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
150
Positive
100

2. How will too much refrigerant effect superheat?
The takeoff fitting
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
It will be low
It will be high

3. What kind of metering device do high-efficiency units usually use?
With 4' saddles
TXV
100
In parallel

4. What tool is used to expand the diameter of soft copper tubing
Btu/hr (output) / wattage (input)
Yes
A swaging tool
Inclined manometer

5. How does ACR copper pipe come?
Infiltration and ventilation
Inches of water column (in. WC)
A piston type metering device
Dehydrated with caps on each end

6. Pressure in ductwork is measured In what?
400
30-35 degrees above ambient
Inches of water column (in. WC)
It rises

7. What is considered normal operating conditions?
18 gauge
Subtract ambient temperature from 100
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Over/under and side by side

8. Which is more efficient - a TXV or a fixed-orifice metering device?
A swaging tool
20 A
Pull a vacuum
TXV

9. What standard weight copper tubing is most often used in the heating and air-conditioning industry?
Fiberglass
L-type
In parallel
Belt drive and direct drive

10. What is the normal evaporator temperature?
Inclined manometer
30 A
20 degrees above ambient
45 degrees F

11. What are normal conditions - as defined by the ARI.
1/4'
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Positive
RLA/FLA x 5

12. What component changes refrigerant from a low pressure gas to a high pressure gas?
5 degrees
Nominal-sized tubing
Outside diameter (OD)
Compressor

13. What sort of pressure will a push-through evaporator have?
40 degrees F
Positive
In series
Static pressure - velocity pressure - and total pressure

14. What is the name of the fitting where the branch line leaves the duct?
The takeoff fitting
400
Inches of water column (in. WC)
100

15. Where do you apply flux when soldering?
300
8
Standard
Outside of the male fitting

16. Which type of wire can handle a higher ampacity?
12000
False
100
Stranded

17. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
45-55%
When it is above a conditioned space
Over 800 degrees F
It will be high

18. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
Rise
Side-by-side and over-and-under
A piston type metering device
To lower the amount of pressure drop through the coil

19. What kind of copper tubing is used for refrigeration or air-conditioning applications?
Over 800 degrees F
They are physically larger
ACR (air-conditioning refrigeration) tubing
Shorted winding - open winding - and grounded winding

20. The evaporator is designed to remove what two types of heat?
Suction
Yes
Latent and sensible
Suction

21. How is ACR tubing sized?
Outside diameter (OD)
300
30 A
Slugging

22. Do you need a trap on a pull-through evaporator?
200
2 minutes
Inches of water column (in. WC)
Yes

23. At what temperature does refrigerant condense in a standard-efficiency unit?
Nitrogen with a small amount of refrigerant
Common
It rises
30-35 degrees above ambient

24. How are the high pressure switch and the low pressure switch wired with the compressor contactor?
Slugging
5 degrees
In series
They are larger

25. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Standard
40 degrees F
Side-by-side and over-and-under

26. What is it called when liquid refrigerant gets into the compressor?
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Slugging
25-ft or 50-ft
Static pressure - velocity pressure - and total pressure

27. What are the components of a hard-start kit?
Potential relay and start capacitor
100
6
Compressor

28. What are the three pressures created by moving air in ductwork?
6
30 degrees F
Static pressure - velocity pressure - and total pressure
Common

29. Why are some ACR tubing lines insulated?
Slugging
S-clips and drives (cleats)
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
It will have a decrease in superheat

30. Does a package unit come from the factory pre-charged?
300
When the system is under pressure
Yes
Btu/hr (output) / wattage (input)

31. How do you calculate cfm?

32. Pressure in ductwork is measured In what?
Yes
The takeoff fitting
Inches of water column (in. WC)
Heat load

33. How is the high pressure switch wired with the low pressure switch?
Pistons
Common
In parallel
200

34. The fan switch opens at what temperature?
Average feet per minute X area in square feet (H' x W'/144)
400
105 degrees F
Outside of the male fitting

35. Superheat should never be below how many degrees
Stranded
5 degrees
In series
ACR (air-conditioning refrigeration) tubing

36. Where is insulation used on copper tubing used for air-conditioning?
2
The suction line or the low-pressure side
40 A
100

37. Most duct insulation is made of what?
Fiberglass
Dehydrated with caps on each end
12000
18 gauge

38. 7' round duct has a ballpark cfm of what?
150
In series
Compressor
High

39. What gauge is thermostat wire?
Yes
18 gauge
400
140 degrees F

40. If the suction pressure rises - what happens to the head pressure?
It also rises
TXV
20 degrees F
A swaging tool

41. What is it called when liquid refrigerant gets into the compressor?
Slugging
With an are rating
Suction
False

42. What kind of copper tubing is used for refrigeration or air-conditioning applications?
ACR (air-conditioning refrigeration) tubing
Static pressure - velocity pressure - and total pressure
Vapor
When the system is under pressure

43. What are the two types of blower drives?
Duct - electrical - and mechanical
True
Belt drive and direct drive
Outside of the male fitting

44. How many amps can 10 g wire handle?
Staples and tape
They are physically larger
30 A
On the common terminal

45. What kind of metering device do high-efficiency units usually use?
No
TXV
Over 800 degrees F
6

46. The crankcase heater on an air-conditioning compressor is used to what?
100 psig
400
Boil the liquid refrigerant out ot the oil within the crankcase
300

47. If the rpm's are 750 - how many poles does the motor have?
RLA/FLA x 5
8
Pull a vacuum
Yes

48. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
45-55%
Any amount
Positive
Rise

49. What component changes refrigerant from a low pressure gas to a high pressure gas?
12000
Compressor
8-12 degrees F
15% silphos

50. What standard weight copper tubing is most often used in the heating and air-conditioning industry?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
L-type
Dehydrated with caps on each end
TXV