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. How will too much refrigerant effect superheat?
Latent and sensible
Common
It will be low
TXV

2. Do you need a vent on a push-through evaporator?
4
On the common terminal
15% silphos
Yes

3. If the suction pressure rises - what happens to the head pressure?
4
It also rises
20 degrees F
With 4' saddles

4. If the rpm's are 750 - how many poles does the motor have?
20 degrees above ambient
8
Indoor fan motor - outdoor fan motor - and the compressor
100

5. How are round ducts connected to one another?
Standard
With a minimum of three evenly spaced self-tapping screws
With 4' saddles
45-55%

6. How do you calculate the area of a circle?
8
Blended refrigerants
Pi x radius squared
Positive

7. How many cfm per ton?
Any amount
400
It will be low
5 degrees

8. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
Stranded
No
Rise
40 degrees F

9. How many BTU's per ton?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Heat load
Inclined manometer
12000

10. Superheat should never be below how many degrees
Heat load
25-ft or 50-ft
Duct with insulation on the inside
5 degrees

11. Do you need a trap on a pull-through evaporator?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Yes
30 degrees F
100

12. What are the two types of blower drives?
Belt drive and direct drive
100 psig
Inside diameter (ID)
To lower the amount of pressure drop through the coil

13. In what state is the refrigerant in the compressor?
5 degrees
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Vapor
ACR (air-conditioning refrigeration) tubing

14. How will too much refrigerant effect subcooling?
Shorted winding - open winding - and grounded winding
To lower the amount of pressure drop through the coil
It will be high
With a minimum of three evenly spaced self-tapping screws

15. What is lined duct?
Duct with insulation on the inside
SEER includes the energy used in the start-up and shut-down cycles
45-55%
40 A

16. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
Nitrogen with a small amount of refrigerant
Yes
They are larger
45-55%

17. How do you calculate cfm?

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

18. Most duct insulation is made of what?
5 degrees
SEER includes the energy used in the start-up and shut-down cycles
Common
Fiberglass

19. What gauge is thermostat wire?
18 gauge
140 degrees F
False
Infiltration and ventilation

20. What sort of pressure will a pull-through evaporator have?
A dirty evaporator
20 degrees F
High
Negative

21. When do you install a trap on a drain line?
Rise
Before the vent
When it is a pull-through evaporator
A dirty evaporator

22. What is considered normal operating conditions?
RLA/FLA x 5
Blended refrigerants
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
100 psig

23. The fan switch opens at what temperature?
20 degrees F
105 degrees F
True
Nitrogen with a small amount of refrigerant

24. Will a dirty condenser cause a rise or fall in pressure?
300
True
Before the vent
Rise

25. What distributes supply air to a room in a structure?
Dehydrated with caps on each end
A diffuser
In parallel
30 A

26. Where do you install a trap on a drain line?
No
Before the vent
A band 4 inches or more in width
Outside diameter (OD)

27. How will too much refrigerant effect superheat?
It will be low
Negative
Boil the liquid refrigerant out ot the oil within the crankcase
Inside diameter (ID)

28. 7' round duct has a ballpark cfm of what?
200
Compressor
Duct with insulation on the inside
150

29. What is the normal evaporator temperature?
Before the vent
45 degrees F
100 psig
Subtract ambient temperature from 100

30. How do you calculate EER?
30 A
S-clips and drives (cleats)
When it is above a conditioned space
Btu/hr (output) / wattage (input)

31. The crankcase heater on an air-conditioning compressor is used to what?
The suction line or the low-pressure side
Boil the liquid refrigerant out ot the oil within the crankcase
20 degrees F
A bypass duct or a dump zone

32. How do you achieve high-efficiency?
By increasing the surface of the condenser coil
Pull a vacuum
Rise
105 degrees F

33. How long should you leave a system off once you kill power before restarting it?
Inches of water column (in. WC)
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Average feet per minute X area in square feet (H' x W'/144)
2 minutes

34. If the rpm's are 1050 - how many poles does the motor have?
400
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
6
Negative

35. What kind of copper tubing is used for refrigeration or air-conditioning applications?
45 degrees F
A swaging tool
Standard
ACR (air-conditioning refrigeration) tubing

36. The load on the evaporater will effect which pressure?
On the common terminal
Yes
It will be high
Suction

37. When do you install an auxillary drain pan?
20 A
When it is above a conditioned space
Individual return air systems and central return air systems
Any amount

38. What type of air conditioning system must be charged using the superheat method?
With a minimum of three evenly spaced self-tapping screws
High
A piston type metering device
40 degrees F

39. On what terminal do you check amperage?
Individual return air systems and central return air systems
Common
300
True

40. What are the three major power-consuming devices on an air-conditioning system?
Indoor fan motor - outdoor fan motor - and the compressor
30-35 degrees above ambient
Outside of the male fitting
Blended refrigerants

41. What are the three pressures created by moving air in ductwork?
It will be high
100
Negative
Static pressure - velocity pressure - and total pressure

42. Can refrigerant line sets be altered in length?
Static pressure - velocity pressure - and total pressure
8
They are larger
Yes

43. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
1/4'
To remove humidity and lower dry bulb temperature
300
45-55%

44. What are the three pressures created by moving air in ductwork?
6
Static pressure - velocity pressure - and total pressure
When the system is under pressure
The takeoff fitting

45. On what terminal do you check amperage?
Common
Vapor
Average feet per minute X area in square feet (H' x W'/144)
2 minutes

46. How many amps can 14 g wire handle?
15 A
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Fiberglass
15% silphos

47. How is flexible duct supported?
No
A band 4 inches or more in width
The suction line or the low-pressure side
200

48. How is insulation around a duct rated?
15% silphos
20 A
True
With an are rating

49. When do you install an auxillary drain pan?
When it is above a conditioned space
Subtract ambient temperature from 100
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
No

50. If the rpm's are 3450 - how many poles does the motor have?
2
Rise
By increasing the surface of the condenser coil
They are physically larger