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 an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
Static pressure - velocity pressure - and total pressure
It will have a decrease in superheat
On the common terminal
400

2. What are the two types of return air systems in residential installations?
Individual return air systems and central return air systems
4
A swaging tool
5 degrees

3. When do you install an auxillary drain pan?
They are larger
Blended refrigerants
In series
When it is above a conditioned space

4. What kind of refrigeratnts must be added in liquid form?
Common
Outside of the male fitting
Duct - electrical - and mechanical
Blended refrigerants

5. How many amps can 10 g wire handle?
ACR (air-conditioning refrigeration) tubing
It will be low
30 A
25-ft or 50-ft

6. Does a package unit come from the factory pre-charged?
Yes
Pi x radius squared
40 degrees F
TXV

7. Where do you apply flux when soldering?
L-type
Outside of the male fitting
40 A
A band 4 inches or more in width

8. If pressure rises - what happens to the superheat?
True
Yes
It will be high
It rises

9. Do you need a vent on a push-through evaporator?
A dirty evaporator
Heat load
Yes
Suction

10. What gauge is thermostat wire?
18 gauge
Before the vent
Any amount
Stranded

11. Do you need a vent on a pull-through evaporator?
8-12 degrees F
Yes
TXV
45-55%

12. Superheat should never be below how many degrees
5 degrees
A band 4 inches or more in width
It rises
With an are rating

13. 9' round duct has a ballpark cfm of what?
Nitrogen with a small amount of refrigerant
Yes
Yes
300

14. At what temperature will soft solder melt?
Below 800 degrees F
Blended refrigerants
100
Compressor

15. What do you use to check for leaks?
Outside diameter (OD)
False
40 A
Nitrogen with a small amount of refrigerant

16. What are the two basic duct connection configurations for package units supply and return air ducts?
Nitrogen with a small amount of refrigerant
By increasing the surface of the condenser coil
Over/under and side by side
Common

17. How many amps can 8 g wire handle?
Yes
40 A
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
It rises

18. What are the two functions of the air-conditioning system?
It will have a decrease in superheat
To remove humidity and lower dry bulb temperature
High
Vapor

19. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
8
Infiltration and ventilation
Potential relay and start capacitor
45-55%

20. When do you install an auxillary drain pan?
When it is above a conditioned space
Pistons
A band 4 inches or more in width
Any amount

21. How long should you leave a system off once you kill power before restarting it?
Pull a vacuum
No
2 minutes
Potential relay and start capacitor

22. What sort of pressure will a push-through evaporator have?
15 A
It will be low
300
Positive

23. What are the two ways that fresh air enters a structure?
It will have a decrease in superheat
Infiltration and ventilation
Heat loss
150

24. What kind of metering device do high-efficiency units usually use?
SEER includes the energy used in the start-up and shut-down cycles
TXV
When the system is under pressure
2

25. What are the two basic duct connection configurations for package units supply and return air ducts?
Over/under and side by side
Heat loss
Boil the liquid refrigerant out ot the oil within the crankcase
By increasing the surface of the condenser coil

26. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
Slugging
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Any amount
Below 800 degrees F

27. What kind of metering device do high-efficiency units usually use?
Boil the liquid refrigerant out ot the oil within the crankcase
TXV
Outside diameter (OD)
Rise

28. How many amps can 8 g wire handle?
Inclined manometer
40 A
A diffuser
20 degrees above ambient

29. When do you install a trap on a drain line?
Yes
Subtract ambient temperature from 100
20 degrees F
When it is a pull-through evaporator

30. How many BTU's per ton?
A piston type metering device
When it is a pull-through evaporator
12000
A band 4 inches or more in width

31. When must a copper joint never be soldered or brazed?
When the system is under pressure
Dehydrated with caps on each end
TXV
40 degrees F

32. Where do you check the amps on a motor?
On the common terminal
It also rises
ACR (air-conditioning refrigeration) tubing
Stranded

33. If the rpm's are 750 - how many poles does the motor have?
RLA/FLA x 5
Pistons
8
200

34. What is the typical temperature difference between a standard-efficiency condenser and the ambient temperature?
2
Over/under and side by side
Vapor
30 degrees F

35. How long should you leave a system off once you kill power before restarting it?
When it is a pull-through evaporator
Slugging
2 minutes
It will be low

36. 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.
400
High
True

37. In what state is the refrigerant in the compressor?
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Inclined manometer
30-35 degrees above ambient
Vapor

38. What kind of copper tubing is used for plumbing and heating applications?
Nominal-sized tubing
To remove humidity and lower dry bulb temperature
Boil the liquid refrigerant out ot the oil within the crankcase
Outside diameter (OD)

39. How many amps can 10 g wire handle?
30 A
Pull a vacuum
Potential relay and start capacitor
105 degrees F

40. What is considered normal operating conditions?
A diffuser
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
ACR (air-conditioning refrigeration) tubing
In series

41. The fan switch closes at what temperature?
Standard
Standard
It will have a decrease in superheat
140 degrees F

42. What sort of pressure will a push-through evaporator have?
Positive
RLA/FLA x 5
Yes
They are larger

43. How much does a drain line need to drop per foot of length?

44. Will a dirty condenser cause a rise or fall in pressure?
140 degrees F
Rise
RLA/FLA x 5
Potential relay and start capacitor

45. How are high-efficiency condenser coils different from standard-efficiency condenser coils?
They are physically larger
30-35 degrees above ambient
A swaging tool
By increasing the surface of the condenser coil

46. What component changes refrigerant from a low pressure gas to a high pressure gas?
A swaging tool
300
Compressor
When it is above a conditioned space

47. On what terminal do you check amperage?
A swaging tool
Common
A band 4 inches or more in width
With 4' saddles

48. 6' round duct has a ballpark cfm of what?
It will be high
100
Staples and tape
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line

49. What distributes supply air to a room in a structure?
100
Common
Average feet per minute X area in square feet (H' x W'/144)
A diffuser

50. How do you calculate cfm?