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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. What are the four materials used to make duct?
30 degrees F
When it is above a conditioned space
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Sheet metal - galvanized sheet metal - fiberglass - and flexduct

2. 9' round duct has a ballpark cfm of what?
30-35 degrees above ambient
Slugging
300
15 A

3. 10' round duct has a ballpark cfm of what?
Indoor fan motor - outdoor fan motor - and the compressor
Blended refrigerants
Shorted winding - open winding - and grounded winding
400

4. What sort of pressure will a pull-through evaporator have?
Yes
When it is a pull-through evaporator
A swaging tool
Negative

5. How do you calculate EER?
When it is a pull-through evaporator
Btu/hr (output) / wattage (input)
Inside diameter (ID)
Suction

6. 8' round duct has a ballpark cfm of what?
Inside diameter (ID)
Nominal-sized tubing
200
Infiltration and ventilation

7. If pressure rises - what happens to the superheat?
It rises
The takeoff fitting
L-type
Subtract ambient temperature from 100

8. When must a copper joint never be soldered or brazed?
A bypass duct or a dump zone
15 A
When the system is under pressure
Potential relay and start capacitor

9. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
Yes
Any amount
Yes
Staples and tape

10. What can cause a decrease in suction pressure on an air-conditioning system?
Side-by-side and over-and-under
Btu/hr (output) / wattage (input)
High
A dirty evaporator

11. What do you do after you braze a system?
20 degrees above ambient
By increasing the surface of the condenser coil
Pull a vacuum
Common

12. A reciprocating compressor has what sort of moving parts?
Outside of the male fitting
Blended refrigerants
No
Pistons

13. How do you calculate ballpark superheat?
False
A diffuser
Subtract ambient temperature from 100
18 gauge

14. How do you achieve high-efficiency?
With 4' saddles
To lower the amount of pressure drop through the coil
By increasing the surface of the condenser coil
4

15. Why are some ACR tubing lines insulated?
Shorted winding - open winding - and grounded winding
No
Heat loss
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line

16. In what state is the refrigerant in the compressor?
True
Dehydrated with caps on each end
Pi x radius squared
Vapor

17. What are the three crafts normally associated with an air-conditioned installation?
On the common terminal
Boil the liquid refrigerant out ot the oil within the crankcase
Average feet per minute X area in square feet (H' x W'/144)
Duct - electrical - and mechanical

18. How are round ducts supported?

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19. Where do you check the amps on a motor?
On the common terminal
Pi x radius squared
Static pressure - velocity pressure - and total pressure
Vapor

20. How do you calculate LRA?
RLA/FLA x 5
To remove humidity and lower dry bulb temperature
A piston type metering device
Standard

21. What are normal conditions - as defined by the ARI.
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
8-12 degrees F
400
Dehydrated with caps on each end

22. At what temperature does refrigerant condense in a standard-efficiency unit?
A bypass duct or a dump zone
30-35 degrees above ambient
Duct - electrical - and mechanical
A band 4 inches or more in width

23. What are the three pressures created by moving air in ductwork?
45 degrees F
15 A
Individual return air systems and central return air systems
Static pressure - velocity pressure - and total pressure

24. How are round ducts connected to one another?
Static pressure - velocity pressure - and total pressure
With a minimum of three evenly spaced self-tapping screws
A diffuser
Suction

25. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
40 degrees F
With a minimum of three evenly spaced self-tapping screws
140 degrees F
30 degrees F

26. When do you install an auxillary drain pan?
Compressor
Yes
When it is above a conditioned space
Belt drive and direct drive

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

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28. The A/C size is calculated by what?
Before the vent
Heat load
RLA/FLA x 5
Boil the liquid refrigerant out ot the oil within the crankcase

29. What is the difference between SEER and EER?
Infiltration and ventilation
A bypass duct or a dump zone
SEER includes the energy used in the start-up and shut-down cycles
They are physically larger

30. At what temperature does refrigerant condense in a high-efficiency unit?
Individual return air systems and central return air systems
Boil the liquid refrigerant out ot the oil within the crankcase
45-55%
20 degrees above ambient

31. Where do you install a trap on a drain line?
45-55%
A band 4 inches or more in width
Before the vent
200

32. What is the range for normal superheat and subcooling?
Negative
L-type
8-12 degrees F
They are physically larger

33. If pressure rises - what happens to the superheat?
To lower the amount of pressure drop through the coil
Fiberglass
It rises
200

34. In what length rolls is soft copper tubing normally available?
30 degrees F
25-ft or 50-ft
2
Subtract ambient temperature from 100

35. Do you need a trap on a pull-through evaporator?
Before the vent
1/4'
Yes
A piston type metering device

36. Superheat should never be below how many degrees
Vapor
L-type
No
5 degrees

37. How do you achieve high-efficiency?
It also rises
It will be low
By increasing the surface of the condenser coil
12000

38. 6' round duct has a ballpark cfm of what?
Before the vent
105 degrees F
30-35 degrees above ambient
100

39. What are the three major power-consuming devices on an air-conditioning system?
Indoor fan motor - outdoor fan motor - and the compressor
Below 800 degrees F
The takeoff fitting
5 degrees

40. 10 SEER is classified as what kind of efficiency?
Duct with insulation on the inside
Potential relay and start capacitor
20 degrees above ambient
Standard

41. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
20 degrees above ambient
It will have a decrease in superheat
When it is above a conditioned space
40 degrees F

42. Where do you install a trap on a drain line?
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
40 degrees F
Before the vent
When it is above a conditioned space

43. Sections of duct board can be fastened together with what?
Staples and tape
Over/under and side by side
6
Slugging

44. Pressure in ductwork is measured In what?
Inches of water column (in. WC)
A bypass duct or a dump zone
Rise
300

45. When must a copper joint never be soldered or brazed?
When the system is under pressure
SEER includes the energy used in the start-up and shut-down cycles
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
No

46. How long should you leave a system off once you kill power before restarting it?
2 minutes
In series
Yes
To lower the amount of pressure drop through the coil

47. What do you use to check for leaks?
12000
1/4'
Nitrogen with a small amount of refrigerant
140 degrees F

48. What are the three crafts normally associated with an air-conditioned installation?
Inclined manometer
20 degrees F
SEER includes the energy used in the start-up and shut-down cycles
Duct - electrical - and mechanical

49. At what temperature does refrigerant condense in a standard-efficiency unit?
Suction
Potential relay and start capacitor
100 psig
30-35 degrees above ambient

50. If the rpm's are 1750 - how many poles does the motor have?
To remove humidity and lower dry bulb temperature
1/4'
Heat loss
4