible. Maybe it is not actually Pellon but looks like it, I use it in my art ceramics work all the time because it has a very smooth surface a stiffness that resists wrinkling and breathes(so it is not a tight woven fabric, more a kind finery felt). No it does not provide any real "loft" just overall "thinness" of bridal vail if that is what is being sought.