HVAC NATE HEAT PUMP
1. On an R-22 system, line diameters and lengths are typically specified for
a vapor pressure drop that does not exceed what?
ANS 6-7PSI or 6F
2. What is the primary purpose of using flux when soldering copper or brass
parts?
ANS Prevent Oxidation
3. The water that results from a defrost cycle of an air to air heat
pump(runoff) must?
ANS Drain off and away from the outdoor coil.
4. Why must the runoff be drained off and away from the outdoor coil?
ANS Exces- sive ice can build up on the bottom of the coil and can
reduce capacity.
5. What is the component that reduces sound transmission and
,prevents water leaks of a package heat pump installed on a roof?
ANS Curb Gasket
6.Why do you need to add a control for a heat pump indoor coil that is
installed on a fossil fuel furnace?
ANS So the heat pump and furnace do not operate at the same time in
normal heating.
7. What happens when you energize a hermetic refrigeration compressor
and the system is in a deep vacuum?
ANS Motor windings could become damaged.
8. What needs to happen in order to consider an evacuation to be
complete?-
ANS System should be evacuated to a vacuum of 500 Microns or below.
9. 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?
ANS 6lbs
10.Where are drive slips typically installed?
ANS On the shorter sides of rectangular duct.
11.What is a necessary check to properly set a heat anticipator?
ANS Heating control circuit amperage
draw.
12.A heat pump operating in normal ice free conditions maintains a certain
temperature difference between the outdoor coil temperature and the sur-
rounding outdoor ambient. What is this temperature referred to as?
ANS Coil TD.
13.What is the smallest refrigerant leak that an electronic leak detector
, should be capable of sensing?
ANS .o5oz per year.
14.When checking the pressures in an operating system with a manifold
gauge set, will refrigerant oil in a hose will have an effect on the gauge?
ANS No
15.What is the absolute pressure at sea level if a gauge pressure is
35 psig?
ANS 49.7psia
16. 100,000 BTUH output
furnace. Return air temp is 65F.
1. On an R-22 system, line diameters and lengths are typically specified for
a vapor pressure drop that does not exceed what?
ANS 6-7PSI or 6F
2. What is the primary purpose of using flux when soldering copper or brass
parts?
ANS Prevent Oxidation
3. The water that results from a defrost cycle of an air to air heat
pump(runoff) must?
ANS Drain off and away from the outdoor coil.
4. Why must the runoff be drained off and away from the outdoor coil?
ANS Exces- sive ice can build up on the bottom of the coil and can
reduce capacity.
5. What is the component that reduces sound transmission and
,prevents water leaks of a package heat pump installed on a roof?
ANS Curb Gasket
6.Why do you need to add a control for a heat pump indoor coil that is
installed on a fossil fuel furnace?
ANS So the heat pump and furnace do not operate at the same time in
normal heating.
7. What happens when you energize a hermetic refrigeration compressor
and the system is in a deep vacuum?
ANS Motor windings could become damaged.
8. What needs to happen in order to consider an evacuation to be
complete?-
ANS System should be evacuated to a vacuum of 500 Microns or below.
9. 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?
ANS 6lbs
10.Where are drive slips typically installed?
ANS On the shorter sides of rectangular duct.
11.What is a necessary check to properly set a heat anticipator?
ANS Heating control circuit amperage
draw.
12.A heat pump operating in normal ice free conditions maintains a certain
temperature difference between the outdoor coil temperature and the sur-
rounding outdoor ambient. What is this temperature referred to as?
ANS Coil TD.
13.What is the smallest refrigerant leak that an electronic leak detector
, should be capable of sensing?
ANS .o5oz per year.
14.When checking the pressures in an operating system with a manifold
gauge set, will refrigerant oil in a hose will have an effect on the gauge?
ANS No
15.What is the absolute pressure at sea level if a gauge pressure is
35 psig?
ANS 49.7psia
16. 100,000 BTUH output
furnace. Return air temp is 65F.
