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 two ways that fresh air enters a structure?
Average feet per minute X area in square feet (H' x W'/144)
High
Infiltration and ventilation
40 degrees F

2. How is ACR tubing sized?
8-12 degrees F
Outside diameter (OD)
A band 4 inches or more in width
A piston type metering device

3. What are the three pressures created by moving air in ductwork?
Inside diameter (ID)
Static pressure - velocity pressure - and total pressure
20 degrees above ambient
Dehydrated with caps on each end

4. What is the typical temperature difference between a high-efficiency condenser and the ambient temperature?
Fiberglass
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
20 degrees F
40 A

5. What is considered normal operating conditions?
400
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Inches of water column (in. WC)
Boil the liquid refrigerant out ot the oil within the crankcase

6. 10 SEER is classified as what kind of efficiency?
Standard
Inches of water column (in. WC)
40 degrees F
Nominal-sized tubing

7. 10' round duct has a ballpark cfm of what?
Inclined manometer
400
A swaging tool
Pi x radius squared

8. Do you need a vent on a pull-through evaporator?
Yes
With an are rating
It will be low
L-type

9. What is the range for normal superheat and subcooling?
8-12 degrees F
Common
20 degrees F
Fiberglass

10. 7' round duct has a ballpark cfm of what?
150
15% silphos
Stranded
A bypass duct or a dump zone

11. What type of air conditioning system must be charged using the superheat method?
Inches of water column (in. WC)
A piston type metering device
Belt drive and direct drive
Inside diameter (ID)

12. How long should you leave a system off once you kill power before restarting it?
Positive
18 gauge
2 minutes
Side-by-side and over-and-under

13. What are the four materials used to make duct?
40 degrees F
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
Yes
Over/under and side by side

14. Sections of duct board can be fastened together with what?
TXV
Staples and tape
Slugging
No

15. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
Heat loss
Over/under and side by side
Static pressure - velocity pressure - and total pressure
A bypass duct or a dump zone

16. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
1/4'
Yes
To lower the amount of pressure drop through the coil
Indoor fan motor - outdoor fan motor - and the compressor

17. What kind of metering device do high-efficiency units usually use?
TXV
Heat load
Nitrogen with a small amount of refrigerant
18 gauge

18. What percentage silver do you need to use for an are-410 system?
15% silphos
30 degrees F
20 degrees above ambient
Any amount

19. Do you need a vent on a pull-through evaporator?
Inches of water column (in. WC)
Yes
Before the vent
Outside diameter (OD)

20. How are the condenser coils different on a high-efficiency unit?
Boil the liquid refrigerant out ot the oil within the crankcase
8-12 degrees F
Heat loss
They are larger

21. What kind of copper tubing is used for plumbing and heating applications?
Staples and tape
Nominal-sized tubing
Yes
Boil the liquid refrigerant out ot the oil within the crankcase

22. When do you install a trap on a drain line?
When it is a pull-through evaporator
Indoor fan motor - outdoor fan motor - and the compressor
Average feet per minute X area in square feet (H' x W'/144)
In series

23. What kind of metering device do high-efficiency units usually use?
Dehydrated with caps on each end
TXV
Pistons
High

24. A reciprocating compressor has what sort of moving parts?
A piston type metering device
Pistons
100 psig
Yes

25. Does a package unit come from the factory pre-charged?
Yes
A band 4 inches or more in width
Inches of water column (in. WC)
Shorted winding - open winding - and grounded winding

26. What component changes refrigerant from a low pressure gas to a high pressure gas?
5 degrees
Compressor
On the common terminal
Before the vent

27. What are the three ways a motor can fail electrically?
Shorted winding - open winding - and grounded winding
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Inside diameter (ID)
Negative

28. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
Belt drive and direct drive
Latent and sensible
40 degrees F
It will be low

29. What are the two ways that fresh air enters a structure?
400
Standard
Infiltration and ventilation
18 gauge

30. What are the three crafts normally associated with an air-conditioned installation?
45 degrees F
100
Duct - electrical - and mechanical
45 degrees F

31. At what temperature does refrigerant condense in a high-efficiency unit?
20 A
Subtract ambient temperature from 100
20 degrees above ambient
ACR (air-conditioning refrigeration) tubing

32. The A/C size is calculated by what?
15% silphos
No
25-ft or 50-ft
Heat load

33. How is the high pressure switch wired with the low pressure switch?
25-ft or 50-ft
Staples and tape
Subtract ambient temperature from 100
In parallel

34. What is the name of the fitting where the branch line leaves the duct?
Heat loss
Below 800 degrees F
The takeoff fitting
20 degrees F

35. 13 SEER is classified as what kind of efficiency?
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
The takeoff fitting
High
8

36. How will too much refrigerant effect subcooling?
With 4' saddles
In parallel
With a minimum of three evenly spaced self-tapping screws
It will be high

37. What percentage silver do you need to use for an are-410 system?
Inside diameter (ID)
15% silphos
8-12 degrees F
Heat load

38. If the rpm's are 3450 - how many poles does the motor have?
45-55%
2
4
To remove humidity and lower dry bulb temperature

39. What is the difference between SEER and EER?
Inside diameter (ID)
It will be low
SEER includes the energy used in the start-up and shut-down cycles
400

40. Can refrigerant line sets be altered in length?
200
Yes
Belt drive and direct drive
Duct with insulation on the inside

41. How is insulation around a duct rated?
Pistons
140 degrees F
With an are rating
20 A

42. 9' round duct has a ballpark cfm of what?
300
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Common
A swaging tool

43. 13 SEER is classified as what kind of efficiency?
High
Belt drive and direct drive
Blended refrigerants
6

44. What is the normal evaporator temperature?
45 degrees F
It will be low
Any amount
30-35 degrees above ambient

45. Do you need a trap on a push-through evaporator?
18 gauge
The suction line or the low-pressure side
20 degrees above ambient
No

46. Do you need a trap on a pull-through evaporator?
Yes
Yes
It will have a decrease in superheat
40 degrees F

47. How many amps can 8 g wire handle?
S-clips and drives (cleats)
Yes
40 A
Yes

48. If the rpm's are 1050 - how many poles does the motor have?
6
8-12 degrees F
Common
20 degrees above ambient

49. How many amps can 14 g wire handle?
Yes
Suction
15 A
High

50. The fan switch closes at what temperature?
To lower the amount of pressure drop through the coil
140 degrees F
To remove humidity and lower dry bulb temperature
Dehydrated with caps on each end