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. Where is insulation used on copper tubing used for air-conditioning?
Infiltration and ventilation
The suction line or the low-pressure side
Pistons
12000

2. Which is more efficient - a TXV or a fixed-orifice metering device?
2
1/4'
TXV
Suction

3. On what terminal do you check amperage?
Common
Blended refrigerants
Heat load
It rises

4. How is the high pressure switch wired with the low pressure switch?
They are physically larger
In parallel
Potential relay and start capacitor
The suction line or the low-pressure side

5. How are high-efficiency condenser coils different from standard-efficiency condenser coils?
45-55%
They are physically larger
Belt drive and direct drive
18 gauge

6. What kind of refrigeratnts must be added in liquid form?
Blended refrigerants
With 4' saddles
Side-by-side and over-and-under
It will have a decrease in superheat

7. What is it called when liquid refrigerant gets into the compressor?
40 degrees F
To lower the amount of pressure drop through the coil
Slugging
RLA/FLA x 5

8. The fan switch closes at what temperature?
18 gauge
1/4'
140 degrees F
40 degrees F

9. What tool is used to expand the diameter of soft copper tubing
They are physically larger
Average feet per minute X area in square feet (H' x W'/144)
A swaging tool
Yes

10. The furnace size is calculated by what?
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
Heat loss
RLA/FLA x 5
In parallel

11. The compressor is cooled by liquid refrigerant. (True of False)
Heat loss
100 psig
False
A swaging tool

12. What is lined duct?
When the system is under pressure
Duct with insulation on the inside
300
400

13. Most duct insulation is made of what?
Infiltration and ventilation
Vapor
Fiberglass
15 A

14. How is insulation around a duct rated?
With 4' saddles
Any amount
Staples and tape
With an are rating

15. When do you install an auxillary drain pan?
To lower the amount of pressure drop through the coil
No
When it is above a conditioned space
Latent and sensible

16. What are the three major power-consuming devices on an air-conditioning system?
ACR (air-conditioning refrigeration) tubing
TXV
Indoor fan motor - outdoor fan motor - and the compressor
100

17. The crankcase heater on an air-conditioning compressor is used to what?
A dirty evaporator
Pistons
200
Boil the liquid refrigerant out ot the oil within the crankcase

18. 10' round duct has a ballpark cfm of what?
Outside diameter (OD)
400
TXV
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line

19. What are the two ways that fresh air enters a structure?
Infiltration and ventilation
200
Blended refrigerants
Outside of the male fitting

20. What type of air conditioning system must be charged using the superheat method?
Shorted winding - open winding - and grounded winding
A piston type metering device
True
Yes

21. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
A swaging tool
With a minimum of three evenly spaced self-tapping screws
A band 4 inches or more in width
It will have a decrease in superheat

22. What is the range for normal superheat and subcooling?
ACR (air-conditioning refrigeration) tubing
8-12 degrees F
Nominal-sized tubing
High

23. What are the two basic duct connection configurations for package units supply and return air ducts?
Positive
Over 800 degrees F
Subtract ambient temperature from 100
Over/under and side by side

24. A reciprocating compressor has what sort of moving parts?
400
Infiltration and ventilation
Pistons
False

25. How will too much refrigerant effect superheat?
45 degrees F
With an are rating
It will be low
Yes

26. How many amps can 10 g wire handle?
30 A
A band 4 inches or more in width
TXV
Suction

27. What is the difference between SEER and EER?
SEER includes the energy used in the start-up and shut-down cycles
Standard
Over/under and side by side
By increasing the surface of the condenser coil

28. Do you need a vent on a pull-through evaporator?
With 4' saddles
True
A bypass duct or a dump zone
Yes

29. Pressure in ductwork is measured In what?
Inches of water column (in. WC)
It will be high
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
300

30. How does ACR copper pipe come?
20 degrees above ambient
Individual return air systems and central return air systems
Dehydrated with caps on each end
105 degrees F

31. Do you need a trap on a pull-through evaporator?
Suction
Dehydrated with caps on each end
Yes
Pistons

32. How much does a drain line need to drop per foot of length?

33. Where do you check the amps on a motor?
Blended refrigerants
2 minutes
On the common terminal
High

34. What do you use to check for leaks?
Nitrogen with a small amount of refrigerant
140 degrees F
Staples and tape
In series

35. In what length rolls is soft copper tubing normally available?
4
A dirty evaporator
25-ft or 50-ft
A swaging tool

36. If the suction pressure rises - what happens to the head pressure?
It also rises
A bypass duct or a dump zone
150
Before the vent

37. Where do you check the amps on a motor?
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
To remove humidity and lower dry bulb temperature
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
On the common terminal

38. How does ACR copper pipe come?
15% silphos
Dehydrated with caps on each end
Subtract ambient temperature from 100
Yes

39. 9' round duct has a ballpark cfm of what?
30 A
300
It will be high
A diffuser

40. What are the three ways a motor can fail electrically?
Shorted winding - open winding - and grounded winding
Yes
TXV
To lower the amount of pressure drop through the coil

41. What is the normal evaporator temperature?
Individual return air systems and central return air systems
45 degrees F
2
6

42. Do you need a vent on a pull-through evaporator?
Stranded
Shorted winding - open winding - and grounded winding
RLA/FLA x 5
Yes

43. If the suction pressure rises - what happens to the head pressure?
Vapor
TXV
It also rises
Side-by-side and over-and-under

44. If the rpm's are 1750 - how many poles does the motor have?
4
30-35 degrees above ambient
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Yes

45. What do you use to connect square and rectangular ductboard together?
Standard
S-clips and drives (cleats)
2 minutes
SEER includes the energy used in the start-up and shut-down cycles

46. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
105 degrees F
When the system is under pressure
Any amount
6

47. How do you calculate the area of a circle?
Pi x radius squared
With 4' saddles
Over/under and side by side
100 psig

48. How many amps can 10 g wire handle?
With a minimum of three evenly spaced self-tapping screws
30 A
Fiberglass
ACR (air-conditioning refrigeration) tubing

49. When must a copper joint never be soldered or brazed?
High
TXV
Rise
When the system is under pressure

50. 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
Before the vent
Boil the liquid refrigerant out ot the oil within the crankcase
2 minutes