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. What are the components of a hard-start kit?
Standard
Potential relay and start capacitor
Static pressure - velocity pressure - and total pressure
20 degrees F

2. What are the three pressures created by moving air in ductwork?
False
When it is a pull-through evaporator
Duct - electrical - and mechanical
Static pressure - velocity pressure - and total pressure

3. How is flexible duct supported?
A band 4 inches or more in width
20 degrees F
Dehydrated with caps on each end
False

4. What are the components of a hard-start kit?
15% silphos
Potential relay and start capacitor
SEER includes the energy used in the start-up and shut-down cycles
On the common terminal

5. How many cfm per ton?
Negative
400
12000
A piston type metering device

6. The fan switch closes at what temperature?
ACR (air-conditioning refrigeration) tubing
With 4' saddles
140 degrees F
Before the vent

7. Where is insulation used on copper tubing used for air-conditioning?
The suction line or the low-pressure side
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
40 degrees F
Below 800 degrees F

8. How much does a drain line need to drop per foot of length?

9. The crankcase heater on an air-conditioning compressor is used to what?
Yes
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Boil the liquid refrigerant out ot the oil within the crankcase
Individual return air systems and central return air systems

10. What is it called when liquid refrigerant gets into the compressor?
Yes
With an are rating
They are larger
Slugging

11. Do you need a trap on a push-through evaporator?
Vapor
400
No
With a minimum of three evenly spaced self-tapping screws

12. What are the two basic duct connection configurations for package units supply and return air ducts?
Over/under and side by side
18 gauge
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
Rise

13. What tool is used to expand the diameter of soft copper tubing
Boil the liquid refrigerant out ot the oil within the crankcase
A swaging tool
When the system is under pressure
200

14. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
With an are rating
To remove humidity and lower dry bulb temperature
40 degrees F
200

15. What are the two types of package units?
Nitrogen with a small amount of refrigerant
Common
Yes
Side-by-side and over-and-under

16. What is the typical pressure differance across a TXV?
400
Btu/hr (output) / wattage (input)
The takeoff fitting
100 psig

17. Where do you install a trap on a drain line?
To lower the amount of pressure drop through the coil
Before the vent
It will be low
40 degrees F

18. What is the name of the fitting where the branch line leaves the duct?
It will be low
Pistons
The takeoff fitting
Fiberglass

19. Can refrigerant line sets be altered in length?
Indoor fan motor - outdoor fan motor - and the compressor
Yes
30-35 degrees above ambient
Suction

20. At what temperature does refrigerant condense in a high-efficiency unit?
40 degrees F
20 degrees above ambient
It will have a decrease in superheat
400

21. How many amps can 8 g wire handle?
400
40 A
30 A
The suction line or the low-pressure side

22. Do you need a vent on a push-through evaporator?
Pi x radius squared
Compressor
Common
Yes

23. What are the three major power-consuming devices on an air-conditioning system?
300
Over 800 degrees F
Indoor fan motor - outdoor fan motor - and the compressor
Static pressure - velocity pressure - and total pressure

24. What are the two types of package units?
Yes
On the common terminal
Side-by-side and over-and-under
6

25. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
Any amount
By increasing the surface of the condenser coil
True
8

26. 10 SEER is classified as what kind of efficiency?
Duct with insulation on the inside
Inclined manometer
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Standard

27. How is flexible duct supported?
True
Average feet per minute X area in square feet (H' x W'/144)
Inclined manometer
A band 4 inches or more in width

28. How does ACR copper pipe come?
Dehydrated with caps on each end
2
30-35 degrees above ambient
5 degrees

29. If the rpm's are 1050 - how many poles does the motor have?
20 A
Boil the liquid refrigerant out ot the oil within the crankcase
L-type
6

30. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
20 degrees above ambient
When it is a pull-through evaporator
20 degrees F
40 degrees F

31. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
30-35 degrees above ambient
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
RLA/FLA x 5
To lower the amount of pressure drop through the coil

32. How do you calculate LRA?
Yes
6
RLA/FLA x 5
TXV

33. How long should you leave a system off once you kill power before restarting it?
TXV
2 minutes
Boil the liquid refrigerant out ot the oil within the crankcase
Stranded

34. Do you need a vent on a pull-through evaporator?
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Yes
True
Any amount

35. What is the difference between SEER and EER?
200
300
Below 800 degrees F
SEER includes the energy used in the start-up and shut-down cycles

36. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
Shorted winding - open winding - and grounded winding
Any amount
Yes
Belt drive and direct drive

37. What percentage silver do you need to use for an are-410 system?
Inclined manometer
15% silphos
TXV
Subtract ambient temperature from 100

38. How long should you leave a system off once you kill power before restarting it?
2 minutes
Stranded
When it is above a conditioned space
20 A

39. What is used to measure static air pressure in ducts.
SEER includes the energy used in the start-up and shut-down cycles
Inclined manometer
The takeoff fitting
95 degrees F outside - 80 degrees F inside - and 50% relative humidity

40. What is the normal evaporator temperature?
Over 800 degrees F
When it is a pull-through evaporator
To remove humidity and lower dry bulb temperature
45 degrees F

41. How do you calculate the area of a circle?
They are physically larger
Pi x radius squared
Fiberglass
Average feet per minute X area in square feet (H' x W'/144)

42. Where do you check the amps on a motor?
Indoor fan motor - outdoor fan motor - and the compressor
On the common terminal
Before the vent
A dirty evaporator

43. The furnace size is calculated by what?
Heat loss
Static pressure - velocity pressure - and total pressure
Yes
8

44. What are the two basic duct connection configurations for package units supply and return air ducts?
Suction
Stranded
Before the vent
Over/under and side by side

45. How is insulation around a duct rated?
High
6
With an are rating
Staples and tape

46. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
Fiberglass
A bypass duct or a dump zone
20 degrees F
It rises

47. What are the four materials used to make duct?
Outside diameter (OD)
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
In series
In series

48. In what length rolls is soft copper tubing normally available?
Over/under and side by side
Infiltration and ventilation
Pi x radius squared
25-ft or 50-ft

49. What are the two types of blower drives?
Belt drive and direct drive
Dehydrated with caps on each end
30 degrees F
140 degrees F

50. Do you need a vent on a push-through evaporator?
400
Individual return air systems and central return air systems
Yes
It rises