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Test your basic knowledge |
Residential Air Conditioning
Start Test
Study First
Subjects
:
engineering
,
nate
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. Which is more efficient - a TXV or a fixed-orifice metering device?
Compressor
Pull a vacuum
TXV
100
2. What are normal conditions - as defined by the ARI.
In series
40 degrees F
A bypass duct or a dump zone
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
3. How long should you leave a system off once you kill power before restarting it?
Over 800 degrees F
2 minutes
Pull a vacuum
In series
4. How do you calculate EER?
Btu/hr (output) / wattage (input)
Outside of the male fitting
False
Before the vent
5. What do you use to connect square and rectangular ductboard together?
S-clips and drives (cleats)
12000
20 A
Heat loss
6. The load on the evaporater will effect which pressure?
With a minimum of three evenly spaced self-tapping screws
30-35 degrees above ambient
40 degrees F
Suction
7. The compressor is cooled by liquid refrigerant. (True of False)
Before the vent
It rises
SEER includes the energy used in the start-up and shut-down cycles
False
8. 6' round duct has a ballpark cfm of what?
Negative
Standard
100
4
9. What tool is used to expand the diameter of soft copper tubing
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
A swaging tool
Stranded
Yes
10. Do you need a trap on a push-through evaporator?
20 degrees above ambient
100 psig
It also rises
No
11. How do you achieve high-efficiency?
L-type
It will be high
By increasing the surface of the condenser coil
Nitrogen with a small amount of refrigerant
12. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
A bypass duct or a dump zone
Potential relay and start capacitor
300
Heat loss
13. How many amps can 14 g wire handle?
15 A
On the common terminal
True
Nitrogen with a small amount of refrigerant
14. What sort of pressure will a push-through evaporator have?
To lower the amount of pressure drop through the coil
20 A
Positive
400
15. When must a copper joint never be soldered or brazed?
Inclined manometer
Below 800 degrees F
When the system is under pressure
Pi x radius squared
16. How are the condenser coils different on a high-efficiency unit?
With 4' saddles
Inside diameter (ID)
They are larger
Btu/hr (output) / wattage (input)
17. How many amps can 14 g wire handle?
1/4'
When it is above a conditioned space
2 minutes
15 A
18. What is the difference between SEER and EER?
They are physically larger
SEER includes the energy used in the start-up and shut-down cycles
6
1/4'
19. The evaporator is designed to remove what two types of heat?
Before the vent
Latent and sensible
Nominal-sized tubing
When it is a pull-through evaporator
20. 8' round duct has a ballpark cfm of what?
2
200
When the system is under pressure
Yes
21. In what state is the refrigerant in the compressor?
TXV
Vapor
Inside diameter (ID)
To lower the amount of pressure drop through the coil
22. What is the design boiling point for most evaporator coils in residential air conditioning?
105 degrees F
Below 800 degrees F
No
40 degrees F
23. How many amps can 8 g wire handle?
Inclined manometer
It will have a decrease in superheat
Pi x radius squared
40 A
24. What are the three pressures created by moving air in ductwork?
Yes
2 minutes
12000
Static pressure - velocity pressure - and total pressure
25. 6' round duct has a ballpark cfm of what?
No
40 degrees F
100
20 degrees above ambient
26. If the rpm's are 1050 - how many poles does the motor have?
A band 4 inches or more in width
2
Standard
6
27. What are the two functions of the air-conditioning system?
S-clips and drives (cleats)
SEER includes the energy used in the start-up and shut-down cycles
To remove humidity and lower dry bulb temperature
Heat loss
28. What are normal conditions - as defined by the ARI.
Btu/hr (output) / wattage (input)
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Compressor
True
29. In what state is the refrigerant in the compressor?
Vapor
100 psig
Duct with insulation on the inside
Duct - electrical - and mechanical
30. What is the normal evaporator temperature?
300
45 degrees F
A piston type metering device
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
31. 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)
25-ft or 50-ft
150
32. How are the condenser coils different on a high-efficiency unit?
They are larger
In series
Yes
30 A
33. Do you need a vent on a pull-through evaporator?
True
Yes
Potential relay and start capacitor
Compressor
34. How will too much refrigerant effect subcooling?
Inches of water column (in. WC)
It will be high
With an are rating
Btu/hr (output) / wattage (input)
35. What standard weight copper tubing is most often used in the heating and air-conditioning industry?
When it is a pull-through evaporator
105 degrees F
30 A
L-type
36. Do you need a trap on a pull-through evaporator?
Duct - electrical - and mechanical
A swaging tool
200
Yes
37. What are the two types of package units?
Side-by-side and over-and-under
SEER includes the energy used in the start-up and shut-down cycles
100
False
38. Where do you check the amps on a motor?
High
On the common terminal
Negative
Compressor
39. What kind of copper tubing is used for refrigeration or air-conditioning applications?
A piston type metering device
ACR (air-conditioning refrigeration) tubing
Stranded
TXV
40. What kind of refrigeratnts must be added in liquid form?
150
Blended refrigerants
1/4'
Any amount
41. When do you install a trap on a drain line?
When it is a pull-through evaporator
6
30 A
Blended refrigerants
42. The evaporator is designed to remove what two types of heat?
ACR (air-conditioning refrigeration) tubing
Yes
5 degrees
Latent and sensible
43. Which type of wire can handle a higher ampacity?
With 4' saddles
Yes
Stranded
Compressor
44. The load on the evaporater will effect which pressure?
No
TXV
Suction
15% silphos
45. What percentage silver do you need to use for an are-410 system?
RLA/FLA x 5
15% silphos
A band 4 inches or more in width
With 4' saddles
46. Do you need a vent on a push-through evaporator?
Inclined manometer
Inches of water column (in. WC)
Yes
8
47. The crankcase heater on an air-conditioning compressor is used to what?
To lower the amount of pressure drop through the coil
Infiltration and ventilation
Boil the liquid refrigerant out ot the oil within the crankcase
Shorted winding - open winding - and grounded winding
48. How is flexible duct supported?
A band 4 inches or more in width
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
A bypass duct or a dump zone
A swaging tool
49. What is the range for normal superheat and subcooling?
Individual return air systems and central return air systems
8-12 degrees F
6
ACR (air-conditioning refrigeration) tubing
50. Superheat should never be below how many degrees
Potential relay and start capacitor
5 degrees
To remove humidity and lower dry bulb temperature
Outside of the male fitting