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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. If the rpm's are 3450 - how many poles does the motor have?
Individual return air systems and central return air systems
RLA/FLA x 5
Heat load
2

2. Where do you apply flux when soldering?
45 degrees F
TXV
Outside of the male fitting
To lower the amount of pressure drop through the coil

3. How is the high pressure switch wired with the low pressure switch?
40 A
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
In parallel
On the common terminal

4. What is the design boiling point for most evaporator coils in residential air conditioning?
40 degrees F
Yes
False
The suction line or the low-pressure side

5. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
Any amount
Yes
They are larger
Boil the liquid refrigerant out ot the oil within the crankcase

6. Most duct insulation is made of what?
Duct - electrical - and mechanical
Yes
Fiberglass
8

7. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
A piston type metering device
Stranded
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
True

8. The A/C size is calculated by what?
20 degrees above ambient
Heat load
It will have a decrease in superheat
A piston type metering device

9. How many amps can 10 g wire handle?
The suction line or the low-pressure side
30 A
It also rises
Average feet per minute X area in square feet (H' x W'/144)

10. If the suction pressure rises - what happens to the head pressure?
It also rises
45 degrees F
Potential relay and start capacitor
Over 800 degrees F

11. On what terminal do you check amperage?
Yes
Common
Stranded
Duct - electrical - and mechanical

12. What standard weight copper tubing is most often used in the heating and air-conditioning industry?
Yes
L-type
Yes
Nominal-sized tubing

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

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14. What are the two types of return air systems in residential installations?
Duct with insulation on the inside
Individual return air systems and central return air systems
Heat load
8

15. 10' round duct has a ballpark cfm of what?
400
45 degrees F
Over/under and side by side
True

16. A reciprocating compressor has what sort of moving parts?
5 degrees
Pistons
False
Yes

17. What kind of copper tubing is used for plumbing and heating applications?
Inside diameter (ID)
Nominal-sized tubing
15 A
Blended refrigerants

18. If the rpm's are 1050 - how many poles does the motor have?
20 degrees F
Standard
It also rises
6

19. What are the two types of blower drives?
Belt drive and direct drive
Fiberglass
A bypass duct or a dump zone
1/4'

20. When must a copper joint never be soldered or brazed?
The takeoff fitting
Subtract ambient temperature from 100
When the system is under pressure
400

21. Do you need a vent on a pull-through evaporator?
400
Inside diameter (ID)
Yes
It will be high

22. What do you use to check for leaks?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Nitrogen with a small amount of refrigerant
Yes
Outside diameter (OD)

23. What kind of refrigeratnts must be added in liquid form?
When the system is under pressure
Heat load
Indoor fan motor - outdoor fan motor - and the compressor
Blended refrigerants

24. How are the high pressure switch and the low pressure switch wired with the compressor contactor?
When it is above a conditioned space
In series
6
With 4' saddles

25. How is insulation around a duct rated?
Rise
It rises
2
With an are rating

26. How do you achieve high-efficiency?
Yes
By increasing the surface of the condenser coil
Infiltration and ventilation
High

27. Where do you check the amps on a motor?
Average feet per minute X area in square feet (H' x W'/144)
On the common terminal
When the system is under pressure
8-12 degrees F

28. 10 SEER is classified as what kind of efficiency?
A diffuser
To lower the amount of pressure drop through the coil
Compressor
Standard

29. What are the three pressures created by moving air in ductwork?
In parallel
Nitrogen with a small amount of refrigerant
Static pressure - velocity pressure - and total pressure
Pistons

30. What are the four materials used to make duct?
A diffuser
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
45 degrees F
40 degrees F

31. Which is more efficient - a TXV or a fixed-orifice metering device?
TXV
To remove humidity and lower dry bulb temperature
Below 800 degrees F
It will be low

32. What component changes refrigerant from a low pressure gas to a high pressure gas?
Pistons
The takeoff fitting
Btu/hr (output) / wattage (input)
Compressor

33. What is used to measure static air pressure in ducts.
To remove humidity and lower dry bulb temperature
20 degrees F
TXV
Inclined manometer

34. Where is insulation used on copper tubing used for air-conditioning?
150
30 A
The suction line or the low-pressure side
Common

35. How is flexible duct supported?
A band 4 inches or more in width
RLA/FLA x 5
Before the vent
A piston type metering device

36. What are the two types of return air systems in residential installations?
Stranded
Individual return air systems and central return air systems
100 psig
With a minimum of three evenly spaced self-tapping screws

37. What is the normal evaporator temperature?
Side-by-side and over-and-under
Latent and sensible
45 degrees F
150

38. What is the typical pressure differance across a TXV?
Blended refrigerants
Inclined manometer
100 psig
When the system is under pressure

39. What is the name of the fitting where the branch line leaves the duct?
30-35 degrees above ambient
The takeoff fitting
4
Staples and tape

40. What tool is used to expand the diameter of soft copper tubing
A swaging tool
In parallel
When the system is under pressure
300

41. What gauge is thermostat wire?
It will have a decrease in superheat
6
Slugging
18 gauge

42. What kind of copper tubing is used for refrigeration or air-conditioning applications?
ACR (air-conditioning refrigeration) tubing
15 A
Latent and sensible
Fiberglass

43. What is lined duct?
Duct with insulation on the inside
In parallel
With 4' saddles
The takeoff fitting

44. 10' round duct has a ballpark cfm of what?
RLA/FLA x 5
400
40 A
Rise

45. 9' round duct has a ballpark cfm of what?
105 degrees F
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Negative
300

46. What distributes supply air to a room in a structure?
Indoor fan motor - outdoor fan motor - and the compressor
A diffuser
20 A
18 gauge

47. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
They are physically larger
18 gauge
It will have a decrease in superheat
Dehydrated with caps on each end

48. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
45-55%
8-12 degrees F
12000
Negative

49. What are the two ways that fresh air enters a structure?
Suction
400
Infiltration and ventilation
200

50. How is nominal-sized tubing sized?
40 degrees F
Inside diameter (ID)
They are physically larger
12000