Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
103 Cards in this Set
- Front
- Back
|
What is the atmospheric pressure for PSIA? |
14.696 PSIA.
|
|
|
What is the atmospheric pressure for "Hg? |
29.921 "Hg |
|
|
What is the atmospheric pressure for "Hg Vac? |
Use 29.921 |
|
|
What is the atmospheric pressure for Microns Hg? |
760,000 Microns Hg |
|
|
What is the atmospheric pressure for In WC? |
408 In WC |
|
|
What is the atmospheric pressure for Ft WC? |
34 Ft WC |
|
|
What is the atmospheric pressure for kPa? |
101.325 kPa |
|
|
What is the equation for conversions? |
Convert To/Convert From x reference |
|
|
What is the formula to convert Celsius to Fahrenheit? |
F = ( C x 1.8 ) + 32 |
|
|
What is the formula to convert Fahrenheit to Celsius? |
C = ( F - 32 ) / 1.8 |
|
|
How do you convert Celsius to Kelvin? |
+273 |
|
|
How do you convert Kelvin to Celsius? |
-273 |
|
|
How do you convert Fahrenheit to Rankine? |
+460 |
|
|
How do you convert Rankine to Fahrenheit? |
-460 |
|
|
How do you convert Rankine to Kelvin? |
/1.8 |
|
|
How do you convert Kelvin to Rankine? |
x 1.8 |
|
|
What is the freezing point of water? |
32 F or 0 C |
|
|
What is the boiling point of water? |
212 F or 100 C |
|
|
What is a BTU? |
"British Thermal Unit" Amount of heat required to raise 1 lb of water 1 F. |
|
|
What is a calorie? |
Metric. Amount of heat required to raise 1 gram of water 1 C. |
|
|
What is conduction? |
Heat travelling from molecule to molecule. |
|
|
What is absolute zero? |
-460 F or -273 C 0 R or 0 K |
|
|
What is convection? |
Transfer of heat from one substance to another by using a fluid. |
|
|
What is radiant heat? |
Heat that passes through air and heats the first solid or water object it comes in contact with. |
|
|
What is sensible heat? |
Heat that causes a rise or fall in temperature without a change it state. It can be felt and also measured with a thermometer. |
|
|
What is latent heat? |
Referred to as hidden heat. It causes a phase change (change of state) with a change in temperature. |
|
|
What is sublimation? |
Solid to gas. |
|
|
What is specific heat? |
amount of heat necessary to raise 1 lb of a substance 1 F or 1kg 1 C. |
|
|
What is the specific heat of water? |
1 btu/lb/F |
|
|
What is the specific heat of air? |
0.24 btu/lb/F |
|
|
What is the specific heat of ice/steam? |
0.50 btu/lb/F |
|
|
What is the specific heat formula? |
Q = mass x specific heat x change in temp |
|
|
What is the sensible heat formula for air? |
Q = CFM x 1.08 x change in temp CFM = cubic feet per minute |
|
|
What is the sensible heat formula for liquid? |
Q = GPM x 500 x change in temp GPM = gallons per minute |
|
|
1 ton of refrigerant is equal to how many BTU's per 24hr/1hr/1min |
288,000 BTU/24 hr 12,00 BTU/1 hr 200 BTU/1 min |
|
|
What is the weight of water? |
62.4 lbs/sq.in |
|
|
What is atmospheric pressure? |
defined as 14.696 psi @ sea level @ 70 F |
|
|
1 psi = ? pascals? |
6890 pascals or 6.890 kPa |
|
|
What is equation for density? |
Mass / Volume lb/ft.cub Kg/m.cub Density is the weight of 1 ft.cub of a substance. |
|
|
What is the equation for volume? |
Volume / Mass |
|
|
What is the equation for specific gravity? |
Density of a substance / density of water water = 62.4 lb/ft.cub air = .075 lb/ft.cub |
|
|
What is the area formula a square? |
A = L x W |
|
|
What is the area formula for a circle? |
A = pie x radius squared |
|
|
What is the area formula for a triangle? |
A = base x height / 2 |
|
|
What is the volume formula for cubes/prisms? |
V = L x W x H |
|
|
What is the volume formula for a cylinder? |
V = pie x radius squared x H |
|
|
What is the volume formula for a sphere? |
V = 4/3 x pie x radius cubed |
|
|
What is the volume formula for a cone? |
V = 1/3 x pie x radius squared x H |
|
|
What is the circumference formula? |
C = 2 x pie x R C = pie x D |
|
|
What is the Pythagorean theorem? |
A squared + B squared = C squared Remember to what where the numbers are on the triangle and put them into the equation accordingly. |
|
|
What is the Falcrum formula? |
Force 1 x Distance 1 = Force 2 x Distance 2 |
|
|
What is the surface area formula for a cone? |
SA = pie x radius(radius + square root of H squared and radius squared) |
|
|
What is the surface area formula for a sphere? |
SA = 4 x pie x radius squared |
|
|
What is the surface area formula for a cylinder? |
SA = 2 x pie x radius(radius + H) |
|
|
What is the surface area formula for a prism? |
SA = 2( LW x LH x WH) |
|
|
What is matter? |
Matter occupies space and has weight. It is in forms of solid, liquid and gas. |
|
|
What is Mass? |
Mass is the property of matter that responds to gravitational attraction. |
|
|
What is Weight? |
Weight is the force that matter applies to a supporting surface. |
|
|
What is Superheat? |
