YACHT VENTILATION SYSTEM CLEANING
the ventilation system?
In the closed internal environment of a large modern yacht, the cleanliness
of its ventilation system is paramount in maintaining this environment
in a healthy condition. Adverse health effects associated with contaminated
air supplied by ventilation machinery and ducting in a poor and dirty
condition are well documented. The efficiency of a dirty ventilation system
is also compromised, the design parameters are not met and the system
becomes unbalanced. Expensive furnishings, panels, curtains and carpets
can also be stained by dirt and mould emitted from a dirty ventilation
system. A dust-lined duct is also the perfect conduit for the spread of
fire. The importance of maintaining the extract system free from dust
and debris is often overlooked. Apart from an unhealthy back draught of
polluted air if the system is turned off for whatever reason, if the inlets
are blocked with dust and debris then the efficiency of the whole system
is compromised, the yacht cannot ventilate as per design and fresh air
changes do not take place as frequently as is required. A grease-laden
galley extract duct and fan presents a serious potential fire hazard.
Current regulations are addressing the importance of maintaining the galley
extract system in a clean condition. Similarly, a laundry dryer extract
duct blocked with dust and debris also presents a fire hazard; a dryer
that cannot vent properly can overheat and ignite the "wick" of dust and
fluff that caused the problem.
needs the ventilation system cleaned?
All yachts require a regular ventilation system cleaning and preventative
maintenance program. New yachts have their systems fitted in the yard
before surrounding metalwork, carpentry, painting, varnishing and other
finishing work is carried out. All of these activities create dust that
will enter ventilation ductwork. Although the system was clean when it
was fitted, by the time the yacht's owner takes delivery the ventilation
system will be contaminated with sawdust, metal fillings, carpet fluff
and other debris. There is no point in beginning a filter maintenance
program if ductwork is already contaminated beyond the air handlers.
Modern yachts have a busy schedule and evermore-complex control and electronic
systems that do not allow the engineer to spend time on maintaining and
cleaning air handlers and fan coil units. No matter how well filter maintenance
is carried out, dust inevitably finds its way into the air supply system;
added to this is debris from corrosion, degraded insulation and worn fan
belts. This, together with the moist environment created by a sea -air
supply, provides an ideal breeding ground for mould and bacteria inside
air handlers, fan coil units and ducting. Air, forced over these growths,
carries them throughout the system and into the internal environment of
the vessel, an obvious health hazard for those breathing the internal
air. From experience gained and feedback from yacht engineers, we recommend
that a ducted or fan coil system be cleaned and decontaminated every two
years in order to maintain the system in a healthy and efficient condition.
Laundry and galley extract systems, which generally work almost non-stop
on a busy yacht, will require an annual cleaning to remove a potential
Will cleaning the ventilation system damage the yacht's interior?
Working aboard luxury yachts requires an awareness and respect for the
expensive furnishings and fittings found aboard these vessels. Many yacht
owners are concerned about damage that may be done to their yachts when
contractors are permitted to work in the interior of the vessel. For this
reason, we have always operated with the same small team of trained and
experienced technicians who, apart from having an in-depth knowledge of
ventilation system cleaning, are accustomed to working tidily and with
great care aboard luxury yachts. All delicate areas are fully protected
before work commences and all dust and debris is collected in a high-volume
vacuum collection machine so that no area within the yacht is re-contaminated.
How is the cleaning carried out?
General: Access for cleaning ducting is normally achieved through
inlets and outlets or by cutting access in the duct walls where required.
Industry standard access doors are then fitted. These are thermally insulated,
quick- release doors that provide easy access for future cleaning and
system inspection. To clean ducting we use an electrical rotary brushing
cable that can be fitted with a variety of brush-heads. On smaller peripheral
ducting a high- pressure air wash system is used. Both methods are industry
standard, although some of our equipment has been customized to work specifically
on yacht air ducting. A high-volume vacuum collection machine is used
to direct and collect the dust and debris dislodged. All variable dampers
are marked prior to cleaning and reset; this ensures the system stays
balanced. Sensors are protected and fire dampers and turning vanes are
checked and cleaned individually. De-graded or mouldy insulation found
within air treatment units or supply outlets is either replaced or coated
with an anti-microbiological growth coating, specially formulated for
use in air-conditioning systems. The components of the system are treated
individually as follows:
The Air handlers: All air
handlers will be opened up, thoroughly vacuumed out and the fan, heating
elements and chiller units blown clean with compressed air. Where it is
deemed necessary, the fan will be removed for a thorough cleaning and
to gain access to any plenum box beyond the fan. An access panel may also
be cut in any plenum box where necessary. The fan bearings are checked
and can be replaced if required. All internal surfaces of the handler
will be wiped with a disinfectant/detergent and any damaged insulation
repaired or replaced. Any rust found will be treated with a water-based
rust converter or other approved marine-quality anti-corrosive paint.
