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 is the normal evaporator temperature?
45 degrees F
Subtract ambient temperature from 100
Outside of the male fitting
20 A

2. How long should you leave a system off once you kill power before restarting it?
The takeoff fitting
In series
100
2 minutes

3. How many cfm per ton?
5 degrees
TXV
400
The takeoff fitting

4. What are the components of a hard-start kit?
Potential relay and start capacitor
They are larger
200
45 degrees F

5. What is a package unit?
20 degrees F
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
SEER includes the energy used in the start-up and shut-down cycles
400

6. What sort of pressure will a push-through evaporator have?
A band 4 inches or more in width
Positive
8-12 degrees F
When it is a pull-through evaporator

7. 13 SEER is classified as what kind of efficiency?
High
Potential relay and start capacitor
Yes
Over/under and side by side

8. What are the three crafts normally associated with an air-conditioned installation?
Dehydrated with caps on each end
Side-by-side and over-and-under
Duct - electrical - and mechanical
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.

9. How is nominal-sized tubing sized?
Heat load
Pi x radius squared
Inside diameter (ID)
In parallel

10. 6' round duct has a ballpark cfm of what?
100
Average feet per minute X area in square feet (H' x W'/144)
In parallel
95 degrees F outside - 80 degrees F inside - and 50% relative humidity

11. Pressure in ductwork is measured In what?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Average feet per minute X area in square feet (H' x W'/144)
Inches of water column (in. WC)
Compressor

12. How is the high pressure switch wired with the low pressure switch?
When it is a pull-through evaporator
In series
In parallel
Negative

13. How do you calculate EER?
A bypass duct or a dump zone
Shorted winding - open winding - and grounded winding
Negative
Btu/hr (output) / wattage (input)

14. What are the three major power-consuming devices on an air-conditioning system?
Yes
ACR (air-conditioning refrigeration) tubing
30 degrees F
Indoor fan motor - outdoor fan motor - and the compressor

15. What standard weight copper tubing is most often used in the heating and air-conditioning industry?
L-type
In series
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
20 degrees above ambient

16. When do you install a trap on a drain line?
4
Heat loss
300
When it is a pull-through evaporator

17. What do you use to check for leaks?
Heat load
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
Nitrogen with a small amount of refrigerant
In parallel

18. What are the two types of blower drives?
Outside diameter (OD)
30 A
Belt drive and direct drive
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.

19. What is the design boiling point for most evaporator coils in residential air conditioning?
8-12 degrees F
40 degrees F
To lower the amount of pressure drop through the coil
Negative

20. How does ACR copper pipe come?
A band 4 inches or more in width
Inside diameter (ID)
When it is a pull-through evaporator
Dehydrated with caps on each end

21. How many amps can 10 g wire handle?
With 4' saddles
30 A
In series
Potential relay and start capacitor

22. At what temperature does refrigerant condense in a high-efficiency unit?
Potential relay and start capacitor
20 degrees above ambient
It rises
45 degrees F

23. In what state is the refrigerant in the compressor?
In series
Vapor
S-clips and drives (cleats)
The takeoff fitting

24. The fan switch closes at what temperature?
140 degrees F
20 A
150
A piston type metering device

25. The load on the evaporater will effect which pressure?
45-55%
On the common terminal
Suction
The suction line or the low-pressure side

26. When do you install an auxillary drain pan?
15% silphos
When it is above a conditioned space
100 psig
Duct - electrical - and mechanical

27. What are the components of a hard-start kit?
Potential relay and start capacitor
In series
8-12 degrees F
15 A

28. If pressure rises - what happens to the superheat?
Below 800 degrees F
They are larger
A piston type metering device
It rises

29. What standard weight copper tubing is most often used in the heating and air-conditioning industry?
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
Yes
L-type
Standard

30. How do you calculate LRA?
RLA/FLA x 5
2 minutes
Heat load
6

31. How is the high pressure switch wired with the low pressure switch?
In series
In parallel
It will be low
A piston type metering device

32. If the rpm's are 750 - how many poles does the motor have?
Below 800 degrees F
8
400
Staples and tape

33. What is the range for normal superheat and subcooling?
8-12 degrees F
A piston type metering device
RLA/FLA x 5
To remove humidity and lower dry bulb temperature

34. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
4
It will have a decrease in superheat
Yes
Latent and sensible

35. 10' round duct has a ballpark cfm of what?
300
200
400
TXV

36. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
30 degrees F
Subtract ambient temperature from 100
A bypass duct or a dump zone
With 4' saddles

37. The fan switch opens at what temperature?
105 degrees F
8-12 degrees F
It will have a decrease in superheat
45-55%

38. What are the two types of blower drives?
300
Belt drive and direct drive
30 A
They are physically larger

39. How many amps can 8 g wire handle?
L-type
40 A
Potential relay and start capacitor
Inside diameter (ID)

40. When do you install a trap on a drain line?
When it is a pull-through evaporator
Common
Duct with insulation on the inside
Potential relay and start capacitor

41. Do you need a vent on a pull-through evaporator?
45-55%
Yes
100 psig
Rise

42. Will a dirty condenser cause a rise or fall in pressure?
Below 800 degrees F
Negative
Rise
Outside diameter (OD)

43. Where do you install a trap on a drain line?
25-ft or 50-ft
45-55%
Before the vent
20 degrees above ambient

44. What is the typical temperature difference between a high-efficiency condenser and the ambient temperature?
20 degrees F
Pistons
30-35 degrees above ambient
20 A

45. What is the typical pressure differance across a TXV?
Shorted winding - open winding - and grounded winding
100 psig
8-12 degrees F
Duct - electrical - and mechanical

46. If the rpm's are 1050 - how many poles does the motor have?
Common
6
Infiltration and ventilation
Nitrogen with a small amount of refrigerant

47. At what temperature will brazing melt?
Yes
It also rises
Over 800 degrees F
ACR (air-conditioning refrigeration) tubing

48. What kind of metering device do high-efficiency units usually use?
TXV
True
Blended refrigerants
Dehydrated with caps on each end

49. What do you do after you braze a system?
Outside diameter (OD)
Pull a vacuum
2
100 psig

50. What is considered normal operating conditions?
Negative
TXV
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
It rises