Chapter 10 - Air Conditioning And Refrigeration

Question 1

What unit of air conditioning are used when the area is close together, being used for similar purposes or have same humidity zones?

Answer 1

Forced air units

Question 2

Once the type of air conditioning unit is chosen what is the next step?

Answer 2

to figure out the appropriate size

Question 3

In a refrigeration system what is the major consideration?

Answer 3

Heat load calculation

Question 4

What two types of air conditioning units are used?

Answer 4

Forced air and hot and chilled water system

Question 5

What refrigerant is used in the absorption refrigeration system?

Answer 5

Either water, ammonia, or lithium bromide

Question 6

Where is the expendable refrigeration system used?

Answer 6

Used in trucks, railroad cars, and shipping containers that contain perishable goods.

Question 7

What 3 types of refrigerant is used in expendable refrigeration systems?

Answer 7

Liquid nitrogen, carbon dioxide, and liquid helium.

Question 8

What type of refrigeration system moves heat from one area to another by the use of electrical energy?

Answer 8

Thermoelectric refrigerant systems

Question 9

What refrigeration systems are used when ultra low temperatures are required?

Answer 9

Multistage refrigeration systems

Question 10

What does TEV stand for?

Answer 10

Thermostatic expansion valve

Question 11

Describe the refrigeration cycle

Answer 11

Enters through the compressor, condenser, metering device, and out the evaporator

Question 12

At two stage compound system can attain a temperature at what degrees?

Answer 12

-80 degrees F

Question 13

A three stage compound system can attain a temperature at what degrees?

Answer 13

-135 degrees F

Question 14

What 2 groups are evaporates divided into?

Answer 14

1.evaporators that cool air that in turn cools the the product. 2. Evaporators that cool a liquid that in turn cools the product

Question 15

What is a control device that responds to changes In temperature and directly or indirectly controls the temperature?

Answer 15

Thermostat

Question 16

What 3 types of thermostats are used?

Answer 16

Heating, cooling and dual.

Question 17

What is the common sensing element in a thermostat?

Answer 17

Bimetal (made of metal and brass)

Question 18

What 3 categories are associated with electrical room thermostats?

Answer 18

Line voltage, low voltage and millivoltage

Question 19

What does AEV stand for?

Answer 19

Automatic expansion valve

Question 20

What is valve is the most widely used expansion device?

Answer 20

TEV

Question 21

What is a receiver?

Answer 21

Storage tank for liquid refrigerant

Question 22

What are the 4 types of single phase motors used in hermetic assemblies?

Answer 22

Split phase, capacitor start induction run, capacitor start capacitor run, and permanent split phase.

Question 23

What type of single phase motor has a limited starting torque and is usually used with window air conditioners?

Answer 23

Split phase

Question 24

What are the 2 basic types of circuits?

Answer 24

Load and control

Question 25

What is a load?

Answer 25

Any device that consumes electrical energy

Question 26

If an ohmeter reads zero what does that mean?

Answer 26

The winding is grounded

Question 27

What is the difference in start and run capacitors?

Answer 27

Start- connected in series with starting windings. Run- connected in the circuit between the line side of the starting and running windings.

Question 28

What type of starting relay is electromagnetic and is used with split phase, induction run motors?

Answer 28

Current

Question 29

What’s the maximum temperature in a cascade refrigeration system?

Answer 29

-50 degrees F

Question 30

3 R’s of refrigeration cycle?

Answer 30

reclaim, recycle, recover

Question 31

Which refrigerant is being phased out?

Answer 31

R-22

Question 32

Which refrigerant replaced the r-22?

Answer 32

R 410A

Question 33

Which refrigerants can we use?

Answer 33

R 134A, R 407C, R410A R417A