ESCO Air Conditioning Exam QUESTIONS WITH COMPLETE 100% VERIFIED SOLUTIONS 2024/2025, Exams of Refrigeration and Air Conditioning

Download ESCO Air Conditioning Exam QUESTIONS WITH COMPLETE 100% VERIFIED SOLUTIONS 2024/2025 and more Exams Refrigeration and Air Conditioning in PDF only on Docsity! ESCO Air Conditioning Exam QUESTIONS WITH COMPLETE 100% VERIFIED SOLUTIONS 2024/2025 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 0 pounds per square inch gauge is The same as atmospheric pressure The temperature at which moisture will start to condense from the air is called Dew point temperature A compound pressure gauge measures Pressure and vacuum Mechanical shaft seal is necessary on a Open drive compressor Liquid slugging is Liquid refrigerant in the compressor clearance space The clearance space in reciprocating compressor Has an effect on compressor capacity Which of the following types of air conditioning compressor is most energy-efficient Scroll Which of the following represent the right order for the functions of a condenser De-superheat, Condenses, Subcools Refrigerant R 134a vapor enters the condenser at 124 psi G, 100°F. it leaves as a liquid from the condenser subcooled 20°F and the pressure will be approximately 87 psig There are three basic types of condensers, air-cooled, water-cooled and the _____________ cooled Evaporative 10 pounds of refrigerant passing through a water cooled condenser will lose 20 BTUs of heat per pound. If 10 pounds of water passes through the condenser with an entering temperature of 80°F the temperature of the water leaving the condenser is 100°F The heat removed from the refrigerant by the condenser is triple evacuate the system to 500 microns with a deep vacuum pump what type of gauge is used to measure microns an electronic vacuum gauge Water will vaporize at ________ temperature in a 28 in hg vacuum 10°F After a system has been opened and the compressor changed the service technician must Replace the filter dryer, leak check, evacuate, and charge Back seating a two-way service valve results in Open service port with normal system flow The R-410 a compound gauge reads 124 psig in the suction line temperature at the condensing unit is 54°F. What is the operating system superheat 12°F When topping off an operating system containing a blended refrigerant introduce the refrigerant as a liquid into the low side using the throttling valve A partially clogged capillary tube can cause A starved evaporator The r134a0 for a high-pressure gauge reads 146 psig in the liquid line temperature at the condensing unit is 95°F. What is the operating system subcooling 15°F An overcharge of refrigerant will cause increased head pressure A customer complains that their air conditioning system is running constantly, but no cooling enough. The suction line is very cold in the compressor is sweating. The most likely cause is a restriction of the return arir or a dirty evaporator A drain trap should be installed on a split system when the Air handler drain is on the negative air side A customer reports that the residential split system had a compressor replaced last week by another service company. Now the unit is not cooling property. When you arrive and inspect the unit you find that the evaporator seems to be starved for refrigerant. On examining the condensing unit, you find that the liquid line is sweating where it leaves the dryer. This is most likely the result of Debris from the burned out compressor has clog the dryer What is generally excepted range for evaporator airflow in CFM's per ton of residential air conditioning 350 to 450 The temperature rise method for determining airflow is CFM=BTU / (1.08 x delta T) 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