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?
SEER includes the energy used in the start-up and shut-down cycles
20 degrees F
To lower the amount of pressure drop through the coil
Pi x radius squared

2. When do you install a trap on a drain line?
To lower the amount of pressure drop through the coil
Individual return air systems and central return air systems
When it is a pull-through evaporator
Indoor fan motor - outdoor fan motor - and the compressor

3. If pressure rises - what happens to the superheat?
It also rises
30-35 degrees above ambient
It rises
TXV

4. What is the normal evaporator temperature?
45 degrees F
12000
Yes
Shorted winding - open winding - and grounded winding

5. 9' round duct has a ballpark cfm of what?
300
Any amount
Outside of the male fitting
95 degrees F outside - 80 degrees F inside - and 50% relative humidity

6. How will too much refrigerant effect superheat?
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
With a minimum of three evenly spaced self-tapping screws
It will be low
Latent and sensible

7. Most duct insulation is made of what?
Yes
6
Over 800 degrees F
Fiberglass

8. The refrigerant within the evaporator will typically boil at what temperature when it is 75 degrees inside with a relative humidity of 50%?
To lower the amount of pressure drop through the coil
Vapor
40 degrees F
400

9. What are the three major power-consuming devices on an air-conditioning system?
12000
Fiberglass
Indoor fan motor - outdoor fan motor - and the compressor
In series

10. What can cause a decrease in suction pressure on an air-conditioning system?
No
Average feet per minute X area in square feet (H' x W'/144)
A dirty evaporator
Shorted winding - open winding - and grounded winding

11. Where do you install a trap on a drain line?
Before the vent
5 degrees
Latent and sensible
Rise

12. How are round ducts connected to one another?
With a minimum of three evenly spaced self-tapping screws
Standard
Yes
40 degrees F

13. What distributes supply air to a room in a structure?
A diffuser
On the common terminal
Below 800 degrees F
20 degrees F

14. What is lined duct?
It will have a decrease in superheat
Duct with insulation on the inside
Pull a vacuum
With an are rating

15. How do you calculate LRA?
Pistons
300
With an are rating
RLA/FLA x 5

16. What sort of pressure will a pull-through evaporator have?
1/4'
Btu/hr (output) / wattage (input)
40 degrees F
Negative

17. Which is more efficient - a TXV or a fixed-orifice metering device?
TXV
30 A
L-type
Pistons

18. What are the three crafts normally associated with an air-conditioned installation?
40 A
Duct - electrical - and mechanical
45-55%
S-clips and drives (cleats)

19. What is the range for normal superheat and subcooling?
Inclined manometer
8-12 degrees F
Outside of the male fitting
A diffuser

20. What kind of copper tubing is used for refrigeration or air-conditioning applications?
20 degrees above ambient
With 4' saddles
Any amount
ACR (air-conditioning refrigeration) tubing

21. What are the two basic duct connection configurations for package units supply and return air ducts?
When it is a pull-through evaporator
With an are rating
Over/under and side by side
Slugging

22. How do you achieve high-efficiency?
40 A
Potential relay and start capacitor
Negative
By increasing the surface of the condenser coil

23. In what length rolls is soft copper tubing normally available?
Over/under and side by side
With a minimum of three evenly spaced self-tapping screws
False
25-ft or 50-ft

24. On what terminal do you check amperage?
Common
Dehydrated with caps on each end
Standard
Nominal-sized tubing

25. What standard weight copper tubing is most often used in the heating and air-conditioning industry?
Nitrogen with a small amount of refrigerant
18 gauge
Nominal-sized tubing
L-type

26. What do you do after you braze a system?
45 degrees F
When the system is under pressure
Outside of the male fitting
Pull a vacuum

27. Superheat should never be below how many degrees
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Potential relay and start capacitor
Yes
5 degrees

28. What do you use to connect square and rectangular ductboard together?
It also rises
They are physically larger
TXV
S-clips and drives (cleats)

29. What kind of metering device do high-efficiency units usually use?
TXV
Potential relay and start capacitor
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Inches of water column (in. WC)

30. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
A bypass duct or a dump zone
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
200

31. What type of air conditioning system must be charged using the superheat method?
A piston type metering device
The takeoff fitting
By increasing the surface of the condenser coil
A dirty evaporator

32. What is considered normal operating conditions?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
In parallel
Potential relay and start capacitor
Belt drive and direct drive

33. What are the two basic duct connection configurations for package units supply and return air ducts?
Subtract ambient temperature from 100
When it is a pull-through evaporator
Inches of water column (in. WC)
Over/under and side by side

34. How many BTU's per ton?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
12000
Positive
2

35. How long should you leave a system off once you kill power before restarting it?
Inclined manometer
18 gauge
No
2 minutes

36. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
Btu/hr (output) / wattage (input)
30-35 degrees above ambient
Any amount
In parallel

37. The evaporator is designed to remove what two types of heat?
A bypass duct or a dump zone
Latent and sensible
400
Over 800 degrees F

38. What are the three crafts normally associated with an air-conditioned installation?
Side-by-side and over-and-under
4
Duct - electrical - and mechanical
A swaging tool

39. How do you calculate the area of a circle?
Pi x radius squared
Duct - electrical - and mechanical
It rises
S-clips and drives (cleats)

40. What is the typical pressure differance across a TXV?
It will be high
Pistons
100 psig
Boil the liquid refrigerant out ot the oil within the crankcase

41. In what length rolls is soft copper tubing normally available?
20 degrees F
25-ft or 50-ft
200
150

42. When do you install a trap on a drain line?
300
45-55%
When it is a pull-through evaporator
100

43. Do you need a trap on a pull-through evaporator?
Yes
Rise
They are larger
Side-by-side and over-and-under

44. 10' round duct has a ballpark cfm of what?
40 A
Pull a vacuum
Nitrogen with a small amount of refrigerant
400

45. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
TXV
Inches of water column (in. WC)
TXV
A bypass duct or a dump zone

46. What kind of metering device do high-efficiency units usually use?
False
RLA/FLA x 5
Outside of the male fitting
TXV

47. How many amps can 8 g wire handle?
Yes
40 A
Latent and sensible
Outside of the male fitting

48. What are the three major power-consuming devices on an air-conditioning system?
It also rises
Indoor fan motor - outdoor fan motor - and the compressor
Positive
Inches of water column (in. WC)

49. In what state is the refrigerant in the compressor?
150
Outside diameter (OD)
Vapor
They are physically larger

50. At what temperature will brazing melt?
Over 800 degrees F
Stranded
45 degrees F
Latent and sensible