Document VJoEoNLn295mQJK4m6MgzGaMq

860 CHAPTER 49 1948 Guide Table 1. Typical Heating and Ventilation Practices for Ships Space Type of Ventilation -- Sup. FVrh. - Type Air' of ` -- -Change Heating Minutes Reuarks Living Quarters_______ __ Mech. Toilets and Showers______ Nat. Chart House. Mech. Office and Similar Spaces.. . Mech; Mess Rooms. Mech. Dining Salons___ Mech. Galley and Pantry. Deck Pantries (No Cook ing Equipment)________ Stores Spaces (Isolated Locations)_____________ Hospital Spaces__________ Soiled Linens and Oilskin Lockers________________ Shops_________________ ___ Mech. & Nat. Mech. & Nat. Mech. or Nat. Mech. Nat. Mech. Group Berthing Spaces.__ Mech. COi Bottle Space___ _____ Battery Room___ _ Laundry Nat. Nat. Mech. Dry Cargo Holds Mech. Stealing Gear Space..... ..... Mech. or Nat. Gyro Room: Mechl Theaters and Halls...... ...... Mech. Passageways and Stair Nat. wells Engine and Boiler Rooms.. Mech. Misc. Machinery_________ Mech. or Nat. Resistor Spaces._____ ____ Nat. Mech. or Nat. Mech. Mech. or Nat. Mech. or Nat. Mech. or Nat. H.B.a or D.R.b : D.R. H.B. or D.R. H.B. or D.K. H.B. or D.R. Mech. or Nat. H.B. or D.R. Mech. T.A.C Mech. Nat. or Mech. Mech. H.B. or D.R. H.B. or D.R. Mech. Mech. or Nat. Mech. or Nat. Mech. ' Mech. Mech. H.B. or D.R. H.B. or D.R. D.R. H.B. Nat. or Mech. Mech. or Nat. Nat. or. Mech. Nat. or Mech. Nat. or 'Mech. Mech. or. Nat. Mech. or Nat. Mech. H.B. or D.R. H.B. or D.R. D.R. 3-6 3-4 5-6 4-6 May be. J4-6 exhausted through Galleys and ^Pantries I May be 3-6 J exhausted j through Galleys (and Pantries. 34-1 Tempered Air Supply 6 15-30, 3-4 ; 6-10 4-10 3-6 10 2 1-4 Tempered Air Supply 20-30 2-6 Unit Heater if desired.' 3-6 4-6 ..... Exhausting Ad-, jacent Quarters. 1-2 2-4 10 H. B.--Hot Blast System. bD. R.--Direct Radiation. T. A.--Tempered Air. Toilets, Washrooms, Showers and . Baths Spaces for these purposes should be fitted with mechanical exhaust ven tilation for odor and steam removal. Generally, the surrounding living or working spaces are exhausted through them. Air requirements on merchant vessels are commonly estimated on the basis of a 4 min rate of change. Where the amount of available air is limited by outside air require ments of air conditioning systems, rates of change as high as. one change Marine Heating, Ventilation, Air Conditioning 861 in 6 min are used for private bathrooms. On naval vessels, the minimum total quantity of exhaust is that which changes the air within the com partment in 6 min, plus 25 cfm for each toilet fixture, plus 50 cfm for each shower head. Heat is obtained by use of convector radiators which should maintain a temperature of 70 F. Galleys, Bakeries, Laundries, and Food Handling Spaces. The problem of the ventilation of spaces fitted for cooking and food preparation is primarily one of heat and smoke or fume removal. Com plete mechanical exhaust is always provided, and the mechanical supply is made equivalent to at least 50 per cent of the exhaust. Sufficient natural supply to provide an indraft is required. The exhaust quantities should be predicated on restricting the ambient temperature rise to about 15 deg above the outside summer design air conditions. The resulting quantity will change the air in these spaces in about % to 1 min. All of tile exhaust should be arranged to'remove air from the space through hoods fitted over the heat producing equipment. The mechanical supply should blow air directly on the personnel, but away from the equipment and so as not to interfere with, the. flow of exhaust air to the hoods. The problem of ventilating laundries is somewhat similar to that for galleys. Experience indicates that the quantity of mechanical supply ventilation should be sufficient to change the air in the spaces in 1 to 4 min. The total exhaust (including tumbler dryers) should be equivalent to at least one air change pier minute and at least equal to 120 per cent of the supply so as to insure an indraft of air. Generally, no heat is required for these spaces in winter, but preheaters are provided to temper the supply to between 45 and 60 F. Storerooms and Cargo Spaces The ventilation provided for these spaces depends on the type of vessel, location of space, and nature of cargo. On merchant vessels ventilation is required for all closed spaces. Even if ventilation is not necessary to preserve the stores or cargo, it is required to prevent the accumulation of toxic or combustible gases and putrid odors. One air change in 15 to 30 min is common practice, except where inflammable liquids or proximity to hot spaces requires additional venti lation. Mechanical supply and natural exhaust are usually used. How ever, where inflammable gases may exist, natural supply and mechanical exhaust are provided. It is the practice on naval vessels to omit ventilation where it is not necessary to preserve the stores, except for those spaces which hold inflam mable liquids. The latter are provided with mechanical exhaust systems and natural supply. As spaces below the waterline are frequently damp, those which are unventilated may require chemical desiccants for remov ing moisture. Refrigerated stores and cargo spaces requiring constant temperature and humidity control require special treatment. AIR CONDITIONING SPACE TREATMENT The extent of the application of air conditioning to new American pas senger ships is fairly well established. All passenger staterooms, except steerage and third class, are usually air conditioned. This includes state-