Why Inside Flue Systems Are Preferred; Why The Flue System Should Penetrate The Highest Heated Space - Enerzone Destination 1.6 Installation And Operation Manual

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 Inferior System Design
Inside flue systems are preferred because Outside flue systems are a problem because when
even when no fire is burning, there is no fire burns they will go into cold downdraught if
normally upward flow in the system. the wood fire is installed low in the house.

8.4.2 WHY THE FLUE SYSTEM SHOULD PENETRATE THE HIGHEST HEATED SPACE

When it is cold outside, the warm air in the house is buoyant so it tends to rise. This tendency of
warm air to rise creates a slight pressure difference in the house. Called 'stack effect', it produces
a slightly negative pressure low in the house (relative to outside) and a slightly positive pressure
zone high in the house. If there is no fire burning in a heater connected to a flue system that is
shorter than the warm space inside the house, the slight negative pressure low in the house will
compete against the desired upward flow in the flue system.
There are two reasons why the flue
system in the house at right will cold
downdraught when it is cold outside
and there is no fire burning in the wood
fire. First, the flue system runs up the
outside of the house, so the air in it is
colder and denser than the warm air in
the house. And second, the flue system
is shorter than the heated space of the
house, meaning the negative pressure
low in the house will pull outside air
down the flue system, through the
wood fire and into the room. Even the
finest wood fire will not work well when
connected to this flue system.
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Destination 1.6 Installation and Operation Manual