Why don't you list "additional temperature ratings" with Reactor Series Liners?

First things first. There are internationally recognized tests for sleeping bag temperature rating (Sea to Summit tests to the ISO standard) and sleeping mat insulation value (Sea to Summit tests to the ASTM standard). There is no standardized test protocol for evaluating the thermal boost provided by a liner; so any 'rating' would just be an educated guess.

Some have suggested adding a liner to the sleeping bag being evaluated in the ISO cold-chamber test; but this would produce a result that was specific to that sleeping bag/pad and it wouldn't be tested according to an accepted protocol because such a protocol does not exist.

There are a huge number of variables that impact the add-on thermal performance you might expect from a liner. Besides environmental conditions, here are two significant factors:

- Some sleeping bags retain warmth far better than others. This is usually due to construction details like hoods, draft collars/draft tubes, and footboxes. (A live, moving sleeper creates opportunities for warmth to be lost that a static test manikin does not. This is not reflected in the ISO or EN temperature rating for a sleeping bag).

– Some sleeping pads insulate better than others (this is often due to internal air movement dissipating warmth. It is not reflected in the R-Value of the pad)

Using a sleeping bag with excellent protection against loss of warmth and a sleeping pad which insulates extremely well, a Reactor Liner might add 7-10°F / 4-6°F

Using a sleeping bag which does not retain warmth well and a sleeping pad which dissipates warmth, the same liner may only add 3°F / 2°C. 

The variance between 3°F and 10°F means that an 'additional temperature estimate' is so vague as to be largely meaningless.

For more information regarding adding warmth with a liner, visit our Blog Post.