Effects of Colors of Insulation

[Coldspring]

I would be more worried about the weave density of the fabric and effect of this on thermal loss of warmth to the outside of the shell or transference of exterior cold air to the inside of the shell into the insulation, than I would be worried about the color. Give me some light grey momentum over black 1.1 ripstop anyday.

[Just Jeff]

Thats cool, I mean hot, I mean....yeah.

yay science.

I like the science that keeps the ninjas away as I slumber in my low emissivity hammock. That's the science I like.

I would be more worried about the weave density of the fabric and effect of this on thermal loss of warmth to the outside of the shell or transference of exterior cold air to the inside of the shell into the insulation, than I would be worried about the color.

Yep - weave density affects convection, which has more impact than radiation IMO.

[stormcrow]

The ninja thing is cool but I just like saying "emissivity" over and over.

Regarding weave density of the fabric, I too think it is very important. I know that much of the calendered, down-proof fabric sold by our usual places that is uncoated and parachute grade has a cfm (cubic feet per minute I belive) of less than 5. Closer to the 2-3 range. This is according to specs given to be by a major supplier. Maybe Momentum is less than that but I do not know how it could be much better than a good calendered ripstop. At least not worth the giant leap in price. That is totally my opinion of course.

My personal experience is that I have had a quilt made from the above mentioned ripstop exposed to some decent wind and low temps and have not noticed the robbing of heat. YMMV of course.

[WV]

Temperature aside, there's a practical reason to have a two-tone top quilt. Even in low light you can tell which is the inside. If the quilt gets tangled or you move it to one side for ventilation in warm weather, then want to snug it up as the night gets colder, it's easier to get the quilt oriented correctly. My favorite summer quilt also has a different color (silver) for the bottom of the footbox, so it's easier to tell head from foot. The footbox bottom is a pocket that holds a thin evazote pad to keep my heels warm, so emissivity is less of an issue.

[Trooper]

After giving this some more thought, and discussing it with a NASA engineer, I'll try to explain what she told me which confirms what we suspected:

Color doesn't matter.

This is because we generally sleep at night with protection from the sun. If we slept during the day and could take advantage of the solar radiation a dark color would be advantageous, but at night solar radiation isn't a factor. So, we are dealing almost exclusively with the heat our bodies produce, which isn't in the visible spectrum, but infrared. The goal here is to insulate with air pockets that we warm with our bodies, such as down.

So we are now free to design our quilts in black so they dry out quickly in the morning or to hide from other ninjas, but not because it will keep you warmer.

[lazy river road]

After giving this some more thought, and discussing it with a NASA engineer, I'll try to explain what she told me which confirms what we suspected:

Color doesn't matter.

This is because we generally sleep at night with protection from the sun. If we slept during the day and could take advantage of the solar radiation a dark color would be advantageous, but at night solar radiation isn't a factor. So, we are dealing almost exclusively with the heat our bodies produce, which isn't in the visible spectrum, but infrared. The goal here is to insulate with air pockets that we warm with our bodies, such as down.

So we are now free to design our quilts in black so they dry out quickly in the morning or to hide from other ninjas, but not because it will keep you warmer.

well If I would of know all this before I ordered my burrow I would of gotten it in Pink Then I could of told my GF it was a present for her and I could order another one for my self.

[warbonnetguy]

if that's indeed true then it would make sense that space blankets do not actually reflect body heat either. alot of people will disagree with that though.

if only visible light (and not infared energy) can be reflected then how do you explain space blankets, that's exactly what they're claimed to do. (reflect back body heat/infared energy)

After giving this some more thought, and discussing it with a NASA engineer, I'll try to explain what she told me which confirms what we suspected:

Color doesn't matter.

This is because we generally sleep at night with protection from the sun. If we slept during the day and could take advantage of the solar radiation a dark color would be advantageous, but at night solar radiation isn't a factor. So, we are dealing almost exclusively with the heat our bodies produce, which isn't in the visible spectrum, but infrared. The goal here is to insulate with air pockets that we warm with our bodies, such as down.

So we are now free to design our quilts in black so they dry out quickly in the morning or to hide from other ninjas, but not because it will keep you warmer.

[PuckerFactor]

I think we're getting a wee bit too technical. The massive amounts of energy from the sun in the form of infrared rays makes body heat look like warm breath on a hot summer day. Even if different color shells reflect/absorb heat, it's way too small to make an appreciable difference. Make your quilts whatever color you want.
/rant

Sorry, but I've seen way too many threads on way too many forums end badly this way. We get caught up in the minutia, and sides get taken, and nobody can prove their way is right/better, and we argue till the thread gets shut down.

Taking a chill pill,
Acer

[Trooper]

if that's indeed true then it would make sense that space blankets do not actually reflect body heat either. alot of people will disagree with that though.

if only visible light (and not infared energy) can be reflected then how do you explain space blankets, that's exactly what they're claimed to do. (reflect back body heat/infared energy)

That's the part that goes over my head. The engineer did explain it to me, and I'm doubtful that I can repeat it correctly. But I'll try: the space blanket does reflect infrared and visible spectrum, but apparently the visible spectrum doesn't add that much warmth.

She used the example of LED, CFL, and halogen, to show how the same amount of produces various amount of heat depending on the source. The LED is more efficient in light production and is more narrow in its spectrum than Halogen, which produces light and a lot of heat as well.

A space blanket reflects light, but given the examples above light is not necessarily an indicator of the heat energy produced. We then got into sound energy and how you can feel it as vibrations but not as warmth. This is where I just started nodding and looking at the door. There was something about absorbtion of the energy versus reflecting visible light, and the example for that was the earth absorbs the solar radiation and releases it. This is explains why the atmosphere is cooler at altitude than near the surface of the earth, despite the atmosphere being closer to the energy source.

Again, I'm sure I've explained it incorrectly, but that is the best that I can remember. But, essentially Brandon, you're right about the space blanket. It reflects, but what we see isn't necessarily what we feel.

[Trooper]

I think we're getting a wee bit too technical. The massive amounts of energy from the sun in the form of infrared rays makes body heat look like warm breath on a hot summer day. Even if different color shells reflect/absorb heat, it's way too small to make an appreciable difference. Make your quilts whatever color you want.
/rant

I think this is the conclusion that we have all come up with. Looks like we're all on the same side, but we have gone way past too technical.