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 are high-efficiency condenser coils different from standard-efficiency condenser coils?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
High
They are physically larger
Common

2. The fan switch opens at what temperature?
When the system is under pressure
105 degrees F
Pistons
ACR (air-conditioning refrigeration) tubing

3. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
They are larger
6
To lower the amount of pressure drop through the coil
Subtract ambient temperature from 100

4. How will too much refrigerant effect superheat?
100 psig
False
It will be low
Pi x radius squared

5. Do you need a vent on a push-through evaporator?
Yes
Blended refrigerants
A swaging tool
No

6. How do you achieve high-efficiency?
15 A
By increasing the surface of the condenser coil
Over/under and side by side
Fiberglass

7. What are the two ways that fresh air enters a structure?
30 degrees F
Infiltration and ventilation
45-55%
Duct with insulation on the inside

8. How are round ducts connected to one another?
TXV
105 degrees F
Positive
With a minimum of three evenly spaced self-tapping screws

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

10. What is lined duct?
RLA/FLA x 5
Common
Duct with insulation on the inside
2 minutes

11. What do you use to connect square and rectangular ductboard together?
S-clips and drives (cleats)
15 A
8
It will have a decrease in superheat

12. What can cause a decrease in suction pressure on an air-conditioning system?
20 A
When it is above a conditioned space
A dirty evaporator
20 degrees F

13. How is ACR tubing sized?
8-12 degrees F
200
Outside diameter (OD)
Average feet per minute X area in square feet (H' x W'/144)

14. If the rpm's are 1750 - how many poles does the motor have?
400
With an are rating
True
4

15. How do you calculate the area of a circle?
Stranded
Pi x radius squared
By increasing the surface of the condenser coil
45-55%

16. When do you install a trap on a drain line?
Outside of the male fitting
Btu/hr (output) / wattage (input)
30-35 degrees above ambient
When it is a pull-through evaporator

17. What is the design boiling point for most evaporator coils in residential air conditioning?
40 degrees F
400
The takeoff fitting
Yes

18. What distributes supply air to a room in a structure?
A diffuser
Slugging
Fiberglass
20 degrees F

19. What kind of copper tubing is used for refrigeration or air-conditioning applications?
ACR (air-conditioning refrigeration) tubing
105 degrees F
In parallel
Inches of water column (in. WC)

20. What are the two basic duct connection configurations for package units supply and return air ducts?
Stranded
Average feet per minute X area in square feet (H' x W'/144)
Over/under and side by side
Outside of the male fitting

21. In what state is the refrigerant in the compressor?
Vapor
L-type
Shorted winding - open winding - and grounded winding
When it is a pull-through evaporator

22. How is flexible duct supported?
On the common terminal
A band 4 inches or more in width
Fiberglass
15% silphos

23. How is flexible duct supported?
When it is above a conditioned space
Vapor
A band 4 inches or more in width
S-clips and drives (cleats)

24. The crankcase heater on an air-conditioning compressor is used to what?
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Boil the liquid refrigerant out ot the oil within the crankcase
Infiltration and ventilation
A dirty evaporator

25. Which type of wire can handle a higher ampacity?
Rise
Stranded
Nitrogen with a small amount of refrigerant
Duct - electrical - and mechanical

26. What is the normal evaporator temperature?
Indoor fan motor - outdoor fan motor - and the compressor
45 degrees F
400
105 degrees F

27. What is the name of the fitting where the branch line leaves the duct?
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
400
The takeoff fitting
They are larger

28. How many BTU's per ton?
Latent and sensible
12000
Infiltration and ventilation
Indoor fan motor - outdoor fan motor - and the compressor

29. What kind of copper tubing is used for plumbing and heating applications?
Outside of the male fitting
To remove humidity and lower dry bulb temperature
Nominal-sized tubing
S-clips and drives (cleats)

30. What tool is used to expand the diameter of soft copper tubing
Below 800 degrees F
Common
A dirty evaporator
A swaging tool

31. Superheat should never be below how many degrees
Indoor fan motor - outdoor fan motor - and the compressor
5 degrees
Btu/hr (output) / wattage (input)
Yes

32. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
A bypass duct or a dump zone
Pi x radius squared
Over 800 degrees F
40 degrees F

33. How will too much refrigerant effect subcooling?
It will be high
20 A
Compressor
140 degrees F

34. 13 SEER is classified as what kind of efficiency?
Subtract ambient temperature from 100
40 degrees F
High
Nitrogen with a small amount of refrigerant

35. How do you calculate ballpark superheat?
It will be high
20 A
Subtract ambient temperature from 100
In parallel

36. What are the two types of return air systems in residential installations?
Individual return air systems and central return air systems
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
45 degrees F
With 4' saddles

37. Where do you check the amps on a motor?
It will be high
False
45 degrees F
On the common terminal

38. In what length rolls is soft copper tubing normally available?
Slugging
False
25-ft or 50-ft
The suction line or the low-pressure side

39. The fan switch closes at what temperature?
Slugging
No
140 degrees F
Over/under and side by side

40. In what length rolls is soft copper tubing normally available?
The suction line or the low-pressure side
25-ft or 50-ft
Staples and tape
They are larger

41. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
They are physically larger
It will have a decrease in superheat
Over 800 degrees F
6

42. What kind of copper tubing is used for refrigeration or air-conditioning applications?
ACR (air-conditioning refrigeration) tubing
With an are rating
Vapor
40 A

43. Where do you apply flux when soldering?
Outside of the male fitting
Infiltration and ventilation
Inches of water column (in. WC)
Indoor fan motor - outdoor fan motor - and the compressor

44. At what temperature will brazing melt?
1/4'
Latent and sensible
Over 800 degrees F
Standard

45. What are the two types of blower drives?
When the system is under pressure
With 4' saddles
Vapor
Belt drive and direct drive

46. Will a dirty condenser cause a rise or fall in pressure?
6
TXV
Rise
Over 800 degrees F

47. If the suction pressure rises - what happens to the head pressure?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Pull a vacuum
TXV
It also rises

48. If the rpm's are 750 - how many poles does the motor have?
5 degrees
8
Suction
15 A

49. When must a copper joint never be soldered or brazed?
Compressor
40 degrees F
Over/under and side by side
When the system is under pressure

50. If the rpm's are 3450 - how many poles does the motor have?
2
Side-by-side and over-and-under
20 degrees above ambient
Pistons