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. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
It will be low
Infiltration and ventilation
A bypass duct or a dump zone
18 gauge

2. How will too much refrigerant effect superheat?
It will be low
100
45 degrees F
Yes

3. What do you use to check for leaks?
Nitrogen with a small amount of refrigerant
A piston type metering device
A band 4 inches or more in width
A bypass duct or a dump zone

4. 10 SEER is classified as what kind of efficiency?
Standard
With a minimum of three evenly spaced self-tapping screws
Stranded
18 gauge

5. 10' round duct has a ballpark cfm of what?
400
8
300
1/4'

6. What is the name of the fitting where the branch line leaves the duct?
True
Pull a vacuum
The takeoff fitting
ACR (air-conditioning refrigeration) tubing

7. What sort of pressure will a push-through evaporator have?
40 degrees F
It will have a decrease in superheat
Boil the liquid refrigerant out ot the oil within the crankcase
Positive

8. How do you calculate LRA?
20 A
RLA/FLA x 5
Heat loss
With an are rating

9. How many cfm per ton?
By increasing the surface of the condenser coil
400
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
2 minutes

10. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
30 A
A bypass duct or a dump zone
Yes
False

11. What are the two functions of the air-conditioning system?
In parallel
To remove humidity and lower dry bulb temperature
TXV
Yes

12. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
45-55%
TXV
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
12000

13. What are normal conditions - as defined by the ARI.
15 A
With 4' saddles
Rise
95 degrees F outside - 80 degrees F inside - and 50% relative humidity

14. What are the two basic duct connection configurations for package units supply and return air ducts?
Over/under and side by side
Indoor fan motor - outdoor fan motor - and the compressor
False
Side-by-side and over-and-under

15. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
25-ft or 50-ft
True
A piston type metering device
On the common terminal

16. 7' round duct has a ballpark cfm of what?
150
40 A
Boil the liquid refrigerant out ot the oil within the crankcase
A bypass duct or a dump zone

17. In what state is the refrigerant in the compressor?
In series
Vapor
Duct - electrical - and mechanical
TXV

18. Where do you apply flux when soldering?
In parallel
They are larger
Outside of the male fitting
Static pressure - velocity pressure - and total pressure

19. The fan switch closes at what temperature?
Dehydrated with caps on each end
Standard
140 degrees F
It will be low

20. Why are some ACR tubing lines insulated?
20 A
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
300
6

21. Most duct insulation is made of what?
High
Fiberglass
A band 4 inches or more in width
A bypass duct or a dump zone

22. The A/C size is calculated by what?
True
Static pressure - velocity pressure - and total pressure
Heat load
Inclined manometer

23. The crankcase heater on an air-conditioning compressor is used to what?
Boil the liquid refrigerant out ot the oil within the crankcase
Heat load
Btu/hr (output) / wattage (input)
A piston type metering device

24. If the rpm's are 1750 - how many poles does the motor have?
4
Subtract ambient temperature from 100
2 minutes
2

25. What are the two ways that fresh air enters a structure?
Indoor fan motor - outdoor fan motor - and the compressor
30 degrees F
5 degrees
Infiltration and ventilation

26. What are the four materials used to make duct?
Static pressure - velocity pressure - and total pressure
Yes
8-12 degrees F
Sheet metal - galvanized sheet metal - fiberglass - and flexduct

27. Do you need a vent on a pull-through evaporator?
L-type
Yes
It also rises
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity

28. On what terminal do you check amperage?
A piston type metering device
Common
Staples and tape
When it is a pull-through evaporator

29. What are the components of a hard-start kit?
It will be high
Heat load
Potential relay and start capacitor
When it is above a conditioned space

30. What kind of copper tubing is used for refrigeration or air-conditioning applications?
25-ft or 50-ft
ACR (air-conditioning refrigeration) tubing
By increasing the surface of the condenser coil
Yes

31. How many amps can 10 g wire handle?
True
18 gauge
Yes
30 A

32. What is used to measure static air pressure in ducts.
L-type
Over/under and side by side
Blended refrigerants
Inclined manometer

33. How do you achieve high-efficiency?
A piston type metering device
Static pressure - velocity pressure - and total pressure
S-clips and drives (cleats)
By increasing the surface of the condenser coil

34. At what temperature will soft solder melt?
S-clips and drives (cleats)
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Below 800 degrees F
Blended refrigerants

35. If pressure rises - what happens to the superheat?
Yes
It rises
15 A
Yes

36. What are the three crafts normally associated with an air-conditioned installation?
RLA/FLA x 5
Duct - electrical - and mechanical
Heat loss
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity

37. If the rpm's are 1050 - how many poles does the motor have?
It will be low
When it is a pull-through evaporator
400
6

38. Most duct insulation is made of what?
Indoor fan motor - outdoor fan motor - and the compressor
20 A
Fiberglass
45 degrees F

39. 6' round duct has a ballpark cfm of what?
6
100
The takeoff fitting
15% silphos

40. When do you install an auxillary drain pan?
150
300
When it is above a conditioned space
Common

41. 8' round duct has a ballpark cfm of what?
200
Nominal-sized tubing
A piston type metering device
False

42. What component changes refrigerant from a low pressure gas to a high pressure gas?
Outside diameter (OD)
SEER includes the energy used in the start-up and shut-down cycles
Compressor
Sheet metal - galvanized sheet metal - fiberglass - and flexduct

43. Where is insulation used on copper tubing used for air-conditioning?
ACR (air-conditioning refrigeration) tubing
Staples and tape
The suction line or the low-pressure side
Compressor

44. When must a copper joint never be soldered or brazed?
It rises
2
When the system is under pressure
Latent and sensible

45. Superheat should never be below how many degrees
On the common terminal
Individual return air systems and central return air systems
5 degrees
Yes

46. What is the typical pressure differance across a TXV?
Pistons
It will be low
Pull a vacuum
100 psig

47. Do you need a trap on a pull-through evaporator?
A diffuser
Latent and sensible
Yes
2 minutes

48. How long should you leave a system off once you kill power before restarting it?
Btu/hr (output) / wattage (input)
Potential relay and start capacitor
Stranded
2 minutes

49. What are the two types of blower drives?
No
Yes
Belt drive and direct drive
100

50. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
105 degrees F
False
To lower the amount of pressure drop through the coil
When the system is under pressure