The filter will be changed and the fan belt checked for correct tension
or wear. To finish, the handler is sprayed with an air-conditioning system
The Supply Ducting: The
supply ducting throughout most of the boat can normally be accessed for
cleaning from the inlets at the air handler and through the individual
outlets. However, where the outlet is through a linear grill or there
is mixing box at the end of the duct, then deckheads will have to be dropped
to achieve access. When plans of the ducting layout are available, then
the ducting will be accessed where necessary to clean ducting not reached
from the outlets. All outlet grills are cleaned and disinfected; these
are normally found covered in mould.
Fan Coil Units:
A lot of the work involved in cleaning fan coil units is gaining access
to them. Usually furniture has to be removed, cupboards dismantled or
panels unscrewed etc. Once accessed and opened up, each unit will be treated
as for the air handlers. The ducting supplying each unit will be cleaned.
The duct between the inlet and outlet of the unit will also be cleaned;
this we have generally found to be full of mould growing on the duct walls.
On each fan-coil unit the chiller, fans, motor, electrics and all internal
areas are blown clean with compressed air, vacuumed out and all surfaces
wiped with a disinfectant. Particularly dirty fan blades are scraped and
wire- brushed to remove all mould and debris. Drip trays will be cleaned.
All filters changed. The inlet and outlet grills will also be cleaned.
Damaged or mouldy insulation found within the unit will be replaced or
repaired. Finally, the unit will be fogged with an A/C system biocide.
The Extract System: An
extract system clogged with an accumulation of dust and debris is very
inefficient and will not extract the volume of air that it was originally
designed to do. Fan blades clogged with dust do not perform efficiently.
All bathroom and general extract ducting will be cleaned with the rotary
brushing cable, as for the supply ducting. Inlet vents are cleaned and
disinfected. All extract fans will be cleaned with compressed air and
particularly dirty fan blades scraped clean. Fan belts and bearings are
checked and replaced as required.
Galley Extract: An extract duct lined with grease is a breeding ground
for bacteria. If grease is allowed to build up, a backwash of foul smelling
air is often noticed in the galley. More importantly, having air forced
over a tube lined with a supply of easily inflammable fuel (grease), is
an obvious fire risk. The galley extract duct will be accessed wherever
possible by cutting apertures in the duct wall. Installing approved access
doors or, where space does not permit this, fitting steel plates sealed
with high-temperature resistant sealant, closes these apertures. Once
accessed, the duct is de-greased by hand. This involves a combination
of scraping, scouring and wiping with non-corrosive degreasers. A small
steam cleaner will also be used where necessary. Hard to access areas
are cleaned with the rotary brushing cable fitted with special nylon coated
wire brush-heads to remove caked- on grease. The galley extract fan will
be removed (if possible), disassembled and thoroughly cleaned. All surfaces
of the galley hood are usually given a thorough de-greasing and any external
stainless steel surfaces are polished.
Laundry Dryer Extract: An extract duct clogged with dust and fluff
does not allow the dryer to exhaust hot air efficiently. An overheated
dryer can ignite the fuse of combustible fibres within the extract duct.
The filters in the dryers will be removed and the area behind them and
around the drum vacuumed out. The fan in the dryer will be blown with
compressed air to remove all dust. The backs of the dryers will be removed,
enabling the fan motor and heating element to be blown clean with compressed
air. Pulling out the dryers will access the ducting system, which will
be cleaned along its length as far as its outlet. Any other extract fans
associated with the system will also be cleaned.
On Completion Of The Job
Much of the work that we carry out on ventilation systems goes unseen,
for obvious access reasons, by those sanctioning or paying for the work.
The yacht's engineer will also want to know what was carried out for his
maintenance records. We therefore consider it important that the work
is recorded with photographs and written details. A full written report,
with before and after photos recorded on a CD-rom, is therefore presented
to the yacht's captain on completion of the work. This report will detail
the state of the systems before and after cleaning, details of work carried
out, locations of installed access panels for future reference and any
recommendations as to future cleaning schedule and improvements that could
be made to the systems.
Fax: (00) 34 971 608337
Mobile: (00) 34 607 768 987