Page 28: of Marine News Magazine (September 2022)

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Feature

HVAC © Vilhelm / Adobe Stock

Air vents on the deck of a car ferry.

enough horsepower chilled water pump. I recall a saltwater sion package to provide power to the compressor, which chiller system installed on a South Florida research ves- is mounted to the front of the engine. The raw water feed sel of 100 feet in length during a period of moderniza- can be siphoned off the pickup for the main engine prior tion. The chiller plant was built on the upper deck into to where it enters the main engine to provide cooling. The a custom-built aluminum box of about 10 feet long by 4 condenser is also low pro? le, and most would be in the feet deep and 7 feet tall. This worked around the lack of engine space mounted above the water line, but not so far space in the engine room and used a larger seawater pump as to cause the pump to have to work harder. The cooling to lift the raw water from the hull sea chest to the upper units are usually set up as low pro? le to be easily mounted deck, close to 20 feet. The cooled or heated water was then behind a bulkhead or below a decking and feed cooling or pumped to 17 different air handlers, in this case split wall heating to the space through four to six vents. Heating in units, for the accommodations and common areas of the these units uses coolant from the engines to help the ef? - vessel. The engineering department had to make sure their ciency of the internal heating coil and generate the heat to preventative maintenance was up to date on these units to warm the space. The system can be set up to use both heat help ensure the system kept running without downtime. and cool at the same time in a de-humidi? cation effort.

The regular inspection and scheduled maintenance of a The systems all need to be maintained. Raw water com- system will prolong its useful operating life. ing in through the hull must be ? ltered through a particu-

Small boats in the 25- through 40-foot range can also late strainer in the sea chest. This needs to be inspected explore the options of an engine driven HVAC system. on a regular basis for obstructions such as sea life and sea

Coming back around to the common theme that boats al- growth. The engineers who design the system need to con- ways lack enough room, this system uses the main propul- sider the amount of water that will be needed, so the de- | MN September 2022 28