Analysis of heat transfer in inflatable sleeping pads

Sleeping bags and sleeping pads present inevitable equipment of all sportsman dedicated to mountaineering. major part of thermal insulation of a person sleeping in a sleeping bag ensures the proper bag,but more than 40% of heat escapes through the sleeping pad (mattress) down to the ground or floor. however,despite the importance of sleeping pads,related research reports are almost missing. in the study,heat transfer mechanisms in hollow sleeping pads filled with the pressure air (to increase their thickness) and modern sleeping pads additionally filled with porous polyurethane foam is theoretically and experimentally analysed. from the theoretical analysis follows,that sleeping pads filled with porous polyurethane structures exhibit approximately 2 times higher thermal resistance then empty inflated pads,due to the reduction of free convection in the internal space of the pads. these theoretical findings were confirmed by the experimental results presented in the paper.