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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. What is the design boiling point for most evaporator coils in residential air conditioning?
Common
40 degrees F
Fiberglass
To lower the amount of pressure drop through the coil

2. What is considered normal operating conditions?
105 degrees F
Infiltration and ventilation
Rise
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity

3. What is used to measure static air pressure in ducts.
100 psig
They are physically larger
Fiberglass
Inclined manometer

4. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Any amount
Suction
Side-by-side and over-and-under

5. Superheat should never be below how many degrees
5 degrees
45-55%
Dehydrated with caps on each end
A dirty evaporator

6. What is a package unit?
ACR (air-conditioning refrigeration) tubing
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Pistons

7. What is the design boiling point for most evaporator coils in residential air conditioning?
A bypass duct or a dump zone
TXV
40 degrees F
8

8. What are the two ways that fresh air enters a structure?
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
In series
Pi x radius squared
Infiltration and ventilation

9. How many amps can 12 g wire handle?
20 A
Average feet per minute X area in square feet (H' x W'/144)
False
With an are rating

10. What are the two ways that fresh air enters a structure?
Shorted winding - open winding - and grounded winding
No
Infiltration and ventilation
True

11. How is flexible duct supported?
A band 4 inches or more in width
Blended refrigerants
In parallel
300

12. What percentage silver do you need to use for an are-410 system?
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
A piston type metering device
Static pressure - velocity pressure - and total pressure
15% silphos

13. How are round ducts connected to one another?
Belt drive and direct drive
TXV
With a minimum of three evenly spaced self-tapping screws
L-type

14. 10 SEER is classified as what kind of efficiency?
SEER includes the energy used in the start-up and shut-down cycles
Vapor
Outside diameter (OD)
Standard

15. What can cause a decrease in suction pressure on an air-conditioning system?
A dirty evaporator
RLA/FLA x 5
To lower the amount of pressure drop through the coil
RLA/FLA x 5

16. What do you do after you braze a system?
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
100 psig
Pull a vacuum
12000

17. What tool is used to expand the diameter of soft copper tubing
A swaging tool
Yes
They are physically larger
ACR (air-conditioning refrigeration) tubing

18. What is the range for normal superheat and subcooling?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
8-12 degrees F
It rises
100 psig

19. If the rpm's are 750 - how many poles does the motor have?
8
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
They are larger

20. What component changes refrigerant from a low pressure gas to a high pressure gas?
Compressor
It will be low
Dehydrated with caps on each end
Vapor

21. The fan switch closes at what temperature?
140 degrees F
They are larger
Heat loss
Belt drive and direct drive

22. How do you calculate LRA?
Staples and tape
A swaging tool
It will be high
RLA/FLA x 5

23. What can cause a decrease in suction pressure on an air-conditioning system?
A dirty evaporator
L-type
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
With 4' saddles

24. Where is insulation used on copper tubing used for air-conditioning?
The suction line or the low-pressure side
Yes
Rise
Btu/hr (output) / wattage (input)

25. When do you install a trap on a drain line?
TXV
200
Btu/hr (output) / wattage (input)
When it is a pull-through evaporator

26. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
Individual return air systems and central return air systems
40 degrees F
20 degrees F
SEER includes the energy used in the start-up and shut-down cycles

27. How many amps can 8 g wire handle?
The suction line or the low-pressure side
To remove humidity and lower dry bulb temperature
40 A
30 A

28. How many amps can 8 g wire handle?
With a minimum of three evenly spaced self-tapping screws
Slugging
40 A
It also rises

29. 13 SEER is classified as what kind of efficiency?
Nominal-sized tubing
High
Dehydrated with caps on each end
8

30. 7' round duct has a ballpark cfm of what?
Vapor
150
Nitrogen with a small amount of refrigerant
Latent and sensible

31. Do you need a vent on a push-through evaporator?
Yes
30 A
18 gauge
Pi x radius squared

32. What standard weight copper tubing is most often used in the heating and air-conditioning industry?
With 4' saddles
Average feet per minute X area in square feet (H' x W'/144)
45-55%
L-type

33. How is the high pressure switch wired with the low pressure switch?
Static pressure - velocity pressure - and total pressure
Inches of water column (in. WC)
Individual return air systems and central return air systems
In parallel

34. In what state is the refrigerant in the compressor?
Yes
Vapor
It rises
40 degrees F

35. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
It will have a decrease in superheat
No
Suction
20 degrees F

36. What kind of copper tubing is used for refrigeration or air-conditioning applications?
4
ACR (air-conditioning refrigeration) tubing
200
Inside diameter (ID)

37. 8' round duct has a ballpark cfm of what?
Staples and tape
Nitrogen with a small amount of refrigerant
200
Static pressure - velocity pressure - and total pressure

38. Where do you apply flux when soldering?
Outside of the male fitting
Compressor
200
Heat loss

39. The fan switch opens at what temperature?
105 degrees F
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
A dirty evaporator
30 A

40. What is the typical temperature difference between a high-efficiency condenser and the ambient temperature?
20 degrees F
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
TXV
It will be low

41. How are the high pressure switch and the low pressure switch wired with the compressor contactor?
1/4'
In series
Fiberglass
30 degrees F

42. If the rpm's are 750 - how many poles does the motor have?
200
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
8

43. Do you need a vent on a pull-through evaporator?
TXV
Fiberglass
Yes
The takeoff fitting

44. What is the typical temperature difference between a standard-efficiency condenser and the ambient temperature?
Outside diameter (OD)
300
Static pressure - velocity pressure - and total pressure
30 degrees F

45. What do you use to connect square and rectangular ductboard together?
S-clips and drives (cleats)
By increasing the surface of the condenser coil
RLA/FLA x 5
It also rises

46. How do you calculate EER?
With 4' saddles
Btu/hr (output) / wattage (input)
A diffuser
400

47. The load on the evaporater will effect which pressure?
Side-by-side and over-and-under
Heat loss
2
Suction

48. The compressor is cooled by liquid refrigerant. (True of False)
When it is above a conditioned space
False
L-type
400

49. What are normal conditions - as defined by the ARI.
25-ft or 50-ft
Outside of the male fitting
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
30 A

50. What are the two basic duct connection configurations for package units supply and return air ducts?
When it is above a conditioned space
Standard
Suction
Over/under and side by side