Other
Nye Thermodynamics: Basic Gas Turbine Theory
Outstanding information (and a lot of it) on gas turbine (jet) engines. Describes the history behind their development and the theory behind their operation. Well written and includes very informative graphics.
Physics Hypertextbook
The Physics Hypertextbook: Refrigerators
This resource provides a detailed discussion about how refrigerators work. Also includes a history of the invention of refrigerators, and the physics behind how they work.
MadSci Network
Msn: How Does an Air Conditioner or Refrigerator Work?
From the Mad Scientist Network. Using a question and answer format, this page explains the answer to the question "How does An air conditioner or refrigerator work?" The scientific principles which underly their operation and the process...
Other
Warm Air: Central Air Conditioning
The operation of conventional air conditioners are described. Their parts and the refrigerant/heat exchange cycle is discussed. The use of alternative geothermal systems are explained.
Other
Warmair.com: Refrigeration Cycle
The expansion-compression-condensation cycle of a refrigerator is discussed and explained. Understandable language but no graphics.