Any vapour above it's saturation temperature. |
|
|
What is Subcooled? |
Any liquid below is saturation temperature. |
|
|
What is Work and its formula? |
Work is a force that causes a body to move. Work = Force x Distance |
|
|
What is Power and its formula? |
Power is the time rate of doing work. Power = Work / 33000 x (time in minutes) |
|
|
What is the formula for Pressure? |
Pressure = Force / Area
lbs/ft.sq |
|
|
What is Energy? |
Energy is the ability to do work. Kinetic + Potential. |
|
|
What is Boyles Law? |
P1 x V1 = P2 x V2 Has a constant temperature. |
|
|
What is Charles Law? |
P1 x T2 = P2 x T1 Has a constant volume. |
|
|
What is Gay Lussacs Law, Charles II Law? |
T1 x V2 = T2 x V1 Has a constant pressure. |
|
|
What is Daltons Law? |
Pt = P1 + P2 + P3 ... |
|
|
What is the General Gas Law? |
P1 x V1 / T1 = P2 x V2 / T2 |
|
|
What is Diffusion? |
It is the ability of a gas to expand uniformly and indefinitely, the boundaries being only limited by the enclosure. |
|
|
What is Adiabiatic Process? |
It allows gas to expand or contract without a change in enthalpy. |
|
|
What is the duty of a refrigerant? |
To transfer heat from an area where it is not desirable to any area where it is needed or makes no difference. |
|
|
What some refrigerant safety issues? |
Toxic, flammable, oxygen displacing. |
|
|
What kind of refrigerant detectors are? |
Electric, soap, ultra violet, sulphur sticks, ultra sonic, halide. |
|
|
What is Azeotrope? |
Refrigerants mixed of 2 or more liquids that have a single boiling and condensing point. R-500 series. |
|
|
What is Zeotrope? |
Refrigerants that have temperature glide and fractionate. R-400 Series. |
|
|
What is Near-Zeotrope? |
Refrigerants that experience less temperature glide. |
|
|
Classify the refrigerants by groups of 100. Ex, 000, 1000, 200. |
R-000: Methane R-100: Ethane R-200: Propane R-300: Cyclic Organic R-400: Zeotropes R-500: Azeotropes R-600: Organic - Carbon Based R-700: Inorganic - Mineral Based R-1000: Unsaturated Organic |
|
|
What are the three groups of Mineral Oil? |
Parafinic, Napthinic, Promatic. Napthinic oils are the most commonly used. They do not mix completely with HCFC's. |
|
|
What are the three groups of Synthetic Oil? |
1 - Alkybenze 2 - Polyalkylene Glycol (PAG) - glycol based lubricant and primarily used in autos. 3 - Ester Based. Usually wax free and used with HFC's. Polyol Ester is most popular but absorbs moisture very readily. |
|
|
What is PVE oil? |
Polyvinyl Ether. Does not hyrdolize and break down into organic components.
|
|
|
Oil in your system can be reduced by? |
1-Proper evaporator design 2-Proper capacity balance 3-Correct refrigerant pipe sizing 4-Avoidance of traps in piping 5-Use of oil separators |
|
|
What are three factors that determine whether oil stays in the evaporator? |
1-Viscosity of the oil 2-Velocity of the refrigerant 3-Geometry of the piping |
|
|
What is viscosity? |
The resistance that oil offer to flow. High viscosity = thicker oil |
|
|
What is Dielectric Strength? |
A measure of resistance the oil has to electric current. |
|
|
What is Flash Point? |
The temperature of oil when the oil is heated and a flame is passes over its surface causing a flash. Higher = better. |
|
|
What is Flock Point? |
The temperature at which was will precipitate from a mixture. |
|
|
What is Fire Point? |
The temperature at which the vapour produced by that given fuel will continue to burn for at least 5 seconds after ignition by an open flames. |
|
|
What is Solubility? |
The property of a solid, liquid or gaseous chemical substance called solute to dissolve in a solid, liquid or gaseous solvent to form a solution of the solute in the solvent. |
|
|
What is Pour Point? |
The temperature at which it becomes semi solid and loses its flow characteristics. |
|
|
What is SSU? |
Saybolt Seconds Universal - a measure of kinematic viscosity used in classical machines. |
|
|
What is Carbon Residue? |
Value to give an approximate indication of the combustibility and deposit forming tendencies of the substance. |
|
|
What is Neutralization Number? |
A measure of the acid or alkaline content of new oils and an indicator of the degree of oxidation degradation of used oils. |
|
|
1 BTU equals how many Foot/lbs? |
778 Foot/lbs. |
|
|
1 Horsepower equals how man watts? |
746 Watts. |
|
|
1 Horsepower equals how many BTU's? |
2545 BTU's. |
|
|
1 Horsepower equals how many Foot/lbs? |
550 Ft/lbs/sec. |
|
|
1 Horsepower equals how many Ff/lbs/min? |
33000 Ft/lbs/min. |
|
|
1 pound equals how many gallons? |
8.33 gallons. |
|
|
1 Watt equals how many BTU's? |
3.412 BTU's |
|
|
What is the specific volume of air? |
13.33 ft.cub/lb |
|
|
What is the density of air? |
.075 lbs/ft.cub |
|
|
What is the specific gravity of water? |
1 |
