Ventilation

Question 1

What are the uses of ventilation?

Answer 1

Cooling of electronic equipment
CBRN 
Habitability 
Main machinery space cooling
Galley ventilation

Question 2

What are the four configurations of ventilation and when are they used?

Answer 2

Fan supply and fan exhaust - to remove large amounts of wild heat, moisture or noxious fumes, eg machinery space, galley, bathrooms
Fan supply and natural exhaust - where supply of fresh air is primary objective, eg store room, workshop
Natural supply and fan exhaust - where removal of noxious gasses and flammable vapours is primary objective, eg paint stores, spirit rooms, inflame stores
Natural supply and natural exhaust - used in minor unoccupied compartments and lobbies.

Question 3

What 6 filters are used in ventilation systems?

Answer 3

Panel filter 
Supply filters
Grease filters
Lint filters
Dust filters
Flameproof gauze's

Question 4

Which areas have special requirements and what are they?

Answer 4

Galleys - fire flaps fitted to exhaust trunking
Store rooms - subject to CO2 build up
Auxiliary machinery spaces - 50% of exhaust terminals found at deck level to prevent build up of gas
Sewage treatment spaces - 15 air changes per hour, separate exhaust system, excess exhaust over supply
Magazines - own air conditioning system

Question 5

In an ATU system, how much air is recirculated and how much is fresh?

Answer 5

33% fresh air

67% recirculated

Question 6

What does a ATU do?

Answer 6

Heats or cools a compartment.

Question 7

What is a ATU?

Answer 7

Air treatment unit.

Question 8

What is an AFU and when is it used?

Answer 8

Air filtration unit.

CBRNDC state 1 condition zulu alpha

Question 9

What are the three sections of an AFU?

Answer 9

Pre-particulate filter
Particulate filter
Gas filter

Question 10

What does a pre-particulate filter do?

Answer 10

Made of paper.

Removes course particle matter including radioactive fall out.

Question 11

What does a particulate filter do?

Answer 11

Made of glass fibre.

Removes particulate such as bacteria by entrapment.

Question 12

What does a gas filter do?

Answer 12

Removes all known chemical warfare agents in the form of gasses or vapours by absorption in the activated charcoal filling.

Question 13

What is a citadel and how does it work?

Answer 13

Whole ship biological, chemical and nuclear shelter.
Formed by closing the ship down to an increased gas tight state.
Works by increasing the atmospheric pressure within the ship above the external pressure using AFU filtered air.

Question 14

When are citadel tests carried out?

Answer 14

Annually
Prior to DED (docking extended duration)
During harbour acceptance trials (HATS)
During sea acceptance trials (SATS)
During FOST work up (flag officer sea trials)

Question 15

What pressure is needed for the citadel to work?

Answer 15

2 “ WG

Question 16

What does a crash stop facility do?

Answer 16

Built into the ventilation system.

It allows all fans to be stopped in case of an emergency eg fire or crash on deck.

Question 17

What should be done before the restarting of ventilation systems?

Answer 17

They should be check to make sure they are clear of smoke, welding fumes and debris.

Question 18

What is an air bleed valve for?

Answer 18

A pressure release valve used to maintain the citadel at the required amount above atmospheric pressure to maintain a degree of habitability. They open at 1/2 “ over the required 2 “ WG pressure.

Question 19

Where is the crash stop board situated?

Answer 19

SCC and HQ1