>>130056>I'm going to cite numbers even though I have no idea what they meanLet's use that handy calculator in the page you linked. Assume an average adult male, surface area 1.9 square meters. Assume a fall or spring day of 10C degrees (50F). The surface temperature of human skin is 32C (89.6F). Plug those numbers in with the most conservative coefficient given for free convection of air (5), and you get 209 watts of heat transfer. A sleeping male body will produce about 70 watts of heat.
This demonstrates that free convection is, in fact, a huge factor in the effectiveness of insulation, which is why any good insulation will eliminate it as much as possible, so as to take advantage of the very low thermal -conductivity- of air.
Don't confuse conduction with convection. They are totally different processes. Air does not conduct much heat, but it convects a huge amount of heat. If inflatable insulation worked, it would be in use.
