The evaporator coil operating temperature for a system with a 20F split, 85F return air, and 71F supply air is: Select one: A. COT = ((85F - 71F)/2) + 20 = 98F. B. COT = 71F - 20 = 51F. C. COT = 85F - 20 = 75F. D. COT = ((85F - 71F)/2) - 20 = 58F. Clear my choice Question 3 Not yet answered Points out of 1.00 Not flaggedFlag question Question text The most common cause of airflow-related problems in air-conditioning units is: Select one: A. Dirty air filters. B. Dirty condenser coils. C. Low refrigerant charge. D. Electrical issues. Clear my choice Question 4 Not yet answered Points out of 1.00 Not flaggedFlag question Question text As a technician's rule of thumb, fan speed should not be adjusted more than ________ percent above or below manufacturer's specifications. Select one: A. 25 B. 50 C. 10 D. Do not adjust the fan speed. Clear my choice Question 5 Not yet answered Points out of 1.00 Not flaggedFlag question Question text A common cause of poor airflow is: Select one: A. Unusual airflow restrictions in the duct. B. A duct system that has been sealed too tight and cannot breathe. C. Improper installation of the thermostatic expansion valve. D. Unusually large ductwork