Part of Lesson Plan: **Introduction to Air Conditioning (updated) by Richard Williams

Activity Overview / Details

I then ask them what we would need if we were to build a virtual A/C system. Over the next few minutes I help them with coming up with the idea of a compressor, a restriction and two radiators and draw them on the white board.

From there we discuss the process. The compressor will pump refrigerant to increase pressure as it tries to make its way past a restriction. I use the analogy of all of the students leaving for the day. As they approach the only exit they tend to bunch up and slow down. After they squeeze through the door they can spread out and move easier. This is what happens to the molecules of refrigerant as they are forced through the restriction. First they pile up and condense at the entrance of the restriction.  Once they are through the restriction the molecules can spread out and they expand into a gas. At that point they will release latent heat. I tell them that the refrigerants we use today basically boil/evaporate at about 32 degrees. From there I lead them to the idea that if we have to do this over and over again we need to now re-condense the refrigerant by re-pressurizing it. So back to the compressor it goes!