CHAPTER 3 - Functional Description
The Model NAC-600 marine air conditioner functions as a mechanically refrigerated air conditioner capable of
providing air circulation, ventilation, air cooling and dehumidification for naval shipboard use with a minimum
capacity of 60,000 BTU/HR. The air conditioning unit functions with the use of a sea water condenser which
rejects heat from the compartment being conditioned. This is accomplished through the use of various
component parts and assemblies allowing for cooling and ventilating through an evaporating section which
discharges cooling air by means of a blower assembly coupled to a fan motor which is energized by an ON-OFF
switch for the means of operation.
The following detailed component item functions are provided to allow for the proper component understanding
of the equipment component defined.
Water Regulating Valve Each unit is equipped with a factory adjusted water regulating valve. This is a pressure
operated type water valve. As the pressure rises in the condenser due to the accumulation of the gas, the valve
is opened permitting water to flow into the condenser to cool the compressed gas. It opens the water circuit only
when water is needed, that is, as the pressure rises. The valve is set to open at a certain pressure. As the
head pressure (compressor discharge pressure) increases, the valve opens further; when the pressure and
temperature drops the water flow is reduced and finally the pressure