Supply Of Combustion Air; Air Supply In Conventional Houses - Enerzone Solution 1.3 Installation And Operation Manual

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, meaning the
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.

8.5.1 Air Supply in Conventional Houses

The safest and most reliable supply of combustion air for your wood stove is from the room in
which it is installed. Room air is already preheated so it will not chill the fire, and its availability is
not affected by wind pressures on the house. Contrary to commonly expressed concerns, almost
all tightly-sealed new houses have enough natural leakage to provide the small amount of air
needed by the stove. The only case in which the wood stove may not have adequate access to
combustion air is if the operation of a powerful exhaust device (such as a kitchen range exhaust)
causes the pressure in the house to become negative relative to outdoors.
Some jurisdictions in the United States require that wood stoves have a supply of combustion air
from outdoors. If you do install an air supply through the wall of the house, be aware that its
pressure can be affected during windy weather. If you notice changes in wood stove performance
in windy weather, and in particular if smoke puffs from the stove, you should disconnect the
outdoor air duct from the stove and remove the duct. In some windy conditions, negative pressure
at the duct weatherhood outside the house wall may draw hot exhaust gases from the stove
backwards through the duct to outdoors. Check the outdoor air duct for soot deposits when the full
system is cleaned and inspected at least once each year.
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Solution 1.3 Installation and Operation Manual