Interest in a Sleeping Bag Temp Rating Standard?

[Frost]

I was discussing sleeping bag temperature ratings with a few other engineers and the idea of an 'At Home' temperature rating test was brought up.

The idea would be to come up with a testing procedure that would be easily replicated by just about anyone at little or no cost ($15 for a thermometer, perhaps). We're thinking it may be possible to calibrate this test using the EN 13537 standard if we can get a few bags that use that rating to test.

If there's any interest in this, I'll put some effort into developing the idea a bit further. I happen to work in a sporting goods store that has a few EN rated bags on display that I think the boss will let me use for testing purposes, so I can do some of the calibration work myself. However, finding a few other folks with EN rated bags that would be willing to do the test as well and forward their results would let me further improve the accuracy.

This would allow DIYers to include a reasonably accurate temperature rating with their write-ups, since 'comfort' tends to be such a subjective thing.

Thoughts?

[HomeMadeHiker]

sounds like a great idea. what we/they use now is darn near worthless.

[Badchef]

Cool idea. Let me know how I can help.

[Badchef]

Also, would this qualify for an Engineering Paper to be published in a Journal?

[Alamosa]

I would certainly be interested in assisting in this project. There was a project on BPL for testing gear - http://www.backpackinglight.com/cgi-...nsulation.html

It doesn't meet the simplicity goal you stated, but it does bring up a lot of concepts that must be addressed as part of the testing.

[Frost]

Alamosa, thanks for the great link. I just purchased the article, it looks like it has some excellent information. If nothing else, hopefully it will point out some of the flaws in my ideas before I run headlong into them in practice.

Badchef, I doubt anything will be innovative enough to warrant a paper in a journal of any sort. In fact, it will be my goal to keep it that way. I'd like for folks to not only be able to perform the test easily on their own, I want them to be able to understand why it works, and what the results mean. It doesn't do much good if you need a degree to interpret the data you end up with.

I'm still kicking around how exactly the scale should work. Temperature is a crummy way of evaluating these systems because it's such a subjective element. A bag that would have me pleasantly warm at 40F would leave my wife hypothermic, or nearly so. A bag that would have her toasty at 40F would have me sweating uncontrollably. We encounter precisely this problem every night in bed even.

I think there will have to be a couple separate evaluation criteria. One an objective R value test, and another to measure how well it prevents air movement.

I'm hoping the procedure will end up in such a way that entire sleep systems could be tested. Hammock, UQ, TQ, pea pod, whatever.

[freakfx]

I wonder if I took my 3L platipus and filled it with hot water and ran a digital thermometer ( i have one I used with my fish tank that has a long cord on it that runs to a digital display, that would allow me to monitor real time temp)

Place it inside the test bag and document the temp change of the water in relation to the air temp in the controlled environment over every 30 minutes for a predetermined amount of time, if there would be some sort of math equation to test the efficiency of the bag.


Maybe this is a bit to complicated but if there are any math wiz's on HF that think this wiould work would be cool to hear what you all think.