Series OSS                                                                                                                              Code No. 112

                                                         AIR-CONDITIONING AND REFRIGERATION – III
                                                                                      (Theory)
Time allowed : 3 hours                                                                                                        Max. Marks: 40

Note :    Attempt any five questions.

1. What are sensible heat load and latent heat load ? Give the sources of heat load.    8

 

2. (a)    Describe an air washer.    4
    (b)    Explain  the  process  of  sensible  cooling,  and  show  it  on psychrometric chart.    4

 

3. (a)    Compare a water-cooled condenser with an air-cooled condenser.    4
    (b)    Give the desirable properties of insulating materials.    4

 

4. Explain the working of a high pressure float valve with the help of a neat sketch.    8

 

5. (a)    Explain  the  difference  between  a  dry  and  a  flooded  type evaporator.    4
    (b)    Give the desirable properties of a good refrigerant.    4

 

6. (a)    Draw the layout of an ice plant.    4
    (b)    What are the advantages of vapour absorption system ?    4

 

7. Briefly answer the following:
(a)    Define bypass factor.
(b)    Give the location of a condenser in a refrigeration system.
(c)    Give the use of a capillary tube.
(d)    Name the refrigerant recommended for cold storage.

 

8. Describe briefly the following processes
(a)    Defrosting of a refrigeration system.
(b)    Charging the system through suction valve.