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r value

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What Does R-Value Mean?

A higher R-value means that the insulation will do a better job of holding in conditioned air, whether that’s heat in the winter or cool air in the summer. It’s not about how much heat the insulation retains, but how slowly it allows heat to move through it. The slower, the better.

Of all the insulating materials used in sleeping bags the heat movement out of the bag when the insulation is LAMILITE is the slowest. Cool air in the summer only applies when you are using a summer weight LAMILITE bag.

Most insulation manufacturers will first list their insulation’s R-Value for a one-inch sample, then they’ll give you a chart demonstrating the other R-Values you can achieve if you install a thicker version of their product

R-Value Chart Rigid Foam Faced Insulation

Conditioned per ATSM C1289, Test method ASTM C5181,2

Thickness (Inches) R-value (in I-P/Imperial)
0.5 3.1
0.625 3.9
0.75 4.5
1.0 6.2
1.5 9.3
2.0 12.4
2.5 15.5
3.0 18.6
3.5 21.7
4.0 24.8

These numbers for a rigid foam product maybe accurate for a foam product but it does not apply to a Lamilite fiberfill insulation.

What I am now going to describe is of equal thicknesses of each product.

Both products insulate in the same way, by capturing air in small spaces. When you examine foam regardless of if it is rigid or soft there are air holes where air is trapped. The foam material does not conduct movement of heat so the air in the holes does not move the heat extremely fast. There is some conductive heat movement in the direction of cold.

When you examine the Lamilite continuous filament fiber you see a significant number of air spaces that have trapped air. The solid part of the rigid foam structure reduces the amount of trapped air. The fiber is so fine that its solid parts allow for significantly greater amounts of air to be trapped.

The thicker the rigid foam is the amount of air space created remains the same on a square foot basis. Yes, the thicker it is the more insulation. As you increase the thickness of the Lamilite the greater the density and the greater the amount of trapped air. If you were to take an equal thickness if rigid foam and compare it to an equal thickness of Lamilite, the weight may actually be the same but the trapped air would be greater in the Lamilite. Therefore, the insulating capability of the Lamilite is greater. The density of the Lamilite makes it much more difficult for heat to move through it and away from you as anybody who has a Lamilite sleeping bag or parka knows.

I have made the comparison of two different of insulations on a flat surface for use in walls of yurt tent structures. The primary weight of Lamilite that I use is fifteen ounces per Linea yard. The thickness is between 5 and 6 inches. The use is in the Super Light, Ultima Thule and Antarctic sleeping bags. One layer top and bottom is used for the Super Light which has a 0 degree F rating. I use 2 layers of the 15 ounce for the Ultima Thule which is rated for -20 degrees F. in rating a sleeping bag one must understand the bag is lying flat so it is stopping heat from rising out of the bag via conduction. The action of conduction is so minimum that it is not a consideration in our Lamilite insulated sleeping bags.

When the Lamilite is hung vertically in a wall the heat in the room is rising as is does in a sleeping bag but it does not move sideways. The surface of the material of the wall will ultimately begin to warm to the ambient air in the room but it will not move through the Lamilite insulation. The thickness of the Lamilite converted to a square yard is 12 ounces is 5 inches thick. If the room temperature is a steady 68 degrees F while the outside temperature is 20 degrees F if you felt the outside surface of the wall, it would be 20 degrees F. There would not be any heat exchange via conduction.

I have sold this Lamilite to people who insulate their vans.

I have been selling Lamilite window coverings for 20 years and this material [3 ounce] has been used in cabins in Alaska to cover their windows.

From my experience working with insulation for 60 years I believe the continuous filament fiber I use for Lamilite is second to no other form of insulation.

R value and clo value are very similar.

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Check out all our products from sleeping bags & shelters to footwear & clothing. Our uniquely developed continuous filament fiber called Lamilite insulation is what sets Wiggy brand insulated products apart. What is Lamilite and why does it perform better than all other forms of insulation? Click here to keep reading & find out more »

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