This may be a really stupid question, but here goes. When packing our frozen food in our CCS food pack, would lining the inside of the pack with a plastic liner bag diminish the insulation qualities of the pack at all? I may build an inner 'cooler' out of polystyrene foam board that could sit inside the liner bag. If I do this, I think the liner bag would help.

Thoughts?

A liner bag won't diminish the insulating ability of the pack. Putting your frozen food in a small cooler within the pack will keep it frozen longer.

A bunch of people have built their own insulated food packs using foam board and/or closed cell foam. As for the pack liner it would add a bit of insulation value. It wouldn't hurt it in any way that I would think of.

I made a simple cooler box out of Reflectix and placed it inside a soft sided cooler in my food barrel that worked pretty well. Used a couple of frozen water bottles.

I'm not a thermodynamic engineer, but I have to think that adding another layer would only enhance the insulation.