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Installation and Operation Manual - Escape 1800
The top of the flue system should be tall enough to be above the air turbulence caused when wind
blows against the house and its roof.
The flue exit shall be located outside the building in which the appliance is installed so that:
- The flue pipe shall extend not less than 4.6 m above the top of the floor protector;
- The minimum height of the flue system within 3 m distance from the highest point of the roof
shall be 600 mm above that point;
- The minimum height of the flue system further than 3 m from the highest point of the roof shall
be 1000 mm above roof penetration;
- No part of any building lies in or above a circular area described by a horizontal radius of 3 m
about the flue system exit.
8.4 The Relationship Between the Chimney and the House
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 backdrafting when there is
no fire in the wood fire, 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.
8.4.1 Why Inside Chimneys Are Preferred
Flue systems that rise straight up from the wood fire flue collar provide the best performance.
Flue systems 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 you light a fire, the initial smoke
goes up the flue system and strong draft builds quickly as the flue system warms up. Flue
systems that exit a house wall and run up outside can cause problems.
Figure 13: Good System Design
Inside flue systems are preferred because even when no fire
is burning, there is normally upward flow in the system.
Figure 14: Inferior System Design
Outside flue systems are a problem because when no fire
burns they will go into cold downdraught if the wood fire is
installed low in the house.
