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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 two types of package units?
Side-by-side and over-and-under
8
A diffuser
Inches of water column (in. WC)

2. What is the typical pressure differance across a TXV?
30 degrees F
Rise
100 psig
Indoor fan motor - outdoor fan motor - and the compressor

3. If the suction pressure rises - what happens to the head pressure?
Over 800 degrees F
It also rises
1/4'
8

4. What are the three pressures created by moving air in ductwork?
High
Blended refrigerants
Static pressure - velocity pressure - and total pressure
150

5. How is nominal-sized tubing sized?
Negative
Inside diameter (ID)
To lower the amount of pressure drop through the coil
25-ft or 50-ft

6. What is the typical pressure differance across a TXV?
Nitrogen with a small amount of refrigerant
100 psig
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Pistons

7. What is the difference between SEER and EER?
SEER includes the energy used in the start-up and shut-down cycles
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
Compressor
Common

8. Which type of wire can handle a higher ampacity?
Rise
100
Stranded
They are physically larger

9. How do you calculate LRA?
A diffuser
15% silphos
RLA/FLA x 5
A band 4 inches or more in width

10. How many BTU's per ton?
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
12000
6
In parallel

11. 7' round duct has a ballpark cfm of what?
150
Below 800 degrees F
105 degrees F
Rise

12. Which is more efficient - a TXV or a fixed-orifice metering device?
18 gauge
It will be high
TXV
Average feet per minute X area in square feet (H' x W'/144)

13. In what state is the refrigerant in the compressor?
Over/under and side by side
Individual return air systems and central return air systems
Yes
Vapor

14. What are the three crafts normally associated with an air-conditioned installation?
Latent and sensible
With an are rating
Duct - electrical - and mechanical
Slugging

15. What tool is used to expand the diameter of soft copper tubing
20 A
RLA/FLA x 5
15% silphos
A swaging tool

16. What are the three major power-consuming devices on an air-conditioning system?
Indoor fan motor - outdoor fan motor - and the compressor
TXV
40 A
Outside of the male fitting

17. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
True
400
It will have a decrease in superheat
5 degrees

18. At what temperature will brazing melt?
Static pressure - velocity pressure - and total pressure
Indoor fan motor - outdoor fan motor - and the compressor
6
Over 800 degrees F

19. What are the two types of return air systems in residential installations?
L-type
Individual return air systems and central return air systems
Average feet per minute X area in square feet (H' x W'/144)
2

20. When do you install a trap on a drain line?
When it is a pull-through evaporator
It will be high
By increasing the surface of the condenser coil
With an are rating

21. What is the difference between SEER and EER?
100 psig
SEER includes the energy used in the start-up and shut-down cycles
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Before the vent

22. How will too much refrigerant effect superheat?
It will be low
In parallel
8-12 degrees F
In series

23. Most duct insulation is made of what?
A piston type metering device
200
Fiberglass
Potential relay and start capacitor

24. The A/C size is calculated by what?
Compressor
TXV
Slugging
Heat load

25. What are the two types of return air systems in residential installations?
Static pressure - velocity pressure - and total pressure
Latent and sensible
15% silphos
Individual return air systems and central return air systems

26. What is the typical temperature difference between a standard-efficiency condenser and the ambient temperature?
Boil the liquid refrigerant out ot the oil within the crankcase
Side-by-side and over-and-under
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
30 degrees F

27. 10 SEER is classified as what kind of efficiency?
Standard
6
With a minimum of three evenly spaced self-tapping screws
Stranded

28. How long should you leave a system off once you kill power before restarting it?
2
2 minutes
It rises
25-ft or 50-ft

29. Will a dirty condenser cause a rise or fall in pressure?
Rise
Fiberglass
25-ft or 50-ft
40 degrees F

30. How is flexible duct supported?
100
A band 4 inches or more in width
Potential relay and start capacitor
Duct - electrical - and mechanical

31. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
2 minutes
5 degrees
A bypass duct or a dump zone
Compressor

32. What is a package unit?
Yes
Dehydrated with caps on each end
Belt drive and direct drive
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.

33. How are the high pressure switch and the low pressure switch wired with the compressor contactor?
In series
Fiberglass
Subtract ambient temperature from 100
To lower the amount of pressure drop through the coil

34. What is the typical temperature difference between a high-efficiency condenser and the ambient temperature?
It rises
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Yes
20 degrees F

35. 8' round duct has a ballpark cfm of what?
45 degrees F
In series
200
105 degrees F

36. 10' round duct has a ballpark cfm of what?
Vapor
Yes
Shorted winding - open winding - and grounded winding
400

37. How are round ducts supported?

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38. What are the two functions of the air-conditioning system?
Heat load
30 A
To remove humidity and lower dry bulb temperature
20 A

39. The furnace size is calculated by what?
Heat loss
15% silphos
TXV
Average feet per minute X area in square feet (H' x W'/144)

40. If pressure rises - what happens to the superheat?
TXV
It rises
200
L-type

41. What do you use to check for leaks?
They are larger
1/4'
The takeoff fitting
Nitrogen with a small amount of refrigerant

42. What are the three ways a motor can fail electrically?
L-type
Shorted winding - open winding - and grounded winding
A band 4 inches or more in width
Sheet metal - galvanized sheet metal - fiberglass - and flexduct

43. How do you achieve high-efficiency?
Latent and sensible
A band 4 inches or more in width
By increasing the surface of the condenser coil
Suction

44. If the rpm's are 3450 - how many poles does the motor have?
It also rises
2
Fiberglass
100

45. How many amps can 10 g wire handle?
30 A
With a minimum of three evenly spaced self-tapping screws
The takeoff fitting
In series

46. How many amps can 14 g wire handle?
Below 800 degrees F
400
When the system is under pressure
15 A

47. How will too much refrigerant effect superheat?
S-clips and drives (cleats)
Nominal-sized tubing
It will be low
A swaging tool

48. What is lined duct?
4
Common
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
Duct with insulation on the inside

49. How are high-efficiency condenser coils different from standard-efficiency condenser coils?
8
12000
They are physically larger
Sheet metal - galvanized sheet metal - fiberglass - and flexduct

50. How are the condenser coils different on a high-efficiency unit?
Static pressure - velocity pressure - and total pressure
Vapor
They are larger
True