Dare you to make sense of colors

[DemostiX]

Right: Dark going all the way to black to best soak up infra-red radiation. And / so it is helpful to grab that infra-red from sunlight in order to dry the quilt, even on cold days, more likely lightly wet from dew than seriously from being drenched.

So: Why do UQs, following your conversations with several makers, differ so in inside color, from having (reflective (?) silver on the underside to black as black can be?

Has anyone confirmed the benefits of one vs another on the top side of the UQ as sizeable?

Note: I can understand black on the outside for reasons first presented, and for stealth.

[TinaLouise]

I personally haven't noticed any differences in my under quilts due to having different colors on the inner layer (the layer that touches the bottom of the hammock). I've made quite a few and the color hasn't made me any warmer or colder. Now I did find a difference when I used breathable vs waterproof DWR material. I found that (for me!!) I like having a breathable ripstop as the inner layer on my under quilts. I like waterproof DWR on the outer layer. Again, the color different make any difference. I even used hot pink!! The only time I've found black to make a difference is if I'm able to lay out my quilts during the daytime. The black will heat up way faster in direct sunlight. I've found color to make a difference on being stealthy. If it makes a difference in how warm a quilt is, I personally am not able to tell it. I'm such a cold sleeper, that I don't think the color would make any difference to me anyways. Maybe to some of you guys that are hot sleepers, you would be able to tell a difference between simular quilts but different colors?

[wisenber]

Having a dark color on at least one side helps with field drying. Since black absorbs more long wave energy (sun light), it will dry a quilt out faster than a lighter colored one.
The silver colored ones are radiant barriers, so they will reflect radiant heat away from the quilt and in theory back to the hammock occupant. The reality is that if your have even a single layer of clothing on over 80% of your radiant heat loss is already blocked, so at best the radiant reflector is reflecting 90% of the remaining 20%.

[Just Jeff]

Practically, I don't think it makes a real difference in how warm you feel. But since we like to get all technical here...

Black both absorbs and transmits heat faster. That means it'll soak up the sunlight's energy quicker in the daytime AND transmit heat away from you faster at night.

Silver is the opposite...if it's on the inner liner of a quilt, it will reflect more energy back at your body (rather than absorbing it) than black will. It's also slower to dissipate the energy that it does absorb.

But I think the difference can probably be measured in a fraction of a degree for this application. Managing condensation, for example, probably has a much larger "felt impact" than color of quilt and liner.

[wisenber]

Practically, I don't think it makes a real difference in how warm you feel. But since we like to get all technical here...

Black both absorbs and transmits heat faster. That means it'll soak up the sunlight's energy quicker in the daytime AND transmit heat away from you faster at night.

Silver is the opposite...if it's on the inner liner of a quilt, it will reflect more energy back at your body (rather than absorbing it) than black will. It's also slower to dissipate the energy that it does absorb.

But I think the difference can probably be measured in a fraction of a degree for this application. Managing condensation, for example, probably has a much larger "felt impact" than color of quilt and liner.

I don't believe the colors make much of a difference when it's dark as there is far less long wave radiation at play. During the day, the dark color will heat up much more (allowing you to dry your gear even when it is below freezing). That is why summer clothing is light colored and also why I keep kicking myself for buying a black Suburban.

[Just Jeff]

That's true for absorbing energy in the sunlight...but it's just as true for dissipating energy in the nighttime.

Either way, I don't think it makes much difference in how warm you feel...but I've never measured it.

[wisenber]

That's true for absorbing energy in the sunlight...but it's just as true for dissipating energy in the nighttime.

Either way, I don't think it makes much difference in how warm you feel...but I've never measured it.

I guess my point was that enthalpy is at play day or night with energy seeking to reach an equilibrium state by migrating from higher concentrations to lower concentrations. The difference between day and night would be that during the day, the sun is the higher concentration and at night YOU are the higher concentration. The amount of radiant heat that any colored object would release or absorb at night is a fraction of the amount of radiant heat to be absorbed or released during the day. The average human gives off about 250 BTU/hr during rest which results in about 75 Watts. With a layer of clothing (not even counting multiple layers or TQ/UQ) the potential for radiant heat loss is reduced by over 80%. If all of that energy were released in the form of radiant heat (which it is not by a long shot), it would still only equate to 15 Watts. Contrast that to a square meter of sunlight putting out an average of 1000 Watts and the order of magnitude becomes more evident.

To quote Sgt. Rock, "Heat reflectors are snake oil."

Disclaimer: The last time I took a thermodynamics class, Reagan was President.

[Just Jeff]

Yeah - sounds like we're saying pretty much the same thing in different ways.

To quote Sgt. Rock, "Heat reflectors are snake oil."

Yup.

[MedicineMan]

and I think that is why WB stopped with his snap in reflector for his Yetis.

[te-wa]

i use silver on the inside just because its pretty much just a generic color. more eyebrows would be raised in question if the underside of my quilts were yellow, or red.. silver is just like gray is for tarps.. there.