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. How will too much refrigerant effect subcooling?
Inside diameter (ID)
It will be high
To remove humidity and lower dry bulb temperature
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.

2. What distributes supply air to a room in a structure?
Average feet per minute X area in square feet (H' x W'/144)
It will be high
A piston type metering device
A diffuser

3. Can refrigerant line sets be altered in length?
Yes
S-clips and drives (cleats)
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
When the system is under pressure

4. 10' round duct has a ballpark cfm of what?
It also rises
A piston type metering device
Yes
400

5. What are the three pressures created by moving air in ductwork?
With an are rating
Boil the liquid refrigerant out ot the oil within the crankcase
It also rises
Static pressure - velocity pressure - and total pressure

6. What can cause a decrease in suction pressure on an air-conditioning system?
A dirty evaporator
8
200
Below 800 degrees F

7. If the rpm's are 750 - how many poles does the motor have?
8
Subtract ambient temperature from 100
15 A
Staples and tape

8. The fan switch opens at what temperature?
105 degrees F
2 minutes
With 4' saddles
Latent and sensible

9. How many amps can 12 g wire handle?
Duct - electrical - and mechanical
20 A
A bypass duct or a dump zone
To remove humidity and lower dry bulb temperature

10. Why are some ACR tubing lines insulated?
200
Yes
Blended refrigerants
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line

11. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
The suction line or the low-pressure side
20 degrees above ambient
Inside diameter (ID)
40 degrees F

12. What are the three ways a motor can fail electrically?
45 degrees F
Shorted winding - open winding - and grounded winding
Any amount
12000

13. How many cfm per ton?
30-35 degrees above ambient
400
Positive
Outside diameter (OD)

14. What is the range for normal superheat and subcooling?
8-12 degrees F
When it is a pull-through evaporator
12000
They are larger

15. If pressure rises - what happens to the superheat?
5 degrees
30 A
It rises
Slugging

16. How do you calculate LRA?
Potential relay and start capacitor
8
High
RLA/FLA x 5

17. The load on the evaporater will effect which pressure?
6
By increasing the surface of the condenser coil
Suction
20 A

18. What do you use to connect square and rectangular ductboard together?
With a minimum of three evenly spaced self-tapping screws
Heat load
S-clips and drives (cleats)
Staples and tape

19. How are the condenser coils different on a high-efficiency unit?
They are larger
It will be high
25-ft or 50-ft
It will be high

20. If the rpm's are 1050 - how many poles does the motor have?
Positive
6
Common
Rise

21. The load on the evaporater will effect which pressure?
Slugging
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Yes
Suction

22. What sort of pressure will a push-through evaporator have?
Positive
High
Negative
Yes

23. What are the two types of package units?
Side-by-side and over-and-under
In parallel
The takeoff fitting
RLA/FLA x 5

24. What are the three crafts normally associated with an air-conditioned installation?
Duct - electrical - and mechanical
30 A
Standard
By increasing the surface of the condenser coil

25. How many amps can 10 g wire handle?
To lower the amount of pressure drop through the coil
Inclined manometer
30 A
ACR (air-conditioning refrigeration) tubing

26. What do you use to connect square and rectangular ductboard together?
Over/under and side by side
4
25-ft or 50-ft
S-clips and drives (cleats)

27. How many amps can 8 g wire handle?
40 A
SEER includes the energy used in the start-up and shut-down cycles
Nitrogen with a small amount of refrigerant
15% silphos

28. What gauge is thermostat wire?
18 gauge
To remove humidity and lower dry bulb temperature
Stranded
Yes

29. The crankcase heater on an air-conditioning compressor is used to what?
Boil the liquid refrigerant out ot the oil within the crankcase
Side-by-side and over-and-under
With 4' saddles
45 degrees F

30. What are the four materials used to make duct?
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
A diffuser
L-type
Staples and tape

31. How many amps can 12 g wire handle?
Before the vent
25-ft or 50-ft
20 A
Before the vent

32. If the rpm's are 1750 - how many poles does the motor have?
Blended refrigerants
4
Infiltration and ventilation
140 degrees F

33. The evaporator is designed to remove what two types of heat?
Latent and sensible
8
400
They are larger

34. Most duct insulation is made of what?
With 4' saddles
Fiberglass
Yes
Negative

35. Where do you install a trap on a drain line?
Before the vent
It rises
It will be low
Latent and sensible

36. What kind of refrigeratnts must be added in liquid form?
Blended refrigerants
Indoor fan motor - outdoor fan motor - and the compressor
Outside of the male fitting
15 A

37. How many amps can 14 g wire handle?
It rises
Positive
15 A
In series

38. What is lined duct?
TXV
40 degrees F
Duct with insulation on the inside
Inclined manometer

39. Which type of wire can handle a higher ampacity?
It will be low
When it is above a conditioned space
Pull a vacuum
Stranded

40. What is the typical pressure differance across a TXV?
To remove humidity and lower dry bulb temperature
L-type
25-ft or 50-ft
100 psig

41. What is a package unit?
30 A
Positive
They are larger
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.

42. How is flexible duct supported?
To remove humidity and lower dry bulb temperature
When the system is under pressure
Side-by-side and over-and-under
A band 4 inches or more in width

43. At what temperature will soft solder melt?
Below 800 degrees F
SEER includes the energy used in the start-up and shut-down cycles
Before the vent
No

44. A reciprocating compressor has what sort of moving parts?
Pistons
A swaging tool
45 degrees F
TXV

45. In what length rolls is soft copper tubing normally available?
25-ft or 50-ft
TXV
A dirty evaporator
To lower the amount of pressure drop through the coil

46. What are the two basic duct connection configurations for package units supply and return air ducts?
12000
Over/under and side by side
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Sheet metal - galvanized sheet metal - fiberglass - and flexduct

47. What is the name of the fitting where the branch line leaves the duct?
45-55%
Inclined manometer
The takeoff fitting
20 degrees above ambient

48. 10' round duct has a ballpark cfm of what?
400
RLA/FLA x 5
Subtract ambient temperature from 100
A swaging tool

49. How is nominal-sized tubing sized?
Belt drive and direct drive
Pull a vacuum
Inside diameter (ID)
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.

50. 7' round duct has a ballpark cfm of what?
150
Before the vent
30-35 degrees above ambient
It will have a decrease in superheat