SUBJECTS
|
BROWSE
|
CAREER CENTER
|
POPULAR
|
JOIN
|
LOGIN
Business Skills
|
Soft Skills
|
Basic Literacy
|
Certifications
About
|
Help
|
Privacy
|
Terms
|
Email
Search
Test your basic knowledge |
Residential Air Conditioning
Start Test
Study First
Subjects
:
engineering
,
nate
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. How is insulation around a duct rated?
Common
A bypass duct or a dump zone
It rises
With an are rating
2. What are the two types of return air systems in residential installations?
Individual return air systems and central return air systems
When it is above a conditioned space
SEER includes the energy used in the start-up and shut-down cycles
A swaging tool
3. What is the typical pressure differance across a TXV?
A bypass duct or a dump zone
Yes
Slugging
100 psig
4. How many cfm per ton?
Blended refrigerants
Any amount
105 degrees F
400
5. On what terminal do you check amperage?
Stranded
They are larger
400
Common
6. Where do you check the amps on a motor?
12000
It also rises
On the common terminal
It also rises
7. What are the four materials used to make duct?
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
Nominal-sized tubing
A dirty evaporator
High
8. What gauge is thermostat wire?
Below 800 degrees F
4
18 gauge
Yes
9. How do you calculate ballpark superheat?
With 4' saddles
A bypass duct or a dump zone
Subtract ambient temperature from 100
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
10. The crankcase heater on an air-conditioning compressor is used to what?
It also rises
Compressor
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Boil the liquid refrigerant out ot the oil within the crankcase
11. What sort of pressure will a pull-through evaporator have?
Negative
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Common
20 degrees F
12. How many BTU's per ton?
18 gauge
Negative
12000
Heat loss
13. Does a package unit come from the factory pre-charged?
150
Yes
High
20 degrees above ambient
14. How do you calculate LRA?
1/4'
RLA/FLA x 5
TXV
It also rises
15. When must a copper joint never be soldered or brazed?
When the system is under pressure
2 minutes
RLA/FLA x 5
Rise
16. If pressure rises - what happens to the superheat?
140 degrees F
ACR (air-conditioning refrigeration) tubing
Fiberglass
It rises
17. What is the typical temperature difference between a high-efficiency condenser and the ambient temperature?
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
Compressor
400
20 degrees F
18. Where do you check the amps on a motor?
Stranded
On the common terminal
It will have a decrease in superheat
Yes
19. What kind of refrigeratnts must be added in liquid form?
Belt drive and direct drive
Vapor
Blended refrigerants
TXV
20. What kind of copper tubing is used for refrigeration or air-conditioning applications?
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
15% silphos
Any amount
ACR (air-conditioning refrigeration) tubing
21. The load on the evaporater will effect which pressure?
Suction
Slugging
Btu/hr (output) / wattage (input)
In parallel
22. How is nominal-sized tubing sized?
Any amount
Suction
40 degrees F
Inside diameter (ID)
23. How will too much refrigerant effect superheat?
Dehydrated with caps on each end
It will be low
20 A
6
24. What do you use to check for leaks?
Heat loss
Duct - electrical - and mechanical
Nitrogen with a small amount of refrigerant
It also rises
25. What distributes supply air to a room in a structure?
300
A diffuser
A dirty evaporator
20 degrees F
26. The fan switch opens at what temperature?
A bypass duct or a dump zone
105 degrees F
Individual return air systems and central return air systems
On the common terminal
27. Where do you apply flux when soldering?
2
Outside of the male fitting
Static pressure - velocity pressure - and total pressure
200
28. At what temperature will brazing melt?
45 degrees F
Nitrogen with a small amount of refrigerant
Over 800 degrees F
When the system is under pressure
29. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
It will have a decrease in superheat
Belt drive and direct drive
They are larger
TXV
30. How are the high pressure switch and the low pressure switch wired with the compressor contactor?
A bypass duct or a dump zone
With an are rating
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
In series
31. Can refrigerant line sets be altered in length?
A band 4 inches or more in width
Yes
100
Pull a vacuum
32. What standard weight copper tubing is most often used in the heating and air-conditioning industry?
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
Staples and tape
L-type
40 A
33. What gauge is thermostat wire?
Potential relay and start capacitor
12000
18 gauge
30-35 degrees above ambient
34. What is used to measure static air pressure in ducts.
Inclined manometer
Before the vent
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
6
35. At what temperature does refrigerant condense in a standard-efficiency unit?
Subtract ambient temperature from 100
Fiberglass
18 gauge
30-35 degrees above ambient
36. How will too much refrigerant effect subcooling?
It will be high
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Vapor
1/4'
37. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
150
S-clips and drives (cleats)
45-55%
Belt drive and direct drive
38. What are the three major power-consuming devices on an air-conditioning system?
Indoor fan motor - outdoor fan motor - and the compressor
Rise
30 A
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
39. Where is insulation used on copper tubing used for air-conditioning?
6
When the system is under pressure
Nitrogen with a small amount of refrigerant
The suction line or the low-pressure side
40. 10 SEER is classified as what kind of efficiency?
Standard
Duct with insulation on the inside
It will have a decrease in superheat
Yes
41. 7' round duct has a ballpark cfm of what?
When it is a pull-through evaporator
RLA/FLA x 5
150
Blended refrigerants
42. What kind of copper tubing is used for plumbing and heating applications?
True
Nominal-sized tubing
2
Yes
43. How do you calculate cfm?
Warning
: Invalid argument supplied for foreach() in
/var/www/html/basicversity.com/show_quiz.php
on line
183
44. At what temperature will brazing melt?
Indoor fan motor - outdoor fan motor - and the compressor
No
Over 800 degrees F
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
45. What is the range for normal superheat and subcooling?
Vapor
45-55%
8-12 degrees F
Belt drive and direct drive
46. How are round ducts connected to one another?
With a minimum of three evenly spaced self-tapping screws
Static pressure - velocity pressure - and total pressure
105 degrees F
15 A
47. When do you install a trap on a drain line?
Duct with insulation on the inside
40 degrees F
When it is a pull-through evaporator
140 degrees F
48. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
6
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
To lower the amount of pressure drop through the coil
45-55%
49. If the rpm's are 1750 - how many poles does the motor have?
140 degrees F
Over/under and side by side
4
Inside diameter (ID)
50. What kind of refrigeratnts must be added in liquid form?
To remove humidity and lower dry bulb temperature
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
S-clips and drives (cleats)
Blended refrigerants