HVAC - "Sick boat syndrome"

Its a big business.

All professional , commercial yachts do it. Yachts guard their reputation in the charter market and protect against lawsuits by sub contracting it out

http://www.aircleaneuropa.net/index2.htm

 

FF is absolutely right. A ductless system offers very high efficiency, SEER ratings from 20-26 are common. With a ductless system you will never have any of those duct problems. In addition some of the units have built in dehumidifiers which keeps things dryer and more comfortable.

Here are some examples. http://www.goductless.com/Ductless-Air-conditioner-Ductless-heat-pumps-s/91.htm

 

I agree, provided that evaporator coil and air filters are regularly cleaned and filters occasionally substituted.

Cheers

 

There is no question improved HVAC system designs will help with this issue. Reliability and maintainability are crucial in the design of any ship system. One only need to examine big ships to realize the following points:

• Much attention is paid to the design of the hull, bulkheads & propulsions systems.
• On the other hand, with some ships the routing of electrical, ventilation & plumbing systems often comes as an after thought.

One only need to inspect where ventilation systems, for example, pass through bulkheads. Are they connected to a fitting (easy remove/replace) or are they just passed through and sealed up with waterproof caulking (difficult removal/replace). All such systems tend to have spots that are prone to contamination. Having the ability to physically or access a certain segment of the system would be critical to ensuring it's free of contamination.

There's no question adding bulkhead fittings to the design of a ventilation system add to the overall weight of a ship, but they also allow easy access & hooking up pressurized cleaning sytems.

After having seen many lousy ship designs (and a few lousy aircraft designs too) I would argue the root of this "sick boat syndrome" is lousy HVAC system design. The only way to guarantee a clean system is to inspect and clean it if necessary, and it's very difficult to do that if you can't get to it after it's built.

There's also scheduling. We all know these big ships are anxious to move thousands of passengers. What's more important?

• Properly inspecting and cleaning a contaminated ventilation system?
  or
• Bringing on the next batch of passengers so you can bag a pile of money?

I've seen they way these ships come in/out of ports. They are well versed in moving thousands of people off, only to rapidly turn around a short time later with another full boat.

At the end of the day the fix will be both improved designs, cleaning methods and proper scheduling. A health inspector should also be able to delay a cruise if a ship fails to pass health & sanitation testing. I know they do delay ship schedules now for this very reason, but standards need to be improved.

 

You have to do it(regular cleaning) with all systems anyway, whether it is ductless or not. Ductless is better IMHO because any problem will be localized and usually not throughout.

 

I've only been on one cruise ship, and I wasn't paying much attention to the physical plant. For the cabins, I wonder if they are all required to have separate air handlers. They certainly would be on land. I'd set them up with a hot/cold water to air heat exchanger built in two parts-

1. A frame or sleeve with all the permanent connections- hot sup/rtn, cold sup/rtn, drain, power, control board, switching valves, ship's bus for remote ops, occupancy sensor input, Tstat input. The occupancy sensor transfers control to the tstat and starts makeup air.

2. A drawer unit with two liquid quick connects, a drainhose, and a cord. This contains the coil, blower, and pan.

Maintenance is a drawer change. Roll the new one in on a cart. Set it on the bed. Remove the old one to the cart. Install new one. This is done every four-six months. Keep enough spares handy that you can do a day's worth all in one shot. Gather the dirty ones up and run them through a cleaner. Modified commercial dish washer works good.

Other odds and ends. If you have to do maintenance on the AC and some vacuum cleaners, do the vacuum cleaners first. When maint. turns a vac back to houskeeping, it should look like new out of the box. If your bloody maint dept. can't fix vacs, how do you expect them to maintain a huge HVAC system. Vacs are the first thing I look at when looking over a hotel. The HVAC system is not a vacuum cleaner.