If I use 3 layers of insulating material = 3 inch of loft
How would 4 layers of insulating material compressed to 3 inches compare ???
Any ideas or thoughts ???
If I use 3 layers of insulating material = 3 inch of loft
How would 4 layers of insulating material compressed to 3 inches compare ???
Any ideas or thoughts ???
Bradley SaintJohn
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That's a really interesting question. If insulation really works mainly by trapping air then I guess the three layers for three inches would work better than the compressed 4 layers. That certainly seems a bit counterintuitive to me, though. I'll be really interested to see what some of the more educated members here would think.
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CBS (Cold Butt Stephen)
which does not explain how insultex works..maybe it is how well the substance prevents the air that is warmed up by you from moving away? so the impermeable barrier would be a better insulator, but then you get into moisture management issues- how much is too much, how warm is too warm, waking up in a puddle while a frost cloud forms over your breathing space, etc. KM(who is up way too early for this heavy of thinking)
Years ago I was an insulator of metal buildings and even pipe . . .
The location was northern Canada . . . and back when -40 was not uncommon.
Pink was just a standard and used in many metal buildings.
If insulation was required to also be a sound barrier
then we would use insulation that was somewhat denser, such as rock wool.
The rock wool seemed to act as well/or-better (???) as a heat insulator as the other products
On pipe the choices are many from fiberglass to Calcium silicate for extremely hot pipe.
The Calcium silicate is a dense chalky material that enables very hot steam pipes to be nearly touched on the outside aluminum skin.
I realize it is somehow the trapped air that is the insulator,
but some how material and density fall into play as well ????
Bradley SaintJohn
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I think you'd have to run some experiments to really find an answer. Just a SWAG but I see a trade-off between the effects of convection & conduction. With no feathers, convection sets the insulation value. With a solid mass of material (can you pack feathers that tightly?), and no air, then conduction sets the insulation value. Too few feathers means too much convection; too many feathers means too much conduction. There's gotta be a "happy point" somewhere in between the two extremes. Probably true when using a filler other than feathers, I'd think, but it would give a different "happy point". Yeah, I left out a lot of stuff but I don't want to think that hard right now, either.
- Frawg
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should be warmer (think overstuff). but eventually you reach a point of diminishing returns i think
I think Frawg's analogy is correct but there are a few more variables, such as the conductivity of the material (e.g. metal conducts better than down).
Reading up on R-value will give you some scientific basis for your answer:
http://en.wikipedia.org/wiki/R-value_%28insulation%29
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IMPOSSIBLE JUST TAKES LONGER
I am certainly no expert at this subject, but sometime back I researched this very thing. My research was limited to down insulation (not things like IX). From what I remember, there are different methods of preventing heat (energy) from transmitting from one object to another. The main ones are convection, conduction and radiation. If there is too much air space in an insulation, the air can move freely resulting in currents, which is convection. Whereas conduction is heat that is transferred through a solid.
When down is fully lofted there is very little conduction but the large air spaces allow some convection. As the down is compressed, the convection is reduced but at the expense of more conduction. The research that I read seemed to indicate that the convection and conduction nearly canceled each other out between the limits of fully lofted to about 2.5 times compressed.
I believe a large component of IX's insulation comes in the form of radiation.
Bradley SaintJohn
Flat Bottom Canoe
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The Transition from Ground Sleeping to Hammocksis the Conversion from Agony To Ecstasy,and Curing Ground-In-somnia.
"Call unto me, and I will answer thee, and show you great and mighty things . . ." Jeremiah 33:3
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http://en.wikipedia.org/wiki/Aerogel
We need to find some of the Aerogel blankets they talk about & make UQs...
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