TM 9-4120-404-14
2-21. OPERATION UNDER EMERGENCY CONDITIONS.
a. NBC (Nuclear, Biological, Chemical). This unit has no
provisions for direct connection to an
external NBC
filtering source. Should it be necessary to operate in conditions requiring use of NBC filtration equipment, see specific
instructions for your shelter or facility installation. For additional general NBC information, refer to MIL-HDBK-116,
Environmental Control of Small Shelters. The following are general suggestions for operation in NBC hazards and do not
apply if they conflict with instructions for your shelter or facility installation.
(1) The fresh air damper should be closed, the opening should be covered with duct tape (Item 3, Appendix E)
and sealed air tight.
(2) The conditioned air inlet louvers should be adjusted (partially or completely) closed in conjunction with the
NBC filter intake volume. This will cause a more positive pressure on inside of shelter or enclosure and keep air from
being drawn.
b. Power Conservation. During periods when full input power is in critically short supply, the air conditioner should
not be turned off completely, but should be operated in VENT mode only.
2-22. INTERIM NBC DECONTAMINATION PROCEDURES. in the event that the air conditioner has been subjected to
NBC contamination, follow the NBC procedures in FM 3-3, FM 3-4, and FM 3-5.
2-22