Test your basic knowledge |

Residential Air Conditioning

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. Does a package unit come from the factory pre-charged?
Static pressure - velocity pressure - and total pressure
Yes
Shorted winding - open winding - and grounded winding
A dirty evaporator

2. What are normal conditions - as defined by the ARI.
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Yes
Fiberglass
20 degrees above ambient

3. What kind of copper tubing is used for refrigeration or air-conditioning applications?
Over/under and side by side
It will be high
8-12 degrees F
ACR (air-conditioning refrigeration) tubing

4. Where do you install a trap on a drain line?
Infiltration and ventilation
Before the vent
Slugging
Outside diameter (OD)

5. What are the four materials used to make duct?
Over 800 degrees F
S-clips and drives (cleats)
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
TXV

6. 7' round duct has a ballpark cfm of what?
150
4
6
Infiltration and ventilation

7. If the rpm's are 1750 - how many poles does the motor have?
Pistons
2 minutes
4
Indoor fan motor - outdoor fan motor - and the compressor

8. Will a dirty condenser cause a rise or fall in pressure?
Rise
Average feet per minute X area in square feet (H' x W'/144)
100 psig
TXV

9. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
By increasing the surface of the condenser coil
Blended refrigerants
They are larger
It will have a decrease in superheat

10. What are normal conditions - as defined by the ARI.
In series
Outside diameter (OD)
25-ft or 50-ft
95 degrees F outside - 80 degrees F inside - and 50% relative humidity

11. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
Positive
Fiberglass
5 degrees
40 degrees F

12. How long should you leave a system off once you kill power before restarting it?
4
2 minutes
105 degrees F
It will be high

13. Most duct insulation is made of what?
Fiberglass
When the system is under pressure
A band 4 inches or more in width
RLA/FLA x 5

14. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
Nominal-sized tubing
True
They are larger
Nitrogen with a small amount of refrigerant

15. What is the design boiling point for most evaporator coils in residential air conditioning?
40 degrees F
It also rises
Yes
Negative

16. What is the name of the fitting where the branch line leaves the duct?
The takeoff fitting
It will have a decrease in superheat
20 degrees F
Inches of water column (in. WC)

17. How do you calculate LRA?
RLA/FLA x 5
20 A
Inches of water column (in. WC)
Before the vent

18. What are the three pressures created by moving air in ductwork?
Static pressure - velocity pressure - and total pressure
In series
High
2

19. Which is more efficient - a TXV or a fixed-orifice metering device?
The suction line or the low-pressure side
Duct - electrical - and mechanical
TXV
Inside diameter (ID)

20. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
To lower the amount of pressure drop through the coil
Infiltration and ventilation
To remove humidity and lower dry bulb temperature
100 psig

21. Where do you install a trap on a drain line?
Blended refrigerants
Before the vent
To remove humidity and lower dry bulb temperature
Yes

22. The compressor is cooled by liquid refrigerant. (True of False)
False
Yes
When the system is under pressure
Staples and tape

23. Do you need a trap on a pull-through evaporator?
TXV
Infiltration and ventilation
300
Yes

24. What type of air conditioning system must be charged using the superheat method?
Over 800 degrees F
A piston type metering device
False
15% silphos

25. What do you use to check for leaks?
By increasing the surface of the condenser coil
Outside of the male fitting
Nitrogen with a small amount of refrigerant
400

26. What gauge is thermostat wire?
Rise
150
Outside of the male fitting
18 gauge

27. The fan switch opens at what temperature?
Stranded
A swaging tool
Individual return air systems and central return air systems
105 degrees F

28. What distributes supply air to a room in a structure?
S-clips and drives (cleats)
A swaging tool
A diffuser
Outside of the male fitting

29. Where do you apply flux when soldering?
Slugging
Outside of the male fitting
It also rises
Btu/hr (output) / wattage (input)

30. What are the three crafts normally associated with an air-conditioned installation?
Duct - electrical - and mechanical
It will be low
A band 4 inches or more in width
100

31. Do you need a vent on a pull-through evaporator?
Yes
Dehydrated with caps on each end
The suction line or the low-pressure side
Belt drive and direct drive

32. What percentage silver do you need to use for an are-410 system?
15% silphos
Outside of the male fitting
Vapor
Fiberglass

33. How do you calculate EER?
300
Btu/hr (output) / wattage (input)
Subtract ambient temperature from 100
With 4' saddles

34. Which is more efficient - a TXV or a fixed-orifice metering device?
TXV
Outside diameter (OD)
Heat loss
Individual return air systems and central return air systems

35. How many amps can 14 g wire handle?
Inside diameter (ID)
Yes
ACR (air-conditioning refrigeration) tubing
15 A

36. What standard weight copper tubing is most often used in the heating and air-conditioning industry?
Inside diameter (ID)
Shorted winding - open winding - and grounded winding
L-type
SEER includes the energy used in the start-up and shut-down cycles

37. If the rpm's are 750 - how many poles does the motor have?
8
When it is a pull-through evaporator
RLA/FLA x 5
15% silphos

38. In what state is the refrigerant in the compressor?
Stranded
6
Vapor
Btu/hr (output) / wattage (input)

39. 10 SEER is classified as what kind of efficiency?
Yes
400
Standard
Yes

40. How are the high pressure switch and the low pressure switch wired with the compressor contactor?
100
2 minutes
In series
False

41. What is the typical temperature difference between a high-efficiency condenser and the ambient temperature?
Inside diameter (ID)
Before the vent
Individual return air systems and central return air systems
20 degrees F

42. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
45-55%
Yes
A dirty evaporator
Yes

43. What do you do after you braze a system?
6
It also rises
Pull a vacuum
The takeoff fitting

44. If the rpm's are 3450 - how many poles does the motor have?
2
With an are rating
Vapor
Indoor fan motor - outdoor fan motor - and the compressor

45. How is flexible duct supported?
A band 4 inches or more in width
Compressor
Boil the liquid refrigerant out ot the oil within the crankcase
When it is a pull-through evaporator

46. Pressure in ductwork is measured In what?
S-clips and drives (cleats)
Yes
It will be high
Inches of water column (in. WC)

47. The fan switch closes at what temperature?
12000
A dirty evaporator
140 degrees F
45-55%

48. What do you do after you braze a system?
Pull a vacuum
18 gauge
2 minutes
They are larger

49. Will a dirty condenser cause a rise or fall in pressure?
150
400
Rise
15 A

50. 9' round duct has a ballpark cfm of what?
300
Btu/hr (output) / wattage (input)
The takeoff fitting
Compressor