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. What are the four materials used to make duct?
150
On the common terminal
The suction line or the low-pressure side
Sheet metal - galvanized sheet metal - fiberglass - and flexduct

2. If pressure rises - what happens to the superheat?
With 4' saddles
It rises
Fiberglass
Yes

3. What is the typical temperature difference between a high-efficiency condenser and the ambient temperature?
20 degrees F
Slugging
8
Shorted winding - open winding - and grounded winding

4. What percentage silver do you need to use for an are-410 system?
Static pressure - velocity pressure - and total pressure
It also rises
30-35 degrees above ambient
15% silphos

5. How do you achieve high-efficiency?
Fiberglass
By increasing the surface of the condenser coil
The suction line or the low-pressure side
8

6. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
Over 800 degrees F
To lower the amount of pressure drop through the coil
Stranded
Sheet metal - galvanized sheet metal - fiberglass - and flexduct

7. What is lined duct?
Duct with insulation on the inside
Side-by-side and over-and-under
40 degrees F
30 A

8. What kind of metering device do high-efficiency units usually use?
To lower the amount of pressure drop through the coil
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
TXV

9. Can refrigerant line sets be altered in length?
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Yes
Standard
Vapor

10. How are the high pressure switch and the low pressure switch wired with the compressor contactor?
On the common terminal
In series
Nitrogen with a small amount of refrigerant
40 degrees F

11. How many amps can 10 g wire handle?
100 psig
30-35 degrees above ambient
150
30 A

12. 7' round duct has a ballpark cfm of what?
20 degrees F
200
The takeoff fitting
150

13. Where do you apply flux when soldering?
Fiberglass
It will have a decrease in superheat
Heat load
Outside of the male fitting

14. 6' round duct has a ballpark cfm of what?
Pistons
Compressor
Rise
100

15. 10' round duct has a ballpark cfm of what?
400
ACR (air-conditioning refrigeration) tubing
Inches of water column (in. WC)
30 degrees F

16. What are the two basic duct connection configurations for package units supply and return air ducts?
400
20 degrees above ambient
Over/under and side by side
30 A

17. Where is insulation used on copper tubing used for air-conditioning?
Infiltration and ventilation
20 A
The suction line or the low-pressure side
Pull a vacuum

18. What tool is used to expand the diameter of soft copper tubing
Shorted winding - open winding - and grounded winding
A swaging tool
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
TXV

19. How is flexible duct supported?
Stranded
A band 4 inches or more in width
A diffuser
Subtract ambient temperature from 100

20. When do you install an auxillary drain pan?
A dirty evaporator
When it is above a conditioned space
Infiltration and ventilation
TXV

21. What sort of pressure will a push-through evaporator have?
Boil the liquid refrigerant out ot the oil within the crankcase
100 psig
Positive
On the common terminal

22. 8' round duct has a ballpark cfm of what?
Before the vent
False
200
In parallel

23. What standard weight copper tubing is most often used in the heating and air-conditioning industry?
300
L-type
Btu/hr (output) / wattage (input)
Yes

24. If the rpm's are 1750 - how many poles does the motor have?
15% silphos
30-35 degrees above ambient
4
300

25. The compressor is cooled by liquid refrigerant. (True of False)
Heat loss
False
The suction line or the low-pressure side
Vapor

26. What do you use to check for leaks?
Potential relay and start capacitor
False
True
Nitrogen with a small amount of refrigerant

27. What is the range for normal superheat and subcooling?
A swaging tool
45-55%
8-12 degrees F
Yes

28. How is ACR tubing sized?
Outside diameter (OD)
Individual return air systems and central return air systems
A diffuser
Yes

29. At what temperature does refrigerant condense in a standard-efficiency unit?
400
5 degrees
Infiltration and ventilation
30-35 degrees above ambient

30. Does a package unit come from the factory pre-charged?
Yes
2
200
140 degrees F

31. How are round ducts connected to one another?
Nominal-sized tubing
In parallel
Slugging
With a minimum of three evenly spaced self-tapping screws

32. If the rpm's are 1050 - how many poles does the motor have?
6
Blended refrigerants
Infiltration and ventilation
In parallel

33. How will too much refrigerant effect subcooling?
Yes
Dehydrated with caps on each end
Inches of water column (in. WC)
It will be high

34. How many amps can 14 g wire handle?
100 psig
30 degrees F
Belt drive and direct drive
15 A

35. What are the two types of return air systems in residential installations?
Individual return air systems and central return air systems
Latent and sensible
It also rises
A diffuser

36. How many cfm per ton?
It will be high
400
5 degrees
Compressor

37. Do you need a vent on a pull-through evaporator?
Yes
Nominal-sized tubing
30-35 degrees above ambient
S-clips and drives (cleats)

38. Which is more efficient - a TXV or a fixed-orifice metering device?
Outside of the male fitting
TXV
Pull a vacuum
Sheet metal - galvanized sheet metal - fiberglass - and flexduct

39. What is a package unit?
150
On the common terminal
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
100 psig

40. What is used to measure static air pressure in ducts.
15 A
Inclined manometer
Inside diameter (ID)
With a minimum of three evenly spaced self-tapping screws

41. What is used to measure static air pressure in ducts.
Yes
Stranded
40 degrees F
Inclined manometer

42. How do you calculate EER?
Btu/hr (output) / wattage (input)
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
8-12 degrees F
SEER includes the energy used in the start-up and shut-down cycles

43. What sort of pressure will a push-through evaporator have?
They are physically larger
100
Positive
They are physically larger

44. What are the two types of return air systems in residential installations?
Individual return air systems and central return air systems
Heat load
A band 4 inches or more in width
20 A

45. 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 be low
140 degrees F
15% silphos

46. On what terminal do you check amperage?
Common
Negative
Staples and tape
Btu/hr (output) / wattage (input)

47. At what temperature will soft solder melt?
Duct - electrical - and mechanical
Inside diameter (ID)
Below 800 degrees F
12000

48. How is the high pressure switch wired with the low pressure switch?
In parallel
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
When the system is under pressure
2 minutes

49. Do you need a trap on a push-through evaporator?
Positive
No
A band 4 inches or more in width
High

50. What are the two ways that fresh air enters a structure?
Heat load
It will be low
Compressor
Infiltration and ventilation