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. A reciprocating compressor has what sort of moving parts?
Yes
S-clips and drives (cleats)
Pistons
Individual return air systems and central return air systems

2. 13 SEER is classified as what kind of efficiency?
A bypass duct or a dump zone
Outside of the male fitting
A dirty evaporator
High

3. Where do you apply flux when soldering?
Pull a vacuum
Outside of the male fitting
18 gauge
High

4. How do you calculate LRA?
TXV
RLA/FLA x 5
Yes
200

5. What kind of copper tubing is used for plumbing and heating applications?
Heat load
The suction line or the low-pressure side
Nominal-sized tubing
The suction line or the low-pressure side

6. How is nominal-sized tubing sized?
By increasing the surface of the condenser coil
It will have a decrease in superheat
Inside diameter (ID)
Heat loss

7. If the rpm's are 1750 - how many poles does the motor have?
Btu/hr (output) / wattage (input)
30 degrees F
4
Inside diameter (ID)

8. What kind of copper tubing is used for refrigeration or air-conditioning applications?
Vapor
ACR (air-conditioning refrigeration) tubing
Outside diameter (OD)
Vapor

9. What is the typical pressure differance across a TXV?
With 4' saddles
18 gauge
45-55%
100 psig

10. At what temperature does refrigerant condense in a high-efficiency unit?
20 degrees F
Indoor fan motor - outdoor fan motor - and the compressor
TXV
20 degrees above ambient

11. Do you need a trap on a push-through evaporator?
No
A piston type metering device
100 psig
Compressor

12. What is it called when liquid refrigerant gets into the compressor?
Slugging
18 gauge
With a minimum of three evenly spaced self-tapping screws
100 psig

13. What is the difference between SEER and EER?
SEER includes the energy used in the start-up and shut-down cycles
It rises
40 A
105 degrees F

14. How many cfm per ton?
Nominal-sized tubing
Compressor
20 degrees F
400

15. What is the normal evaporator temperature?
45 degrees F
By increasing the surface of the condenser coil
Nominal-sized tubing
Pull a vacuum

16. What standard weight copper tubing is most often used in the heating and air-conditioning industry?
L-type
8-12 degrees F
The suction line or the low-pressure side
30-35 degrees above ambient

17. What is the typical temperature difference between a standard-efficiency condenser and the ambient temperature?
18 gauge
It will have a decrease in superheat
A piston type metering device
30 degrees F

18. How are the condenser coils different on a high-efficiency unit?
Latent and sensible
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
They are larger
95 degrees F outside - 80 degrees F inside - and 50% relative humidity

19. How do you calculate LRA?
RLA/FLA x 5
Stranded
They are physically larger
It will be high

20. When must a copper joint never be soldered or brazed?
When the system is under pressure
They are physically larger
200
By increasing the surface of the condenser coil

21. The crankcase heater on an air-conditioning compressor is used to what?
30 degrees F
Boil the liquid refrigerant out ot the oil within the crankcase
Subtract ambient temperature from 100
Pistons

22. A reciprocating compressor has what sort of moving parts?
Pistons
TXV
In parallel
Pi x radius squared

23. How many amps can 8 g wire handle?
40 A
Yes
It will be low
Subtract ambient temperature from 100

24. In what length rolls is soft copper tubing normally available?
40 A
Vapor
25-ft or 50-ft
Potential relay and start capacitor

25. In what length rolls is soft copper tubing normally available?
TXV
25-ft or 50-ft
45 degrees F
Yes

26. Can refrigerant line sets be altered in length?
To lower the amount of pressure drop through the coil
Pi x radius squared
Yes
Before the vent

27. How will too much refrigerant effect subcooling?
Duct with insulation on the inside
It will be high
40 degrees F
Stranded

28. What is the name of the fitting where the branch line leaves the duct?
When the system is under pressure
The takeoff fitting
30 degrees F
It will be low

29. How do you calculate the area of a circle?
Pi x radius squared
In series
400
Latent and sensible

30. What type of air conditioning system must be charged using the superheat method?
Outside diameter (OD)
Heat load
A piston type metering device
Subtract ambient temperature from 100

31. Superheat should never be below how many degrees
RLA/FLA x 5
L-type
Yes
5 degrees

32. Most duct insulation is made of what?
Fiberglass
Yes
Latent and sensible
150

33. 10 SEER is classified as what kind of efficiency?
1/4'
A diffuser
Common
Standard

34. Where is insulation used on copper tubing used for air-conditioning?
They are physically larger
Outside diameter (OD)
The suction line or the low-pressure side
Boil the liquid refrigerant out ot the oil within the crankcase

35. How do you achieve high-efficiency?
20 A
By increasing the surface of the condenser coil
A band 4 inches or more in width
A diffuser

36. What are the two basic duct connection configurations for package units supply and return air ducts?
Over/under and side by side
Common
In parallel
L-type

37. Pressure in ductwork is measured In what?
25-ft or 50-ft
Outside of the male fitting
Inches of water column (in. WC)
30 degrees F

38. At what temperature does refrigerant condense in a standard-efficiency unit?
Over 800 degrees F
30-35 degrees above ambient
8
8

39. What do you do after you braze a system?
15 A
Pull a vacuum
25-ft or 50-ft
20 A

40. What is used to measure static air pressure in ducts.
Inclined manometer
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
40 degrees F
False

41. The fan switch opens at what temperature?
With a minimum of three evenly spaced self-tapping screws
20 degrees F
Dehydrated with caps on each end
105 degrees F

42. What are the two functions of the air-conditioning system?
A dirty evaporator
Compressor
To remove humidity and lower dry bulb temperature
Vapor

43. What are the three pressures created by moving air in ductwork?
20 degrees above ambient
Negative
Static pressure - velocity pressure - and total pressure
Positive

44. What are the two types of return air systems in residential installations?
ACR (air-conditioning refrigeration) tubing
They are physically larger
Individual return air systems and central return air systems
Yes

45. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
Infiltration and ventilation
It will have a decrease in superheat
To lower the amount of pressure drop through the coil
200

46. How do you achieve high-efficiency?
Indoor fan motor - outdoor fan motor - and the compressor
Staples and tape
Compressor
By increasing the surface of the condenser coil

47. What are the two types of package units?
When it is a pull-through evaporator
A piston type metering device
Outside of the male fitting
Side-by-side and over-and-under

48. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
Btu/hr (output) / wattage (input)
15 A
Heat loss
True

49. What are the three pressures created by moving air in ductwork?
Positive
Potential relay and start capacitor
Static pressure - velocity pressure - and total pressure
25-ft or 50-ft

50. What are the two types of blower drives?
25-ft or 50-ft
Compressor
Vapor
Belt drive and direct drive