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. 8' round duct has a ballpark cfm of what?
Pull a vacuum
When it is above a conditioned space
200
300

2. How do you calculate ballpark superheat?
SEER includes the energy used in the start-up and shut-down cycles
The takeoff fitting
Subtract ambient temperature from 100
Over 800 degrees F

3. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
Outside diameter (OD)
In parallel
Latent and sensible
40 degrees F

4. The evaporator is designed to remove what two types of heat?
4
Latent and sensible
15 A
In parallel

5. How will too much refrigerant effect superheat?
105 degrees F
When it is a pull-through evaporator
No
It will be low

6. What tool is used to expand the diameter of soft copper tubing
A swaging tool
By increasing the surface of the condenser coil
100 psig
S-clips and drives (cleats)

7. The furnace size is calculated by what?
Heat loss
ACR (air-conditioning refrigeration) tubing
Standard
ACR (air-conditioning refrigeration) tubing

8. When do you install an auxillary drain pan?
40 A
When it is above a conditioned space
False
1/4'

9. Do you need a trap on a push-through evaporator?
No
A diffuser
It will be low
Duct with insulation on the inside

10. What are normal conditions - as defined by the ARI.
A bypass duct or a dump zone
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
8-12 degrees F
Duct - electrical - and mechanical

11. A reciprocating compressor has what sort of moving parts?
Positive
Pistons
Potential relay and start capacitor
Staples and tape

12. What is the typical temperature difference between a standard-efficiency condenser and the ambient temperature?
Yes
Potential relay and start capacitor
30 degrees F
45-55%

13. If the rpm's are 3450 - how many poles does the motor have?
Slugging
2
When it is a pull-through evaporator
Yes

14. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
2
True
45-55%
RLA/FLA x 5

15. The crankcase heater on an air-conditioning compressor is used to what?
Duct with insulation on the inside
Nominal-sized tubing
Boil the liquid refrigerant out ot the oil within the crankcase
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity

16. What kind of copper tubing is used for refrigeration or air-conditioning applications?
ACR (air-conditioning refrigeration) tubing
Slugging
20 degrees F
30 degrees F

17. The A/C size is calculated by what?
Yes
Heat load
Subtract ambient temperature from 100
Vapor

18. At what temperature does refrigerant condense in a high-efficiency unit?
Pistons
True
20 degrees above ambient
A bypass duct or a dump zone

19. Where do you check the amps on a motor?
On the common terminal
No
In series
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.

20. How is flexible duct supported?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
A band 4 inches or more in width
6
Any amount

21. At what temperature will soft solder melt?
With an are rating
150
Heat load
Below 800 degrees F

22. Superheat should never be below how many degrees
Indoor fan motor - outdoor fan motor - and the compressor
5 degrees
25-ft or 50-ft
It will be low

23. The fan switch closes at what temperature?
400
1/4'
140 degrees F
Btu/hr (output) / wattage (input)

24. What can cause a decrease in suction pressure on an air-conditioning system?
15% silphos
The takeoff fitting
A dirty evaporator
150

25. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
8
Yes
40 degrees F
Heat load

26. What are the three pressures created by moving air in ductwork?
Static pressure - velocity pressure - and total pressure
A diffuser
When the system is under pressure
Infiltration and ventilation

27. How is the high pressure switch wired with the low pressure switch?
Pistons
In parallel
Before the vent
Compressor

28. What are the three crafts normally associated with an air-conditioned installation?
6
8-12 degrees F
Duct - electrical - and mechanical
400

29. 10' round duct has a ballpark cfm of what?
By increasing the surface of the condenser coil
Suction
400
No

30. How are high-efficiency condenser coils different from standard-efficiency condenser coils?
To remove humidity and lower dry bulb temperature
They are physically larger
Staples and tape
Inches of water column (in. WC)

31. The crankcase heater on an air-conditioning compressor is used to what?
Over 800 degrees F
With a minimum of three evenly spaced self-tapping screws
Nitrogen with a small amount of refrigerant
Boil the liquid refrigerant out ot the oil within the crankcase

32. What gauge is thermostat wire?
When it is a pull-through evaporator
The takeoff fitting
18 gauge
Sheet metal - galvanized sheet metal - fiberglass - and flexduct

33. What gauge is thermostat wire?
They are larger
18 gauge
150
Dehydrated with caps on each end

34. What is the range for normal superheat and subcooling?
100 psig
8-12 degrees F
Below 800 degrees F
True

35. How do you calculate LRA?
Outside of the male fitting
The takeoff fitting
Potential relay and start capacitor
RLA/FLA x 5

36. How long should you leave a system off once you kill power before restarting it?
40 degrees F
2 minutes
8
In parallel

37. Does a package unit come from the factory pre-charged?
High
25-ft or 50-ft
Yes
A piston type metering device

38. The fan switch opens at what temperature?
Before the vent
Duct with insulation on the inside
Dehydrated with caps on each end
105 degrees F

39. What distributes supply air to a room in a structure?
A diffuser
In series
Infiltration and ventilation
Positive

40. How does ACR copper pipe come?
By increasing the surface of the condenser coil
Static pressure - velocity pressure - and total pressure
It also rises
Dehydrated with caps on each end

41. Which is more efficient - a TXV or a fixed-orifice metering device?
TXV
High
Latent and sensible
Common

42. What is the difference between SEER and EER?
Nitrogen with a small amount of refrigerant
Heat load
SEER includes the energy used in the start-up and shut-down cycles
Duct with insulation on the inside

43. The load on the evaporater will effect which pressure?
SEER includes the energy used in the start-up and shut-down cycles
Suction
Average feet per minute X area in square feet (H' x W'/144)
Btu/hr (output) / wattage (input)

44. What kind of metering device do high-efficiency units usually use?
TXV
When it is a pull-through evaporator
Over/under and side by side
Heat load

45. 7' round duct has a ballpark cfm of what?
150
25-ft or 50-ft
Staples and tape
Positive

46. How is insulation around a duct rated?
Inside diameter (ID)
Pi x radius squared
Potential relay and start capacitor
With an are rating

47. A reciprocating compressor has what sort of moving parts?
When it is a pull-through evaporator
25-ft or 50-ft
Inches of water column (in. WC)
Pistons

48. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
Below 800 degrees F
Individual return air systems and central return air systems
True
Dehydrated with caps on each end

49. What do you use to check for leaks?
12000
Dehydrated with caps on each end
Nitrogen with a small amount of refrigerant
Dehydrated with caps on each end

50. How is ACR tubing sized?
Outside diameter (OD)
Yes
A bypass duct or a dump zone
It will have a decrease in superheat