Troubleshooting Challenge 410A

bumity is 60.7%

Indoor dry bulb temp 80°F Indoor wet bulb temp 70°F

Refrigerant R410A

Outdoor ambient temp 89°F hot

Suction line temp 75°F

Liquid line temp 128ºF

Actual Condensing pressure 485 PSIG (131.1 °F)

Actual Evaporator pressure 144 PSIG (50.33 °F)

Diagnose the problem (Only one)

Low Evaporator Airflow (Low load)

Refrigerant Undercharged

Refrigerant Overcharged

High heat load (High Indoor Temperature or Leak in return duct)

The force on a cutting tool are 2600n vertically downward and 2100 horizontal. determine the resultant force acting on the tool and the angle at which it acts.

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

An ideal otto cycle with air as the working fluid has a compression ratio of 8. the minimum and maximum temperatures in the cycle are 300 k and 1340 k. use constant specific heats at room temperature to determine (a) the amount of heat transferred to the air during the heat- addition kj/kg, (b) the thermal efficiency, and (c) the thermal efficiency of a carnot cycle ope limits. process, in rating between the same temperature