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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 is ACR tubing sized?
Positive
Any amount
Outside diameter (OD)
Subtract ambient temperature from 100

2. 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
Inclined manometer
It also rises
SEER includes the energy used in the start-up and shut-down cycles

3. Superheat should never be below how many degrees
No
40 degrees F
5 degrees
In parallel

4. What type of air conditioning system must be charged using the superheat method?
A piston type metering device
15 A
40 A
It will be low

5. If the rpm's are 3450 - how many poles does the motor have?
Shorted winding - open winding - and grounded winding
200
2
Staples and tape

6. How does ACR copper pipe come?
Nominal-sized tubing
Any amount
Dehydrated with caps on each end
On the common terminal

7. What is the range for normal superheat and subcooling?
Infiltration and ventilation
8-12 degrees F
When the system is under pressure
A swaging tool

8. Does a package unit come from the factory pre-charged?
Yes
No
20 degrees F
Negative

9. Which type of wire can handle a higher ampacity?
40 A
Stranded
High
20 degrees above ambient

10. How are round ducts connected to one another?
With a minimum of three evenly spaced self-tapping screws
20 A
Btu/hr (output) / wattage (input)
With an are rating

11. Most duct insulation is made of what?
Any amount
Nominal-sized tubing
The takeoff fitting
Fiberglass

12. Pressure in ductwork is measured In what?
Nitrogen with a small amount of refrigerant
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Inches of water column (in. WC)

13. Where do you apply flux when soldering?
With an are rating
With a minimum of three evenly spaced self-tapping screws
It also rises
Outside of the male fitting

14. Where do you apply flux when soldering?
400
Outside of the male fitting
150
Average feet per minute X area in square feet (H' x W'/144)

15. Will a dirty condenser cause a rise or fall in pressure?
S-clips and drives (cleats)
Rise
Belt drive and direct drive
With 4' saddles

16. How many BTU's per ton?
Compressor
12000
15% silphos
Pi x radius squared

17. The A/C size is calculated by what?
20 degrees F
Inclined manometer
Heat load
45 degrees F

18. What sort of pressure will a pull-through evaporator have?
Heat load
Negative
Average feet per minute X area in square feet (H' x W'/144)
It also rises

19. Why are some ACR tubing lines insulated?
Infiltration and ventilation
30-35 degrees above ambient
Negative
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line

20. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
Below 800 degrees F
It will be low
Heat loss
It will have a decrease in superheat

21. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
2 minutes
S-clips and drives (cleats)
When it is a pull-through evaporator
To lower the amount of pressure drop through the coil

22. Where do you install a trap on a drain line?
TXV
Before the vent
Slugging
Pi x radius squared

23. What kind of refrigeratnts must be added in liquid form?
6
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
Blended refrigerants
18 gauge

24. What is the name of the fitting where the branch line leaves the duct?
They are physically larger
Inches of water column (in. WC)
The takeoff fitting
It will be high

25. At what temperature does refrigerant condense in a standard-efficiency unit?
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
1/4'
30-35 degrees above ambient
30 A

26. What are the two functions of the air-conditioning system?
With an are rating
Any amount
To remove humidity and lower dry bulb temperature
RLA/FLA x 5

27. If the suction pressure rises - what happens to the head pressure?
15% silphos
When it is above a conditioned space
It also rises
40 degrees F

28. 10' round duct has a ballpark cfm of what?
400
Yes
A dirty evaporator
Static pressure - velocity pressure - and total pressure

29. What are the two ways that fresh air enters a structure?
Infiltration and ventilation
30 degrees F
Before the vent
Pull a vacuum

30. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
A band 4 inches or more in width
40 degrees F
Yes
To lower the amount of pressure drop through the coil

31. What is the typical pressure differance across a TXV?
6
It will have a decrease in superheat
100 psig
A band 4 inches or more in width

32. In what state is the refrigerant in the compressor?
The suction line or the low-pressure side
To remove humidity and lower dry bulb temperature
Yes
Vapor

33. What is a package unit?
It will be high
Yes
Suction
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.

34. Which is more efficient - a TXV or a fixed-orifice metering device?
RLA/FLA x 5
Stranded
Yes
TXV

35. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
Staples and tape
Side-by-side and over-and-under
6
It will have a decrease in superheat

36. When must a copper joint never be soldered or brazed?
When the system is under pressure
Duct - electrical - and mechanical
Outside of the male fitting
Outside of the male fitting

37. How much does a drain line need to drop per foot of length?

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38. 6' round duct has a ballpark cfm of what?
8
20 degrees above ambient
100
A swaging tool

39. Pressure in ductwork is measured In what?
TXV
Btu/hr (output) / wattage (input)
TXV
Inches of water column (in. WC)

40. 7' round duct has a ballpark cfm of what?
150
30 A
4
Duct - electrical - and mechanical

41. How are the high pressure switch and the low pressure switch wired with the compressor contactor?
Compressor
40 degrees F
In series
True

42. Can refrigerant line sets be altered in length?
Rise
30 A
It will be high
Yes

43. What do you use to connect square and rectangular ductboard together?
S-clips and drives (cleats)
150
Suction
A piston type metering device

44. If the rpm's are 1750 - how many poles does the motor have?
40 A
Pull a vacuum
4
300

45. Where is insulation used on copper tubing used for air-conditioning?
The suction line or the low-pressure side
Inside diameter (ID)
Nitrogen with a small amount of refrigerant
Pistons

46. The evaporator is designed to remove what two types of heat?
Standard
Latent and sensible
With a minimum of three evenly spaced self-tapping screws
False

47. The load on the evaporater will effect which pressure?
TXV
Btu/hr (output) / wattage (input)
When the system is under pressure
Suction

48. The crankcase heater on an air-conditioning compressor is used to what?
It also rises
Inside diameter (ID)
200
Boil the liquid refrigerant out ot the oil within the crankcase

49. How do you calculate the area of a circle?
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
8-12 degrees F
Pi x radius squared
Over/under and side by side

50. The evaporator is designed to remove what two types of heat?
Over/under and side by side
Latent and sensible
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
12000