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. Will a dirty condenser cause a rise or fall in pressure?
Rise
Belt drive and direct drive
Heat load
Inside diameter (ID)

2. How are round ducts connected to one another?
It rises
With a minimum of three evenly spaced self-tapping screws
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
40 A

3. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
Nominal-sized tubing
Potential relay and start capacitor
30-35 degrees above ambient
A bypass duct or a dump zone

4. What distributes supply air to a room in a structure?
With an are rating
A band 4 inches or more in width
A diffuser
To lower the amount of pressure drop through the coil

5. How is ACR tubing sized?
105 degrees F
A bypass duct or a dump zone
Outside diameter (OD)
Inches of water column (in. WC)

6. What are the three crafts normally associated with an air-conditioned installation?
Duct - electrical - and mechanical
Inclined manometer
When the system is under pressure
No

7. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
Boil the liquid refrigerant out ot the oil within the crankcase
Duct with insulation on the inside
No
Any amount

8. Which type of wire can handle a higher ampacity?
Stranded
Latent and sensible
105 degrees F
45 degrees F

9. What sort of pressure will a pull-through evaporator have?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Negative
Yes
It will be low

10. Superheat should never be below how many degrees
Belt drive and direct drive
5 degrees
2 minutes
Inside diameter (ID)

11. How does ACR copper pipe come?
105 degrees F
RLA/FLA x 5
8-12 degrees F
Dehydrated with caps on each end

12. What is it called when liquid refrigerant gets into the compressor?
40 degrees F
Belt drive and direct drive
20 A
Slugging

13. A reciprocating compressor has what sort of moving parts?
Pistons
When it is above a conditioned space
Common
When the system is under pressure

14. What is considered normal operating conditions?
150
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Outside of the male fitting

15. What kind of refrigeratnts must be added in liquid form?
Common
Standard
Blended refrigerants
Below 800 degrees F

16. In what state is the refrigerant in the compressor?
TXV
Vapor
The suction line or the low-pressure side
A swaging tool

17. The compressor is cooled by liquid refrigerant. (True of False)
Boil the liquid refrigerant out ot the oil within the crankcase
Over 800 degrees F
False
In parallel

18. How are high-efficiency condenser coils different from standard-efficiency condenser coils?
It will be high
They are physically larger
In parallel
ACR (air-conditioning refrigeration) tubing

19. If pressure rises - what happens to the superheat?
It rises
Inclined manometer
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
S-clips and drives (cleats)

20. What do you use to check for leaks?
Nitrogen with a small amount of refrigerant
18 gauge
5 degrees
Inclined manometer

21. The crankcase heater on an air-conditioning compressor is used to what?
Boil the liquid refrigerant out ot the oil within the crankcase
They are larger
Over/under and side by side
8-12 degrees F

22. How long should you leave a system off once you kill power before restarting it?
SEER includes the energy used in the start-up and shut-down cycles
It will have a decrease in superheat
A dirty evaporator
2 minutes

23. The A/C size is calculated by what?
Heat load
The takeoff fitting
Vapor
Dehydrated with caps on each end

24. Why are some ACR tubing lines insulated?
Yes
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
The suction line or the low-pressure side
Standard

25. 6' round duct has a ballpark cfm of what?
Individual return air systems and central return air systems
15% silphos
150
100

26. At what temperature does refrigerant condense in a high-efficiency unit?
20 degrees above ambient
Potential relay and start capacitor
105 degrees F
High

27. How many amps can 10 g wire handle?
100 psig
Indoor fan motor - outdoor fan motor - and the compressor
On the common terminal
30 A

28. What is a package unit?
A piston type metering device
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Rise
Outside of the male fitting

29. 10' round duct has a ballpark cfm of what?
Inclined manometer
400
40 degrees F
Indoor fan motor - outdoor fan motor - and the compressor

30. What kind of metering device do high-efficiency units usually use?
When it is above a conditioned space
15% silphos
TXV
Staples and tape

31. How is insulation around a duct rated?
ACR (air-conditioning refrigeration) tubing
With an are rating
Stranded
Negative

32. How many cfm per ton?
400
Boil the liquid refrigerant out ot the oil within the crankcase
30-35 degrees above ambient
Infiltration and ventilation

33. Which is more efficient - a TXV or a fixed-orifice metering device?
TXV
A diffuser
The suction line or the low-pressure side
Vapor

34. How is ACR tubing sized?
Nominal-sized tubing
Outside diameter (OD)
Nitrogen with a small amount of refrigerant
Vapor

35. How do you calculate LRA?
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Outside diameter (OD)
RLA/FLA x 5
It rises

36. What tool is used to expand the diameter of soft copper tubing
Average feet per minute X area in square feet (H' x W'/144)
Belt drive and direct drive
A swaging tool
Stranded

37. What is the typical temperature difference between a high-efficiency condenser and the ambient temperature?
On the common terminal
4
S-clips and drives (cleats)
20 degrees F

38. What is the difference between SEER and EER?
Fiberglass
A band 4 inches or more in width
SEER includes the energy used in the start-up and shut-down cycles
By increasing the surface of the condenser coil

39. Which type of wire can handle a higher ampacity?
Individual return air systems and central return air systems
SEER includes the energy used in the start-up and shut-down cycles
Stranded
Belt drive and direct drive

40. At what temperature does refrigerant condense in a high-efficiency unit?
20 degrees above ambient
A swaging tool
To lower the amount of pressure drop through the coil
When it is above a conditioned space

41. What are the two functions of the air-conditioning system?
20 A
Standard
To remove humidity and lower dry bulb temperature
100

42. What is the range for normal superheat and subcooling?
Latent and sensible
8
8-12 degrees F
Individual return air systems and central return air systems

43. Can refrigerant line sets be altered in length?
Compressor
30 degrees F
Yes
5 degrees

44. The load on the evaporater will effect which pressure?
Suction
Potential relay and start capacitor
Any amount
On the common terminal

45. What are the three ways a motor can fail electrically?
Inclined manometer
Slugging
Blended refrigerants
Shorted winding - open winding - and grounded winding

46. When do you install a trap on a drain line?
When it is a pull-through evaporator
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
When it is above a conditioned space
Outside of the male fitting

47. What are the two functions of the air-conditioning system?
6
Individual return air systems and central return air systems
To remove humidity and lower dry bulb temperature
5 degrees

48. At what temperature will brazing melt?
Over 800 degrees F
It will have a decrease in superheat
Outside diameter (OD)
It will be low

49. Where do you check the amps on a motor?
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Nominal-sized tubing
RLA/FLA x 5
On the common terminal

50. The compressor is cooled by liquid refrigerant. (True of False)
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
False
The suction line or the low-pressure side
The suction line or the low-pressure side