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 many BTU's per ton?
S-clips and drives (cleats)
12000
Positive
Pistons

2. What are the three pressures created by moving air in ductwork?
When it is a pull-through evaporator
Static pressure - velocity pressure - and total pressure
Pull a vacuum
140 degrees F

3. How do you calculate ballpark superheat?
Individual return air systems and central return air systems
Subtract ambient temperature from 100
Below 800 degrees F
Btu/hr (output) / wattage (input)

4. What are the two types of blower drives?
It also rises
SEER includes the energy used in the start-up and shut-down cycles
20 A
Belt drive and direct drive

5. The evaporator is designed to remove what two types of heat?
Latent and sensible
Yes
They are larger
400

6. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
Stranded
A bypass duct or a dump zone
12000
15 A

7. The evaporator is designed to remove what two types of heat?
They are larger
Latent and sensible
Indoor fan motor - outdoor fan motor - and the compressor
400

8. Which type of wire can handle a higher ampacity?
Stranded
A bypass duct or a dump zone
Slugging
105 degrees F

9. Sections of duct board can be fastened together with what?
Staples and tape
ACR (air-conditioning refrigeration) tubing
8
30-35 degrees above ambient

10. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
2
105 degrees F
To lower the amount of pressure drop through the coil
Individual return air systems and central return air systems

11. Can refrigerant line sets be altered in length?
Boil the liquid refrigerant out ot the oil within the crankcase
When it is a pull-through evaporator
Standard
Yes

12. How do you achieve high-efficiency?
Compressor
45-55%
150
By increasing the surface of the condenser coil

13. The compressor is cooled by liquid refrigerant. (True of False)
False
In parallel
Slugging
To remove humidity and lower dry bulb temperature

14. On what terminal do you check amperage?
30-35 degrees above ambient
Common
Outside of the male fitting
Nitrogen with a small amount of refrigerant

15. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
Yes
Any amount
Pull a vacuum
Fiberglass

16. What are the three major power-consuming devices on an air-conditioning system?
Indoor fan motor - outdoor fan motor - and the compressor
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
When the system is under pressure
The suction line or the low-pressure side

17. At what temperature will soft solder melt?
Below 800 degrees F
400
Nominal-sized tubing
A diffuser

18. When do you install a trap on a drain line?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
20 degrees above ambient
8-12 degrees F
When it is a pull-through evaporator

19. The compressor is cooled by liquid refrigerant. (True of False)
The takeoff fitting
False
12000
Before the vent

20. How are the high pressure switch and the low pressure switch wired with the compressor contactor?
A bypass duct or a dump zone
In series
45 degrees F
Duct with insulation on the inside

21. What do you use to connect square and rectangular ductboard together?
RLA/FLA x 5
150
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
S-clips and drives (cleats)

22. What is used to measure static air pressure in ducts.
Inclined manometer
Indoor fan motor - outdoor fan motor - and the compressor
Indoor fan motor - outdoor fan motor - and the compressor
On the common terminal

23. Why are some ACR tubing lines insulated?
With a minimum of three evenly spaced self-tapping screws
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
They are larger
Pull a vacuum

24. How are the condenser coils different on a high-efficiency unit?
Boil the liquid refrigerant out ot the oil within the crankcase
40 degrees F
40 degrees F
They are larger

25. If pressure rises - what happens to the superheat?
By increasing the surface of the condenser coil
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
It rises
Duct - electrical - and mechanical

26. What is used to measure static air pressure in ducts.
Subtract ambient temperature from 100
They are physically larger
Outside diameter (OD)
Inclined manometer

27. How many amps can 10 g wire handle?
Shorted winding - open winding - and grounded winding
30 A
200
To remove humidity and lower dry bulb temperature

28. Sections of duct board can be fastened together with what?
They are physically larger
30 A
A swaging tool
Staples and tape

29. What is it called when liquid refrigerant gets into the compressor?
Slugging
20 degrees F
Btu/hr (output) / wattage (input)
Yes

30. What kind of metering device do high-efficiency units usually use?
Below 800 degrees F
In series
TXV
Belt drive and direct drive

31. What are the two types of return air systems in residential installations?
Duct with insulation on the inside
Yes
Pull a vacuum
Individual return air systems and central return air systems

32. How is insulation around a duct rated?
45-55%
20 degrees F
ACR (air-conditioning refrigeration) tubing
With an are rating

33. What are normal conditions - as defined by the ARI.
With an are rating
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Btu/hr (output) / wattage (input)
Vapor

34. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
Fiberglass
In parallel
Suction
True

35. Where is insulation used on copper tubing used for air-conditioning?
25-ft or 50-ft
The suction line or the low-pressure side
8
Compressor

36. What is the typical temperature difference between a standard-efficiency condenser and the ambient temperature?
It will be high
Heat loss
Standard
30 degrees F

37. What is the difference between SEER and EER?
SEER includes the energy used in the start-up and shut-down cycles
When the system is under pressure
With an are rating
Yes

38. What sort of pressure will a push-through evaporator have?
105 degrees F
Positive
Pistons
Over 800 degrees F

39. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
Compressor
45-55%
Outside of the male fitting
It will be low

40. How are round ducts connected to one another?
Potential relay and start capacitor
L-type
With a minimum of three evenly spaced self-tapping screws
A dirty evaporator

41. If the rpm's are 1750 - how many poles does the motor have?
4
To remove humidity and lower dry bulb temperature
In series
Before the vent

42. Does a package unit come from the factory pre-charged?
25-ft or 50-ft
A band 4 inches or more in width
Yes
A dirty evaporator

43. 13 SEER is classified as what kind of efficiency?
Rise
They are physically larger
High
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.

44. What are the three major power-consuming devices on an air-conditioning system?
It also rises
High
Duct with insulation on the inside
Indoor fan motor - outdoor fan motor - and the compressor

45. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
By increasing the surface of the condenser coil
Side-by-side and over-and-under
Yes
Any amount

46. 7' round duct has a ballpark cfm of what?
On the common terminal
Static pressure - velocity pressure - and total pressure
150
Fiberglass

47. How many amps can 14 g wire handle?
40 A
Vapor
15 A
Shorted winding - open winding - and grounded winding

48. The A/C size is calculated by what?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Duct with insulation on the inside
Static pressure - velocity pressure - and total pressure
Heat load

49. What is the typical temperature difference between a high-efficiency condenser and the ambient temperature?
Rise
Standard
20 degrees F
Yes

50. 8' round duct has a ballpark cfm of what?
They are physically larger
It will be high
200
Nominal-sized tubing