Hiya, thanks for your questions! I hope you are ready for information overload!
Here are your answers:
1. It depends on the situation. There are many variables, such as conditions, which bag is used with the coupler, what pads you are using (and whether or not you are using the pads effectively-i.e. not blowing moist air into the valves when the nightly low temperatures are likely to drop below freezing), metabolism, and how warm or cold the two people tend to sleep.
2. The summer coupler is designed to be used with hoodless semi-rectangular bags like the Ponderosa, the Alder and the Mitylite. For these models, there are no left or right hand zippered options, they are all made as left zippered bags but they can be flipped over if someone wants to use them with the zipper on the opposite side since there is no hood.
The hooded semi rectangular bags such as the Terralite, Sycamore, Sequoia, Bristlecone, or Cypress can also be opened up and mated to a summer coupler, however, there is going to be more down distributed on the top of any bag which has a hood. (60% of the down will be on top and 40% of the down will be on the bottom). When the bag is flipped over, one side will have more down than the other but you can shift the down around within the bag to even it out. These bags are offered in either a left or a right hand zipper and either will work when the bag is opened up and zipped to a summer coupler.
The Bristlecone and Cypress are colder weather bags so they have a block of netting at the side to create separate down chambers for the top and bottom of the bag. In these two models the down distribution cannot be adjusted so one person would have less down above them than the other (and since the bottom of the bag is the side with less down that person would also have a hood over their face when the bag is opened up and mated to a coupler.). Also the zipper lengths on the hooded semi-rectangular bags is slightly different on the bottom zipper than our hoodless semi-rectangular bags so there is a little bit of extra coupler that remains as extra material at each side towards the bottom.
3. The bottom edge measures 24” across each side to the center stitch line. The lower sleeve panel measures 22” across from each side to the center seam.
4. The Terralite can be used with a summer coupler however, as explained in the answer for question #2, the bottom (vislon) zipper length is a little shorter on the hooded semi-rectangular bags than it is on the bags without hoods. This means that there will be a little bit of extra coupler at each side just below where the coil zipper ends and the top of the vislon zipper finishes.
Hope this helps!
Date published: 2016-09-23