This is the third in a series of Heat Pump 101 videos from instructor and author, John Siegenthaler, P.E.. “Thermodynamic Basics” was the previous lesson in the series. You can enroll in John’s Heat Pump 101 course for free to learn the very basics of heat pumps in less than an hour.


The three modes of heat transfer are:

  1. Conduction – heat moves from one solid material to another at a lower temperature
  2. Convection – heat moves between fluids or between a solid and a fluid at a lower temperature
  3. Thermal radiation – heat movement by electromagnetic radiation emitted by a material and absorbed by a cooler surface

These all sound complicated, but if you can remember an example of each, then the concepts are easy to remember. These are important terms that help us understand and talk about the nature of HVAC and how heat pumps work.

The next video in this series is covers the ‘natural’ vs. ‘artificial’ processes by which heat is transferred. If you want to see that video now or jump ahead to the others, you can find them all in John Siegenthaler’s free Heat Pump 101 course.