system used on the ship to distribute the conditioned air. As we
know that the ventilation of cargo spaces is necessary and this prevents the
cargo from getting spoiled. There are various cargo that need to maintain at
much lower temperature. Apart from this, the living spaces need to be
maintained at much lower temperature. This ensures that the working environment
is kept good and helps in increasing the productivity of the system.
ships and very common in every ship. Since it is simple in construction,
it is very simple to be installed. As name suggest, single duct is used to
distribute the fresh air conditioned all around the spaces. Usually one or two
central units are used to distribute conditioned air to a number of cabins or
spaces via a single pipe or duct.
with the air conditioned spaces and it is dehumidified to
distribute to other parts. Since the humidity in the warm climate is much, the
air needs to de-humidify. The degree of coldness is controlled with the help of
volume of air entering the space. This all process is controlled with the help
of central unit, and measure of coldness and hotness is maintained by this
central unit. In cold climates the air mixture is warmed and humidified usually
by steam. Thus, it decreases the dryness of the air and provides moisture in
the air to appropriate amount. It is very simple system to work with.
But now a question arises why we use a twin duct system. Well twin duct
provides us more flexibility as compared to the single duct system. And
this is the reason why this system is commonly used in the passenger ships. In
this system also, we have a central unit, that deals with the cooled and dehumidified air and this is distributed all
around places with its own dedicated duct. Now the other duct is used for
supply the air which has been reheated.
two ducts are fitted in each place. Now the users can adjust the flow through
these ducts and thus can get the desirable among cooling or heating of the
space. This is what makes two duct systems more favorable than the
previous duct system. In the places where climate is colder, a pre-heater
is fitted in the supply duct. It helps to heat the air and thus make it warm
enough to warm up the room.
used in the refrigeration system to supply the
conditioned air from the conditioning unit to the source. Construction and
material cost that is involved in making of single duct system is
relatively less. In making the twin duct system, there are complications
and construction cost is also high as compared to previous system.