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Alan Bradley
(ahbradley)
What is the clo/tog of one and N layers of bubblewrap on 01/22/2007 13:24:19 MST Print View

What is the clo/tog of one and multiple layers of bubblewrap?

Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
Re: What is the clo/tog of one and N layers of bubblewrap on 01/22/2007 15:38:19 MST Print View

Bubble wrap is a trademark of Sealed Air Corporation and is used primarily for packaging. It is made out of polyethylene with air bubble size options up to ½ inch.

The air bubbles provide effective conductive/convective thermal resistance but no IR thermal resistance. Hence, you need to put foil on either side of the bubble for it to be an effective insulator. These foil covered bubble wrap products have different trade names but their characteristics are all similar. At an average temp of 70F, the inherent 1” thermal resistance value of these types of products is about 5.5 R value, 6.1 clo, or 9.8 tog.

Thermal resistance values are additive. For example, ¼” thick foil covered bubble wrap would provide ¼ of the 1” thermal resistance values.

Alan Bradley
(ahbradley)
Does this mean bubble wrap needs foil to keep a human warm? on 01/26/2007 08:40:15 MST Print View

Thanks.

I have another question.

Does this mean bubble wrap needs foil to keep a human warm,
or just that it would keep them warmer if it had a foil layer? Does an opaque fabric over it make any difference?

Edited by ahbradley on 01/26/2007 08:41:05 MST.

Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
Re: Does this mean bubble wrap needs foil to keep a human warm? on 01/26/2007 09:23:00 MST Print View

Alan-You can approach the warmth of a blue foam pad, of the same thickness, if you use a comparable thickness of foil encased BubbleWrap. An opaque surface would result in comaprable warmth to an air mattress of the same thickness (much less warmth).

Edited by richard295 on 01/26/2007 10:50:41 MST.

Gene .
(Tracker)

Locale: New England
Re: Re: Does this mean bubble wrap needs foil to keep a human warm? on 01/26/2007 10:01:34 MST Print View

This is why I suggestted the use of Reflectix brand bubble insulation for a ground mat, as opposed to plain bubble wrap.

Rick Dreher
(halfturbo) - MLife

Locale: Northernish California
Re: Does this mean bubble wrap needs foil to keep a human warm? on 01/26/2007 12:39:53 MST Print View

Bottom line on bubble pad support of any kind, reflective or not, is that it's of little insulative value as a sleeping pad. I've found it to be reasonably comfy in very warm conditions, but absolutely freezing otherwise.

What's likely at work is large amounts of conductive and convective heat loss, versus radiant loss.

Alan Bradley
(ahbradley)
I was thinking more of an overlayer for torso rather than ground pad on 01/27/2007 06:14:44 MST Print View

I was thinking more of an overlayer for torso rather than ground pad (eg to go over a Paramo jacket when stop for lunch etc). Is the foil layer still needed for this?