Why The Chimney Should Penetrate The Highest Heated Space; Supply Of Combustion Air - Drolet DB03105 Installation And Operation Manual

Report prepared for: Guillaume Thibodeau-Fortin (Stove Builder International Inc.) on 12/1/2017 8:00:00 AM
100 - Owner's manual ESCAPE 1800 (43 of 59)
Installation and Operation Manual for Escape 1800

8.4.2 Why the chimney 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 chimney 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
chimney.
There are two reasons why the
chimney in the house at right will
cold backdraft when it is cold
outside and there is no fire
burning in the stove. First, the
chimney 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 chimney
is shorter than the heated space
of the house,
negative pressure low in the
house will pull outside air down
the chimney, through the stove
and into the room. Even the finest
stove will not work well when
connected to this chimney.

8.5 Supply of Combustion Air

In Canada, wood stoves are not required to have a supply of combustion air from outdoors
(except in mobile homes) because research has shown that these supplies do not give
protection against house depressurization and may fail to supply combustion air during
windy weather.
However, to protect against the risk of smoke spillage due to house depressurization, a
carbon monoxide (CO) detector/alarm is required in the room in which the stove is
installed. The CO detector will provide warning if for any reason the wood stove fails to
function correctly.Carbon monoxide, is a colorless, odorless gas that is produced during
combustion of wood and other fuels. CO fumes are toxic and can be fatal. CO is not
specifically heavier or lighter than air. Therefore, it is best to install the detector at table top
level rather than on the ceiling like a smoke detector.
Stove Builder International Inc. | 35697 | Rev: Nov 30 2017 11:01AM | Uncontrolled Copy
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