Turning Sleeping Bag Inside Out?
Is there any reason why I can't turn my HMG quilt inside out for a slightly more varied experience? The inside of mine is silver and the outside is navy. If it's warmer, would turning the silver toward the sun better reflect light, rather than reflecting heat back towards my body? Is there something about this approach that I might be missing? I've never seen anyone do it before and I'm curious. I also like silver better than navy, so consider this a pointless aesthetic question, as well.
There would be some minor caveats such as the pad attachment clips and draw string orientation would be upside down. Our quilt is symmetrical, so flipping it inside out doesn’t affect the fit/geometry in a major way. You could still wrap it around you as normal.
Many companies, in the past and current, strategically use colorways on the inside of quilts/bags. A black shell fabric inherently dries faster as it absorbs more light than other colors on the spectrum. Flip it inside out, throw it out in the sun, and let it bake. In field use, especially with ultralight (quick drying) fabrics and high quality down... it doesn't make a significant difference given outdoor conditions are so variable and the ultralight examples dry so efficiently with a bit of wind and sun.
Personally, I've never found turning a quilt inside out facilitates faster drying in field use. The outside shell generally gets the brunt of condensation/dew while your heat producing body is slowly drying the quilt from the inside during the night. The outer shell is more subjected to getting wet (think touching your footbox to the wall of a tent with condensation or just waking up with your bag (and everything else you humped into the forest) covered in dew.
On reflecting heat with 7d ultralight shell fabrics. In theory, yes. The color spectrum does have some science with it. In real world use, I doubt it makes any significant difference with 7d in the field. Our fabrics have very little reflective properties. Mechanical venting is far more effective at dissipating heat.
When you start to incorporate thermally reflective material in the design of a bag, you can increase warmth and some manufacturers take this approach on alpine/expedition bags. In the simplest form, it’s incorporating the technology of reflective space blankets while overcoming breathability challenges.
Another instance is constructing the inside of a quilt with a high visibility interior for emergency circumstances. Not many people want a blaze orange exterior for aesthetic reasons, but having a high visibility piece of equipment, with a large surface area, SAR has a greater chance of seeing you from the bird in the sky. Flip that high visibility interior to the outside and signal a helicopter like your life depends on it.
There’s no reason why you couldn’t flip your ultralight quilt inside out and use it as such but it shouldn’t make a significant difference with reflecting or retaining warmth.
Thank you so much for this thorough and thoughtful answer! Exactly what I was looking for and I really appreciate it. My perfect quilt would be black and blaze orange... but I guess I'm weird 🤣1