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 do you do after you braze a system?
20 degrees F
Yes
Pull a vacuum
Staples and tape

2. At what temperature will brazing melt?
Belt drive and direct drive
A piston type metering device
Over 800 degrees F
Below 800 degrees F

3. What distributes supply air to a room in a structure?
A diffuser
200
Over 800 degrees F
Vapor

4. Will a dirty condenser cause a rise or fall in pressure?
30-35 degrees above ambient
20 degrees F
Rise
4

5. Which is more efficient - a TXV or a fixed-orifice metering device?
Slugging
It also rises
200
TXV

6. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
A bypass duct or a dump zone
Dehydrated with caps on each end
8-12 degrees F
Any amount

7. How is the high pressure switch wired with the low pressure switch?
ACR (air-conditioning refrigeration) tubing
In parallel
Outside diameter (OD)
Stranded

8. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
30 degrees F
When it is above a conditioned space
A bypass duct or a dump zone
Standard

9. What percentage silver do you need to use for an are-410 system?
A swaging tool
4
Potential relay and start capacitor
15% silphos

10. What can cause a decrease in suction pressure on an air-conditioning system?
High
Vapor
When the system is under pressure
A dirty evaporator

11. How does ACR copper pipe come?
With a minimum of three evenly spaced self-tapping screws
Dehydrated with caps on each end
Belt drive and direct drive
By increasing the surface of the condenser coil

12. If the rpm's are 1050 - how many poles does the motor have?
40 A
200
A piston type metering device
6

13. When must a copper joint never be soldered or brazed?
When the system is under pressure
A piston type metering device
Potential relay and start capacitor
Duct with insulation on the inside

14. In what length rolls is soft copper tubing normally available?
Any amount
25-ft or 50-ft
By increasing the surface of the condenser coil
Common

15. The fan switch opens at what temperature?
105 degrees F
S-clips and drives (cleats)
High
1/4'

16. What kind of refrigeratnts must be added in liquid form?
TXV
20 degrees above ambient
Blended refrigerants
Dehydrated with caps on each end

17. A reciprocating compressor has what sort of moving parts?
Pistons
2 minutes
A diffuser
Potential relay and start capacitor

18. How many amps can 10 g wire handle?
40 A
When the system is under pressure
30 A
Individual return air systems and central return air systems

19. What type of air conditioning system must be charged using the superheat method?
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
15 A
A piston type metering device
Belt drive and direct drive

20. If the rpm's are 3450 - how many poles does the motor have?
Subtract ambient temperature from 100
Pull a vacuum
2
140 degrees F

21. 6' round duct has a ballpark cfm of what?
With a minimum of three evenly spaced self-tapping screws
Btu/hr (output) / wattage (input)
150
100

22. What are the three crafts normally associated with an air-conditioned installation?
Nitrogen with a small amount of refrigerant
A dirty evaporator
12000
Duct - electrical - and mechanical

23. Which is more efficient - a TXV or a fixed-orifice metering device?
TXV
Stranded
To lower the amount of pressure drop through the coil
Over 800 degrees F

24. What are the two types of return air systems in residential installations?
Negative
Below 800 degrees F
Subtract ambient temperature from 100
Individual return air systems and central return air systems

25. What sort of pressure will a push-through evaporator have?
Positive
When the system is under pressure
20 degrees F
Static pressure - velocity pressure - and total pressure

26. How is flexible duct supported?
100
Heat loss
105 degrees F
A band 4 inches or more in width

27. How do you calculate the area of a circle?
Pi x radius squared
Rise
100
TXV

28. Do you need a vent on a push-through evaporator?
8
With a minimum of three evenly spaced self-tapping screws
Yes
Inside diameter (ID)

29. Do you need a trap on a pull-through evaporator?
Yes
Nitrogen with a small amount of refrigerant
A dirty evaporator
Before the vent

30. What is the difference between SEER and EER?
Btu/hr (output) / wattage (input)
SEER includes the energy used in the start-up and shut-down cycles
Subtract ambient temperature from 100
Outside of the male fitting

31. What kind of copper tubing is used for refrigeration or air-conditioning applications?
ACR (air-conditioning refrigeration) tubing
By increasing the surface of the condenser coil
Individual return air systems and central return air systems
Staples and tape

32. When do you install a trap on a drain line?
15% silphos
Outside of the male fitting
Boil the liquid refrigerant out ot the oil within the crankcase
When it is a pull-through evaporator

33. The compressor is cooled by liquid refrigerant. (True of False)
False
ACR (air-conditioning refrigeration) tubing
It will be low
It will be high

34. How will too much refrigerant effect superheat?
S-clips and drives (cleats)
Below 800 degrees F
12000
It will be low

35. Why are some ACR tubing lines insulated?
Suction
No
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
With an are rating

36. How do you calculate cfm?

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

37. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
Shorted winding - open winding - and grounded winding
Any amount
45-55%
Blended refrigerants

38. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
Latent and sensible
To lower the amount of pressure drop through the coil
40 A
Nominal-sized tubing

39. How are round ducts supported?

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

40. If the rpm's are 1750 - how many poles does the motor have?
15 A
4
20 A
45-55%

41. If pressure rises - what happens to the superheat?
30-35 degrees above ambient
It rises
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
105 degrees F

42. What gauge is thermostat wire?
18 gauge
S-clips and drives (cleats)
Fiberglass
No

43. Which type of wire can handle a higher ampacity?
45-55%
Stranded
Duct with insulation on the inside
Compressor

44. The evaporator is designed to remove what two types of heat?
When the system is under pressure
6
Latent and sensible
No

45. Where do you install a trap on a drain line?
140 degrees F
Over 800 degrees F
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
Before the vent

46. What are the two basic duct connection configurations for package units supply and return air ducts?
RLA/FLA x 5
15 A
Positive
Over/under and side by side

47. What are the three pressures created by moving air in ductwork?
40 degrees F
200
Static pressure - velocity pressure - and total pressure
8

48. If pressure rises - what happens to the superheat?
It rises
It will have a decrease in superheat
150
Below 800 degrees F

49. What is the name of the fitting where the branch line leaves the duct?
The takeoff fitting
Nitrogen with a small amount of refrigerant
False
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity

50. What is used to measure static air pressure in ducts.
Inclined manometer
Over 800 degrees F
Over 800 degrees F
RLA/FLA x 5