TM 5-852-9/AFR 88-19, Vol. IX
(b) Shower room ventilation. Exhaust fans should be installed to remove the moisture from
shower or bath areas. Exhaust fans should not be placed within individual shower stalls as this causes cold
drafts: the best location is just outside the shower room door. In gang showers, ventilation openings can be
in the shower room, but should be near the exit.
(6) Dining hall/kitchen exhaust systems. Exhaust fans should not be installed on the roof or the
exterior of the building, or immediately above the grease filters where the ambient temperatures may be too
extreme for the electric motors. Also, grease which passes the filters is deposited within and on the exhaust
fan motor and belt drive. It is difficult to clean all spaces within the hood and the discharge ducts. Grease can
accumulate and drip down through the seams and onto the ranges. Properly designed stainless steel ducts
should be used. In all kitchen hood designs, provide openings to allow easy cleaning of discharge ducts. Fans
should be kept readily accessible for frequent cleaning and maintenance by installing them inside the building,
with only the fan rotor exposed to grease accumulation. Hood designs should minimize grease collection
features and facilitate cleaning. Hoods on systems with intermittent fan operation should be designed so that
cold air cannot enter the duct system and cause condensation on the exposed surfaces. Package kitchen hood,
fan, grease extraction, and heat recovery units should be investigated from the standpoint of energy
conservation savings. This type of system installation may be feasible based on the facility size and operation
time. Package systems will usually require a heated enclosure (penthouse) to prevent freeze-up problems with
the heat recovery and during grease wash-down cycle.
(7) Exterior fans. When using or specifying exterior fans, be sure they will operate in the cold
ambient temperatures which will occur at the individual site. If specified fans and motors cannot operate in
the ambient temperature, they should be installed on the interior of the building.
4-4. Central heating and electric power plants.
a. Central plants. Where several facilities are built together or in the same general area, consideration
should be given to heating these buildings or composite camps from a central source. Utility design shall be
in accordance with TM 5-852-5/AFR 88-19 Vol. 5, although the need for a central distribution system in
arctic areas is stressed in this manual. Consideration should be given to installing a central system for several
reasons: (1) because most facilities are remote, expert maintenance personnel may not be available at the site;
(2) consolidation of facilities reduces maintenance; (3) necessary parts and supplies are in short availability;
(4) there are fewer fire hazards in a central plant; and (5) maintaining supply in one fuel tank versus separate
fuel tanks minimizes the number of personnel exposed to the cold weather. If a central heating plant has
trouble, however, the whole base is in trouble. Therefore, redundancy of vulnerable systems can be important,
but complete backup is not essential.
b. Heat recovery systems. In general, arctic facilities are in isolated locations. Since supplies are
transported to most of these sites by airplane or annual supply ships, economy dictates reduced fuel
consumption. As pointed out previously, additional insulation can cut fuel needs to a certain degree. Since
electric power is generated at most sites by diesel generating plants, consideration should be given to the
feasibility of using waste heat recovery equipment. Waste heat from diesel generators can be used for space
heating, melting snow, or domestic hot water heating. Low pressure steam or hot water can be generated by
waste heat recovery equipment. Engine jacket water can be used directly in building heating systems, or
indirectly, through heat exchangers which heat a secondary liquid used in the building heating system. The
indirect method is preferred because this: eliminates interference with engine jacket water flow; achieves
better temperature control; and eliminates thermal shock to the engine. Heat recovery from the engine jacket
water and exhaust gases can increase the diesel engine thermal efficiency by 30 to 60 percent. In remote
areas, fuel costs (including shipment) can be extremely high, making maximum utilization of heat recovery
systems important.
4-5. Humidity.
a. General. In the arctic, control of relative humidity for occupied spaces is important. The following
discussion of the effects of high and low humidities illustrates the need for effective control.
b. Low humidity. Cold air contains very small amounts of moisture. For example, if outside air at -29EF
and 100 percent saturation is heated to 70EF, the resultant relative humidity would be approximately
1 percent. The effects of low humidity are:
(1) Effects on human comfort. When the air is dry, moisture evaporates more readily from skin and
makes people feel chilly even with inside temperatures of 75EF or more. Dry air removes moisture from the
nasal passages and throat, causing an uncomfortably tight irritated feeling. Doctors state that relative humidity
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