Basic Definitions

Basic Definitions

1. Heat - A form of energy that cannot be destroyed. Can be moved from a conditioned space to an area where it is harmless.
2. Heat Flow - Moves warmer to cooler and can be viewed as "downhill".
3. Solid - Form of matter that maintains its shape unsupported and applies pressure downward only.
4. Liquid - Form of matter that assumes the shape of its container. Applies greatest force at bottom and force decreases coming up the sides
5. Gas (Vapor) - Form of matter that applies force equally in all directions within a sealed container. Conforms to the shape of the container.
6. BTU - The amount of energy required to change the temperature of 1 lb of water 1 degree F. The basic unit of heating/cooling devices (1 Ton of refrigeration = 12,000 BTU/Hr)
7. Sensible Heat - Heat energy as measured by temperature.
8. Latent Heat - The energy required to change state without changing temperature. The basis of modern refrigeration, since state change BTUs far exceed sensible BTUs.
9. Specific Heat - Heat required to change the temperature of 1 lb of a specific substance one degree F for that substance. Water provides a baseline at 1.0
10. Ton of Refrigeration - The heat absorbed by a ton of ice melting in 24 hours without a change in temperature. 1 Ton of refrigeration = 12,000 BTU/Hr
11. Ambient Temperature - The temperature of the medium (usually air or water) surrounding an object
12. Conduction - A method of Heating using direct physical contact of 2 objects. Transfers energy molecule-to-molecule.
13. Radiation - A method of Heating where an object is heated without affecting the intervening space
14. Convection - A method of transferring heat using a transport medium (usually air or water)
15. Dry Ice - Solid Carbon Dioxide. Dangerous to place in a sealed container. Uses sublimation to convert from a solid to a gas at -108 degrees F.
16. Pressure at Sea Level - 14.7 psi. Will show as 0 when measured by a gauge