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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. In what length rolls is soft copper tubing normally available?
Yes
Below 800 degrees F
S-clips and drives (cleats)
25-ft or 50-ft

2. 8' round duct has a ballpark cfm of what?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
200
Btu/hr (output) / wattage (input)
Yes

3. When do you install a trap on a drain line?
150
Yes
No
When it is a pull-through evaporator

4. What sort of pressure will a push-through evaporator have?
Pull a vacuum
Inside diameter (ID)
Individual return air systems and central return air systems
Positive

5. Do you need a vent on a push-through evaporator?
150
To lower the amount of pressure drop through the coil
Yes
Belt drive and direct drive

6. What do you use to connect square and rectangular ductboard together?
Pull a vacuum
Static pressure - velocity pressure - and total pressure
S-clips and drives (cleats)
2

7. Do you need a trap on a pull-through evaporator?
Shorted winding - open winding - and grounded winding
30 degrees F
To lower the amount of pressure drop through the coil
Yes

8. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
A bypass duct or a dump zone
100
Slugging
Nitrogen with a small amount of refrigerant

9. The crankcase heater on an air-conditioning compressor is used to what?
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
Inclined manometer
Boil the liquid refrigerant out ot the oil within the crankcase
Below 800 degrees F

10. What tool is used to expand the diameter of soft copper tubing
300
Before the vent
With a minimum of three evenly spaced self-tapping screws
A swaging tool

11. How are high-efficiency condenser coils different from standard-efficiency condenser coils?
25-ft or 50-ft
A swaging tool
They are physically larger
Slugging

12. What is the design boiling point for most evaporator coils in residential air conditioning?
20 degrees above ambient
4
Any amount
40 degrees F

13. How are the high pressure switch and the low pressure switch wired with the compressor contactor?
150
Dehydrated with caps on each end
In series
When the system is under pressure

14. How many amps can 10 g wire handle?
Over/under and side by side
Rise
ACR (air-conditioning refrigeration) tubing
30 A

15. What is the name of the fitting where the branch line leaves the duct?
Shorted winding - open winding - and grounded winding
20 degrees F
When it is a pull-through evaporator
The takeoff fitting

16. Most duct insulation is made of what?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Yes
Fiberglass
The suction line or the low-pressure side

17. How are the condenser coils different on a high-efficiency unit?
40 degrees F
Outside diameter (OD)
A bypass duct or a dump zone
They are larger

18. In what length rolls is soft copper tubing normally available?
Duct - electrical - and mechanical
Rise
Static pressure - velocity pressure - and total pressure
25-ft or 50-ft

19. 7' round duct has a ballpark cfm of what?
Average feet per minute X area in square feet (H' x W'/144)
150
Btu/hr (output) / wattage (input)
Inches of water column (in. WC)

20. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
25-ft or 50-ft
Standard
To lower the amount of pressure drop through the coil
400

21. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
2 minutes
45-55%
Over 800 degrees F
30-35 degrees above ambient

22. The fan switch opens at what temperature?
ACR (air-conditioning refrigeration) tubing
Indoor fan motor - outdoor fan motor - and the compressor
105 degrees F
A bypass duct or a dump zone

23. 10' round duct has a ballpark cfm of what?
400
4
They are larger
30 A

24. What are the two types of package units?
TXV
Stranded
Pistons
Side-by-side and over-and-under

25. 6' round duct has a ballpark cfm of what?
100
105 degrees F
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Yes

26. Which is more efficient - a TXV or a fixed-orifice metering device?
300
TXV
Positive
40 A

27. How are the condenser coils different on a high-efficiency unit?
To remove humidity and lower dry bulb temperature
40 degrees F
The suction line or the low-pressure side
They are larger

28. 10 SEER is classified as what kind of efficiency?
Standard
With an are rating
True
A band 4 inches or more in width

29. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
Common
Latent and sensible
6
It will have a decrease in superheat

30. Will a dirty condenser cause a rise or fall in pressure?
Rise
Duct - electrical - and mechanical
1/4'
105 degrees F

31. 8' round duct has a ballpark cfm of what?
Subtract ambient temperature from 100
A swaging tool
200
Latent and sensible

32. What standard weight copper tubing is most often used in the heating and air-conditioning industry?
L-type
1/4'
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
150

33. What is the normal evaporator temperature?
Suction
Over 800 degrees F
45 degrees F
It will have a decrease in superheat

34. How many amps can 8 g wire handle?
40 degrees F
40 A
A dirty evaporator
A swaging tool

35. What is the normal evaporator temperature?
True
45 degrees F
Indoor fan motor - outdoor fan motor - and the compressor
4

36. What percentage silver do you need to use for an are-410 system?
1/4'
15% silphos
Compressor
Average feet per minute X area in square feet (H' x W'/144)

37. What is it called when liquid refrigerant gets into the compressor?
Yes
Slugging
30 A
TXV

38. What kind of copper tubing is used for refrigeration or air-conditioning applications?
Outside of the male fitting
Duct - electrical - and mechanical
8
ACR (air-conditioning refrigeration) tubing

39. When do you install an auxillary drain pan?
4
TXV
When the system is under pressure
When it is above a conditioned space

40. How do you achieve high-efficiency?
The suction line or the low-pressure side
By increasing the surface of the condenser coil
Pi x radius squared
It will be low

41. What are the two types of blower drives?
Belt drive and direct drive
2
Individual return air systems and central return air systems
It will be low

42. What gauge is thermostat wire?
Positive
L-type
18 gauge
RLA/FLA x 5

43. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
It will have a decrease in superheat
Static pressure - velocity pressure - and total pressure
Indoor fan motor - outdoor fan motor - and the compressor
When it is a pull-through evaporator

44. Will a dirty condenser cause a rise or fall in pressure?
SEER includes the energy used in the start-up and shut-down cycles
Rise
Yes
When it is a pull-through evaporator

45. Superheat should never be below how many degrees
1/4'
Shorted winding - open winding - and grounded winding
5 degrees
In series

46. How long should you leave a system off once you kill power before restarting it?
Pull a vacuum
2 minutes
Standard
Duct with insulation on the inside

47. What sort of pressure will a pull-through evaporator have?
Fiberglass
Heat load
Negative
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity

48. The compressor is cooled by liquid refrigerant. (True of False)
It will be low
False
A band 4 inches or more in width
RLA/FLA x 5

49. How do you calculate cfm?

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50. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
2
1/4'
Any amount
30 degrees F