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. Do you need a vent on a pull-through evaporator?
Yes
Btu/hr (output) / wattage (input)
When it is above a conditioned space
200

2. How do you calculate ballpark superheat?
A swaging tool
Subtract ambient temperature from 100
8
RLA/FLA x 5

3. Superheat should never be below how many degrees
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
A diffuser
5 degrees
18 gauge

4. What can cause a decrease in suction pressure on an air-conditioning system?
They are larger
Any amount
A dirty evaporator
30-35 degrees above ambient

5. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
45-55%
100 psig
False
Slugging

6. What are the three crafts normally associated with an air-conditioned installation?
Duct - electrical - and mechanical
Static pressure - velocity pressure - and total pressure
400
12000

7. 9' round duct has a ballpark cfm of what?
Inside diameter (ID)
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
300
They are physically larger

8. Does a package unit come from the factory pre-charged?
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Yes
Static pressure - velocity pressure - and total pressure
True

9. At what temperature will brazing melt?
A swaging tool
2
Indoor fan motor - outdoor fan motor - and the compressor
Over 800 degrees F

10. What is lined duct?
Heat load
Duct with insulation on the inside
Btu/hr (output) / wattage (input)
Yes

11. What do you do after you braze a system?
When it is above a conditioned space
Pull a vacuum
Subtract ambient temperature from 100
95 degrees F outside - 80 degrees F inside - and 50% relative humidity

12. In what length rolls is soft copper tubing normally available?
25-ft or 50-ft
Heat load
Outside of the male fitting
They are physically larger

13. How do you achieve high-efficiency?
By increasing the surface of the condenser coil
True
Duct with insulation on the inside
High

14. What kind of copper tubing is used for plumbing and heating applications?
Stranded
Heat load
Belt drive and direct drive
Nominal-sized tubing

15. If the rpm's are 3450 - how many poles does the motor have?
Over 800 degrees F
2
8
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity

16. At what temperature does refrigerant condense in a standard-efficiency unit?
Inches of water column (in. WC)
Btu/hr (output) / wattage (input)
30-35 degrees above ambient
150

17. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
It will have a decrease in superheat
Belt drive and direct drive
Any amount
Potential relay and start capacitor

18. How do you calculate ballpark superheat?
Subtract ambient temperature from 100
100
140 degrees F
200

19. 13 SEER is classified as what kind of efficiency?
Outside diameter (OD)
Outside of the male fitting
Static pressure - velocity pressure - and total pressure
High

20. Where do you install a trap on a drain line?
A bypass duct or a dump zone
Dehydrated with caps on each end
Before the vent
It will be high

21. How many amps can 12 g wire handle?
Duct with insulation on the inside
20 A
15 A
30-35 degrees above ambient

22. What sort of pressure will a pull-through evaporator have?
Outside of the male fitting
Negative
Rise
False

23. What is lined duct?
Stranded
Duct with insulation on the inside
2
12000

24. What is considered normal operating conditions?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
To remove humidity and lower dry bulb temperature
30-35 degrees above ambient
30 A

25. What distributes supply air to a room in a structure?
A diffuser
They are physically larger
In parallel
By increasing the surface of the condenser coil

26. The crankcase heater on an air-conditioning compressor is used to what?
Boil the liquid refrigerant out ot the oil within the crankcase
30-35 degrees above ambient
150
Belt drive and direct drive

27. What is considered normal operating conditions?
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Btu/hr (output) / wattage (input)
It will be low

28. How many amps can 8 g wire handle?
Over/under and side by side
40 A
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
2

29. At what temperature will brazing melt?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
In parallel
Over 800 degrees F
140 degrees F

30. What can cause a decrease in suction pressure on an air-conditioning system?
A dirty evaporator
ACR (air-conditioning refrigeration) tubing
Nominal-sized tubing
Infiltration and ventilation

31. The compressor is cooled by liquid refrigerant. (True of False)
Boil the liquid refrigerant out ot the oil within the crankcase
Nominal-sized tubing
Slugging
False

32. Where do you apply flux when soldering?
Outside of the male fitting
Pi x radius squared
15% silphos
Suction

33. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
40 A
Heat load
15 A
Any amount

34. How are round ducts connected to one another?
SEER includes the energy used in the start-up and shut-down cycles
With a minimum of three evenly spaced self-tapping screws
With an are rating
It will have a decrease in superheat

35. What are the three ways a motor can fail electrically?
Average feet per minute X area in square feet (H' x W'/144)
20 degrees F
400
Shorted winding - open winding - and grounded winding

36. If pressure rises - what happens to the superheat?
Compressor
Inclined manometer
Heat loss
It rises

37. When do you install an auxillary drain pan?
By increasing the surface of the condenser coil
They are larger
When it is above a conditioned space
True

38. 6' round duct has a ballpark cfm of what?
100
400
Yes
A piston type metering device

39. What is a package unit?
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Side-by-side and over-and-under
Boil the liquid refrigerant out ot the oil within the crankcase
Below 800 degrees F

40. If the rpm's are 750 - how many poles does the motor have?
TXV
8
Compressor
Duct with insulation on the inside

41. If the rpm's are 1750 - how many poles does the motor have?
4
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Any amount
Inside diameter (ID)

42. What kind of refrigeratnts must be added in liquid form?
Below 800 degrees F
Blended refrigerants
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
RLA/FLA x 5

43. How are round ducts connected to one another?
With an are rating
5 degrees
With a minimum of three evenly spaced self-tapping screws
Yes

44. The load on the evaporater will effect which pressure?
Compressor
Suction
Pull a vacuum
With 4' saddles

45. What component changes refrigerant from a low pressure gas to a high pressure gas?
They are larger
Duct - electrical - and mechanical
Compressor
2 minutes

46. Will a dirty condenser cause a rise or fall in pressure?
S-clips and drives (cleats)
Individual return air systems and central return air systems
Rise
95 degrees F outside - 80 degrees F inside - and 50% relative humidity

47. What tool is used to expand the diameter of soft copper tubing
A piston type metering device
100
A swaging tool
To lower the amount of pressure drop through the coil

48. What is it called when liquid refrigerant gets into the compressor?
Slugging
Individual return air systems and central return air systems
105 degrees F
Yes

49. What distributes supply air to a room in a structure?
200
A diffuser
30 A
Latent and sensible

50. What do you use to check for leaks?
Outside of the male fitting
Yes
Nitrogen with a small amount of refrigerant
It rises