CONVECTION IN HORIZONTAL INSULATION

摘要

Measured and calculated critical modified Rayleigh numbers for the onset of convection and the increase in heat transfer through a porous layer due to natural and forced convection is presented. Configurations relevant for attic insulations are investigated, such as permeable and impermeable upper surface, insulation in contact with an air space with or without forced convection, and homogeneous and inhomogeneous insulation where the inhomogenities are due to either permeable areas or joists.