Very important when using a (coal, wood, etc.) stove is a good, regularly swept chimney, and adequate ventilation. ( See also CO poisoning.)

A fireplace with an open fire against the wall is called fireplace. The ornate fireplace mantel is called chimney. And the flue too. The space inside a chimney is called a flue.


The chimney is the support (brace) of smoke catcherabove a trap against the wall built fireplace.

schoorstenen2Draft is the rise of warm air. A good supply of fresh outdoor air, and flue-gas exhaust is needed. Draft (or draught) is generated to pull fresh air through the burning fuel.

Cracks or a chimney door (behind the stove,to get sootout of thechimney) that is not closed properly give false draft!
An insulated chimney draws better.

The chimney must be sufficiently high and at least two feet above the ridge of the roof.
The horizontal connection of the stove to the chimney should be as short as possible.
Due to a low chimney recoil arises.
Kickback by cold chimney: heat the chimney with some newspapers rolled up to a torch and kept (burning) in the stove until the draft takes the right direction.

The diameter depends on the type of stove or fireplace. As a rule of thumb, take a minimum of 15 cm for a heater and 20 cm for a fireplace.
Too large a diameter is not good:
there is a danger of the infiltration and precipitating air
risk of condensation because the flue gases cool quickly in the flue.
The diameter of the chimney must not be smaller than the diameter of the discharge connector of the device.
The diameter must be the same everywhere.

A round pipe gives a better draw than a square shape. In this form, the friction and heat exchange surface area in relation to the cross-section is the smallest.

The chimney should be as vertical and straight as possible with a minimum of bends .
The use of bends in the pipe reduces the draft. If there are bends to be used 2 x 45° is preferred over 1 x 90°. It is also easier to wipe. Use a maximum of two elbows per flue.

Can you connect several heaters on the same chimney?
Yes, but not at the same height, meaning not back to back. But for example, a bread oven in the basement, a stove in the kitchen and a gas heater in the attic is perfectly possible. (More firing also means more sweeping!) Between the connections must be at least 50 cm.

Outside, on top of the chimney you can make a cover, chimney cowl or hood to
- repel rain entry into the channel. Moisture promotes soot
- to increase draft in the chimney (which makes the fire burn better)
- prevent birds to build nests in the channel
- to avoid emission of sparks from a fireplace

A rain cap keeps precipitation from the chimney.

A chimney cowl or wind directional cap is a helmet shaped chimney cap that rotates to align with the wind and prevents a backdraft of smoke and wind back down the chimney. Also a H cap prevents backpuffing from turbulences.

A chimney damper is a metal plate that can be positioned to close off the chimney when not in use and prevent outside air from entering. Of course it should be opened to permit hot gases to exhaust.

A throat damper is a metal plate at the base of the chimney, just above the firebox,to regulate draft. It is never completely closed (there is an edge cut or a hole in).


Sweep the chimney at least once every year. (Mandotory in many countries.) More often if you fired pine. Just a rope with a weight, and a bunch of wire or (steel)ribbon, twigs ... or a special sweeper to lower several times to the bottom. At the bottom there is usually a (soot) hatch to shovel soot out, otherwise you temporarily remove the stove.

There are also flexible plastic stakes with brushes that you can push upwards from below through the chimney. So you can wipe without getting on the roof.



For a wood stove the flue is minimum 4 and maximum 20 meters long.

Smoke always contains water. The gas can be saturated with up to 100% water vapor. That amount also depends on the temperature. The excess water vapor condenses at a given temperature and pressure, the "dew point", and produces together with soot from the chimney an aggressive fluid. Colder air contains less moisture than warm, and reaches his dew point faster.
The material of the chimney must reduce condensation maximal by reaching fast the temperature of the smoke. So make sure there is sufficient insulation of the flue.



Potato peelings against soot (creosote) and chimney fire?
It is a persistent and widespread fact(?): burning potato peelings in the fireplace or stove would reduce soot and the risk of chimney fire. Even chimney sweeps, insurers, stove vendors and fire services proclaim this. Here and there also a half and lame explanation is given.
Potatoes contain a lot of water, cellulose, starch and some minerals.
That is found, except for starch, also in wood and other organic material. So does the starch make any difference? Or maybe a tiny bit of a mineral?
Some gambles on forums:
Bet 1: a momentary thrust of saturated water vapor of moist peeling makes the (soot) deposits go? That would also have to go using wet wood.
Bet 2: the soot would be sealed or covered so it don’t burn anymore, or hardly ? That would have to succeed with all starch?
Bet 3: dry peelings create a hotter flame and smoke. This temperature change would crumble the soot by the different expansion coefficients of soot and chimney. This would work also with zinc, aluminum or coal burning?

A well-founded explanation is, however nowhere to be found. It seems more an urban legend. Maybe it works for those who believe in it?

I believe (hmm) that there is a plausible explanation for the burning of potato peels: the germ inhibitors sprinkled on them are very bad for pigs and for the compost heap. Well , what do you do with it?
(First wash the peels, and possibly also cook them for the pigs.)