Ventilation Flashcards
Uses of Ventilation
• Cooling of Electronic Equipment
• CBRN
• Habitability
• Main Machinery Space Cooling
• Galley Ventilation
Name all ventilation configurations
Fan Supply / Fan Exhaust
Fan Supply / Natural Exhaust
Natural Supply / Fan Exhaust
Natural Supply / Natural Exhaust
When is Fan Supply Fan Exhaust used?
Fitted where it is necessary to remove large quantities of Wild Heat, Moisture or Noxious Fumes
Where is Fan Supply Fan Exhaust used?
Machinery spaces, Galleys, Laundries, WCs and Bathrooms
When is Fan Supply natural exhaust used?
Fitted where the supply of fresh air to compartments is the primary objective
Where is Fan Supply natural exhaust used?
Store rooms and Workshops
When is natural supply, Fan Exhaust used?
Fitted where the removal of noxious gases and flammable vapours is the primary object.
Where is natural supply Fan Exhaust used?
This is only used in minor unoccupied compartments and lobbies
Name types of filter
Panel
Supply
Grease
Lint
Dust
Flameproof Gauzes
What is a panel filter
Re-circulating trunking associated with air conditioning systems
What is a supply filter?
Polyurethane filters fitted in ATUs between the plenum chamber and the cooler
What is a grease filter?
Fitted to exhaust canopies over deep fat fryers and ranges in galleys
What is a Lint filter?
Fitted to prevent the accumulation of fluff and fibres in the exhaust trunking of the laundry
What is a dust filter?
Fitted to computer and sonar instrument spaces and sick bays
What is a flameproof gauze filter?
Are fitted to inflammable stores, paint shops, hangers, vehicle decks and magazines
Name all the spaces that require special filters
Galleys
Storerooms
Aux Machinery Spaces
Sewage Treatment Spaces
Magazines
Special requirement of Galleys
· Have Fire Flaps fitted to their exhaust trunking
Special requirement of store rooms
subject to the build-up of toxic fumes (CO2) which is heavier than air.
Special requirement of Auxilliary machine spaces
To prevent any build-up of gas 50% of exhaust terminals will be found at deck level.
Special requirement of Sewege Treatment Spaces
These spaces require 15 air changes per hour with a separate exhaust system and a slight excess of exhaust capacity from that of the supply.
Special requirement of Magazines
fitted with their own air conditioning system which allows 100% treated fresh air
ATU Air Percentages
under normal conditions use 33% Fresh air and 67% Re-circulated
ATU
Air Treatment Unit
AFU
Air Filtration Unit
When are AFUs Used
CBRNDC state 1, Condition ZULU ALFA
3 sections of AFUs
- Pre particulate filter
- Particulate filter
- Gas filter
What is pre particulate filter?
A paper filter which removes coarse particulate matter including radio-active fall-out
What is a particulate filter
Made of glass fibre; designed to remove particulate such as bacteria by entrapment
What is a gas filter
Designed to remove all known chemical warfare agents in the form of gases or vapours from the airstream by absorption in the activated charcoal filling
What is a citadel?
whole ship chemical, biological and nuclear shelter
• Formed by closing the ship down to an increased gas tight state
How does a citadel work?
works by increasing the atmospheric pressure within the ship above external pressure using air filtered by AFU units
Why are citadel tests done?
For the citadel to function correctly, the gas tightness must be checked regularly, and any defects made good.
Name all the citadel tests
- Annually
- Prior to DED (Docking Extended Duration)
- During Harbour Acceptance Trials (HATS)
- During Sea Acceptance Trials (SATS)
- All ships will be required to carry out a Citadel Test during FOST Work-up
What pressure is effective for a citadel to work efficiently
Half inch water gauge
Why is a crash stop facility used?
crash stop facility is built into the ventilation system to allow all fans to be stopped in case of an emergency, e.g. FIRE or CRASH ON DECK.
Why do we restart vent systems?
RESTART of VENT SYSTEMS: before any ventilation is restarted the vent intakes should be checked they are clear of Smoke, Welding fumes and Debris.
Where is Crash Stop Board situated?
SCC
