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. At what temperature will soft solder melt?
SEER includes the energy used in the start-up and shut-down cycles
4
Outside diameter (OD)
Below 800 degrees F

2. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
Pistons
Slugging
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
45-55%

3. On what terminal do you check amperage?
30 degrees F
40 degrees F
Belt drive and direct drive
Common

4. What type of air conditioning system must be charged using the superheat method?
Rise
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
45-55%
A piston type metering device

5. What are the two types of return air systems in residential installations?
Pi x radius squared
30 degrees F
Shorted winding - open winding - and grounded winding
Individual return air systems and central return air systems

6. How many amps can 12 g wire handle?
20 A
Pull a vacuum
It also rises
Belt drive and direct drive

7. 8' round duct has a ballpark cfm of what?
In parallel
200
40 A
Inches of water column (in. WC)

8. How do you calculate the area of a circle?
ACR (air-conditioning refrigeration) tubing
It will be high
Pi x radius squared
6

9. What kind of refrigeratnts must be added in liquid form?
The suction line or the low-pressure side
True
Blended refrigerants
2

10. Where do you apply flux when soldering?
When it is a pull-through evaporator
Outside of the male fitting
Inside diameter (ID)
Stranded

11. What sort of pressure will a push-through evaporator have?
Positive
8-12 degrees F
Static pressure - velocity pressure - and total pressure
False

12. At what temperature will brazing melt?
When the system is under pressure
300
Heat load
Over 800 degrees F

13. What is lined duct?
Duct with insulation on the inside
Nitrogen with a small amount of refrigerant
45 degrees F
200

14. A reciprocating compressor has what sort of moving parts?
In parallel
Nominal-sized tubing
Negative
Pistons

15. If the rpm's are 1050 - how many poles does the motor have?
It will have a decrease in superheat
Vapor
140 degrees F
6

16. What can cause a decrease in suction pressure on an air-conditioning system?
A dirty evaporator
Negative
100
Dehydrated with caps on each end

17. What is used to measure static air pressure in ducts.
Average feet per minute X area in square feet (H' x W'/144)
20 degrees above ambient
400
Inclined manometer

18. What do you do after you braze a system?
5 degrees
Pull a vacuum
Subtract ambient temperature from 100
Inclined manometer

19. What kind of refrigeratnts must be added in liquid form?
Blended refrigerants
False
Heat load
TXV

20. When do you install a trap on a drain line?
When it is a pull-through evaporator
Yes
Outside diameter (OD)
On the common terminal

21. How does ACR copper pipe come?
45 degrees F
To lower the amount of pressure drop through the coil
20 degrees above ambient
Dehydrated with caps on each end

22. What tool is used to expand the diameter of soft copper tubing
By increasing the surface of the condenser coil
When it is a pull-through evaporator
SEER includes the energy used in the start-up and shut-down cycles
A swaging tool

23. The furnace size is calculated by what?
140 degrees F
When it is a pull-through evaporator
To lower the amount of pressure drop through the coil
Heat loss

24. How do you calculate EER?
Outside diameter (OD)
Nominal-sized tubing
100 psig
Btu/hr (output) / wattage (input)

25. If the rpm's are 3450 - how many poles does the motor have?
Yes
30 degrees F
2
S-clips and drives (cleats)

26. At what temperature will brazing melt?
Yes
A dirty evaporator
Over 800 degrees F
2 minutes

27. What component changes refrigerant from a low pressure gas to a high pressure gas?
Compressor
No
30 A
L-type

28. How many amps can 10 g wire handle?
It will have a decrease in superheat
Indoor fan motor - outdoor fan motor - and the compressor
30 A
40 degrees F

29. Do you need a vent on a push-through evaporator?
Any amount
Staples and tape
Yes
To lower the amount of pressure drop through the coil

30. The fan switch closes at what temperature?
Nominal-sized tubing
140 degrees F
40 degrees F
Inches of water column (in. WC)

31. 13 SEER is classified as what kind of efficiency?
Dehydrated with caps on each end
High
TXV
Blended refrigerants

32. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
Outside diameter (OD)
When it is a pull-through evaporator
1/4'
It will have a decrease in superheat

33. What is it called when liquid refrigerant gets into the compressor?
Slugging
8
300
15% silphos

34. Superheat should never be below how many degrees
5 degrees
A bypass duct or a dump zone
2 minutes
Inclined manometer

35. Most duct insulation is made of what?
Fiberglass
Staples and tape
TXV
A diffuser

36. What are the three major power-consuming devices on an air-conditioning system?
Yes
Yes
L-type
Indoor fan motor - outdoor fan motor - and the compressor

37. How is insulation around a duct rated?
12000
With an are rating
A bypass duct or a dump zone
Duct - electrical - and mechanical

38. What kind of metering device do high-efficiency units usually use?
Outside diameter (OD)
30 degrees F
TXV
With an are rating

39. The A/C size is calculated by what?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Heat load
When the system is under pressure
No

40. At what temperature does refrigerant condense in a high-efficiency unit?
Pistons
It will be low
Indoor fan motor - outdoor fan motor - and the compressor
20 degrees above ambient

41. The fan switch closes at what temperature?
30-35 degrees above ambient
In parallel
S-clips and drives (cleats)
140 degrees F

42. If the rpm's are 1750 - how many poles does the motor have?
Fiberglass
L-type
Inside diameter (ID)
4

43. 6' round duct has a ballpark cfm of what?
100
15% silphos
20 A
Average feet per minute X area in square feet (H' x W'/144)

44. What is it called when liquid refrigerant gets into the compressor?
Compressor
By increasing the surface of the condenser coil
Slugging
200

45. How are the high pressure switch and the low pressure switch wired with the compressor contactor?
When it is above a conditioned space
40 degrees F
Indoor fan motor - outdoor fan motor - and the compressor
In series

46. How will too much refrigerant effect subcooling?
It will be high
Boil the liquid refrigerant out ot the oil within the crankcase
Common
Average feet per minute X area in square feet (H' x W'/144)

47. What are the two types of blower drives?
30-35 degrees above ambient
2 minutes
Belt drive and direct drive
25-ft or 50-ft

48. What gauge is thermostat wire?
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
False
Suction
18 gauge

49. What is the typical temperature difference between a high-efficiency condenser and the ambient temperature?
Rise
20 degrees F
150
By increasing the surface of the condenser coil

50. When must a copper joint never be soldered or brazed?
When the system is under pressure
Negative
Pi x radius squared
100 psig