Public-Sleeping Bag Loft Measurement Procedure

Methinks that the actual methodolody for measurning/determining sleeping bag loft and warmth is not so important as it is to ensure that whichever method we use, that it be simple, objective, and standardized.

I compare this to measuring temperature. Be it celcius or fahrenheit — once people become familiar with the system, it's a great starting point no matter where in the world they are! Sure, we can feel colder or warmer depending on whether we are wet, hungry or tired — or dry, well fed and well rested — even if the DEGREE itself is exactly the same. But with a bit of experience, most all of us today can read the temperature and quickly make intuitive adjustments — and react accordingly.

Sleeping bags are the same. A standard meaurement will give all of us the same starting point regardless of brands — thus allowing us to compare across brands — something we can't really do today. And then, with a bit of experience, we can intuitively make adjustments to apply the standard to ourselves individually.

IMO, a bag rated at whatever warmth should be able to achieve that by itself — NOT with any "hidden" assumption that users need to wear multiple layers! What I would like to see:

1. Loft — Measurement in inches or centimeters should be the maximum loft for the top half of the bag. By maximum, I am allowing for bags with continuous baffles where down can be shifted up. When shifted up, what's the max. loft that can be achieved atop the sleeper?

2. Warmth — EU method or MontBell's method, etc. — again, the specific method matters less, as long as it is simple, objective, and standardized. The warmth should assume an "average" sleeper wearing a base layer (long tees and bottoms), dry, reasonably well fed and rested, sleeping inside a tent. Once we have this, it should be pretty simple for folks to compare across the board, and also to "translate" the standard to their own individual conditions and warmth requirements.

Hi Guys-

Sorry, I didn't mean to be devious, tantalizing, or exclusionary. We're just doing some mundane housekeeping to better standardize our procedure across different products and reviewers.

"There's nothing to see here. Move along please…" ;-)

Cheers,

-Mike

Mike – I still have to get in my 2 cents. If you start having loft measurements, I would really like to see both double side and single side measurements. With some companies using different top and bottom down distributions this becomes important in knowing the relative warmth and most of them don't disclose this info.

Why, the only loft that really counts if loft over the body in several areas like chest, legs, and footbox. Simply knowing the bottom has down or not is enough for me. The bottom loft means nothing much.

Top vs bottom loft proportions are further complicated by continuous baffle designs that allow the down to be redistributed.

I think the two posts above would support my view up above for measuring "maximum top" loft. For fixed baffles, that would simply be the top (the bottom is ignored). For continuous baffles, maximum top means measuring the top loft after shifting the insulation up from the bottom.