more Clo points

FOLLOW UP TO CLO TESTING

There are other reasons as if they are necessary why Clo testing needs to be clarified and why the testing of insulations as standalone materials is not a valid method and is unacceptable.

Recently I had each of the three primary weights of Lamilite/Climashield Clo tested, but I encased each weight with the single ply nylon taffeta that I have used for over 30 years for my sleeping bags; starting with Olam in 1977. The result for each layer was as follows; L-6 is 2.7 Clo, L is 4.5 Clo and L-1 is 5.7 Clo. Each weight was tested 3 times and these are the respective average results.

When each of these weights is used in a sleeping bag they are as follows L-6 for the over bag rated to +35 degrees however, it has been used successfully to +25 degrees. The L-12 is used in the Ultra-Light +20 degree bag which has been successfully used to 0 degrees, and the Super Light uses the L-15 rated to zero degrees and has successfully been used at -15 degrees. Each of these bags has one layer of insulation on top and bottom. However when you add the second layer of L-15 to the top of the Ultima Thule which I rate as a -20 degree bag it has proven to perform on numerous occasions as low as -50 degrees and lower.

If I compare the “theoretical clo value for comfort sleep” chart that was published in 1976 by Natick Labs I find that the Over bag has a Clo value of 4, the Ultra-Light has a Clo value of 5.5, the Super Light Clo value is 7 and the Ultima Thule Clo value is 8.5. There are two lines on the chart starting at a temperature and going diagonally up and through predetermined Clo lines. One represents normal sleep and the other 6 hours sleep. I chose the normal sleep line.

This raises the question as to what a correct Clo value should be for my bags based upon temperature and as an example is the Ultima Thule a -20 degree bag with a Clo of 8.5 or a -50 degree bag with a Clo of 10.8 as shown on the chart? Keep in mind that the Ultima Thule bag has been used many times at the -50 degree temperature.

What is not taken into consideration when these testing companies test insulations has to do with not knowing how to best test the insulation to begin with. The insulations should always be tested in the manner that they are used in the environment they are to be used in, NOT A LABORATORY.

All insulating materials used for sleeping bags or clothing products are encased in a shell and lining material which will add to the temperature capability of the insulation as it becomes a part of the package. How about the method used to construct all of these products, almost always the insulating medium has to be quilted. Yes you can test without quilting the material but then the product cannot be used for use since the insulating medium will deteriorate due to the lack of quilting to hold it in place. Once the material is quilted the quilting creates cold spots in and of its presence. Therefore, the results must be stated with respect to the fact that they were quilted versus in the unquilted natural state.

Enter continuous filament fiberfill which can be quilted but is completely unnecessary since the quilting will compromise its efficiency as it does any other form of insulation.

I discovered in 1968 the best way to use the continuous filament fiberfill was in a NON-QUILTED construction method. Why (?) because by eliminating the quilting you had a uniform loft and when the continuous filament fiberfill is sewn around its perimeter it was locked in place for as long as the stitches existed. The negative aspect of quilting is eliminated. Laminating it just made it economical to work with and allowed the fiber to stay in its natural state. Now you can understand why I started with testing of completed sleeping bags in the field versus in a laboratory with humans using my products versus a manikin.

If all who make cold weather products such as clothing or sleeping bags followed my lead ALL of the testing laboratories that own manikins would have to find another use for them.

As for my sleeping bags and clothing products I can only guide people in their use because I would be disingenuous if I maintained a ridged attitude as to their performance capabilities. It is for this reason that I am conservative in my ratings and state that the ratings of my sleeping bags is based upon being in a shelter such as a tent.The only information that I have is that what I make will outperform every other similar product made any place in the world regardless of the material that is used as insulation. I do know that each and every product I make will perform at the temperatures I rate them, I also have learned from my thousands of customers that my products do perform at temperatures in some case far lower than what I originally rated them.

I truly believe that in the near future many more companies will be using continuous filament fiberfill for their insulated products laminated first and if not they will slowly go by the wayside. In the future continuous filament fiberfill will still reign supreme and will not be replace by any other insulating medium!