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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. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
TXV
40 degrees F
Any amount
Negative

2. At what temperature will soft solder melt?
Heat loss
They are larger
Below 800 degrees F
Pistons

3. How is flexible duct supported?
Blended refrigerants
The suction line or the low-pressure side
Vapor
A band 4 inches or more in width

4. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
Staples and tape
When it is above a conditioned space
True
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line

5. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
It rises
45-55%
They are larger
L-type

6. In what state is the refrigerant in the compressor?
When it is above a conditioned space
Vapor
When the system is under pressure
20 A

7. How are high-efficiency condenser coils different from standard-efficiency condenser coils?
It will have a decrease in superheat
Yes
They are physically larger
40 degrees F

8. What sort of pressure will a push-through evaporator have?
They are larger
With a minimum of three evenly spaced self-tapping screws
Positive
6

9. If the suction pressure rises - what happens to the head pressure?
Fiberglass
20 degrees F
It also rises
Below 800 degrees F

10. What is the normal evaporator temperature?
20 degrees F
Belt drive and direct drive
It will be high
45 degrees F

11. How is nominal-sized tubing sized?
Inside diameter (ID)
The suction line or the low-pressure side
Infiltration and ventilation
Suction

12. At what temperature will brazing melt?
100 psig
15 A
A swaging tool
Over 800 degrees F

13. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
2 minutes
Before the vent
45-55%
40 A

14. How is ACR tubing sized?
Outside diameter (OD)
Btu/hr (output) / wattage (input)
No
40 degrees F

15. What is the difference between SEER and EER?
False
Outside of the male fitting
SEER includes the energy used in the start-up and shut-down cycles
Belt drive and direct drive

16. How is flexible duct supported?
When it is above a conditioned space
It rises
A band 4 inches or more in width
With a minimum of three evenly spaced self-tapping screws

17. If pressure rises - what happens to the superheat?
Potential relay and start capacitor
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
It rises
1/4'

18. What percentage silver do you need to use for an are-410 system?
A dirty evaporator
Average feet per minute X area in square feet (H' x W'/144)
They are physically larger
15% silphos

19. What kind of copper tubing is used for plumbing and heating applications?
Common
Nominal-sized tubing
TXV
Heat loss

20. At what temperature does refrigerant condense in a high-efficiency unit?
20 degrees above ambient
A piston type metering device
Vapor
Suction

21. How are round ducts connected to one another?
40 degrees F
Boil the liquid refrigerant out ot the oil within the crankcase
A swaging tool
With a minimum of three evenly spaced self-tapping screws

22. Do you need a vent on a pull-through evaporator?
They are larger
True
Suction
Yes

23. Why are some ACR tubing lines insulated?
Nominal-sized tubing
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
45 degrees F
In series

24. A reciprocating compressor has what sort of moving parts?
Side-by-side and over-and-under
Pistons
105 degrees F
2 minutes

25. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
It will be low
Outside of the male fitting
With an are rating
Any amount

26. What are normal conditions - as defined by the ARI.
25-ft or 50-ft
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Staples and tape
20 A

27. What kind of copper tubing is used for refrigeration or air-conditioning applications?
18 gauge
To remove humidity and lower dry bulb temperature
ACR (air-conditioning refrigeration) tubing
Individual return air systems and central return air systems

28. How will too much refrigerant effect subcooling?
A band 4 inches or more in width
It will be high
Outside of the male fitting
Btu/hr (output) / wattage (input)

29. The compressor is cooled by liquid refrigerant. (True of False)
4
Average feet per minute X area in square feet (H' x W'/144)
False
Positive

30. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
It rises
RLA/FLA x 5
To lower the amount of pressure drop through the coil
8

31. Pressure in ductwork is measured In what?
8-12 degrees F
Inches of water column (in. WC)
Outside diameter (OD)
SEER includes the energy used in the start-up and shut-down cycles

32. What is it called when liquid refrigerant gets into the compressor?
Duct - electrical - and mechanical
Slugging
Outside diameter (OD)
Outside of the male fitting

33. How much does a drain line need to drop per foot of length?

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34. What is the typical temperature difference between a high-efficiency condenser and the ambient temperature?
40 degrees F
20 degrees F
It will be low
Duct - electrical - and mechanical

35. How many amps can 14 g wire handle?
30 degrees F
15 A
Outside diameter (OD)
TXV

36. 7' round duct has a ballpark cfm of what?
Any amount
100
When it is above a conditioned space
150

37. If the rpm's are 1750 - how many poles does the motor have?
5 degrees
30-35 degrees above ambient
4
15% silphos

38. What sort of pressure will a push-through evaporator have?
Positive
In parallel
Pull a vacuum
Pistons

39. What is the name of the fitting where the branch line leaves the duct?
Dehydrated with caps on each end
40 degrees F
100
The takeoff fitting

40. The A/C size is calculated by what?
Stranded
6
Fiberglass
Heat load

41. Which type of wire can handle a higher ampacity?
Nominal-sized tubing
S-clips and drives (cleats)
In parallel
Stranded

42. How is the high pressure switch wired with the low pressure switch?
Yes
Yes
Individual return air systems and central return air systems
In parallel

43. What is considered normal operating conditions?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
L-type
RLA/FLA x 5

44. What is the design boiling point for most evaporator coils in residential air conditioning?
With an are rating
40 degrees F
Heat load
15 A

45. Sections of duct board can be fastened together with what?
SEER includes the energy used in the start-up and shut-down cycles
Over 800 degrees F
20 degrees F
Staples and tape

46. The crankcase heater on an air-conditioning compressor is used to what?
Nitrogen with a small amount of refrigerant
It also rises
Boil the liquid refrigerant out ot the oil within the crankcase
Static pressure - velocity pressure - and total pressure

47. Which type of wire can handle a higher ampacity?
Yes
By increasing the surface of the condenser coil
Stranded
A piston type metering device

48. What is the typical temperature difference between a standard-efficiency condenser and the ambient temperature?
30 degrees F
RLA/FLA x 5
400
High

49. 8' round duct has a ballpark cfm of what?
140 degrees F
200
Staples and tape
Pull a vacuum

50. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
Static pressure - velocity pressure - and total pressure
It will have a decrease in superheat
400
25-ft or 50-ft