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. 10 SEER is classified as what kind of efficiency?
High
Standard
A band 4 inches or more in width
ACR (air-conditioning refrigeration) tubing

2. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
Heat loss
Yes
Any amount
It will be high

3. 7' round duct has a ballpark cfm of what?
Fiberglass
False
150
To remove humidity and lower dry bulb temperature

4. If pressure rises - what happens to the superheat?
It rises
Duct - electrical - and mechanical
It will be low
400

5. How many amps can 12 g wire handle?
20 A
A bypass duct or a dump zone
Duct - electrical - and mechanical
45-55%

6. The crankcase heater on an air-conditioning compressor is used to what?
It rises
Boil the liquid refrigerant out ot the oil within the crankcase
Yes
Yes

7. What is the difference between SEER and EER?
SEER includes the energy used in the start-up and shut-down cycles
2
Before the vent
Staples and tape

8. In what length rolls is soft copper tubing normally available?
100
20 A
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
25-ft or 50-ft

9. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
To lower the amount of pressure drop through the coil
Staples and tape
To remove humidity and lower dry bulb temperature
TXV

10. What are the three pressures created by moving air in ductwork?
Over/under and side by side
Static pressure - velocity pressure - and total pressure
It rises
A band 4 inches or more in width

11. How many amps can 8 g wire handle?
Yes
When it is a pull-through evaporator
40 A
When the system is under pressure

12. 13 SEER is classified as what kind of efficiency?
High
False
When the system is under pressure
It will be low

13. 10' round duct has a ballpark cfm of what?
L-type
Staples and tape
300
400

14. How is nominal-sized tubing sized?
L-type
Inside diameter (ID)
Common
140 degrees F

15. 10' round duct has a ballpark cfm of what?
Any amount
40 A
A dirty evaporator
400

16. How is insulation around a duct rated?
With an are rating
When it is a pull-through evaporator
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Individual return air systems and central return air systems

17. What are the two types of return air systems in residential installations?
A bypass duct or a dump zone
They are larger
Individual return air systems and central return air systems
To lower the amount of pressure drop through the coil

18. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
Inclined manometer
Below 800 degrees F
A bypass duct or a dump zone
Pi x radius squared

19. The fan switch closes at what temperature?
140 degrees F
With a minimum of three evenly spaced self-tapping screws
15% silphos
Any amount

20. What tool is used to expand the diameter of soft copper tubing
Btu/hr (output) / wattage (input)
Yes
A swaging tool
When it is above a conditioned space

21. How does ACR copper pipe come?
Dehydrated with caps on each end
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
The takeoff fitting
Inclined manometer

22. What do you do after you braze a system?
No
Pull a vacuum
Suction
High

23. How will too much refrigerant effect superheat?
Over/under and side by side
200
It will be low
400

24. How are the high pressure switch and the low pressure switch wired with the compressor contactor?
On the common terminal
In series
It will be low
Individual return air systems and central return air systems

25. Superheat should never be below how many degrees
Subtract ambient temperature from 100
5 degrees
Stranded
Indoor fan motor - outdoor fan motor - and the compressor

26. What are the two basic duct connection configurations for package units supply and return air ducts?
TXV
Over/under and side by side
With an are rating
It also rises

27. Where do you install a trap on a drain line?
Before the vent
20 degrees F
Inclined manometer
Nominal-sized tubing

28. What is it called when liquid refrigerant gets into the compressor?
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
Slugging
100 psig
Heat load

29. Where is insulation used on copper tubing used for air-conditioning?
30 A
40 degrees F
400
The suction line or the low-pressure side

30. What are the three crafts normally associated with an air-conditioned installation?
Duct - electrical - and mechanical
Yes
To remove humidity and lower dry bulb temperature
When it is a pull-through evaporator

31. What percentage silver do you need to use for an are-410 system?
Dehydrated with caps on each end
15% silphos
1/4'
SEER includes the energy used in the start-up and shut-down cycles

32. If the rpm's are 3450 - how many poles does the motor have?
Subtract ambient temperature from 100
Before the vent
2
On the common terminal

33. 9' round duct has a ballpark cfm of what?
105 degrees F
300
Shorted winding - open winding - and grounded winding
8-12 degrees F

34. The A/C size is calculated by what?
Heat load
By increasing the surface of the condenser coil
A piston type metering device
Vapor

35. At what temperature will brazing melt?
Standard
TXV
Over 800 degrees F
Negative

36. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
45-55%
Inclined manometer
Side-by-side and over-and-under
Staples and tape

37. What is it called when liquid refrigerant gets into the compressor?
With a minimum of three evenly spaced self-tapping screws
True
Nominal-sized tubing
Slugging

38. How many amps can 8 g wire handle?
A dirty evaporator
In series
40 A
ACR (air-conditioning refrigeration) tubing

39. When must a copper joint never be soldered or brazed?
When the system is under pressure
It also rises
Yes
When it is above a conditioned space

40. How many cfm per ton?
Boil the liquid refrigerant out ot the oil within the crankcase
300
400
With a minimum of three evenly spaced self-tapping screws

41. What is the range for normal superheat and subcooling?
8-12 degrees F
Common
Standard
95 degrees F outside - 80 degrees F inside - and 50% relative humidity

42. What are the four materials used to make duct?
High
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
With a minimum of three evenly spaced self-tapping screws
Sheet metal - galvanized sheet metal - fiberglass - and flexduct

43. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
Yes
True
It will have a decrease in superheat
It will be low

44. What is the normal evaporator temperature?
It will have a decrease in superheat
2
Stranded
45 degrees F

45. If the rpm's are 1750 - how many poles does the motor have?
Side-by-side and over-and-under
18 gauge
4
Blended refrigerants

46. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
When it is above a conditioned space
SEER includes the energy used in the start-up and shut-down cycles
It will have a decrease in superheat
12000

47. 8' round duct has a ballpark cfm of what?
200
20 A
20 A
No

48. 10 SEER is classified as what kind of efficiency?
With an are rating
The suction line or the low-pressure side
Standard
It will be high

49. How do you calculate EER?
8
Static pressure - velocity pressure - and total pressure
18 gauge
Btu/hr (output) / wattage (input)

50. How long should you leave a system off once you kill power before restarting it?
Side-by-side and over-and-under
The suction line or the low-pressure side
2 minutes
Inside diameter (ID)