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Passenger Vessel Report Healthy HVAC Key to Passenger Vessel Profitability It can be argued that HVAC systems on Cruise ships consume the most amount of energy next only to propulsion. Managing HVAC system maintenance properly can result in operational cost savings on Passenger Vessels. Let's assume, on average, that cruise ships have approximately 75 Air Handling Units per vessel. A minor increase in energy transfer can result in significant savings, and best, these improvements are quantifiable, easily measured with existing technology. Marine HVAC systems are the lungs of the ship, as the systems are designed to provide clean, conditioned and odor free air to all areas of the vessel. Air exchange rates in cabins are essential to the health and comfort of the passenger and crew, which ultimately is essential to the profitability of the vessel. If the system is plugged, broken and not maintained properly, air exchange rates will be reduced. Results of poor maintenance practices can result in mold and fungus growth in the system either on the coils or supply plenums at the Air Handling units or on the Air supply diffusers in the cabins. Air extraction systems used in the galleys and laundries remove food grease and laundry lint. These systems require regular cleaning and maintenance. The cleaning and maintenance of Marine HVAC system can be looked at from two different perspectives; Safety and Comfort. Safety Return duct before cleaning and after cleaning (above). (Photo credit: to Clean Air Services) Coast Guard, SOLAS and USPH are concerned with Safety. The risk of fire, either in the galley grease extraction system or in the laundry lint extraction system, is a real potential if not serviced on a regular basis. Galley Grease systems are cleaned from the Grease hood in the Galley through all the associated ductwork and to the discharge duct or plenum of the ship. Grease collects on all interior surfaces, components, dampers and on fan impellers and fan housing. Grease is congealed and liquefied throughout the system. It is not unusual for a HVAC service provider to remove 100 kilos or more from a Grease extraction system Grease reduction systems exist to reduce the amount of grease that actually enters the duct work. Steel baffles and other types of washable filters or wash down systems are used as the first stage of grease reduction. New UV Light systems are in use today on a few ships but the word is still out as to the effectiveness and applicability. Maintenance is an issue. Cleaning of the Grease duct work is best done by hand scrapping methods. Duct work is opened for access to the entire system. Fans are disassembled and all components are cleaned. These systems are generally not designed for the introduction of high pressure water into the duct work. Fire Rated A60 steel Grease duct work will corrode and rust as a result of water within the systems. Main laundry, dryer lint extraction systems are also at risk of fires. Laundry lint is very flammable and must be removed from the air stream and prevented from collecting on the internal surfaces of the ductwork. Commercial dryers used on most ships have lint collection devices. The OEM style Lint filters can be damaged and the lint by passes the filter, moving into the duct work. Older technology has used Cyclonic type machines that can reduce the lint reaching the duct work but are still likely to allow for bypass. New types of lint removal systems are available that can remove 95% of dryer lint at one micron. Comfort A dirty grease extraction duct note heavy build up of grease. (Photo credit: to Clean Air Services) Passenger and Crew cabins must have a supply of clean odor free conditioned air which is exchanged at a rate deter- mined by the HVAC designer to the ship. The extraction system (usually in the cabin toilet deckhead) will, over time, become blocked with fabric lint, hair and dust. This blockage of the cabin extraction system reduces the amount of air that can be pulled or extracted from the cabin. This generally results in an odorous, warm/hot cabin. Blocked or reduced extraction will also reduce the amount of supply air in the cabin space, further limiting the systems ability to breathe effectively. The supply side of the Cabin HVAC system can be contaminated with various debris including mold and/or fungus. As fresh air is brought into the system, spores of mold and fungus enter the ships HVAC system. Under the right conditions, this contamination can reach very high levels of growth. Mold and fungus can grow through the system and even propagate in the supply diffusers in the cabins. Itchy eyes, coughing, sneezing and musty odors are complaints that will be made to the hotel management The experienced HVAC service provider will comprehensively clean and remove all contamination from 100% of the internal sections of duct and all associated components. This should be performed without damaging any components to ensure the integrity of the system. All too often poor work practices result in broken duct work and damaged components that ultimately render the cabin system inefficient. This results in passenger complaints. The selection of the Marine HVAC service company is critical to ensure the proper complete cleaning and refurbishment of the systems. The Goal of the service provider should be to bring the system back to the original operational design specifications. Working within Marine environments as a Riding Crew, the ability to work with others during challenging Dry Dock service periods are just some things to consider. Some questions to ask; � How long has the company provided Marine HVAC service work? � What percentage of the companies work is Marine HVAC service? � Can the company supply references? � Will the company provide a personnel profile for the Technicians and Managers for the project? � Will the company provide a written specification with a measurable standard of performance? � Will the company provide production reports on a Daily basis to ship management? � Will the company provide a complete photo documented report showing before and after conditions of the work performed? Qualified and experienced HVAC service providers will join the vessel to perform detailed assessments and investigations to assess the conditions of the HVAC systems. A pictorial depiction and complete written assessment of the HVAC system provides Ship Management with the information to determine what portion of the system needs cleaning and when to schedule the work. Some companies provide secured Online data bases for the review of the Fleets HVAC systems and will provide the tools for the management of the future HVAC maintenance requirements. The preceding was provided by Michael P. Waddington, Clean Air Services Canada Ltd. Contact Waddington at Tel. 604-888-7488; Email mpw@cleanairservices.com; or visit www.cleanairservices.com Maritime Reporter & Engineering News 18