Sig Marine Sig100, Руководство по эксплуатации и установке

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the volume of air entering the boat, and the boat will gradually
become depressurized. With lower pressure in the boat than outside,
there will be a tendency for air to be drawn back into the boat from all
available openings including down the chimney.
2. Air movement in the boat. Second, air movement in the boat must
not interfere with the chimney. As air flows out through the one
window, air is drawn from another to replace it. This is called the
stack effect, since the boat acts like a stack, or chimney. If the stack
effect
is powerful enough, it will overcome the chimney's upward
draft and pull replacement air (and smoke) into the boat through the
chimney.
3. Competition for available air. Third, there must not be too much
competition from other devices in the boat, such as exhaust fans, a
large engine or air-exchange systems. If something else is sucking the
air out of the boat, the chimney might not be powerful enough to
overcome it, and exhaust might be drawn into the boat from the
chimney.
4. Proper chimney design. And finally, a chimney must be designed to
accommodate the volume and type of exhaust being emitted by the
appliances it serves. This involves correct sizing, adequate height, and
proper construction. See the “Chimney Pipe” section on pg. 9.
Since the chimney draft is affected by so many factors, draft problems
can be complicated to find.
Testing the Draft
To find where the air is being drawn, twist a paper towel into a wick, light it
and blow it out to create smoke. Placing the smoking wick near the open
hatches, windows or vents will lead you to the location. Installing or opening
opposing vents will allow the air to come in from a path of least resistance
and not disturb the draft in the chimney.
Downdraft
A common reason for downdraft is burning the heater too low (too much air
in the burner and not enough fuel). If the flames are burning below the top
burner ring and inside the burner pot then it is burning inefficiently causing
the draft to be too weak going up the chimney allowing downdraft down the
chimney. When the flames are burning above the top ring then the natural
draft is at its strongest so it can fight against downdraft.