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 typical temperature difference between a high-efficiency condenser and the ambient temperature?
20 degrees F
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
It will have a decrease in superheat
When it is a pull-through evaporator

2. 10 SEER is classified as what kind of efficiency?
In series
With a minimum of three evenly spaced self-tapping screws
105 degrees F
Standard

3. What kind of copper tubing is used for plumbing and heating applications?
It will be high
Standard
Nominal-sized tubing
Shorted winding - open winding - and grounded winding

4. How do you achieve high-efficiency?
TXV
105 degrees F
By increasing the surface of the condenser coil
Belt drive and direct drive

5. The A/C size is calculated by what?
Blended refrigerants
Heat load
It will have a decrease in superheat
True

6. What do you do after you braze a system?
TXV
15 A
TXV
Pull a vacuum

7. How many amps can 12 g wire handle?
2 minutes
20 A
Yes
When it is a pull-through evaporator

8. How long should you leave a system off once you kill power before restarting it?
Inches of water column (in. WC)
2 minutes
It will have a decrease in superheat
18 gauge

9. On what terminal do you check amperage?
Suction
When it is above a conditioned space
Common
S-clips and drives (cleats)

10. How do you calculate the area of a circle?
Pull a vacuum
When it is a pull-through evaporator
Potential relay and start capacitor
Pi x radius squared

11. Do you need a vent on a pull-through evaporator?
Yes
Indoor fan motor - outdoor fan motor - and the compressor
A band 4 inches or more in width
The suction line or the low-pressure side

12. What kind of refrigeratnts must be added in liquid form?
When it is above a conditioned space
2
Blended refrigerants
Belt drive and direct drive

13. How are the condenser coils different on a high-efficiency unit?
Fiberglass
They are larger
False
Blended refrigerants

14. What is the normal evaporator temperature?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
45 degrees F
No
Potential relay and start capacitor

15. Do you need a trap on a push-through evaporator?
They are larger
Duct - electrical - and mechanical
300
No

16. What kind of metering device do high-efficiency units usually use?
TXV
The takeoff fitting
By increasing the surface of the condenser coil
Belt drive and direct drive

17. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
Negative
40 degrees F
30 A
Infiltration and ventilation

18. Do you need a trap on a push-through evaporator?
20 degrees F
Yes
No
In series

19. What type of air conditioning system must be charged using the superheat method?
Blended refrigerants
Latent and sensible
Average feet per minute X area in square feet (H' x W'/144)
A piston type metering device

20. 10 SEER is classified as what kind of efficiency?
20 degrees F
100 psig
Standard
Duct - electrical - and mechanical

21. At what temperature does refrigerant condense in a standard-efficiency unit?
40 degrees F
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
30-35 degrees above ambient
Heat load

22. How many cfm per ton?
400
Boil the liquid refrigerant out ot the oil within the crankcase
They are physically larger
In parallel

23. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
In parallel
A bypass duct or a dump zone
15% silphos
Individual return air systems and central return air systems

24. Will a dirty condenser cause a rise or fall in pressure?
Vapor
200
1/4'
Rise

25. How does ACR copper pipe come?
Inches of water column (in. WC)
Dehydrated with caps on each end
Shorted winding - open winding - and grounded winding
25-ft or 50-ft

26. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
Shorted winding - open winding - and grounded winding
18 gauge
True
140 degrees F

27. What is the difference between SEER and EER?
SEER includes the energy used in the start-up and shut-down cycles
Fiberglass
A bypass duct or a dump zone
Individual return air systems and central return air systems

28. How will too much refrigerant effect superheat?
It will be low
Btu/hr (output) / wattage (input)
Average feet per minute X area in square feet (H' x W'/144)
Duct with insulation on the inside

29. How do you calculate ballpark superheat?
30 A
Subtract ambient temperature from 100
With a minimum of three evenly spaced self-tapping screws
With 4' saddles

30. What are the three crafts normally associated with an air-conditioned installation?
Duct - electrical - and mechanical
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Individual return air systems and central return air systems
Boil the liquid refrigerant out ot the oil within the crankcase

31. The compressor is cooled by liquid refrigerant. (True of False)
The suction line or the low-pressure side
With an are rating
SEER includes the energy used in the start-up and shut-down cycles
False

32. Sections of duct board can be fastened together with what?
Pull a vacuum
L-type
Staples and tape
A piston type metering device

33. Do you need a trap on a pull-through evaporator?
Suction
A bypass duct or a dump zone
Yes
On the common terminal

34. 13 SEER is classified as what kind of efficiency?
15 A
Infiltration and ventilation
400
High

35. What are the two functions of the air-conditioning system?
Inclined manometer
Yes
To remove humidity and lower dry bulb temperature
Yes

36. How are the high pressure switch and the low pressure switch wired with the compressor contactor?
With a minimum of three evenly spaced self-tapping screws
2
In series
Pistons

37. 6' round duct has a ballpark cfm of what?
L-type
To lower the amount of pressure drop through the coil
Btu/hr (output) / wattage (input)
100

38. Where do you apply flux when soldering?
Side-by-side and over-and-under
RLA/FLA x 5
Blended refrigerants
Outside of the male fitting

39. What is it called when liquid refrigerant gets into the compressor?
A band 4 inches or more in width
Slugging
With 4' saddles
Yes

40. The crankcase heater on an air-conditioning compressor is used to what?
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
A band 4 inches or more in width
Boil the liquid refrigerant out ot the oil within the crankcase
30-35 degrees above ambient

41. If the rpm's are 750 - how many poles does the motor have?
8
30 degrees F
Suction
Yes

42. Pressure in ductwork is measured In what?
Inches of water column (in. WC)
5 degrees
4
Stranded

43. When must a copper joint never be soldered or brazed?
When the system is under pressure
Standard
RLA/FLA x 5
Pi x radius squared

44. How many amps can 12 g wire handle?
20 A
When the system is under pressure
Yes
Staples and tape

45. The fan switch opens at what temperature?
Staples and tape
Side-by-side and over-and-under
105 degrees F
Common

46. Most duct insulation is made of what?
300
Nominal-sized tubing
It will have a decrease in superheat
Fiberglass

47. Superheat should never be below how many degrees
On the common terminal
It rises
5 degrees
A diffuser

48. How do you calculate LRA?
RLA/FLA x 5
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
L-type
Any amount

49. How is insulation around a duct rated?
Nitrogen with a small amount of refrigerant
4
With an are rating
It also rises

50. What are the two basic duct connection configurations for package units supply and return air ducts?
40 A
Staples and tape
Over/under and side by side
Average feet per minute X area in square feet (H' x W'/144)