Osburn Matrix Installation and Operation Manual
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8.4
THE RELATIONSHIP BETWEEN THE FLUE SYSTEM AND THE HOUSE
Because the flue system is the engine that drives the wood heating system, it must have the right
characteristics. The signs of bad system design are cold downdraught 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 flue system should be installed up through the heated
space of the house, not out and up an outside wall. Second, the flue system should penetrate the
top of the building at or near the highest heated space.
8.4.1
WHY INSIDE FLUE SYSTEMS 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.
Good System Design
Inside flue systems are preferred because even
when no fire is burning, there is normally upward
flow in the system.
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.
