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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. How do you calculate ballpark superheat?
20 A
Subtract ambient temperature from 100
100
A diffuser

2. How is the high pressure switch wired with the low pressure switch?
In parallel
The takeoff fitting
Vapor
40 degrees F

3. What is the design boiling point for most evaporator coils in residential air conditioning?
Inside diameter (ID)
TXV
40 degrees F
When it is above a conditioned space

4. What are the two functions of the air-conditioning system?
To remove humidity and lower dry bulb temperature
Staples and tape
False
Pistons

5. The load on the evaporater will effect which pressure?
No
Suction
When it is above a conditioned space
Inclined manometer

6. What is used to measure static air pressure in ducts.
Inclined manometer
When it is a pull-through evaporator
30 degrees F
400

7. Why are some ACR tubing lines insulated?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
It will be high
Static pressure - velocity pressure - and total pressure

8. Where do you check the amps on a motor?
On the common terminal
Indoor fan motor - outdoor fan motor - and the compressor
When it is a pull-through evaporator
15 A

9. At what temperature will brazing melt?
Average feet per minute X area in square feet (H' x W'/144)
Indoor fan motor - outdoor fan motor - and the compressor
Over 800 degrees F
A band 4 inches or more in width

10. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
Duct - electrical - and mechanical
True
8
With 4' saddles

11. Which is more efficient - a TXV or a fixed-orifice metering device?
It will be high
Nitrogen with a small amount of refrigerant
TXV
40 A

12. How do you achieve high-efficiency?
140 degrees F
By increasing the surface of the condenser coil
A bypass duct or a dump zone
Over 800 degrees F

13. How are round ducts connected to one another?
Side-by-side and over-and-under
Yes
Belt drive and direct drive
With a minimum of three evenly spaced self-tapping screws

14. 10' round duct has a ballpark cfm of what?
400
A bypass duct or a dump zone
200
Side-by-side and over-and-under

15. How are the high pressure switch and the low pressure switch wired with the compressor contactor?
Boil the liquid refrigerant out ot the oil within the crankcase
When the system is under pressure
150
In series

16. At what temperature will soft solder melt?
Below 800 degrees F
100
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

17. How do you calculate cfm?

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18. How is ACR tubing sized?
20 A
Outside diameter (OD)
Pull a vacuum
Static pressure - velocity pressure - and total pressure

19. How long should you leave a system off once you kill power before restarting it?
25-ft or 50-ft
Shorted winding - open winding - and grounded winding
4
2 minutes

20. What is the range for normal superheat and subcooling?
Staples and tape
20 A
It also rises
8-12 degrees F

21. Where do you apply flux when soldering?
Below 800 degrees F
Heat loss
20 degrees above ambient
Outside of the male fitting

22. In what state is the refrigerant in the compressor?
By increasing the surface of the condenser coil
It will be high
Vapor
L-type

23. 10' round duct has a ballpark cfm of what?
A dirty evaporator
400
ACR (air-conditioning refrigeration) tubing
15% silphos

24. Does a package unit come from the factory pre-charged?
20 A
150
Standard
Yes

25. How many amps can 12 g wire handle?
18 gauge
Outside diameter (OD)
Over 800 degrees F
20 A

26. What type of air conditioning system must be charged using the superheat method?
Rise
30-35 degrees above ambient
A piston type metering device
45 degrees F

27. 10 SEER is classified as what kind of efficiency?
Standard
2 minutes
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Suction

28. If the suction pressure rises - what happens to the head pressure?
Any amount
S-clips and drives (cleats)
Positive
It also rises

29. What is it called when liquid refrigerant gets into the compressor?
Outside of the male fitting
When it is a pull-through evaporator
2
Slugging

30. How do you calculate the area of a circle?
Pi x radius squared
Average feet per minute X area in square feet (H' x W'/144)
Common
15 A

31. What sort of pressure will a pull-through evaporator have?
Static pressure - velocity pressure - and total pressure
Any amount
Negative
Stranded

32. How do you calculate EER?
Btu/hr (output) / wattage (input)
Yes
To remove humidity and lower dry bulb temperature
By increasing the surface of the condenser coil

33. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
To lower the amount of pressure drop through the coil
It will have a decrease in superheat
When it is above a conditioned space
Subtract ambient temperature from 100

34. The furnace size is calculated by what?
Latent and sensible
Inside diameter (ID)
ACR (air-conditioning refrigeration) tubing
Heat loss

35. How does ACR copper pipe come?
30 degrees F
When it is a pull-through evaporator
Pistons
Dehydrated with caps on each end

36. How long should you leave a system off once you kill power before restarting it?
A dirty evaporator
2
Stranded
2 minutes

37. 8' round duct has a ballpark cfm of what?
Before the vent
Pull a vacuum
Outside of the male fitting
200

38. Where do you install a trap on a drain line?
Before the vent
It also rises
Yes
15 A

39. The evaporator is designed to remove what two types of heat?
Any amount
Over 800 degrees F
Stranded
Latent and sensible

40. What is the normal evaporator temperature?
Boil the liquid refrigerant out ot the oil within the crankcase
45 degrees F
Fiberglass
Inside diameter (ID)

41. What standard weight copper tubing is most often used in the heating and air-conditioning industry?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Compressor
A band 4 inches or more in width
L-type

42. If the rpm's are 1050 - how many poles does the motor have?
150
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
8-12 degrees F
6

43. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
Outside diameter (OD)
A bypass duct or a dump zone
SEER includes the energy used in the start-up and shut-down cycles
Yes

44. 6' round duct has a ballpark cfm of what?
100
4
105 degrees F
Vapor

45. Which type of wire can handle a higher ampacity?
Stranded
On the common terminal
Pistons
8

46. The compressor is cooled by liquid refrigerant. (True of False)
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
False
Yes
Average feet per minute X area in square feet (H' x W'/144)

47. How many amps can 14 g wire handle?
Indoor fan motor - outdoor fan motor - and the compressor
30 A
15 A
No

48. What are the three crafts normally associated with an air-conditioned installation?
Heat loss
Duct - electrical - and mechanical
TXV
High

49. What do you use to connect square and rectangular ductboard together?
Yes
A diffuser
S-clips and drives (cleats)
Staples and tape

50. The A/C size is calculated by what?
8
300
On the common terminal
Heat load