NATE/ICE Test 2022/2023 with 100% correct answers

formula to convert celsius to fahrenheit F = (1.8 x C) + 32 formula to convert fahrenheit to celsius C = .56 (F - 32) specific heat the amount of heat required to raise 1 lb of a substance 1 degree fahrenheit sensible heat Is the heat that came be measured or sensed by a thermometer latent heat hidden heat that changes the state of a substance Btu The amount of heat requires to raise one pound of water one degree Fahrenheit The amount of heat that it takes to change 1 lb of 212 degrees Fahrenheit water to 1 lb of 212 steam is 970 Btu that amount of heat requires to change 1 lb of 32 degrees Fahrenheit ice to 1 lb of 32 water is 144 Btu conduction Is the transfer of heat from one molecule to another convection The transfer of heat from one place to another by fluid radiation The transfer of heat from a heat source to a solid object through space one ton of refrigerant is equivalent to _____ But per hour 12,000 when a substances changes from liquid to gas is latent heat of vaporization when a substance changes from gas to a liquid is called latent heat of condensation when a substance changes from a solid to a gas sublimation an _____ refrigerant is a mixture of two or more refrigerants that performs as a single component refrigerant azeotropic a _____ refrigerant is a mixture of two or more refrigerants that have different boiling points near-azeotropic a _____ refrigerant is a mixture of two or more refrigerants that have different boiling points zeotropic a _____ refrigerant is a blend of three refrigerants that acts as a zeotropic refrigerant ternary zeotropic and near-azeotropic refrigerant must be charged into a system as a _____ or the refrigerant will change it's composition liquid dewpoint line used to measure superheat bubble like used to measure subcooling temperature glide The temperature difference between the vapor and liquid state of a near-azeotropic, a zeotropic, and ternary blend refrigerant an zeotropic refrigerant has a temperature glide of _____ zero a near-azeotropic refrigerant has a temperature glide above _____ up to _____ degrees fahrenheit * zero * 10 _____ occurs when a zeotropic or a ternary refrigerant is added to a system as a gas fractionation mineral oils are often referred to as _____ oils petroleum mineral oils are most commonly used with CFC refrigerants synthetic oils are _____ chemicals produced to function as lubricants man-made synthetic lubricants absorbs more _____ than a mineral oil moisture polyol ester lubercants should be stored in their own container because _____ can permeate through certain materials maisture polyol ester oils is the only lubricant suitable to use with _____ R-134A _____ oil is a synthetic oil made by mixing benzene and propylene Alkylbenzene alkylbenzene oil is commonly used with _____ refrigerant and can be used with CFC refrigerants HCFC floc point Is the temperature at which oil starts to produce a waxy substance pour point Is the ability of oil to flow with refrigerants at a very low temperatures miscibility Is the ability of a fluid to readily mix with another fluid hygroscopic oil had a _____ ability to absorb moisture high if moisture levels seen more than _____ ppm in an air conditioning or refrigeration system, corrosion will result. 100 reciprocating compressors use _____ to compress the refrigerant gas pistons positive displacement compressors: * reciprocating * rotary * screw * scroll nonpositive displacement compressors: centrifugal screw compressors are used one large _____ systems tonnage scroll compressors are _____% higher in efficiency than reciprocating types 10 scroll compressors use _____ spiral portions that are meshed together to compress refrigerant gas two scroll compressors can handle _____ floodback better than reciprocating compressors liquid reciprocating compressors use _____, _____, and _____ to compress refrigerant gas * pistons * cylinders * valves three classifications of compressors: * hermetic * semihermetic * open The _____ compressor is welded, nonservicing type that is driven by an internal motor hermetic The _____ compressor is bolted together and is servivicable. it is driven by an internal motor semihermetic The _____ compressor is bolted together and is servicable. it is driven by an external motor open an open compressor uses two types of drives. * belt driven * direct drive two types of compressor lubrication * splash * forced multistage compressors commonly use a _____ thermostat two-stage multistage compressors use two compressors connected together to operate _____ system one