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 is a package unit?
By increasing the surface of the condenser coil
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
RLA/FLA x 5
L-type

2. Do you need a trap on a pull-through evaporator?
Yes
With 4' saddles
40 A
TXV

3. Will a dirty condenser cause a rise or fall in pressure?
Rise
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
A dirty evaporator
Outside diameter (OD)

4. What are the three pressures created by moving air in ductwork?
True
45 degrees F
Static pressure - velocity pressure - and total pressure
Yes

5. A reciprocating compressor has what sort of moving parts?
Pistons
Yes
Over/under and side by side
Boil the liquid refrigerant out ot the oil within the crankcase

6. If the rpm's are 750 - how many poles does the motor have?
8
2 minutes
45-55%
Common

7. Will a dirty condenser cause a rise or fall in pressure?
Rise
SEER includes the energy used in the start-up and shut-down cycles
A diffuser
Potential relay and start capacitor

8. The fan switch closes at what temperature?
When it is a pull-through evaporator
140 degrees F
Shorted winding - open winding - and grounded winding
Yes

9. What do you use to check for leaks?
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
On the common terminal
Nitrogen with a small amount of refrigerant
Infiltration and ventilation

10. 10 SEER is classified as what kind of efficiency?
In parallel
It will be low
Standard
They are physically larger

11. Do you need a vent on a pull-through evaporator?
400
A diffuser
Yes
Duct - electrical - and mechanical

12. If pressure rises - what happens to the superheat?
It rises
It will be low
300
Inclined manometer

13. When do you install an auxillary drain pan?
40 degrees F
When it is above a conditioned space
Negative
Over 800 degrees F

14. If the suction pressure rises - what happens to the head pressure?
Individual return air systems and central return air systems
It also rises
140 degrees F
A band 4 inches or more in width

15. Do you need a vent on a push-through evaporator?
Nominal-sized tubing
Latent and sensible
Compressor
Yes

16. How many amps can 10 g wire handle?
30 A
Staples and tape
RLA/FLA x 5
With 4' saddles

17. What sort of pressure will a push-through evaporator have?
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Positive
Blended refrigerants
2 minutes

18. What are the three major power-consuming devices on an air-conditioning system?
20 A
Indoor fan motor - outdoor fan motor - and the compressor
Heat load
Subtract ambient temperature from 100

19. How are high-efficiency condenser coils different from standard-efficiency condenser coils?
Average feet per minute X area in square feet (H' x W'/144)
They are physically larger
Boil the liquid refrigerant out ot the oil within the crankcase
When the system is under pressure

20. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
Stranded
True
300
Yes

21. Pressure in ductwork is measured In what?
1/4'
Inches of water column (in. WC)
A bypass duct or a dump zone
20 A

22. The crankcase heater on an air-conditioning compressor is used to what?
Boil the liquid refrigerant out ot the oil within the crankcase
100
ACR (air-conditioning refrigeration) tubing
Positive

23. 7' round duct has a ballpark cfm of what?
They are larger
No
140 degrees F
150

24. If the suction pressure rises - what happens to the head pressure?
The takeoff fitting
It also rises
Dehydrated with caps on each end
Common

25. How many amps can 14 g wire handle?
5 degrees
15 A
Compressor
18 gauge

26. How is nominal-sized tubing sized?
Boil the liquid refrigerant out ot the oil within the crankcase
They are physically larger
The takeoff fitting
Inside diameter (ID)

27. What do you use to connect square and rectangular ductboard together?
15 A
L-type
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
S-clips and drives (cleats)

28. The furnace size is calculated by what?
High
Heat loss
Pistons
Infiltration and ventilation

29. What kind of copper tubing is used for refrigeration or air-conditioning applications?
100
ACR (air-conditioning refrigeration) tubing
True
When it is a pull-through evaporator

30. If the rpm's are 1750 - how many poles does the motor have?
40 A
40 A
Pi x radius squared
4

31. If the rpm's are 3450 - how many poles does the motor have?
They are larger
2
Duct - electrical - and mechanical
True

32. What is the normal evaporator temperature?
Rise
To remove humidity and lower dry bulb temperature
45 degrees F
Over/under and side by side

33. How do you calculate EER?
Nominal-sized tubing
Yes
Btu/hr (output) / wattage (input)
Dehydrated with caps on each end

34. What is the design boiling point for most evaporator coils in residential air conditioning?
45 degrees F
A piston type metering device
140 degrees F
40 degrees F

35. What kind of copper tubing is used for plumbing and heating applications?
TXV
Nominal-sized tubing
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Before the vent

36. 10' round duct has a ballpark cfm of what?
It will be low
Common
400
Inside diameter (ID)

37. How long should you leave a system off once you kill power before restarting it?
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
2 minutes
It also rises
Nitrogen with a small amount of refrigerant

38. How do you calculate ballpark superheat?
Inches of water column (in. WC)
Outside of the male fitting
Subtract ambient temperature from 100
S-clips and drives (cleats)

39. When do you install a trap on a drain line?
With an are rating
By increasing the surface of the condenser coil
Negative
When it is a pull-through evaporator

40. Sections of duct board can be fastened together with what?
Staples and tape
To remove humidity and lower dry bulb temperature
In parallel
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.

41. What are the three crafts normally associated with an air-conditioned installation?
Latent and sensible
Duct - electrical - and mechanical
A dirty evaporator
Vapor

42. In what state is the refrigerant in the compressor?
They are physically larger
Standard
Side-by-side and over-and-under
Vapor

43. The fan switch opens at what temperature?
When the system is under pressure
Slugging
20 degrees F
105 degrees F

44. What is it called when liquid refrigerant gets into the compressor?
4
A dirty evaporator
Slugging
Inches of water column (in. WC)

45. How will too much refrigerant effect subcooling?
It will be high
It rises
Outside of the male fitting
Slugging

46. The load on the evaporater will effect which pressure?
Belt drive and direct drive
Suction
Average feet per minute X area in square feet (H' x W'/144)
Over 800 degrees F

47. The evaporator is designed to remove what two types of heat?
Heat load
Inside diameter (ID)
Latent and sensible
Yes

48. 10' round duct has a ballpark cfm of what?
Inches of water column (in. WC)
400
20 A
It will be high

49. What are the three pressures created by moving air in ductwork?
Pi x radius squared
1/4'
Static pressure - velocity pressure - and total pressure
Rise

50. How many cfm per ton?
Outside diameter (OD)
Average feet per minute X area in square feet (H' x W'/144)
6
400