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. When must a copper joint never be soldered or brazed?
High
SEER includes the energy used in the start-up and shut-down cycles
30 degrees F
When the system is under pressure

2. If the rpm's are 1750 - how many poles does the motor have?
A piston type metering device
300
400
4

3. At what temperature will brazing melt?
105 degrees F
40 A
Over 800 degrees F
False

4. What are the four materials used to make duct?
Average feet per minute X area in square feet (H' x W'/144)
Yes
No
Sheet metal - galvanized sheet metal - fiberglass - and flexduct

5. How is the high pressure switch wired with the low pressure switch?
Yes
In parallel
300
Blended refrigerants

6. When must a copper joint never be soldered or brazed?
In parallel
Yes
When the system is under pressure
In series

7. What is it called when liquid refrigerant gets into the compressor?
300
Slugging
4
15% silphos

8. If the rpm's are 750 - how many poles does the motor have?
Staples and tape
8
200
It rises

9. Do you need a vent on a pull-through evaporator?
They are physically larger
Infiltration and ventilation
In parallel
Yes

10. Where do you apply flux when soldering?
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
S-clips and drives (cleats)
Outside of the male fitting
100

11. What is the typical temperature difference between a standard-efficiency condenser and the ambient temperature?
RLA/FLA x 5
A bypass duct or a dump zone
30 degrees F
It will have a decrease in superheat

12. What is the design boiling point for most evaporator coils in residential air conditioning?
The suction line or the low-pressure side
Heat load
Btu/hr (output) / wattage (input)
40 degrees F

13. Where is insulation used on copper tubing used for air-conditioning?
The suction line or the low-pressure side
12000
Individual return air systems and central return air systems
In series

14. What are the two types of return air systems in residential installations?
Yes
Negative
Individual return air systems and central return air systems
It will have a decrease in superheat

15. How do you achieve high-efficiency?
To lower the amount of pressure drop through the coil
Compressor
By increasing the surface of the condenser coil
Pi x radius squared

16. 7' round duct has a ballpark cfm of what?
Stranded
They are physically larger
150
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity

17. 10' round duct has a ballpark cfm of what?
TXV
45-55%
With an are rating
400

18. How long should you leave a system off once you kill power before restarting it?
Yes
2 minutes
Standard
Duct - electrical - and mechanical

19. How do you calculate EER?
Boil the liquid refrigerant out ot the oil within the crankcase
150
Btu/hr (output) / wattage (input)
A band 4 inches or more in width

20. Why are some ACR tubing lines insulated?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
6
Belt drive and direct drive
Yes

21. In what length rolls is soft copper tubing normally available?
25-ft or 50-ft
With 4' saddles
To lower the amount of pressure drop through the coil
L-type

22. The furnace size is calculated by what?
Inside diameter (ID)
18 gauge
Heat loss
L-type

23. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
Duct with insulation on the inside
Inclined manometer
Nominal-sized tubing
40 degrees F

24. 9' round duct has a ballpark cfm of what?
To lower the amount of pressure drop through the coil
300
12000
High

25. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
8
Belt drive and direct drive
To lower the amount of pressure drop through the coil
A piston type metering device

26. What is the typical temperature difference between a high-efficiency condenser and the ambient temperature?
RLA/FLA x 5
40 degrees F
20 degrees F
Standard

27. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
Yes
12000
True
It will be high

28. What kind of copper tubing is used for plumbing and heating applications?
Static pressure - velocity pressure - and total pressure
Nominal-sized tubing
25-ft or 50-ft
A swaging tool

29. At what temperature does refrigerant condense in a high-efficiency unit?
12000
20 degrees above ambient
300
The takeoff fitting

30. When do you install an auxillary drain pan?
A bypass duct or a dump zone
When it is above a conditioned space
20 A
95 degrees F outside - 80 degrees F inside - and 50% relative humidity

31. A reciprocating compressor has what sort of moving parts?
A swaging tool
Pistons
Yes
To remove humidity and lower dry bulb temperature

32. 8' round duct has a ballpark cfm of what?
200
A diffuser
By increasing the surface of the condenser coil
Shorted winding - open winding - and grounded winding

33. How is the high pressure switch wired with the low pressure switch?
Btu/hr (output) / wattage (input)
Pi x radius squared
In parallel
Duct - electrical - and mechanical

34. In what length rolls is soft copper tubing normally available?
25-ft or 50-ft
Boil the liquid refrigerant out ot the oil within the crankcase
Over/under and side by side
Heat loss

35. What do you use to connect square and rectangular ductboard together?
12000
18 gauge
SEER includes the energy used in the start-up and shut-down cycles
S-clips and drives (cleats)

36. What do you do after you braze a system?
S-clips and drives (cleats)
Staples and tape
Pull a vacuum
40 A

37. What sort of pressure will a pull-through evaporator have?
Belt drive and direct drive
A dirty evaporator
Negative
Indoor fan motor - outdoor fan motor - and the compressor

38. If the rpm's are 1750 - how many poles does the motor have?
4
15 A
Yes
Slugging

39. What type of air conditioning system must be charged using the superheat method?
Average feet per minute X area in square feet (H' x W'/144)
Over 800 degrees F
A piston type metering device
400

40. What are the two ways that fresh air enters a structure?
With an are rating
RLA/FLA x 5
Infiltration and ventilation
150

41. What are the two basic duct connection configurations for package units supply and return air ducts?
Over/under and side by side
200
Inches of water column (in. WC)
The takeoff fitting

42. What sort of pressure will a push-through evaporator have?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
30-35 degrees above ambient
30 A
Positive

43. What is the range for normal superheat and subcooling?
Dehydrated with caps on each end
8-12 degrees F
6
Rise

44. What are the three crafts normally associated with an air-conditioned installation?
When it is above a conditioned space
TXV
Over 800 degrees F
Duct - electrical - and mechanical

45. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
L-type
To lower the amount of pressure drop through the coil
Inclined manometer
Any amount

46. What gauge is thermostat wire?
18 gauge
SEER includes the energy used in the start-up and shut-down cycles
100
With an are rating

47. The compressor is cooled by liquid refrigerant. (True of False)
On the common terminal
False
400
Average feet per minute X area in square feet (H' x W'/144)

48. Why are some ACR tubing lines insulated?
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
L-type
When it is a pull-through evaporator
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line

49. What is the name of the fitting where the branch line leaves the duct?
200
A piston type metering device
The takeoff fitting
Static pressure - velocity pressure - and total pressure

50. On what terminal do you check amperage?
20 degrees F
It will have a decrease in superheat
Vapor
Common