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?
TXV
It will have a decrease in superheat
A swaging tool
Duct - electrical - and mechanical

2. What sort of pressure will a push-through evaporator have?
Compressor
Below 800 degrees F
15 A
Positive

3. What is a package unit?
A dirty evaporator
False
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
20 A

4. On what terminal do you check amperage?
Btu/hr (output) / wattage (input)
200
Common
25-ft or 50-ft

5. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
They are physically larger
Rise
45 degrees F
To lower the amount of pressure drop through the coil

6. In what state is the refrigerant in the compressor?
Vapor
The takeoff fitting
Below 800 degrees F
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity

7. What is considered normal operating conditions?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
300
L-type
Yes

8. What kind of metering device do high-efficiency units usually use?
30 degrees F
Latent and sensible
20 A
TXV

9. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
Indoor fan motor - outdoor fan motor - and the compressor
30-35 degrees above ambient
45-55%
45 degrees F

10. The A/C size is calculated by what?
Heat load
With an are rating
Duct with insulation on the inside
When it is above a conditioned space

11. Why are some ACR tubing lines insulated?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Yes
15 A
ACR (air-conditioning refrigeration) tubing

12. How many cfm per ton?
Yes
400
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
30 degrees F

13. How is the high pressure switch wired with the low pressure switch?
Yes
In parallel
When it is a pull-through evaporator
With an are rating

14. Which type of wire can handle a higher ampacity?
Yes
Nitrogen with a small amount of refrigerant
30-35 degrees above ambient
Stranded

15. What is a package unit?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Inside diameter (ID)
100
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.

16. Can refrigerant line sets be altered in length?
Over/under and side by side
Fiberglass
Suction
Yes

17. How is the high pressure switch wired with the low pressure switch?
Stranded
In parallel
Yes
Heat loss

18. How do you calculate the area of a circle?
Suction
Pi x radius squared
Common
40 A

19. Sections of duct board can be fastened together with what?
Staples and tape
12000
L-type
They are physically larger

20. What sort of pressure will a pull-through evaporator have?
S-clips and drives (cleats)
Negative
Yes
A piston type metering device

21. What are the two types of package units?
Side-by-side and over-and-under
Pistons
Suction
Over 800 degrees F

22. 8' round duct has a ballpark cfm of what?
200
20 A
No
A swaging tool

23. Will a dirty condenser cause a rise or fall in pressure?
Rise
RLA/FLA x 5
Heat load
Staples and tape

24. Most duct insulation is made of what?
Side-by-side and over-and-under
30-35 degrees above ambient
Inclined manometer
Fiberglass

25. What are the four materials used to make duct?
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
Nitrogen with a small amount of refrigerant
On the common terminal
Potential relay and start capacitor

26. How is ACR tubing sized?
30 A
Staples and tape
In parallel
Outside diameter (OD)

27. If the rpm's are 1750 - how many poles does the motor have?
When the system is under pressure
15% silphos
4
Pull a vacuum

28. The A/C size is calculated by what?
100
Heat load
Rise
Btu/hr (output) / wattage (input)

29. How will too much refrigerant effect subcooling?
It will be high
False
Vapor
20 degrees F

30. How many amps can 8 g wire handle?
Nominal-sized tubing
High
20 degrees above ambient
40 A

31. At what temperature will soft solder melt?
2
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Below 800 degrees F
Common

32. How do you calculate EER?
Btu/hr (output) / wattage (input)
300
Any amount
15% silphos

33. Do you need a trap on a pull-through evaporator?
On the common terminal
Compressor
Yes
By increasing the surface of the condenser coil

34. How many cfm per ton?
When the system is under pressure
Over/under and side by side
400
When it is a pull-through evaporator

35. What kind of copper tubing is used for refrigeration or air-conditioning applications?
25-ft or 50-ft
It rises
Infiltration and ventilation
ACR (air-conditioning refrigeration) tubing

36. What do you do after you braze a system?
Positive
Pull a vacuum
200
Staples and tape

37. How does ACR copper pipe come?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Dehydrated with caps on each end
Outside diameter (OD)
Staples and tape

38. How many amps can 14 g wire handle?
15 A
45 degrees F
100 psig
Duct with insulation on the inside

39. In what state is the refrigerant in the compressor?
ACR (air-conditioning refrigeration) tubing
With an are rating
Vapor
Side-by-side and over-and-under

40. What is it called when liquid refrigerant gets into the compressor?
High
45 degrees F
Slugging
Latent and sensible

41. A reciprocating compressor has what sort of moving parts?
Pistons
False
Over 800 degrees F
Compressor

42. 10' round duct has a ballpark cfm of what?
400
Over/under and side by side
It also rises
Before the vent

43. Where do you apply flux when soldering?
Outside of the male fitting
20 degrees F
A swaging tool
Shorted winding - open winding - and grounded winding

44. What are the two types of blower drives?
A band 4 inches or more in width
By increasing the surface of the condenser coil
15 A
Belt drive and direct drive

45. How do you calculate the area of a circle?
45-55%
15% silphos
Pi x radius squared
Rise

46. The evaporator is designed to remove what two types of heat?
Vapor
Negative
Indoor fan motor - outdoor fan motor - and the compressor
Latent and sensible

47. 6' round duct has a ballpark cfm of what?
100
Infiltration and ventilation
40 degrees F
Positive

48. How are high-efficiency condenser coils different from standard-efficiency condenser coils?
With 4' saddles
It rises
Yes
They are physically larger

49. What type of air conditioning system must be charged using the superheat method?
S-clips and drives (cleats)
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
A piston type metering device
95 degrees F outside - 80 degrees F inside - and 50% relative humidity

50. The compressor is cooled by liquid refrigerant. (True of False)
4
200
A band 4 inches or more in width
False