Refrigeration and Air Conditioning Interview Questions

Best Refrigeration and Air Conditioning Interview Questions and Answers

Dear Readers, Welcome to Refrigeration and Air Conditioning Interview Questions and Answers have been designed specially to get you acquainted with the nature of questions you may encounter during your Job interview for the subject of Refrigeration and Air Conditioning Interview Questions. These Refrigeration and Air Conditioning Questions are very important for campus placement test and job interviews. As per my experience good interviewers hardly plan to ask any particular questions during your Job interview and these model questions are asked in the online technical test and interview of many IT & Non IT Industries.

1. Define Refrigeration?

Ans : Refrigeration may be defined as a process of producing cold by extracting heat from a body or space and heat thus removed is rejected to atmosphere or space where it is unobjectionable.

2. What is Mechanical Refrigeration ? 

Ans : Producing cold by machine.

 

3. Classify the different Refrigeration Systems . 

Ans : It may be of the following three types 1. Vapor Compression Refrigeration System 2. Vapor absorption Refrigeration System  3. Air Refrigeration Systems .

 

4. What are the basic Units of Mechanical Refrigeration systems ? 

Ans : Refrigeration system has 4 basic units

a. An Evaporator – The cooling Unit

b. A pump or Compressor

c. A Condenser – The heat disposer

d. A liquid mixing device – Expansion valve or cylinder or capillary tube

 

5. Which Unit Produces Cooling Effect in the refrigeration system ?

Ans : The evaporator

 

6. What is the Unit of Refrigeration ? 

Ans : As Power Unit of mechanical devices is given by H.P , for electrical equipment the unit of power is kW or MW . In the same way the unit of refrigeration is  ” Tonnes of Refrigeration ” .

 

7. What is One Tonne of Refrigeration ? 

Ans: One Tonne of Refrigeration means machine is capable of removing heat from a body equal to the heat absorbed by one tonne of ice when it melts from 0 ° C to 0 ° C Water in 24 hours . Here one tonne is equal to 2000 lb .

 

8. What is the capacity of one tonne machine in MKS system ? 

Ans : In MKS system a machine having capacity to produce cooling effect of 50 kcal/minute is known to be a “One Tonne Machine” .

 

9. Define Co-efficient of Performance.  

Ans : In case of engine the performance is judged the efficiency of the engine. That is – Efficiency = Work Done / Heat Supplied .

And in case of refrigeration the process is first reversed that is we have to supply work to obtain lower temperature  or say for that removal of heat. Thus performance of refrigeration is just reversed . That is – N/W

Where – N = The rate of heat abstracted from the body in given time technically called “Net Refrigeration Effect” and W = Work Done .

Thus COP = Net Refrigeration Effect / Work Done Supplied . This is Called Theoretical COP .

 

10. What is Relative COP ? 

Ans : It is the ratio of actual COP and Theoretical COP .

 

11. What is the basic difference between air conditioning and refrigeration ?

Answer : Refrigeration solely deals with cooling . One of the major applications of the air conditioning is cooling but it also involves the artificial tampering of the natural conditions. In air conditioning the cooling is coupled with heating. It also takes care of circulation of the air, purity of the cooled air and also humidity of the controlled space. Refrigeration and air conditioning are interrelated.

 

12. What are applications of the refrigeration ?

Answer: Ice making, Preservation and transportation of the perishables, Industrial Purposes, Air conditioning.

 

13. Show the classification of air-conditioning systems .

Answer : air-conditioning systems are classified on the basis of 3 major points

a. Major functions : It involves  1. comfort air condition systems and 2. Industrial Air conditioning

b. Season of the year : 1. Winter air-conditioning  2. Summer air-conditioning  3. Year round air-conditioning

c. Equipment arrangement : 1. Unitary Systems 2. Central Systems

 

14. What are applications of air-conditioning systems ?

Answer : Air conditioning application involves human comfort. Summer air conditioning is very popular in offices and large industries.

 

15. Which Unit Produces Cooling Effect in the refrigeration system ?

The evaporator

 

16. What is the Unit of Refrigeration ? 

As Power Unit of mechanical devices is given by H.P , for electrical equipment the unit of power is kW or MW . In the same way the unit of refrigeration is  ” Tonnes of Refrigeration ” .

 

17. What is One Tonne of Refrigeration ? 

One Tonne of Refrigeration means machine is capable of removing heat from a body equal to the heat absorbed by one tonne of ice when it melts from 0 ° C to 0 ° C Water in 24 hours . Here one tonne is equal to 2000 lb .

 

18. Describe Refrigeration system with Reversed Rankin Cycle . Draw T-S and P-h Diagram of the cycle with Sub-cooling and Super-heating. . 

Please Follow This Link .  T-S and P-h diagram with subcooling and superheating. 

Stay Tuned more questions from the chapter refrigeration and air-conditioning are coming.