HVAC NATE Heat Pump |171 questions| with correct answers

On an R-22 system, line diameters and lengths are typically specified for a vapor pressure drop that does not exceed what? CORRECT ANSWER 6-7PSI or 6F What is the primary purpose of using flux when soldering copper or brass parts? CORRECT ANSWER Prevent Oxidation The water that results from a defrost cycle of an air to air heat pump(runoff) must? CORRECT ANSWER Drain off and away from the outdoor coil. Why must the runoff be drained off and away from the outdoor coil? CORRECT ANSWER Excessive ice can build up on the bottom of the coil and can reduce capacity. What is the component that reduces sound transmission and prevents water leaks of a package heat pump installed on a roof? CORRECT ANSWER Curb Gasket Why do you need to add a control for a heat pump indoor coil that is installed on a fossil fuel furnace? CORRECT ANSWER So the heat pump and furnace do not operate at the same time in normal heating. What happens when you energize a hermetic refrigeration compressor and the system is in a deep vacuum? CORRECT ANSWER Motor windings could become damaged. What needs to happen in order to consider an evacuation to be complete? CORRECT ANSWER System should be evacuated to a vacuum of 500 Microns or below. A system is supplied from the factory with charge for a 15 foot line set. The data plate shows the required system charge to be 5 pounds 10 ounces. The line set uses a 3/8 inch liquid line and is 25 feet long. The manufacturer's instruction sheet specifies 0.6 ounces of refrigerant to be added for each added foot of refrigerant line length. How much refrigerant is needed to completely charge the system? CORRECT ANSWER 6lbs