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. Why are some ACR tubing lines insulated?
Pi x radius squared
Compressor
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Shorted winding - open winding - and grounded winding

2. What is used to measure static air pressure in ducts.
S-clips and drives (cleats)
Any amount
Inclined manometer
On the common terminal

3. The A/C size is calculated by what?
Vapor
45-55%
Heat load
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity

4. When must a copper joint never be soldered or brazed?
Outside of the male fitting
When the system is under pressure
A piston type metering device
Indoor fan motor - outdoor fan motor - and the compressor

5. Do you need a vent on a push-through evaporator?
100
Average feet per minute X area in square feet (H' x W'/144)
Yes
It also rises

6. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
20 degrees F
150
True
With a minimum of three evenly spaced self-tapping screws

7. How many amps can 10 g wire handle?
6
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
30 A
20 degrees above ambient

8. What are the two basic duct connection configurations for package units supply and return air ducts?
They are larger
8-12 degrees F
Over/under and side by side
Inclined manometer

9. How do you calculate the area of a circle?
No
Belt drive and direct drive
Suction
Pi x radius squared

10. Does a package unit come from the factory pre-charged?
Vapor
8-12 degrees F
Yes
Nitrogen with a small amount of refrigerant

11. The fan switch closes at what temperature?
Heat load
Below 800 degrees F
2
140 degrees F

12. How will too much refrigerant effect superheat?
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Negative
Yes
It will be low

13. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
True
Pistons
When it is a pull-through evaporator
Yes

14. Where do you install a trap on a drain line?
Btu/hr (output) / wattage (input)
Before the vent
105 degrees F
Belt drive and direct drive

15. What can cause a decrease in suction pressure on an air-conditioning system?
Positive
A dirty evaporator
Inches of water column (in. WC)
When the system is under pressure

16. Which type of wire can handle a higher ampacity?
S-clips and drives (cleats)
No
Stranded
To lower the amount of pressure drop through the coil

17. What component changes refrigerant from a low pressure gas to a high pressure gas?
TXV
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Shorted winding - open winding - and grounded winding
Compressor

18. Can refrigerant line sets be altered in length?
Yes
Inches of water column (in. WC)
30-35 degrees above ambient
Heat load

19. What distributes supply air to a room in a structure?
Rise
L-type
False
A diffuser

20. When do you install an auxillary drain pan?
When it is above a conditioned space
Inches of water column (in. WC)
Outside diameter (OD)
ACR (air-conditioning refrigeration) tubing

21. How are round ducts connected to one another?
It also rises
Inches of water column (in. WC)
With a minimum of three evenly spaced self-tapping screws
Outside of the male fitting

22. When do you install a trap on a drain line?
When it is above a conditioned space
A band 4 inches or more in width
20 degrees above ambient
When it is a pull-through evaporator

23. The furnace size is calculated by what?
Duct with insulation on the inside
A piston type metering device
Any amount
Heat loss

24. What kind of copper tubing is used for plumbing and heating applications?
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Nominal-sized tubing
True
Heat load

25. What is the design boiling point for most evaporator coils in residential air conditioning?
In parallel
40 degrees F
False
A diffuser

26. What are the three crafts normally associated with an air-conditioned installation?
Duct - electrical - and mechanical
RLA/FLA x 5
Btu/hr (output) / wattage (input)
8-12 degrees F

27. How many BTU's per ton?
Common
12000
25-ft or 50-ft
Dehydrated with caps on each end

28. Will a dirty condenser cause a rise or fall in pressure?
Rise
RLA/FLA x 5
Staples and tape
20 degrees above ambient

29. How do you achieve high-efficiency?
Yes
Compressor
By increasing the surface of the condenser coil
The takeoff fitting

30. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
Fiberglass
105 degrees F
Pistons
Any amount

31. The evaporator is designed to remove what two types of heat?
40 A
In parallel
45-55%
Latent and sensible

32. At what temperature will brazing melt?
45-55%
TXV
Belt drive and direct drive
Over 800 degrees F

33. What are the two types of return air systems in residential installations?
40 A
Inside diameter (ID)
Individual return air systems and central return air systems
400

34. Do you need a vent on a push-through evaporator?
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Yes
Side-by-side and over-and-under
By increasing the surface of the condenser coil

35. What are the four materials used to make duct?
Belt drive and direct drive
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
SEER includes the energy used in the start-up and shut-down cycles

36. How many BTU's per ton?
4
12000
When it is a pull-through evaporator
Over 800 degrees F

37. How many amps can 10 g wire handle?
30 A
30-35 degrees above ambient
Rise
On the common terminal

38. What are the two types of blower drives?
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Belt drive and direct drive
30 A
30-35 degrees above ambient

39. If the rpm's are 1750 - how many poles does the motor have?
2 minutes
Heat loss
18 gauge
4

40. Pressure in ductwork is measured In what?
Inches of water column (in. WC)
Inclined manometer
45 degrees F
Individual return air systems and central return air systems

41. The evaporator is designed to remove what two types of heat?
150
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Latent and sensible
High

42. What kind of refrigeratnts must be added in liquid form?
Blended refrigerants
Belt drive and direct drive
It will be low
Indoor fan motor - outdoor fan motor - and the compressor

43. What is the design boiling point for most evaporator coils in residential air conditioning?
With 4' saddles
Compressor
40 degrees F
They are larger

44. What do you use to check for leaks?
Below 800 degrees F
Nitrogen with a small amount of refrigerant
False
Negative

45. What is the typical temperature difference between a high-efficiency condenser and the ambient temperature?
Slugging
400
It rises
20 degrees F

46. What kind of copper tubing is used for plumbing and heating applications?
20 degrees above ambient
Heat load
Nominal-sized tubing
Yes

47. What do you use to connect square and rectangular ductboard together?
In parallel
In parallel
400
S-clips and drives (cleats)

48. What are the two basic duct connection configurations for package units supply and return air ducts?
Over/under and side by side
Yes
L-type
Staples and tape

49. Where is insulation used on copper tubing used for air-conditioning?
True
The suction line or the low-pressure side
6
Yes

50. How are round ducts connected to one another?
S-clips and drives (cleats)
A dirty evaporator
With a minimum of three evenly spaced self-tapping screws
45-55%