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. How does ACR copper pipe come?
Duct with insulation on the inside
30-35 degrees above ambient
Dehydrated with caps on each end
On the common terminal

2. What is the design boiling point for most evaporator coils in residential air conditioning?
It will have a decrease in superheat
40 A
Duct with insulation on the inside
40 degrees F

3. The fan switch opens at what temperature?
8
105 degrees F
Before the vent
Nominal-sized tubing

4. How do you calculate EER?
Inclined manometer
A swaging tool
A piston type metering device
Btu/hr (output) / wattage (input)

5. How are high-efficiency condenser coils different from standard-efficiency condenser coils?
Nitrogen with a small amount of refrigerant
15% silphos
They are physically larger
Btu/hr (output) / wattage (input)

6. How many amps can 10 g wire handle?
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
100
30 A
Dehydrated with caps on each end

7. 10 SEER is classified as what kind of efficiency?
Outside of the male fitting
On the common terminal
Standard
45 degrees F

8. Do you need a trap on a push-through evaporator?
A piston type metering device
No
Over 800 degrees F
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity

9. What sort of pressure will a pull-through evaporator have?
Btu/hr (output) / wattage (input)
Heat loss
8
Negative

10. How is insulation around a duct rated?
Static pressure - velocity pressure - and total pressure
Before the vent
With an are rating
True

11. The fan switch closes at what temperature?
Pi x radius squared
140 degrees F
On the common terminal
200

12. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
When it is above a conditioned space
45-55%
RLA/FLA x 5
20 degrees F

13. How is the high pressure switch wired with the low pressure switch?
In parallel
They are physically larger
Over 800 degrees F
Yes

14. Does a package unit come from the factory pre-charged?
Yes
Nominal-sized tubing
Over 800 degrees F
Below 800 degrees F

15. Where do you install a trap on a drain line?
Below 800 degrees F
By increasing the surface of the condenser coil
Before the vent
A dirty evaporator

16. At what temperature will brazing melt?
Over 800 degrees F
False
Average feet per minute X area in square feet (H' x W'/144)
Yes

17. What is lined duct?
Before the vent
Indoor fan motor - outdoor fan motor - and the compressor
Staples and tape
Duct with insulation on the inside

18. How do you calculate the area of a circle?
Btu/hr (output) / wattage (input)
To remove humidity and lower dry bulb temperature
Yes
Pi x radius squared

19. What are the three ways a motor can fail electrically?
Shorted winding - open winding - and grounded winding
18 gauge
They are physically larger
Standard

20. What kind of refrigeratnts must be added in liquid form?
Standard
45 degrees F
Outside diameter (OD)
Blended refrigerants

21. How many amps can 14 g wire handle?
Pull a vacuum
15 A
RLA/FLA x 5
Heat loss

22. What are the three major power-consuming devices on an air-conditioning system?
Over/under and side by side
Indoor fan motor - outdoor fan motor - and the compressor
15 A
Negative

23. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
It will be high
It will have a decrease in superheat
1/4'
Indoor fan motor - outdoor fan motor - and the compressor

24. 7' round duct has a ballpark cfm of what?
In series
150
Subtract ambient temperature from 100
Heat load

25. If the rpm's are 1750 - how many poles does the motor have?
Btu/hr (output) / wattage (input)
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
With a minimum of three evenly spaced self-tapping screws
4

26. How is flexible duct supported?
Heat load
Nitrogen with a small amount of refrigerant
2 minutes
A band 4 inches or more in width

27. Can refrigerant line sets be altered in length?
It will be low
ACR (air-conditioning refrigeration) tubing
5 degrees
Yes

28. 9' round duct has a ballpark cfm of what?
300
No
Yes
Common

29. Pressure in ductwork is measured In what?
Fiberglass
L-type
Static pressure - velocity pressure - and total pressure
Inches of water column (in. WC)

30. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
Any amount
In series
Yes
45-55%

31. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
To lower the amount of pressure drop through the coil
Any amount
Yes
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity

32. Will a dirty condenser cause a rise or fall in pressure?
Inside diameter (ID)
Rise
18 gauge
True

33. What percentage silver do you need to use for an are-410 system?
15% silphos
2
200
Inclined manometer

34. What are the three pressures created by moving air in ductwork?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Static pressure - velocity pressure - and total pressure
Inside diameter (ID)
Slugging

35. What tool is used to expand the diameter of soft copper tubing
A swaging tool
200
6
Heat load

36. What are the two functions of the air-conditioning system?
To remove humidity and lower dry bulb temperature
Duct with insulation on the inside
Fiberglass
Negative

37. How long should you leave a system off once you kill power before restarting it?
18 gauge
Slugging
2 minutes
With an are rating

38. What gauge is thermostat wire?
False
The takeoff fitting
A dirty evaporator
18 gauge

39. How is insulation around a duct rated?
30 A
Staples and tape
Btu/hr (output) / wattage (input)
With an are rating

40. Where do you install a trap on a drain line?
Side-by-side and over-and-under
Before the vent
6
8

41. What are the three pressures created by moving air in ductwork?
Static pressure - velocity pressure - and total pressure
Over/under and side by side
18 gauge
A dirty evaporator

42. If the rpm's are 3450 - how many poles does the motor have?
The takeoff fitting
2
A dirty evaporator
Heat load

43. How does ACR copper pipe come?
Rise
20 degrees above ambient
Dehydrated with caps on each end
S-clips and drives (cleats)

44. What is the typical pressure differance across a TXV?
30-35 degrees above ambient
100 psig
15 A
The takeoff fitting

45. If pressure rises - what happens to the superheat?
30 A
400
Subtract ambient temperature from 100
It rises

46. How do you calculate EER?
Individual return air systems and central return air systems
Btu/hr (output) / wattage (input)
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Dehydrated with caps on each end

47. Do you need a trap on a pull-through evaporator?
Stranded
Yes
15 A
In series

48. At what temperature does refrigerant condense in a standard-efficiency unit?
Fiberglass
8-12 degrees F
30-35 degrees above ambient
To remove humidity and lower dry bulb temperature

49. How is nominal-sized tubing sized?
Inside diameter (ID)
Negative
2 minutes
With 4' saddles

50. How many amps can 12 g wire handle?
Static pressure - velocity pressure - and total pressure
100 psig
20 A
When it is above a conditioned space