Details

Snapshot 1: no insulation

Snapshot 2: thin insulation

Snapshot 3: thick insulation

This Demonstration calculates and plots the steady state heat flow per unit area, (in watts/), through an insulated or uninsulated wall. You can choose the wall's thickness, (in cm), and its thermal conductivity, (in watts/m °C); the insulation's thickness, (in cm), and its thermal conductivity, (in watts/m °C); the surface heat transfer coefficients at either side of the wall, and (in °C); and the temperature difference, (in °C), between the inside and outside. The calculations are done using the equation , whose parameters can be modified by moving the sliders. The red dot on the plot marks the flow rate per unit area for a chosen by moving the top slider. The top graphic depicts the heat resistances as a schematic diagram (not to scale).

Reference: R. L. Earle with M. D. Earle, Unit Operations in Food Processing, NZIFST, Inc., 1983.