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. In what length rolls is soft copper tubing normally available?
Average feet per minute X area in square feet (H' x W'/144)
Duct - electrical - and mechanical
25-ft or 50-ft
It rises

2. At what temperature will soft solder melt?
Below 800 degrees F
Yes
4
200

3. What is the typical temperature difference between a high-efficiency condenser and the ambient temperature?
45-55%
On the common terminal
Vapor
20 degrees F

4. At what temperature does refrigerant condense in a high-efficiency unit?
Positive
Inside diameter (ID)
20 degrees above ambient
Duct - electrical - and mechanical

5. If pressure rises - what happens to the superheat?
Yes
TXV
Duct with insulation on the inside
It rises

6. How will too much refrigerant effect superheat?
15% silphos
L-type
A piston type metering device
It will be low

7. What are the two functions of the air-conditioning system?
To remove humidity and lower dry bulb temperature
With an are rating
To lower the amount of pressure drop through the coil
Btu/hr (output) / wattage (input)

8. What is the design boiling point for most evaporator coils in residential air conditioning?
40 degrees F
Stranded
Pull a vacuum
High

9. What are the four materials used to make duct?
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
True
Negative
Inches of water column (in. WC)

10. What sort of pressure will a push-through evaporator have?
100 psig
400
Positive
Stranded

11. 7' round duct has a ballpark cfm of what?
150
It will have a decrease in superheat
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
When it is above a conditioned space

12. Does a package unit come from the factory pre-charged?
Yes
Over 800 degrees F
Potential relay and start capacitor
Pistons

13. Where do you apply flux when soldering?
Pistons
ACR (air-conditioning refrigeration) tubing
Stranded
Outside of the male fitting

14. 10' round duct has a ballpark cfm of what?
400
It will be high
45 degrees F
A diffuser

15. What is the difference between SEER and EER?
Btu/hr (output) / wattage (input)
SEER includes the energy used in the start-up and shut-down cycles
Yes
30-35 degrees above ambient

16. What component changes refrigerant from a low pressure gas to a high pressure gas?
The suction line or the low-pressure side
Compressor
Blended refrigerants
6

17. Do you need a vent on a push-through evaporator?
Heat load
TXV
Yes
Duct with insulation on the inside

18. Where is insulation used on copper tubing used for air-conditioning?
The suction line or the low-pressure side
By increasing the surface of the condenser coil
30 A
Side-by-side and over-and-under

19. If the rpm's are 750 - how many poles does the motor have?
4
8
They are physically larger
S-clips and drives (cleats)

20. When do you install a trap on a drain line?
Negative
Outside of the male fitting
Positive
When it is a pull-through evaporator

21. What are the three pressures created by moving air in ductwork?
20 degrees above ambient
Static pressure - velocity pressure - and total pressure
40 A
Individual return air systems and central return air systems

22. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
Any amount
Suction
On the common terminal
Heat load

23. How many BTU's per ton?
The suction line or the low-pressure side
Pi x radius squared
Dehydrated with caps on each end
12000

24. Where do you install a trap on a drain line?
5 degrees
Common
Before the vent
Over 800 degrees F

25. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
True
S-clips and drives (cleats)
Infiltration and ventilation
Btu/hr (output) / wattage (input)

26. What is the typical pressure differance across a TXV?
A diffuser
Negative
100 psig
Blended refrigerants

27. What do you use to connect square and rectangular ductboard together?
2 minutes
S-clips and drives (cleats)
Pistons
Infiltration and ventilation

28. What component changes refrigerant from a low pressure gas to a high pressure gas?
They are larger
100 psig
Suction
Compressor

29. The fan switch closes at what temperature?
Infiltration and ventilation
140 degrees F
When it is above a conditioned space
S-clips and drives (cleats)

30. How many amps can 12 g wire handle?
8-12 degrees F
It rises
300
20 A

31. A reciprocating compressor has what sort of moving parts?
Pistons
Over 800 degrees F
Indoor fan motor - outdoor fan motor - and the compressor
Nitrogen with a small amount of refrigerant

32. The compressor is cooled by liquid refrigerant. (True of False)
Pi x radius squared
False
20 degrees F
Vapor

33. How many amps can 14 g wire handle?
15 A
Staples and tape
A dirty evaporator
300

34. What are the three major power-consuming devices on an air-conditioning system?
Heat load
Latent and sensible
300
Indoor fan motor - outdoor fan motor - and the compressor

35. Can refrigerant line sets be altered in length?
Yes
It rises
Yes
They are physically larger

36. How many cfm per ton?
400
Infiltration and ventilation
Vapor
Individual return air systems and central return air systems

37. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
40 degrees F
45 degrees F
Infiltration and ventilation
S-clips and drives (cleats)

38. At what temperature will brazing melt?
20 A
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Over 800 degrees F
15% silphos

39. What are normal conditions - as defined by the ARI.
It rises
100 psig
SEER includes the energy used in the start-up and shut-down cycles
95 degrees F outside - 80 degrees F inside - and 50% relative humidity

40. What kind of copper tubing is used for refrigeration or air-conditioning applications?
Over 800 degrees F
ACR (air-conditioning refrigeration) tubing
TXV
RLA/FLA x 5

41. What is lined duct?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Indoor fan motor - outdoor fan motor - and the compressor
Below 800 degrees F
Duct with insulation on the inside

42. What are the two basic duct connection configurations for package units supply and return air ducts?
30 A
Average feet per minute X area in square feet (H' x W'/144)
ACR (air-conditioning refrigeration) tubing
Over/under and side by side

43. How many amps can 12 g wire handle?
TXV
20 A
Yes
Suction

44. If the rpm's are 1750 - how many poles does the motor have?
300
4
True
140 degrees F

45. The fan switch opens at what temperature?
Nitrogen with a small amount of refrigerant
20 degrees F
100
105 degrees F

46. At what temperature will brazing melt?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
18 gauge
140 degrees F
Over 800 degrees F

47. What kind of refrigeratnts must be added in liquid form?
It also rises
Shorted winding - open winding - and grounded winding
It will be high
Blended refrigerants

48. At what temperature does refrigerant condense in a high-efficiency unit?
15% silphos
20 degrees above ambient
Negative
Nominal-sized tubing

49. How is insulation around a duct rated?
Shorted winding - open winding - and grounded winding
With an are rating
With a minimum of three evenly spaced self-tapping screws
Heat load

50. Where do you install a trap on a drain line?
Nominal-sized tubing
400
Yes
Before the vent