Air Conditioning System

Question 1

State the labels of the Freon compressors per plant, and state which ones are the same size.
State the other components of the Air Con System INSIDE THE E/R.

Answer 1

A1 and B1 are same size, A2 is smaller.
S/W pump, Chilled Water pump

Question 2

State the coverage of Zone A and Zone B of the Aircon system.

Answer 2

Zone A: Rest of ship with aircon coverage
Zone B: Mess 1, 2, 7, 8

Question 3

What is done to allow the C/W to always circulate?
How is emergency cooling provided for the condenser?

Answer 3

Leave interconnecting v/v open
Use fire p/ps 1 and 6

Question 4

Where is the C/W expansion tank located? State the C/W top-up procedure.

Answer 4

FWD E/R, overhead STBD side MCR viewing window

1. Open 2 top-up v/vs below C/W expansion tank, near the floorboard.
2. Close top-up v/vs once desired C/W p/p discharge pressure is reached.

Question 5

State the C/W bleeding procedure.

Answer 5

If there is air or excessive C/W in the system, bleed it out by opening bleeding valves at AHU 5/10, close to the deckhead near the door.

The air or C/W will exit through a “gooseneck” coming out of the ceiling of AHU 5/10.

Close v/vs once desired C/W p/p discharge pressure is reached.

Question 6

State the shutdown procedure for the aircon system.

Answer 6

1. Go to LOP and switch to “OFF”. Wait for aircon to off
2. Start and run C/W p/p independently until 13°C (MCR panel):
   i. Press 3 -> TEST
   ii. Scroll down to chiller p/p option
   iii. Press 1 -> ENTER to start p/p
   iv. There will be a password prompt. Enter the password.
   v. Press 0 to stop
3. Off circuit breakers for compressors and p/ps
4. Close the C/W p/p inlet/outlet v/vs and Chiller inlet/outlet v/vs

Question 7

State the startup procedure for the aircon system.

Answer 7

1. Open the C/W p/p inlet/outlet v/vs and Chiller inlet/outlet v/vs
2. On circuit breakers for compressors and p/ps
3. Do a soft reset followed by a hard reset (MCR panel):
   i. Soft reset (reset circuit): Press 1 -> STAT -> 1 -> ENTER
   ii. Hard reset (reset system): Press and hold “RESET” for 1s
4. Go to LOP and switch to “LOCAL”. This will turn on the aircon

Question 8

State the 7 main components in the AHU.

Answer 8

1. Centrifugal fan
2. Insulating case
3. Cooler element
4. Air filter
5. Electric heater element
6. Mixing chamber
7. Chilled water control valve panel

Question 9

State the following pressure parameters:
S/W p/p discharge p
Condenser outlet p
C/W p/p discharge p
Circuit suction
Circuit discharge
Oil p. differential

Answer 9

S/W p/p discharge p: 2 bar
Condenser outlet p: 2 bar
C/W p/p discharge p: 5.5 – 8 bar
Circuit suction:150 – 300kPa
Circuit discharge: 600 – 1000kPa
Oil p. differential: 150 – 600kPa

Question 10

State the following temperature parameters:
Accommodation
Hospital areas and med facilities
Gun bay and Ammo rooms
Chiller inlet temp
Chiller outlet temp
Motor temp
Saturated condensation temp
Saturated suction temp
Lube oil temperature
Jacket Water temperature

Answer 10

Accommodation: 24°C
Hospital areas and med facilities: 20°C
Gun bay and Ammo rooms: 28°C
Chiller inlet temp: 7 – 12°C
Chiller outlet temp: 2.2 – 10.5°C
Motor temp: 70 – 80°C
Saturated condensation temp: 31 – 40°C
Saturated suction temp: >5.5°C
Lube oil - 85°C
Jacket Water - 82°C

Question 11

State 4 safety considerations when operating the aircon system.

Answer 11

Do not mix Freon
Check bottle Expiry Date
Check for leakages
Only Qualified Personnel can operate the system

Question 12

What is the main function of an AHU?

Answer 12

To facilitate the heat exchange between chilled water and air and the filtering of cold air for consumption.

Question 13

State the total quantity of AHU for Zone A and Zone B air conditioning unit respectively.

Answer 13

Zone A: 17
Zone B: 4