When emergency situation has been corrected, reset emergency button by turning collar behind button one-
quarter turn clockwise. Button will pop out and again be in the ready position.
When emergency button is reset, ventilation system must be restarted by performing procedures in
paragraphs 7-9.2 and 7-9.3.
Section IV. Heating and air conditioning (HAC) system
7-11 Description. The dayroom and workshop are provided with heated and cooled air from an HAC unit on the forward
bulkhead in the workshop. This unit forces either heated or cooled air through overhead ductwork into the workshop and
dayroom. Bulkheads in both rooms are well insulated so that a reasonable temperature is maintained. The control to
select either heating or air conditioning (AC) is on upper right side of box containing heating element above the AC unit
(Figure 7-9). The AC controls (Figure 7-10) are on front of the unit. The heating unit, located in ductwork above the AC
unit, uses an electrically powered element. Both heating and AC use the blower fan in the AC unit to move air into the
dayroom and workshop. The thermostat for the heating portion of this system is on the port bulkhead in dayroom near the
refrigerator receptacle. Both dayroom and workshop are also equipped with a mushroom-style, nonpowered ventilator in
the deckhouse top.
The AC unit's watercooling condenser is provided seawater from one of two sources. If seawater pumps in void 2
starboard are operating, and the proper valves open, they provide seawater for cooling the AC condenser and for cooling
the chlorination unit. When these pumps are not operating, seawater for cooling is provided by an AC cooling water
pump. This pump draws seawater from the forward seachest through a set of AC seawater strainers in void 2 port and
provides water for cooling both the AC unit and the chlorination unit. For details, see TM 55-1930-209-14&P-2, Seawater
Installation of this system is shown in drawings referenced in Appendix A. Components are listed in Table 7-3.
7-12 Capabilities. This system provides sufficient heating or cooling to maintain the dayroom and workshop at normal
7-13 Special limitations. The HAC system is designed to heat and cool the workshop and dayroom only. Doors from
workshop and dayroom to ROWPU space and weatherdeck must be closed when this system is in operation. Failure to
do so overloads the system and will lead to its early failure.
7-14 Performance characteristics. The AC unit provides up to 60,000 Btu of cooling per hour, and the heating unit
provides heat equivalent of 15 kW.
7-15 Operating Instructions
7-15.1 Operating controls and Indicators
Heating and AC selector switch (Figure 7-9). On side of heating element box above AC unit. Selects OFF, AC or
HEAT by rotating switch.
AC controls (Figure 7-10). On front of AC unit in workshop.
Left switch controls fan and AC unit with settings of OFF/FAN/COOL. OFF position turns off both fan and
AC. FAN position turns fan on for use with either AC or heating element. COOL position turns on AC and
Right switch selects amount of cooling to be obtained from AC unit. Turn clockwise to increase cooling,
counterclockwise to decrease cooling.
AC electrical switch. Switch handle sticks out of lower right comer of AC unit bottom front panel. Tums
electric power ON (upper position) or OFF (lower position).