Up until now HeatSinkCalculator has only provided the option to analyze heat sinks under going natural convection with the base oriented vertically. Today we have added the option to perform an analysis when the base is oriented horizontally. There are many design situations where it is preferable or even necessary to orient the heat sink horizontally.
Below is a graph comparing the source temperature of a typical aluminum heat sink under going natural convection when oriented vertically and horizontally. The power source is the same size as the heat sink base. Radiation is not included.
The temperature difference between the two orientations is at most 7.5% with the heat sink analyzed for this example. A comparison of heat sinks with differing dimensions will show that certain heat sink designs will perform better when oriented horizontally. A general rule of thumb is that the performance of a heat sink oriented vertical is only slightly better than one oriented horizontally.