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Q6. A. Draw a block diagram for a fully automated accommodation air conditioning unit, labelling the component parts and indicating the directions of air flow; B. Explain why the unit includes means of dehumidification and humidification; C. A chart is used for ensuring that the accommodation conditions are within the so-called Comfort Zone: what useful information does the chart give?

Q3. With the aid of a simple sketch, explain the “trouble spots” in a basic air-conditioning unit and with reference to your sketch, explain the following: -

(a). How is capacity control achieved?

(b). How is humidity control achieved & why is it important? How the problem of increase in humidity of cooled air is overcome?

(c). How discomfort caused by the excessive drying effect of heated air is overcome?

(d) Why are generally blower run with v belts? State possible reasons if the blower is vibrating?

Q5. With the aid of a simple sketch, explain the “trouble spots” in a basic air-conditioning unit and with reference to your sketch, explain the following: -

(a). How the problem of increase in humidity of cooled air is overcome?

(b). How discomfort caused by the excessive drying effect of heated air is overcome?

(c). With a simple drawing, explain Psychrometric Chart.

Q7. With reference to air conditioning units

a) With the aid of a sketch, explain the operation of a unit that includes means of dehumidifying, humidifying, and refrigerated cooling.

b) (i) Describe the conditions that could lead to legionella growth.

(ii) List the precautions necessary in the maintenance of air conditioning systems to reduce the risk of legionnaires disease being contacted.

Q8. Explain the thermodynamic cycle involved in the air conditioning system on board a ship, detailing the key components and their functions. Additionally, describe the unloading and loading mechanisms used in the system to maintain efficiency and manage varying cooling loads. (16)