Why aren't quilts and sleeping bags rated in R value?

**kayak karl** · 09-19-2011, 16:01

i agree. glad we got HF and all its members. i can tell you that I can take any JRB or Tewa quilt 10 degrees below their rating, that Keen boots hold true to their size 13 and Mountain Hardware clothes run long and are great for tall guys. these are things we talk about.

i think we set our own standards and help the manufactures when they stray off.

**Alamosa** · 09-19-2011, 16:05

I would have to disagree with that assessment. Many different materials are used in home building and they all have an R-Value rating - fiberglass insulation, expanding foam insulation, foam and fiber board, even glass windows have an R-value. The the application and inconsistencies of usage have even more variations.

As long as the standard rating evaluates the bag/quilt/jackets ability to resist the transfer of heat, the user can then apply the knowledge of how their usage may vary.

I have long wondered why the standard rating used in Europe has not made it across. It may be prohibitively expensive for cottage industries, but there really isn't much of an excuse the major manufacturers. At the very least I would have expected them to come up with a competing US standard by now.

**nothermark** · 09-19-2011, 16:12

"It's math, math is too technical so nobody wants it".

**Alamosa** · 09-19-2011, 16:19

Originally Posted by nothermark

"It's math, math is too technical so nobody wants it".

Are you referring to the old-math or new-math and are you using imperial or metric measurements?

**kayak karl** · 09-19-2011, 16:31

Originally Posted by nothermark

"It's math, math is too technical so nobody wants it".

5 out of 4 people don't understand math.

**Southpaw** · 09-19-2011, 16:36

Everytime I tell people (while working on their A/C heat pumps) that there isn't a such thing as cold, they look at me like I have three heads.

**kayak karl** · 09-19-2011, 16:51

Originally Posted by Southpaw

Everytime I tell people (while working on their A/C heat pumps) that there isn't a such thing as cold, they look at me like I have three heads.

went to a class. we went into a big room and picked up balloons. then through a narrow hallway. we couldn't get through unless we threw balloons over the partitions. we then went back in big room and did it again till all the balloons were out of big room.

The big room was 'A' coil
Hallway, compressor
Balloons were heat
We were freon.

never forgot again LOL

**Southpaw** · 09-19-2011, 17:11

Originally Posted by kayak karl

went to a class. we went into a big room and picked up balloons. then through a narrow hallway. we couldn't get through unless we threw balloons over the partitions. we then went back in big room and did it again till all the balloons were out of big room.

The big room was 'A' coil
Hallway, compressor
Balloons were heat
We were freon.

never forgot again LOL

That's a great analogy, except they were missing a metering device and second coil for condensing. I might use that sometime. I wish I had been taught using fun stuff like that. Oddly enough, I learned more about HVAC in my Physics class I took for electrical maintenance than I ever did before I got my EPA license.

**default** · 09-19-2011, 17:22

i think my assessment was slightly off the mark

i know theres a lot of different types of insulation materials for both home and personal use. but each has its value set in "optimal" settings, when used as its supposed to. a window may have a high R value, but if its not hung and sealed properly, then the value OVERALL is useless.

lets say pink fiberglass insulation has a value of 6 out of 10 value (totally making this up, so go with me) and thats a decent number. as long as you follow best practice and directions, when youre done the number is still 6, because its made in a uniform way and is used in a uniform manner and is in a controlled environment.

now lets talk about UQ's, who have different variables per each, because there is no standard.

lets say I make a UQ with down and RipStop. now, theres several ways to make it, with or without baffles, sewn thru or not. each modification adds to the help of the insulative values, one variable is Loft.

if down has an R value of 3 per oz with full loft (lets say 1") and a value of 1 if compressed, theres a big difference.

now,IF i make the UQ with baffles to allow the perfect 1" loft no matter what i do, i then have to make sure that im getting the down perfectly even and not putting more than an ounce per area.

IF i do all that for EVERY UQ i make, then i can start putting R values on them IF i have the R numbers all figured and correct.

then, at the end of the day, my UQ that has an R value that would translate to being warm to 40* may not be if hung wrong, or maybe even lower if you have it hung properly and are wearing layers.

same thing with CCF and air pads, which are meant to be squished when laid on and therefore may have a higher R value where its not compressed compared to where it is.

i think all that made sense. and my highschool HVAC teacher told us that cold is the absence of heat

**DemostiX** · 09-20-2011, 18:17

Originally Posted by dejoha

<snip>
A sheet of plastic or tyvek may have hi r-values, but wrapping yourself in them may not give you the same warmth as a sleeping bag. There are a lot of factors in play.

????

Neither of these have high R values. To the contrary.

The R value is on a ratio scale, and the inverse of the U value, which actually indicates the heat flow per unit or per area. A barrier to heat transfer (with specified characteristics) of R value (r1) stops twice the flow of heat of another barrier with value (r1) /2. Some minimum heat-transfer level must be established for the ratio scale. I believe it is about equal to heat-flow resistance of a pane of 1/8" glass.

It isn't easy designing the standards and testing environments, but the insulating value of glazing can be specified; and so can the insulating value of the whole window. And they matter less than they should if the poorest-paid and most over-worked guy on the crew is the one filling all spaces between the jambs and sills and framing, and if the builder doesn't care that he doesn't care if the job is well done.

In fact, there are standards and proceedures for testing the EEC has come up for (somewhat) equivalencing and comparing sleeping bags. You need to go to the specs and see if they are applicable for hammock use. Without looking at them, I'd bet that the specification punishes failure to keep all parts of a test dummy from losing heat. Warm torso is worth less if heat loss through the feet is not controlled. Once you find the specs and standards, you would need to see if they are applicable to you; they may specify particular occupant dimensions and it may be known that you, far from average, don't fit the model. Imagine, for instance a sleeping bag which drapes poorly, has no draft tube,and which lacks cinching. An extremely skinny person might lose more heat than the model predicts in such a bag due to drafts.

It isn't easy being a specifications engineer.