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. Where do you apply flux when soldering?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Shorted winding - open winding - and grounded winding
Outside of the male fitting
Btu/hr (output) / wattage (input)

2. A reciprocating compressor has what sort of moving parts?
Pistons
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
They are physically larger
45 degrees F

3. What is the typical pressure differance across a TXV?
False
400
100 psig
Static pressure - velocity pressure - and total pressure

4. The furnace size is calculated by what?
Heat loss
With 4' saddles
Static pressure - velocity pressure - and total pressure
SEER includes the energy used in the start-up and shut-down cycles

5. What are the two basic duct connection configurations for package units supply and return air ducts?
Over/under and side by side
On the common terminal
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
100 psig

6. 8' round duct has a ballpark cfm of what?
The suction line or the low-pressure side
200
They are physically larger
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity

7. How long should you leave a system off once you kill power before restarting it?
With an are rating
Yes
2 minutes
It rises

8. What can cause a decrease in suction pressure on an air-conditioning system?
A dirty evaporator
40 A
100 psig
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity

9. How do you calculate LRA?
RLA/FLA x 5
Pistons
Yes
Positive

10. If the rpm's are 1050 - how many poles does the motor have?
40 A
Pull a vacuum
6
Before the vent

11. The compressor is cooled by liquid refrigerant. (True of False)
False
Average feet per minute X area in square feet (H' x W'/144)
Nominal-sized tubing
Heat load

12. On what terminal do you check amperage?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Inches of water column (in. WC)
Common
30 A

13. What is the design boiling point for most evaporator coils in residential air conditioning?
Outside diameter (OD)
40 degrees F
30-35 degrees above ambient
Side-by-side and over-and-under

14. Does a package unit come from the factory pre-charged?
L-type
Yes
Heat load
Positive

15. What tool is used to expand the diameter of soft copper tubing
A swaging tool
30 A
Staples and tape
It will be high

16. 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
Staples and tape
Before the vent

17. Do you need a trap on a pull-through evaporator?
RLA/FLA x 5
When it is above a conditioned space
Btu/hr (output) / wattage (input)
Yes

18. How are high-efficiency condenser coils different from standard-efficiency condenser coils?
100
Yes
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
They are physically larger

19. What kind of refrigeratnts must be added in liquid form?
Duct with insulation on the inside
Blended refrigerants
Heat load
Yes

20. What is the difference between SEER and EER?
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
Latent and sensible
SEER includes the energy used in the start-up and shut-down cycles
They are physically larger

21. What distributes supply air to a room in a structure?
Blended refrigerants
Heat loss
A diffuser
Yes

22. 13 SEER is classified as what kind of efficiency?
High
Before the vent
Outside diameter (OD)
15 A

23. If the rpm's are 1750 - how many poles does the motor have?
30 degrees F
Compressor
4
A dirty evaporator

24. How will too much refrigerant effect superheat?
Staples and tape
It will have a decrease in superheat
By increasing the surface of the condenser coil
It will be low

25. Pressure in ductwork is measured In what?
Individual return air systems and central return air systems
Shorted winding - open winding - and grounded winding
Inches of water column (in. WC)
30-35 degrees above ambient

26. How are the high pressure switch and the low pressure switch wired with the compressor contactor?
Outside diameter (OD)
In series
Dehydrated with caps on each end
Subtract ambient temperature from 100

27. What is the typical temperature difference between a standard-efficiency condenser and the ambient temperature?
When the system is under pressure
Before the vent
Vapor
30 degrees F

28. How do you calculate EER?
20 A
1/4'
Btu/hr (output) / wattage (input)
Staples and tape

29. Do you need a vent on a pull-through evaporator?
Rise
In series
Yes
Duct - electrical - and mechanical

30. 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
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Below 800 degrees F

31. What are the two types of package units?
Side-by-side and over-and-under
300
They are larger
Inside diameter (ID)

32. What are the three pressures created by moving air in ductwork?
400
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Inches of water column (in. WC)
Static pressure - velocity pressure - and total pressure

33. What do you use to connect square and rectangular ductboard together?
When it is a pull-through evaporator
S-clips and drives (cleats)
When it is above a conditioned space
20 A

34. Most duct insulation is made of what?
When it is above a conditioned space
Pi x radius squared
Belt drive and direct drive
Fiberglass

35. What are the four materials used to make duct?
A dirty evaporator
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
True
SEER includes the energy used in the start-up and shut-down cycles

36. What percentage silver do you need to use for an are-410 system?
Inches of water column (in. WC)
15% silphos
By increasing the surface of the condenser coil
The suction line or the low-pressure side

37. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
100 psig
15 A
4
True

38. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
It will have a decrease in superheat
Infiltration and ventilation
Slugging
40 degrees F

39. 10' round duct has a ballpark cfm of what?
400
Shorted winding - open winding - and grounded winding
Heat load
140 degrees F

40. The compressor is cooled by liquid refrigerant. (True of False)
They are physically larger
Yes
It will be high
False

41. What are the two types of blower drives?
Belt drive and direct drive
RLA/FLA x 5
SEER includes the energy used in the start-up and shut-down cycles
True

42. At what temperature will brazing melt?
Inside diameter (ID)
Over 800 degrees F
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Shorted winding - open winding - and grounded winding

43. How many amps can 12 g wire handle?
20 A
20 degrees F
20 degrees F
Subtract ambient temperature from 100

44. What are the two ways that fresh air enters a structure?
Inside diameter (ID)
Standard
Infiltration and ventilation
Inclined manometer

45. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
Duct - electrical - and mechanical
Any amount
False
Slugging

46. When do you install a trap on a drain line?
When it is a pull-through evaporator
Nominal-sized tubing
A band 4 inches or more in width
2 minutes

47. The fan switch closes at what temperature?
With an are rating
Belt drive and direct drive
Inches of water column (in. WC)
140 degrees F

48. What is the range for normal superheat and subcooling?
Latent and sensible
Indoor fan motor - outdoor fan motor - and the compressor
8-12 degrees F
Yes

49. What are the three ways a motor can fail electrically?
100 psig
Shorted winding - open winding - and grounded winding
When it is above a conditioned space
18 gauge

50. What is a package unit?
Suction
TXV
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
A bypass duct or a dump zone