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. If pressure rises - what happens to the superheat?
It rises
30 A
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Staples and tape

2. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
400
A bypass duct or a dump zone
RLA/FLA x 5
When it is above a conditioned space

3. What is the typical temperature difference between a standard-efficiency condenser and the ambient temperature?
30 degrees F
A dirty evaporator
15% silphos
12000

4. Do you need a vent on a pull-through evaporator?
Shorted winding - open winding - and grounded winding
Yes
140 degrees F
1/4'

5. How will too much refrigerant effect superheat?
It will be low
It will be high
6
Btu/hr (output) / wattage (input)

6. What is the typical pressure differance across a TXV?
In parallel
100 psig
True
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity

7. The fan switch opens at what temperature?
150
105 degrees F
Rise
Positive

8. What is the normal evaporator temperature?
Inches of water column (in. WC)
Nitrogen with a small amount of refrigerant
With an are rating
45 degrees F

9. Which is more efficient - a TXV or a fixed-orifice metering device?
Duct with insulation on the inside
TXV
A band 4 inches or more in width
Latent and sensible

10. Where is insulation used on copper tubing used for air-conditioning?
Potential relay and start capacitor
The suction line or the low-pressure side
300
Stranded

11. How do you calculate EER?
Btu/hr (output) / wattage (input)
ACR (air-conditioning refrigeration) tubing
25-ft or 50-ft
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.

12. What type of air conditioning system must be charged using the superheat method?
A piston type metering device
Nitrogen with a small amount of refrigerant
45-55%
1/4'

13. Which is more efficient - a TXV or a fixed-orifice metering device?
TXV
A band 4 inches or more in width
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Common

14. If the rpm's are 1050 - how many poles does the motor have?
When it is a pull-through evaporator
30 degrees F
Subtract ambient temperature from 100
6

15. 13 SEER is classified as what kind of efficiency?
Yes
Individual return air systems and central return air systems
On the common terminal
High

16. At what temperature does refrigerant condense in a standard-efficiency unit?
Latent and sensible
Vapor
30-35 degrees above ambient
With 4' saddles

17. What kind of refrigeratnts must be added in liquid form?
12000
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
By increasing the surface of the condenser coil
Blended refrigerants

18. The crankcase heater on an air-conditioning compressor is used to what?
A dirty evaporator
When it is above a conditioned space
30 A
Boil the liquid refrigerant out ot the oil within the crankcase

19. What are the two types of package units?
105 degrees F
Side-by-side and over-and-under
Pistons
Negative

20. Do you need a trap on a pull-through evaporator?
15 A
TXV
Yes
30-35 degrees above ambient

21. When must a copper joint never be soldered or brazed?
Btu/hr (output) / wattage (input)
When the system is under pressure
Static pressure - velocity pressure - and total pressure
RLA/FLA x 5

22. If pressure rises - what happens to the superheat?
By increasing the surface of the condenser coil
Any amount
Subtract ambient temperature from 100
It rises

23. Why are some ACR tubing lines insulated?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
A swaging tool
Fiberglass
Over 800 degrees F

24. What are the three crafts normally associated with an air-conditioned installation?
200
Duct - electrical - and mechanical
It will be high
Any amount

25. The evaporator is designed to remove what two types of heat?
40 degrees F
Below 800 degrees F
Before the vent
Latent and sensible

26. What can cause a decrease in suction pressure on an air-conditioning system?
A dirty evaporator
Nominal-sized tubing
Pistons
It rises

27. When must a copper joint never be soldered or brazed?
Fiberglass
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
12000
When the system is under pressure

28. What do you use to check for leaks?
Nitrogen with a small amount of refrigerant
Any amount
They are larger
A band 4 inches or more in width

29. What sort of pressure will a pull-through evaporator have?
Negative
30 A
12000
2

30. At what temperature does refrigerant condense in a high-efficiency unit?
20 degrees above ambient
140 degrees F
40 A
L-type

31. If the rpm's are 1750 - how many poles does the motor have?
100 psig
4
Pistons
Over/under and side by side

32. How do you achieve high-efficiency?
30 A
Rise
Inside diameter (ID)
By increasing the surface of the condenser coil

33. How does ACR copper pipe come?
Average feet per minute X area in square feet (H' x W'/144)
Dehydrated with caps on each end
Btu/hr (output) / wattage (input)
400

34. Can refrigerant line sets be altered in length?
Over 800 degrees F
Yes
ACR (air-conditioning refrigeration) tubing
Duct with insulation on the inside

35. How are high-efficiency condenser coils different from standard-efficiency condenser coils?
They are physically larger
A diffuser
6
Sheet metal - galvanized sheet metal - fiberglass - and flexduct

36. At what temperature will brazing melt?
Nitrogen with a small amount of refrigerant
With 4' saddles
30 A
Over 800 degrees F

37. When do you install a trap on a drain line?
Yes
30-35 degrees above ambient
When it is a pull-through evaporator
15% silphos

38. What is a package unit?
The suction line or the low-pressure side
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
High
Inclined manometer

39. How many amps can 14 g wire handle?
They are larger
Individual return air systems and central return air systems
40 degrees F
15 A

40. What are the two basic duct connection configurations for package units supply and return air ducts?
Over/under and side by side
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Slugging
Inches of water column (in. WC)

41. What are the components of a hard-start kit?
Potential relay and start capacitor
200
105 degrees F
1/4'

42. What do you use to connect square and rectangular ductboard together?
It rises
S-clips and drives (cleats)
40 degrees F
TXV

43. What distributes supply air to a room in a structure?
30-35 degrees above ambient
2 minutes
A diffuser
It will have a decrease in superheat

44. Which type of wire can handle a higher ampacity?
12000
Stranded
Boil the liquid refrigerant out ot the oil within the crankcase
L-type

45. 10 SEER is classified as what kind of efficiency?
Standard
When the system is under pressure
Btu/hr (output) / wattage (input)
Below 800 degrees F

46. Do you need a vent on a push-through evaporator?
2 minutes
No
Yes
Below 800 degrees F

47. How many cfm per ton?
400
Heat loss
It rises
SEER includes the energy used in the start-up and shut-down cycles

48. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
40 degrees F
140 degrees F
TXV
15 A

49. What do you do after you braze a system?
Pull a vacuum
A swaging tool
20 degrees F
It also rises

50. The fan switch closes at what temperature?
25-ft or 50-ft
140 degrees F
Infiltration and ventilation
20 degrees F