Century Heating CB00023, Инструкция по установке и эксплуатации

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Page 38 Installation and Operation Manual - FW3200
ENGLISH
9.3 Minimum Chimney Height
The top of the chimney should be tall enough
to be above the air turbulence caused when
wind blows against the house and its roof.
The chimney must extend at least 3 ft. (1 m)
above the highest point of contact with the
roof, and at least 2 ft. (60 cm) higher than
any roof line or obstacle within a horizontal
distance of 10 ft. (3 m).
9.4 Chimney Location
Because the venting system is the engine that drives the wood heating system, it must have the
right characteristics. The signs of bad system design are cold back drafting when there is no fire
in the stove, slow kindling of new fires, and smoke roll-out when the door is opened for loading.
There are two guidelines to follow. First, the chimney should be installed up through the heated
space of the house, not out and up an outside wall. Second, the chimney should penetrate to
the top of the building at or near the highest heated space.
Venting systems that rise straight up from the stove flue collar provide the best performance.
Chimneys that rise inside the warm space of the house tend to provide a small amount of draft
even when there is no fire burning. This means that when a fire is lit, the smoke goes up the
chimney and strong draft build quickly as the chimney flue warms up. Chimneys that exit a
house wall and run up outside can cause problems.
Good System Design Inferior System Design
When it is cold outside, the warm air in the house is buoyant so it tends to rise. This creates
a slight pressure difference in the house. Called ‘stack effect’, it produces a slightly negative
pressure in the lower part of the house (compared to the outside) and a slightly positive pressure
zone in the high part of the house.