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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 do you achieve high-efficiency?
40 degrees F
Individual return air systems and central return air systems
By increasing the surface of the condenser coil
5 degrees

2. What type of air conditioning system must be charged using the superheat method?
A piston type metering device
Over 800 degrees F
30 A
Pistons

3. A reciprocating compressor has what sort of moving parts?
With a minimum of three evenly spaced self-tapping screws
8-12 degrees F
Pistons
Duct with insulation on the inside

4. How does ACR copper pipe come?
Outside of the male fitting
2
Dehydrated with caps on each end
20 degrees F

5. What sort of pressure will a pull-through evaporator have?
Subtract ambient temperature from 100
100 psig
Negative
Yes

6. 10' round duct has a ballpark cfm of what?
Positive
400
18 gauge
Side-by-side and over-and-under

7. At what temperature does refrigerant condense in a high-efficiency unit?
When it is above a conditioned space
ACR (air-conditioning refrigeration) tubing
20 degrees above ambient
95 degrees F outside - 80 degrees F inside - and 50% relative humidity

8. What are the three ways a motor can fail electrically?
Boil the liquid refrigerant out ot the oil within the crankcase
Average feet per minute X area in square feet (H' x W'/144)
1/4'
Shorted winding - open winding - and grounded winding

9. What sort of pressure will a push-through evaporator have?
8-12 degrees F
Pull a vacuum
8-12 degrees F
Positive

10. How many BTU's per ton?
Outside diameter (OD)
12000
2
TXV

11. Pressure in ductwork is measured In what?
With 4' saddles
1/4'
Inches of water column (in. WC)
Individual return air systems and central return air systems

12. If the rpm's are 750 - how many poles does the motor have?
In series
8
Nitrogen with a small amount of refrigerant
RLA/FLA x 5

13. What are the components of a hard-start kit?
Compressor
A piston type metering device
Potential relay and start capacitor
With an are rating

14. Will a dirty condenser cause a rise or fall in pressure?
Static pressure - velocity pressure - and total pressure
Vapor
Rise
Heat load

15. What are the two basic duct connection configurations for package units supply and return air ducts?
Over/under and side by side
Inside diameter (ID)
30-35 degrees above ambient
Infiltration and ventilation

16. How are round ducts connected to one another?
105 degrees F
300
With a minimum of three evenly spaced self-tapping screws
Slugging

17. What component changes refrigerant from a low pressure gas to a high pressure gas?
False
Compressor
Outside of the male fitting
2

18. What are the three pressures created by moving air in ductwork?
Vapor
Static pressure - velocity pressure - and total pressure
Over 800 degrees F
High

19. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
It also rises
Over/under and side by side
Staples and tape
40 degrees F

20. Why are some ACR tubing lines insulated?
Shorted winding - open winding - and grounded winding
Yes
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
A bypass duct or a dump zone

21. What kind of refrigeratnts must be added in liquid form?
Blended refrigerants
ACR (air-conditioning refrigeration) tubing
A bypass duct or a dump zone
A piston type metering device

22. If pressure rises - what happens to the superheat?
Before the vent
100 psig
It rises
TXV

23. Most duct insulation is made of what?
30 degrees F
They are physically larger
Duct with insulation on the inside
Fiberglass

24. Superheat should never be below how many degrees
Pi x radius squared
Before the vent
5 degrees
It will be high

25. What can cause a decrease in suction pressure on an air-conditioning system?
On the common terminal
Below 800 degrees F
A dirty evaporator
Yes

26. How is ACR tubing sized?
True
Stranded
Outside diameter (OD)
Inside diameter (ID)

27. How do you calculate LRA?
RLA/FLA x 5
300
A diffuser
It will be low

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

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29. How are high-efficiency condenser coils different from standard-efficiency condenser coils?
20 degrees F
30 A
They are physically larger
15% silphos

30. What are the two types of package units?
TXV
Common
20 A
Side-by-side and over-and-under

31. Do you need a trap on a pull-through evaporator?
Average feet per minute X area in square feet (H' x W'/144)
It also rises
Yes
Vapor

32. 8' round duct has a ballpark cfm of what?
A bypass duct or a dump zone
200
It will have a decrease in superheat
Yes

33. Can refrigerant line sets be altered in length?
Yes
Shorted winding - open winding - and grounded winding
Over/under and side by side
40 A

34. What are the two types of return air systems in residential installations?
Individual return air systems and central return air systems
High
Belt drive and direct drive
Heat load

35. What kind of refrigeratnts must be added in liquid form?
Heat loss
TXV
To remove humidity and lower dry bulb temperature
Blended refrigerants

36. What percentage silver do you need to use for an are-410 system?
In series
15% silphos
By increasing the surface of the condenser coil
Stranded

37. The crankcase heater on an air-conditioning compressor is used to what?
Pull a vacuum
Before the vent
300
Boil the liquid refrigerant out ot the oil within the crankcase

38. At what temperature will brazing melt?
Over 800 degrees F
Outside of the male fitting
Yes
25-ft or 50-ft

39. How are the condenser coils different on a high-efficiency unit?
18 gauge
Inside diameter (ID)
105 degrees F
They are larger

40. How do you calculate EER?
18 gauge
With 4' saddles
Btu/hr (output) / wattage (input)
Compressor

41. In what state is the refrigerant in the compressor?
45-55%
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Vapor
20 degrees F

42. If the rpm's are 3450 - how many poles does the motor have?
Below 800 degrees F
RLA/FLA x 5
2
40 A

43. What are the two types of return air systems in residential installations?
140 degrees F
It will be high
Yes
Individual return air systems and central return air systems

44. What is the name of the fitting where the branch line leaves the duct?
2 minutes
When it is above a conditioned space
Stranded
The takeoff fitting

45. How many amps can 12 g wire handle?
With 4' saddles
Yes
20 A
5 degrees

46. What is a package unit?
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.
105 degrees F
It will have a decrease in superheat

47. What do you do after you braze a system?
Pull a vacuum
TXV
When it is a pull-through evaporator
Blended refrigerants

48. If the rpm's are 1750 - how many poles does the motor have?
Latent and sensible
A diffuser
Side-by-side and over-and-under
4

49. What is considered normal operating conditions?
Pistons
105 degrees F
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Outside of the male fitting

50. What are the two ways that fresh air enters a structure?
Infiltration and ventilation
They are larger
A band 4 inches or more in width
When it is a pull-through evaporator