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 distributes supply air to a room in a structure?
Shorted winding - open winding - and grounded winding
6
30-35 degrees above ambient
A diffuser

2. Can refrigerant line sets be altered in length?
It will be low
Duct with insulation on the inside
Yes
Yes

3. When do you install an auxillary drain pan?
When it is above a conditioned space
It also rises
30 degrees F
45 degrees F

4. What are the two types of package units?
40 A
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
With an are rating
Side-by-side and over-and-under

5. How do you calculate the area of a circle?
Individual return air systems and central return air systems
To remove humidity and lower dry bulb temperature
Pi x radius squared
Inside diameter (ID)

6. 10' round duct has a ballpark cfm of what?
Inches of water column (in. WC)
400
Heat load
Shorted winding - open winding - and grounded winding

7. What are the two types of package units?
Before the vent
When it is a pull-through evaporator
Side-by-side and over-and-under
Pistons

8. Do you need a vent on a push-through evaporator?
Yes
Boil the liquid refrigerant out ot the oil within the crankcase
Potential relay and start capacitor
Subtract ambient temperature from 100

9. The furnace size is calculated by what?
Yes
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Heat loss
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.

10. What are the two functions of the air-conditioning system?
To remove humidity and lower dry bulb temperature
In series
A band 4 inches or more in width
2

11. What tool is used to expand the diameter of soft copper tubing
Side-by-side and over-and-under
A swaging tool
TXV
S-clips and drives (cleats)

12. How long should you leave a system off once you kill power before restarting it?
Rise
To remove humidity and lower dry bulb temperature
2 minutes
The takeoff fitting

13. What are the three pressures created by moving air in ductwork?
Subtract ambient temperature from 100
Pi x radius squared
Static pressure - velocity pressure - and total pressure
Sheet metal - galvanized sheet metal - fiberglass - and flexduct

14. What can cause a decrease in suction pressure on an air-conditioning system?
It also rises
By increasing the surface of the condenser coil
A dirty evaporator
Yes

15. What are the three crafts normally associated with an air-conditioned installation?
A swaging tool
Over 800 degrees F
Duct - electrical - and mechanical
15% silphos

16. How many amps can 8 g wire handle?
Dehydrated with caps on each end
Potential relay and start capacitor
40 A
15 A

17. When do you install a trap on a drain line?
Vapor
Outside diameter (OD)
4
When it is a pull-through evaporator

18. A reciprocating compressor has what sort of moving parts?
With a minimum of three evenly spaced self-tapping screws
Pistons
Subtract ambient temperature from 100
15 A

19. The evaporator is designed to remove what two types of heat?
With 4' saddles
Latent and sensible
Static pressure - velocity pressure - and total pressure
It will have a decrease in superheat

20. What is the difference between SEER and EER?
No
Below 800 degrees F
Nitrogen with a small amount of refrigerant
SEER includes the energy used in the start-up and shut-down cycles

21. The crankcase heater on an air-conditioning compressor is used to what?
A diffuser
40 degrees F
Boil the liquid refrigerant out ot the oil within the crankcase
Any amount

22. How do you calculate ballpark superheat?
Dehydrated with caps on each end
Subtract ambient temperature from 100
Outside diameter (OD)
Common

23. What is lined duct?
Duct with insulation on the inside
300
No
To remove humidity and lower dry bulb temperature

24. Do you need a trap on a pull-through evaporator?
Positive
Yes
15% silphos
In series

25. Do you need a vent on a pull-through evaporator?
Side-by-side and over-and-under
It also rises
Yes
100

26. When must a copper joint never be soldered or brazed?
With 4' saddles
When the system is under pressure
A dirty evaporator
25-ft or 50-ft

27. What gauge is thermostat wire?
Average feet per minute X area in square feet (H' x W'/144)
It will be low
18 gauge
No

28. Superheat should never be below how many degrees
When the system is under pressure
5 degrees
To remove humidity and lower dry bulb temperature
It also rises

29. Why are some ACR tubing lines insulated?
15 A
Suction
With 4' saddles
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line

30. How do you calculate the area of a circle?
30 A
Pi x radius squared
Positive
Staples and tape

31. 7' round duct has a ballpark cfm of what?
150
Common
Belt drive and direct drive
The suction line or the low-pressure side

32. How do you calculate EER?
Yes
Btu/hr (output) / wattage (input)
Dehydrated with caps on each end
Compressor

33. What is considered normal operating conditions?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
It will be low
Pull a vacuum
Outside diameter (OD)

34. What are the two types of blower drives?
Blended refrigerants
When it is above a conditioned space
Belt drive and direct drive
Vapor

35. Where do you check the amps on a motor?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Potential relay and start capacitor
100 psig
On the common terminal

36. When do you install a trap on a drain line?
100 psig
When it is a pull-through evaporator
140 degrees F
Indoor fan motor - outdoor fan motor - and the compressor

37. What percentage silver do you need to use for an are-410 system?
15% silphos
2 minutes
A dirty evaporator
45-55%

38. What is the range for normal superheat and subcooling?
8-12 degrees F
Heat load
Infiltration and ventilation
Indoor fan motor - outdoor fan motor - and the compressor

39. If the rpm's are 1050 - how many poles does the motor have?
Heat loss
It also rises
45 degrees F
6

40. What are the two basic duct connection configurations for package units supply and return air ducts?
Heat loss
With an are rating
High
Over/under and side by side

41. What are the two ways that fresh air enters a structure?
Infiltration and ventilation
30 degrees F
Indoor fan motor - outdoor fan motor - and the compressor
Average feet per minute X area in square feet (H' x W'/144)

42. What is lined duct?
45-55%
By increasing the surface of the condenser coil
Duct with insulation on the inside
Blended refrigerants

43. What do you do after you braze a system?
Pull a vacuum
A dirty evaporator
Duct with insulation on the inside
They are physically larger

44. If the suction pressure rises - what happens to the head pressure?
When the system is under pressure
In series
With 4' saddles
It also rises

45. Pressure in ductwork is measured In what?
In parallel
45-55%
Inches of water column (in. WC)
Duct - electrical - and mechanical

46. What are normal conditions - as defined by the ARI.
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Before the vent
To remove humidity and lower dry bulb temperature
A band 4 inches or more in width

47. At what temperature will soft solder melt?
Heat load
Duct - electrical - and mechanical
Below 800 degrees F
On the common terminal

48. What kind of copper tubing is used for plumbing and heating applications?
Staples and tape
8-12 degrees F
Nominal-sized tubing
5 degrees

49. In what state is the refrigerant in the compressor?
Suction
Pull a vacuum
Vapor
300

50. When do you install an auxillary drain pan?
When it is above a conditioned space
Infiltration and ventilation
100 psig
150