Measuring Loft in Down Bags and Quilts

[ADK Walker]

Is it apples to apples? Does a bag manufacture like Western Mountaineering publish the loft thickness of the bag zipped up (measuring the top layer AND bottom layer) or is that a single layer measurement as in just the top portion of the bag.

Are quilts like those from EE publishing the loft thickness of their quilt opened up (ie a single layer)?

Background:

I have the WM Caribou 35 with a published loft of 3.5". I'm looking at the EE Revelation 20 quilt with a loft of 2.5".

The Reg/Wide 850 Revelation comes in at 21oz. (with a fill weight of 14.3oz)

The Reg. WM Caribou comes in at 21 oz. (with a fill weight of 10oz)

Can I reasonably compare this bag to this quilt in terms of comfort/sleeping insulation while using a NeoAir Xlite?

[Runner2017]

Is it apples to apples? Does a bag manufacture like Western Mountaineering publish the loft thickness of the bag zipped up (measuring the top layer AND bottom layer) or is that a single layer measurement as in just the top portion of the bag.

Are quilts like those from EE publishing the loft thickness of their quilt opened up (ie a single layer)?

Background:

I have the WM Caribou 35 with a published loft of 3.5". I'm looking at the EE Revelation 20 quilt with a loft of 2.5".

The Reg/Wide 850 Revelation comes in at 21oz. (with a fill weight of 14.3oz)

The Reg. WM Caribou comes in at 21 oz. (with a fill weight of 10oz)

Can I reasonably compare this bag to this quilt in terms of comfort/sleeping insulation while using a NeoAir Xlite?You need to email WM to find the answer though they have loft info on its website.

Their contact:

(844) 361-5382

[email protected]

[Venchka]

WM measures total loft at the lowest point in the area of your shins. Divide total loft by 2 for top loft.
Quilts specify top loft.
There is a chart at Backpacking Light that correlates top loft and temperature.
Wayne

[ADK Walker]

Thanks Wayne! Just what I was looking for.

[MuddyWaters]

There is a lot more Loft in the feet and chest area of a bag than there is in your average quilt.

And, with continuous baffles like in the western mountaineering you can shift down to the top of you adding more insulation on top.... Higher Loft... When needed. Cuz you really don't need anything under you.

Also , your bag is differential cut and have the trapezoidal foot box, so your elbows and toes do not Poke thru down causing cold spots. The absolute worse is the sewn flat foot box of some quilts. Thank God EE wised up and change theirs, it was a POS.

The simple answer no a quilt IS NOT as warm as a bag of similar reported Loft, and that's before we even get into the issues of drafts.

Now go look at katabatic quilts. Draft collar, trapezoidal foot box, differential cut.
That's why they're the premium quilt. More should strive for that quality.

[4eyedbuzzard]

There is a lot more Loft in the feet and chest area of a bag than there is in your average quilt.

And, with continuous baffles like in the western mountaineering you can shift down to the top of you adding more insulation on top.... Higher Loft... When needed. Cuz you really don't need anything under you.

Also , your bag is differential cut and have the trapezoidal foot box, so your elbows and toes do not Poke thru down causing cold spots. The absolute worse is the sewn flat foot box of some quilts. Thank God EE wised up and change theirs, it was a POS.

The simple answer no a quilt IS NOT as warm as a bag of similar reported Loft, and that's before we even get into the issues of drafts.

Now go look at katabatic quilts. Draft collar, trapezoidal foot box, differential cut.
That's why they're the premium quilt. More should strive for that quality.Actually, the OP's bag (and mine ;) ), the WM Caribou, is a sewn through box construction but with vertical box baffles on the top side http://www.westernmountaineering.com/product-details/sleeping-bag-fill-construction/ . But, if it was differential cut, etc., I agree with the rest of your post. Those technicalities aside, it is likely warmer than a quilt of similar loft, but a few ounces heavier.

[ADK Walker]

4eyebuzzard, What's your opinion on the Caribou? I've had mine since the late fall but have yet to take the tags off it yet. I bought it with summer Sierra trips in mind like the JMT in July/August.