MIL-HDBK-1028/8A
3.5.3
Heating and Cooling. Refer to NAVFAC DM-3.03, Heating,
Ventilating, Air Conditioning and Dehumidifying Systems. Outdoor design
temperatures shall be in accordance with NAVFAC P-89, Engineering Weather
Data.
3.5.3.1
Clean Areas. Indoor winter and summer design temperatures shall be
68 degrees and 78 degrees Fahrenheit (20 degrees and 26 degrees Celsius),
respectively. Recirculation of air is not permitted if a central air system
is provided.
3.5.3.2
Pesticide Mixing and Storage Areas. Winter design temperature for
the mixing area shall be 55 degrees Fahrenheit (13 degrees Celsius); for the
storage area, 50 degrees Fahrenheit (10 degrees Celsius). Maximum temperature
for the storage area is 100 degrees Fahrenheit (38 degrees Celsius).
3.5.4
Ventilation. Refer to NAVFAC DM-3.03 and MIL-HDBK-1003/17,
Industrial Ventilation Systems.
3.5.4.1
Clean Areas. Outdoor air provided for ventilation shall be
exhausted through the toilets and pesticide mixing and storage areas to
control migration of odor, dust, and vapor. Vent the dryer to the outdoors.
3.5.4.2
Mixing and Storage Areas. Provide a separate ventilation system
for the mixing and storage areas. System shall be provided with roof mounted,
centrifugal fan selected for six air changes per hour (minimum). Fans shall
discharge vertically. Replacement air shall be heated to 55 degrees
Fahrenheit (13 degrees Celsius). Design the system to maintain a negative
pressure in the mixing and storage areas relative to the clean areas by
supplying approximately 95 percent of the air exhausted, with the remainder
being from infiltration of ventilation air supplied to the clean areas.
Locate the exhaust stack and supply air intakes far enough apart to prevent
recirculation of contaminated air; do not rely on prevailing winds to prevent
recirculation. Position supply and exhaust register to provide good mixing to
ensure proper dilution (refer to Industrial Ventilation, A Manual of
Recommended Practice by the American Conference of Governmental Industrial
Hygienists (ACGIH), Chapter 2, for general principles of dilution
ventilation). Provide a motorized damper at the air intake louver and at the
exhaust fan discharge. Damper shall close when the ventilation system is
turned off. Provide a ventilation system control switch with light to
indicate "ON" at the entrance to the pesticide handling areas, and a sign at
the switch which reads, "VENTILATION SYSTEM SHOULD OPERATE CONTINUOUSLY. DO
NOT ENTER UNLESS VENTILATION SYSTEM HAS OPERATED FOR AT LEAST TEN MINUTES."
Operational note: The ventilation system should operate continuously to
minimize exposure to air borne pesticide dust and vapors and to avoid
inadvertent contamination of the clean areas. If the ventilation system
is shut down for an extended period, i.e., over a weekend or from an
outage, it should be turned on at least 10 minutes (one air change)
20
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