This would be six 4-inch ventilators,
which is not likely to be practical. You could
approach this requirement by using, say, four
5-inch ventilators (78.4 sq. in.) or between
two and four 4-inch ventilators combined
with hatches, dodgers, or ventilated compan-
ionway doors, and arranged so they can be
left open in bad weather.
Or
Example: Our example master state-
room is 3.02 meters long×2.68 meters wide.
It has a head compartment in one corner that
is 1 meter×1.43 meters.
Net stateroom square footage is:
3.02 m long×2.68 m wide=8.1 m^2
−1.0 m long×1.43 m wide =−1.43 m^2
Total =6.67 m^2
For temperate climates
6.67 m^2 ÷ 144 =0.0463 m^2 ×10,000 cm^2 /m^2 =
463 cm^2
0.0463 m^2 ×10,000 cm^2 /m^2 =463 cm^2
This would be six 10.2 cm ventilators,
which is not likely to be practical. You could
approach this requirement by using, say, four
12.7 cm ventilators (507 cm^2 ) or between two
and four 10.2 cm ventilators combined with
hatches, dodgers, or ventilated companion-
way doors and arranged so they can be left
open in bad weather.
Windows, Hatches,
and Skylights
The fact is that properly designed windows,
skylights, and hatches can and should con-
tribute to vent area in warm weather. By in-
cluding these items, you can approach or
even exceed Rod Stephens’ rule. Figure 14-6
shows a motor cruiser my office designed.
This is similar to the vessel we had at the
Miami Boat Show. Note that almost every
window you see opens. The wheelhouse roof
has a huge skylight, and there are large slid-
ing doors. Even when it’s raining and
unpleasant out, at least a quarter of these
windows or hatches can be left partly open
without water coming in. (Which ones to
open depends on wind and spray direction,
obviously.) In most conditions, the total vent
area in use—even in bad weather—is greater
than Rod Stephens’ rule. In fact, the first two
of these boats did not have air-conditioning at
all, including Summer Kyle, based out of
Florida. At the same time, with the hot-water
cabin-heating system and the windows and
hatches buttoned up, this boat is also warm
and snug in 30°F (−1°C) weather. Buttoned up
like this, the numerous mushroom vents still
provide adjustable fresh air, which is vital.
Figure 14-8 shows the inside of Summer
Kyle, giving the inside view of another of
these vessels from my office and showing the
amount of both light and air designed in.
Chapter 14:Ventilation of Passenger and Storage Areas
Figure 14-6. The
47-footPeregrine/
Nancy Lankin.
Nearly every
window on this
boat opens.