Test your basic knowledge |

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. The fan switch opens at what temperature?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
4
105 degrees F
Sheet metal - galvanized sheet metal - fiberglass - and flexduct

2. How is insulation around a duct rated?
Nominal-sized tubing
Static pressure - velocity pressure - and total pressure
With an are rating
20 A

3. How will too much refrigerant effect superheat?
400
100
It will be low
With a minimum of three evenly spaced self-tapping screws

4. How are the condenser coils different on a high-efficiency unit?
They are larger
100
It rises
4

5. If the rpm's are 3450 - how many poles does the motor have?
2
Heat loss
When it is a pull-through evaporator
140 degrees F

6. Do you need a trap on a push-through evaporator?
40 degrees F
Dehydrated with caps on each end
No
Suction

7. Will a dirty condenser cause a rise or fall in pressure?
Static pressure - velocity pressure - and total pressure
In parallel
When the system is under pressure
Rise

8. What do you use to check for leaks?
Shorted winding - open winding - and grounded winding
30 A
5 degrees
Nitrogen with a small amount of refrigerant

9. How are the high pressure switch and the low pressure switch wired with the compressor contactor?
A band 4 inches or more in width
When it is a pull-through evaporator
No
In series

10. The compressor is cooled by liquid refrigerant. (True of False)
False
Latent and sensible
Outside of the male fitting
Negative

11. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
300
It will have a decrease in superheat
100 psig
With 4' saddles

12. What are the three crafts normally associated with an air-conditioned installation?
Yes
They are physically larger
Duct - electrical - and mechanical
105 degrees F

13. How do you calculate cfm?

14. What is the typical temperature difference between a standard-efficiency condenser and the ambient temperature?
6
Inside diameter (ID)
30 degrees F
30 A

15. 9' round duct has a ballpark cfm of what?
When it is a pull-through evaporator
300
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Negative

16. What do you do after you braze a system?
400
Pull a vacuum
Yes
45 degrees F

17. 10 SEER is classified as what kind of efficiency?
40 degrees F
RLA/FLA x 5
30 degrees F
Standard

18. How are round ducts supported?

19. What are the two basic duct connection configurations for package units supply and return air ducts?
Over/under and side by side
Yes
It rises
40 A

20. What are the two ways that fresh air enters a structure?
Average feet per minute X area in square feet (H' x W'/144)
Infiltration and ventilation
Shorted winding - open winding - and grounded winding
45-55%

21. How is the high pressure switch wired with the low pressure switch?
Pull a vacuum
In parallel
A diffuser
Pi x radius squared

22. 6' round duct has a ballpark cfm of what?
200
Average feet per minute X area in square feet (H' x W'/144)
100
Shorted winding - open winding - and grounded winding

23. What are the three ways a motor can fail electrically?
40 degrees F
They are physically larger
SEER includes the energy used in the start-up and shut-down cycles
Shorted winding - open winding - and grounded winding

24. What is a package unit?
25-ft or 50-ft
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Rise
Nitrogen with a small amount of refrigerant

25. What are the three pressures created by moving air in ductwork?
It will be low
Static pressure - velocity pressure - and total pressure
12000
Over 800 degrees F

26. What kind of copper tubing is used for refrigeration or air-conditioning applications?
ACR (air-conditioning refrigeration) tubing
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
25-ft or 50-ft
Side-by-side and over-and-under

27. When do you install a trap on a drain line?
False
When it is a pull-through evaporator
Yes
400

28. What are the two ways that fresh air enters a structure?
It will be low
Infiltration and ventilation
Latent and sensible
150

29. What are the two types of blower drives?
Fiberglass
Btu/hr (output) / wattage (input)
Belt drive and direct drive
When it is above a conditioned space

30. Where is insulation used on copper tubing used for air-conditioning?
Nominal-sized tubing
A bypass duct or a dump zone
Heat load
The suction line or the low-pressure side

31. What are the two functions of the air-conditioning system?
Yes
Dehydrated with caps on each end
A swaging tool
To remove humidity and lower dry bulb temperature

32. How are round ducts connected to one another?
No
With a minimum of three evenly spaced self-tapping screws
Shorted winding - open winding - and grounded winding
Inclined manometer

33. How many amps can 8 g wire handle?
When it is above a conditioned space
A bypass duct or a dump zone
A band 4 inches or more in width
40 A

34. What percentage silver do you need to use for an are-410 system?
A dirty evaporator
Staples and tape
Blended refrigerants
15% silphos

35. What are the three major power-consuming devices on an air-conditioning system?
Nitrogen with a small amount of refrigerant
On the common terminal
Indoor fan motor - outdoor fan motor - and the compressor
Dehydrated with caps on each end

36. What kind of metering device do high-efficiency units usually use?
True
TXV
Yes
Latent and sensible

37. How many amps can 14 g wire handle?
15 A
Yes
Rise
Duct with insulation on the inside

38. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
It will be low
True
It will be high
They are larger

39. Which type of wire can handle a higher ampacity?
A diffuser
Over 800 degrees F
Stranded
2

40. 13 SEER is classified as what kind of efficiency?
Negative
2 minutes
L-type
High

41. How are the high pressure switch and the low pressure switch wired with the compressor contactor?
In series
Belt drive and direct drive
False
Over/under and side by side

42. How many BTU's per ton?
When it is a pull-through evaporator
12000
Below 800 degrees F
Yes

43. A reciprocating compressor has what sort of moving parts?
On the common terminal
A dirty evaporator
To remove humidity and lower dry bulb temperature
Pistons

44. How will too much refrigerant effect subcooling?
They are larger
It will be high
Potential relay and start capacitor
Any amount

45. How many BTU's per ton?
15% silphos
Duct - electrical - and mechanical
12000
300

46. The crankcase heater on an air-conditioning compressor is used to what?
Boil the liquid refrigerant out ot the oil within the crankcase
40 degrees F
Nominal-sized tubing
40 A

47. What is used to measure static air pressure in ducts.
Potential relay and start capacitor
200
Belt drive and direct drive
Inclined manometer

48. How long should you leave a system off once you kill power before restarting it?
Rise
It rises
2 minutes
Inclined manometer

49. How does ACR copper pipe come?
Dehydrated with caps on each end
20 degrees F
Side-by-side and over-and-under
A band 4 inches or more in width

50. If the rpm's are 3450 - how many poles does the motor have?
2
The takeoff fitting
105 degrees F
Pi x radius squared