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. What kind of refrigeratnts must be added in liquid form?
With an are rating
Blended refrigerants
Nominal-sized tubing
Subtract ambient temperature from 100

2. What is considered normal operating conditions?
Suction
It rises
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Standard

3. At what temperature will soft solder melt?
Nitrogen with a small amount of refrigerant
Below 800 degrees F
By increasing the surface of the condenser coil
Standard

4. If the rpm's are 1750 - how many poles does the motor have?
140 degrees F
A dirty evaporator
Slugging
4

5. How do you calculate cfm?

6. Why are some ACR tubing lines insulated?
Suction
Yes
6
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line

7. How are the high pressure switch and the low pressure switch wired with the compressor contactor?
2 minutes
45 degrees F
In series
Inches of water column (in. WC)

8. 9' round duct has a ballpark cfm of what?
300
Staples and tape
Average feet per minute X area in square feet (H' x W'/144)
Pistons

9. What kind of copper tubing is used for refrigeration or air-conditioning applications?
A dirty evaporator
Over 800 degrees F
ACR (air-conditioning refrigeration) tubing
Potential relay and start capacitor

10. Pressure in ductwork is measured In what?
Inches of water column (in. WC)
Dehydrated with caps on each end
On the common terminal
To lower the amount of pressure drop through the coil

11. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
Potential relay and start capacitor
20 A
40 A
True

12. How is nominal-sized tubing sized?
Infiltration and ventilation
Duct with insulation on the inside
45 degrees F
Inside diameter (ID)

13. How will too much refrigerant effect subcooling?
1/4'
It will be high
It will be low
In parallel

14. Which type of wire can handle a higher ampacity?
100 psig
Stranded
The takeoff fitting
Static pressure - velocity pressure - and total pressure

15. 8' round duct has a ballpark cfm of what?
Side-by-side and over-and-under
Duct with insulation on the inside
200
By increasing the surface of the condenser coil

16. When do you install a trap on a drain line?
When it is a pull-through evaporator
It also rises
Fiberglass
In series

17. What are the two basic duct connection configurations for package units supply and return air ducts?
Over/under and side by side
20 degrees F
Yes
30 degrees F

18. What are the components of a hard-start kit?
Inches of water column (in. WC)
20 degrees F
Potential relay and start capacitor
It will be high

19. How are the condenser coils different on a high-efficiency unit?
When the system is under pressure
On the common terminal
Duct - electrical - and mechanical
They are larger

20. What gauge is thermostat wire?
18 gauge
RLA/FLA x 5
20 A
Belt drive and direct drive

21. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
Belt drive and direct drive
Any amount
Side-by-side and over-and-under
Subtract ambient temperature from 100

22. What are the components of a hard-start kit?
Over 800 degrees F
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Potential relay and start capacitor
A swaging tool

23. When do you install a trap on a drain line?
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Staples and tape
40 degrees F
When it is a pull-through evaporator

24. What percentage silver do you need to use for an are-410 system?
15 A
15% silphos
Yes
A dirty evaporator

25. What tool is used to expand the diameter of soft copper tubing
A swaging tool
Shorted winding - open winding - and grounded winding
5 degrees
Inches of water column (in. WC)

26. The crankcase heater on an air-conditioning compressor is used to what?
400
Boil the liquid refrigerant out ot the oil within the crankcase
4
8-12 degrees F

27. Most duct insulation is made of what?
L-type
Nitrogen with a small amount of refrigerant
Heat load
Fiberglass

28. How do you calculate cfm?

29. What kind of copper tubing is used for plumbing and heating applications?
Suction
Nominal-sized tubing
They are larger
300

30. How will too much refrigerant effect superheat?
Nominal-sized tubing
Standard
It will be low
Over 800 degrees F

31. How do you calculate EER?
4
Duct with insulation on the inside
Btu/hr (output) / wattage (input)
Outside of the male fitting

32. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
TXV
Inclined manometer
15 A
40 degrees F

33. How is nominal-sized tubing sized?
Inside diameter (ID)
Any amount
On the common terminal
8

34. 6' round duct has a ballpark cfm of what?
S-clips and drives (cleats)
Potential relay and start capacitor
100
Positive

35. What is it called when liquid refrigerant gets into the compressor?
Heat load
40 degrees F
SEER includes the energy used in the start-up and shut-down cycles
Slugging

36. Can refrigerant line sets be altered in length?
Dehydrated with caps on each end
Btu/hr (output) / wattage (input)
Duct - electrical - and mechanical
Yes

37. What are the three crafts normally associated with an air-conditioned installation?
45 degrees F
4
Duct - electrical - and mechanical
No

38. What is lined duct?
20 A
Duct with insulation on the inside
Any amount
30 degrees F

39. The furnace size is calculated by what?
Heat loss
A swaging tool
Yes
Outside of the male fitting

40. The fan switch closes at what temperature?
Boil the liquid refrigerant out ot the oil within the crankcase
140 degrees F
Outside of the male fitting
Nominal-sized tubing

41. How is insulation around a duct rated?
Yes
SEER includes the energy used in the start-up and shut-down cycles
Inches of water column (in. WC)
With an are rating

42. If the rpm's are 750 - how many poles does the motor have?
To remove humidity and lower dry bulb temperature
It will be low
Standard
8

43. Where do you apply flux when soldering?
Outside of the male fitting
Yes
Negative
Compressor

44. What percentage silver do you need to use for an are-410 system?
Inches of water column (in. WC)
They are physically larger
400
15% silphos

45. What sort of pressure will a push-through evaporator have?
Common
Outside of the male fitting
Suction
Positive

46. How long should you leave a system off once you kill power before restarting it?
S-clips and drives (cleats)
2 minutes
Compressor
When it is a pull-through evaporator

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

48. How many amps can 12 g wire handle?
20 A
400
1/4'
100

49. What are the three major power-consuming devices on an air-conditioning system?
15% silphos
Indoor fan motor - outdoor fan motor - and the compressor
Pull a vacuum
RLA/FLA x 5

50. What is the design boiling point for most evaporator coils in residential air conditioning?
2 minutes
Inches of water column (in. WC)
40 degrees F
In series