cabin side), there are remote solar panels
available to power each vent.
Electric-Powered Air:
Blowers and Ducts
Larger boats may have compartments on a
lower deck or inboard, where it isn’t conve-
nient or possible to install a vent directly
through the cabin roof. On a 180-footer (55 m)
with twin lower decks, this gets into full
HVAC design with integrated heating and
air-conditioning. On vessels under 90 feet
(27 m) or so, you can generally provide natural
ventilation through relatively short ducts and
keep the air-conditioning and heating separate.
In fact, this may be the best approach because
even if the heating and air-conditioning system
go offline, the separate, simple ventilation
system will still provide basic comfort.
Again, you can determine the air required
by either the VCR for a given compartment or
the number of people expected to be in that
compartment. But you have to allow for the
losses in the ducting system that directs the
air to the compartment. Detailed analysis of aChapter 14:Ventilation of Passenger and Storage Areas
Vents and Hoods
Before air-conditioning became so common on boats, ventilation was given much higher prior-
ity than it seems to get today.Cowl vents came in many sizes and shapes,including beautiful
polished-brass cowls made of sheet metal.Screw-in rain and spray hoods were used on round
portlights.These permitted the windows to be left wide open even in a heavy rain.A venturi
vent was not uncommon.This vent uses the energy in the wind flow to create a suction to ex-
haust cabin air, and often both an inlet and outlet are included in the same vent.All of these are
worth keeping in mind and applying today.For instance, rain and spray hoods could be con-
figured to fit more common rectangular windows.They could be fabricated from plastic and
can snap in place rather than screw in.Sheet metal cowl ventRain hoods for round portlight Venturi vent