Air Conditioning Certification Exam (Exam Code A-02) Questions & Answers Already Passed

Heat which causes a change in temperature of a substance is called; - sensible heat. Heat which causes a change in state of a material without a change in temperature is called; - latent heat. Heat which is added to a vapor after the change of state occurs is called; - superheat. Heat can travel by; - conduction, convection, radiation. The movement of heat by way of fluid (or air) is called; - convection . The movement of heat by direct contact is called; - conduction . The standard unit for measuring the quantity of heat in a substance is; - the British Thermal Unit (Btu). A refrigerat gives up heat when; - it condenses. It is desirable for refrigerant in the suction line to be slightly superheated in order to; - insure liquid refrigerant does not enter the compressor. The state of refrigerant in the suction line should be; - low pressure/ low temperature. The state of the refrigerant entering the condenser is; - high pressure/ highly superheated liquid. The evaporator; - Transfers heat from the refrigerant to the ambient air.Which of the following is NOT a thermodynamic property of refrigerants? a) Critical point. b) Saturation point. c) Enthalpy. d) Flammability. - d) Flammability. The sequential order of steps in the vapor - compression process are; - compression, condensation, expansion, vaporization. If a 30 pound cylinder of reclaimed R-12 refrigerant has been stored over night at 70°F, the pressure in the cylinder should be approximately; - 70.2 Psig.