Hergom H-03/70 Instrucciones Para Instalación, Uso Y Mantenimiento página 22

2. - Creosote formation and cleaning.
When wood is burnt slowly is produces tar and other organic vapours, which, when
combined with atmospheric damp, form creosote. The creosote vapours can condense if the
walls of the chimney are cold. If the creosote ignites it can produce extremely strong and
dangerous fires. Any accumulation of this must be eliminated.
Due to the accumulation of creosote depending on several variables it is very difficult
to predict when the chimney should be cleaned.
Visual inspection is the safest way of making sure that the chimney and heater are
free of creosote.
For this reason, we recommend that there should be easy access to these in
installations.
If the chimney ignites (it can catch fire purely due to the excessive accumulation of creosote)
close all the air inlets to the appliance (primary and secondary), including closing the air inlet
to the room where it is installed. This will help the flames to go out by themselves.
3. - Options
If you are going to build a chimney for the H-03 Cast Iron Wood Burner, you have two
choices:
a) Brick chimney.
b) Metal chimney.
The studies show that there is no great difference between metal and brick with regard
to the performance of the pull. It is up to you choose one or the other as appropriate.
Whenever possible, locate your chimney within the house. This will obtain a better pull,
cause less creosote to accumulate and last longer.
The advantages of brick chimneys are:
a) The mass of bricks and tiles reduces the cooling of the smoke in the
chimney.
b) The characteristics of tiles to accumulate heat allow the house to stay hot for
longer, after the fire has gone out.
c) They can be built to specific tastes.
d) If well constructed, they can be more fire resistant than metal ones.
Brick chimneys must be well lined to prevent smoke from cooling.
They must be built from materials which can stand high temperatures and corrosion.
They can be round, square, etc.: what matters is their size.
For brick chimneys the measures shown in the TECHNICAL DATA section must be
respected for the H-03 Cast Iron Wood Burner.
The advantages of the metal chimney are:
a) Easy installation.
b) They allow slight changes in the direction of the chimney, which allows more
flexibility in choosing the location where the wood burner will be installed.
c) Due to the existence of curved elbows, the angles which make the pull
difficult are eliminated.