Density
Weight in pounds of one cubic foot of a substance; how tightly packed molecules are in a substance
Force
Any interaction that, when unopposed, changes the motion of an object
Heat
Energy associated with the movement of molecules
Latent heat
Heat added to or removed from a substance that causes a change in state but not a change in temperature
Matter
Anything that has weight and occupies space
Pressure
Force applied per unit area
Refrigeration
Process of lowering the temperature of a substance or a given space using transfer of heat (absorbs or ejects latent heat)
Sensible heat
Heat added to or removed from a substance that causes a change in temperature of an object or substance
Radiation
Heat transfer is the form of a wave
BTU
The amount of heat required to change the temperature of 1 lbs of pure water by 1� at atmospheric pressure
Heat
Form of energy
Refrigeration ton
12,000 BTU
Superheat
Is Sensible heat added to a vapor above its boiling point
Subcooling
Is the sensible heat removed from a liquid below its condensing temperature
Total heat
Sensible heat + latent heat
Conduction
Heat is transferred by means of direct physical contact between two substances
Convection
Movement of heat by means of the circulated fluid or air
Boyles law
Volume of vapor varies inversely to pressure, as long as temperature remains constant
Charles vapor law
Relationship between volume and temperature of vapor when pressure is constant
Pascals pressure law
Pressure applied upon confined fluid transmitted with equal intensity throughout fluid in all directions
Dalton's partial pressure law
Total pressure of confined mix of vapors is some of the pressure of each vapor in mixture
Water boils at
217F
Refrigeration Process
Lowering the temp of a substance or a given space using transfer of heat
Sensible heat range/ ideal heat
8-12/10
What happens in condenser
Desuperheat
Condense
Subcool
Total Heat
Sensible heat - Latent Heat/ total energy calculated from absolute 0 in BTUs
Super heat formula
Sensible Temp-Suction pressure/Evap temp
Sub Cool formula
Condensing temp-Liquid line
Closed container, must be touching and same substance
what three conditions must be present for a pressure and temperature relationship to exist?
due to lowering atmospheric pressure
why is it that water boils at a much lower temperature at higher elevation?
pressure will increase
what happens to the pressure of a gas( in a closed container) if the volume is decreased in half?
Saturation temp
When a liquids temperature is raised to its boiling point this is known as _____
Floodback
Prevents the liquid from entering the TXV
Flashgas
Prevents excess gas from getting into the inlet side of the TXV
DP/CT
135
/105