ESCO Air Conditioning Exam 100% VERIFIED ANSWERS 2024/2025 CORRECT, Study Guides, Projects, Research of Business Administration

Download ESCO Air Conditioning Exam 100% VERIFIED ANSWERS 2024/2025 CORRECT and more Study Guides, Projects, Research Business Administration in PDF only on Docsity! ESCO Air Conditioning Exam 100% VERIFIED ANSWERS 2024/2025 CORRECT Heat which causes a change in temperature of a substance is called Sensible heat Heat added to a substance without a rise in temperature Latent heat Heat added to the refrigerant in a vapor state after the evaporation process is called Superheat Scroll compressor move refrigerant by Involute Spirals The movement of heat by way of fluid is called Convection The movement of heat by direct contact is Conduction The standard unit for measuring the quantity of heat in a substance is BTUs Refrigerant gives up heat when It condenses Why must refrigerant in the suction line be slightly warmer than the saturation temperature? Prevent liquid slugging of the compressor The state of the refrigerant in the suction line should be Low pressure / Low temperature vapor The state of the refrigerant entering the condenser is High pressure / Highly superheated vapor The evaporator Transfers heat from the refrigerated space to the refrigerant Which of the following is not a thermodynamic property of refrigerants Flammability The sequential order of steps in the vapor compressions process are Compression, Condensation, Expansion, Vaporization If a 30 pound cylinder of reclaimed R 410 a refrigerant has been stored overnight at 70° the pressure in the cylinder should be approximately 201 psig Fan airflow pressures are usually measured in Inches of water column 0 pounds per square inch absolute is A pressure which cannot be further reduced Constant evaporator superheat The automatic expansion valve is designed to maintain Constant evaporator pressure The thermostatic expansion valve has three operating pressures Evaporator pressure, Spring pressure, and Sensor bulb pressure When mounting a thermostatic expansion valve sensor bulb, which of the following is not true It must be installed lower than the valve body In an air conditioning system that uses a thermostatic expansion valve, the temperature of the evaporator outlet will usually be Warmer than the evaporator inlet In automatic expansion valve is best suited When the system load remains fairly constant Which of the following is not true of a capillary tube metering device They maintain a constant evaporator temperature A decrease in superheat causes the thermostatic expansion valve to begin to Close A rise in evaporator pressure causes the automatic expansion valve to begin to Close A thermal electric expansion valve is controlled by NTC thermistor In a direct expansion evaporator system, the refrigerant enters the evaporator as A mixture of liquid with some "flash-gas" Which of the following is the most important consideration in the selection of an evaporator coil. Match the coil to the Condensing unit and the latent/sensible loads In the evaporator Latent heat is transferred from the refrigerated space to the refrigerant A liquid line filter-drier should be placed between the Condenser and the Metering device The only way to minimize flash gas is by Sub-cooling the liquid refrigerant entering the metering device closer to the evaporator temperature A liquid receiver is used to store liquid refrigerant An accumulator is used to Prevent liquid refrigerant from reaching the compressor A sight glass would be normally located in the liquid line before the metering device Bubbles in a sight glass would be an indication of TXV with an excessive superheat setting The oil separator is installed in the Discharge Line Which of the following is true of a solenoid valve in a pump down system Its located before the metering device The purpose of an evaporator pressure regulating valve is to prevent evaporator pressure from falling below a set limit A liquid to suction heat exchanger is often used to increse liquid subcooling The oil pressure safety switch is operated by _________. the difference between crankcase pressure and oil pump pressure A low pressure cut off switch is used to establish a minimum operating pressure in the evaporator A partially iced over evaporator can be caused by an undercharge _________ can be use for a leak detection with all high-pressure refrigerant Soap bubbles The flow rate of a TXV is used in R 410A systems as compared to R22 systems is Approximately 15% greater When using an electronica leak detector the sensor probe should be moved at approximately 1 inch for every two seconds Moisture in a refrigeration system will cause What is the recommended residential indoor relative humidity for summer 50% In inefficient compressor is usually indicated by ________ Head pressure and ________ Suction pressure Higer than normal/ Lower than normal Which of the following is not a symptom of hermetic system that is low on refrigerant High head pressure Frost on the suction line indicates That its temperature is below the dew point and its below 32 degrees An increase in head pressure causes___refrigerant to flow through a capillary tube More With an automatic expansion valve, an increase in evaporator load will cause the Automatic expansion valve to close When a TEV or capillary tube is used as a metering device a low refrigerant charge will cause Low head pressure What is the maximum operating pressure setting for an acetylene torch 15 psig When connecting copper to steal the recommended brazing filler alloy is 45% silver alloy Solid contaminants such as sludge and carbon from a severe hermetic compressor motor burn out are best removed By flushing the system and then installing filter dryers in both the liquid and suction lines If the cut off play is removed from the blower assembly how will this affect blower performance It would reduce airflow At a residential service call no cooling complaint, the service technician finds the unit to be completely out of refrigerant. The technician decides to use a trace amount of refrigerant and___in order to pressurize the system Inert gas A technician has found an air-conditioning system with a leak in the liquid line. After the line is repaired the system is evacuated in properly recharged. When the system restarted the compressor is noisy and running hot. The most probable cause of the noise is Low oil in the system And air-conditioning system that is oversized can cause Inefficient dehumidification of the condition space While troubleshooting a residential split system the service technician find slow operating pressures in los system amperage draw. This could be an indication of Low airflow across the evaporator Air or other non-condensable gases in a capillary tube air conditioning system will cause the symptoms High suction pressure and high discharge pressure A refrigerant overcharge in a capillary tube air conditioning system will cause the symptoms High suction pressure and high discharge pressure A compressor that has a broken reed valve will cause the symptoms High suction pressure and low discharge pressure A low refrigerant charge in an air conditioning system will cause the symptoms Low suction pressure and low discharge pressure A TEV sensing bulb which becomes detached from the suction line will cause the symptoms High suction pressure and lower than normal discharge pressure A faulty condenser fan motor on an air conditioning system will cause the symptoms High suction pressure and high discharge pressure A dirty evaporator in an air conditioning system will cause the symptoms Low suction pressure and low discharge pressure