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 can cause a decrease in suction pressure on an air-conditioning system?
A dirty evaporator
Pistons
In series
Nitrogen with a small amount of refrigerant

2. What are the two types of package units?
Staples and tape
Infiltration and ventilation
Side-by-side and over-and-under
105 degrees F

3. What is it called when liquid refrigerant gets into the compressor?
Inclined manometer
Slugging
The suction line or the low-pressure side
Yes

4. The A/C size is calculated by what?
Average feet per minute X area in square feet (H' x W'/144)
Standard
With an are rating
Heat load

5. How many BTU's per ton?
With a minimum of three evenly spaced self-tapping screws
They are larger
Below 800 degrees F
12000

6. Most duct insulation is made of what?
20 degrees F
It will be low
Potential relay and start capacitor
Fiberglass

7. What is the design boiling point for most evaporator coils in residential air conditioning?
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
A piston type metering device
100 psig
40 degrees F

8. How many amps can 12 g wire handle?
20 A
With a minimum of three evenly spaced self-tapping screws
Before the vent
100

9. How is the high pressure switch wired with the low pressure switch?
In parallel
Individual return air systems and central return air systems
12000
Suction

10. Do you need a trap on a push-through evaporator?
They are larger
No
On the common terminal
The suction line or the low-pressure side

11. What are the four materials used to make duct?
45-55%
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
Vapor
Nominal-sized tubing

12. At what temperature does refrigerant condense in a standard-efficiency unit?
30-35 degrees above ambient
400
A bypass duct or a dump zone
With an are rating

13. How do you calculate ballpark superheat?
No
A diffuser
Subtract ambient temperature from 100
Fiberglass

14. What component changes refrigerant from a low pressure gas to a high pressure gas?
Any amount
High
Compressor
A band 4 inches or more in width

15. How are the high pressure switch and the low pressure switch wired with the compressor contactor?
To remove humidity and lower dry bulb temperature
In series
False
On the common terminal

16. If the rpm's are 750 - how many poles does the motor have?
8-12 degrees F
8
Inside diameter (ID)
20 A

17. What is the difference between SEER and EER?
Yes
Yes
SEER includes the energy used in the start-up and shut-down cycles
To remove humidity and lower dry bulb temperature

18. When do you install an auxillary drain pan?
Duct - electrical - and mechanical
When it is above a conditioned space
Pi x radius squared
20 A

19. What kind of metering device do high-efficiency units usually use?
30 degrees F
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Pistons
TXV

20. What is considered normal operating conditions?
Yes
15 A
Blended refrigerants
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity

21. How is insulation around a duct rated?
40 degrees F
Yes
With an are rating
Nominal-sized tubing

22. What gauge is thermostat wire?
In series
18 gauge
Rise
Staples and tape

23. In what state is the refrigerant in the compressor?
RLA/FLA x 5
Vapor
Subtract ambient temperature from 100
95 degrees F outside - 80 degrees F inside - and 50% relative humidity

24. If the rpm's are 1050 - how many poles does the motor have?
With a minimum of three evenly spaced self-tapping screws
Infiltration and ventilation
Staples and tape
6

25. How does ACR copper pipe come?
Dehydrated with caps on each end
Potential relay and start capacitor
45-55%
TXV

26. Do you need a trap on a pull-through evaporator?
RLA/FLA x 5
Yes
Inside diameter (ID)
Pistons

27. What sort of pressure will a pull-through evaporator have?
20 degrees above ambient
Negative
When it is above a conditioned space
20 A

28. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
They are larger
Blended refrigerants
It will be low
A bypass duct or a dump zone

29. What are the two ways that fresh air enters a structure?
Inches of water column (in. WC)
30-35 degrees above ambient
Positive
Infiltration and ventilation

30. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
100 psig
Any amount
Yes

31. Which type of wire can handle a higher ampacity?
20 degrees above ambient
Latent and sensible
High
Stranded

32. How are high-efficiency condenser coils different from standard-efficiency condenser coils?
They are physically larger
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
20 A
Negative

33. How many amps can 8 g wire handle?
40 A
To lower the amount of pressure drop through the coil
Pi x radius squared
Rise

34. When do you install a trap on a drain line?
140 degrees F
When it is a pull-through evaporator
Compressor
They are larger

35. The load on the evaporater will effect which pressure?
Btu/hr (output) / wattage (input)
Below 800 degrees F
40 A
Suction

36. What are the two types of return air systems in residential installations?
Individual return air systems and central return air systems
40 degrees F
Stranded
Inclined manometer

37. Can refrigerant line sets be altered in length?
18 gauge
Yes
A swaging tool
ACR (air-conditioning refrigeration) tubing

38. What is the name of the fitting where the branch line leaves the duct?
TXV
The takeoff fitting
Dehydrated with caps on each end
Static pressure - velocity pressure - and total pressure

39. What distributes supply air to a room in a structure?
A diffuser
Blended refrigerants
Below 800 degrees F
To remove humidity and lower dry bulb temperature

40. How long should you leave a system off once you kill power before restarting it?
Negative
2 minutes
No
Boil the liquid refrigerant out ot the oil within the crankcase

41. Superheat should never be below how many degrees
Positive
A swaging tool
5 degrees
Pull a vacuum

42. Will a dirty condenser cause a rise or fall in pressure?
Positive
High
30 A
Rise

43. The load on the evaporater will effect which pressure?
Boil the liquid refrigerant out ot the oil within the crankcase
With 4' saddles
140 degrees F
Suction

44. Will a dirty condenser cause a rise or fall in pressure?
Inches of water column (in. WC)
100 psig
Rise
SEER includes the energy used in the start-up and shut-down cycles

45. What is the normal evaporator temperature?
Duct with insulation on the inside
45 degrees F
30-35 degrees above ambient
20 degrees above ambient

46. What are the components of a hard-start kit?
TXV
Duct with insulation on the inside
Potential relay and start capacitor
High

47. What is the design boiling point for most evaporator coils in residential air conditioning?
L-type
40 degrees F
With an are rating
They are larger

48. Which is more efficient - a TXV or a fixed-orifice metering device?
140 degrees F
TXV
No
Yes

49. How do you calculate EER?
Btu/hr (output) / wattage (input)
Staples and tape
The suction line or the low-pressure side
Nominal-sized tubing

50. How many BTU's per ton?
The suction line or the low-pressure side
Pistons
12000
20 degrees F