What is a good heating stove?

  • It is a slow combustion heater to build a controlled fire in.
  • A good fireplace or stove holds on to the heat, instead of letting it fly up the chimney.
  • Technically a slow combustion heater is both a combustion changer and a
    heat exchanger.
  • It burns the wood efficiently and gets the heat into the house.

 

How big a stove or fireplace do I need?

It depends on:

  • The size of your house / room
  • The insulation of your house
  • The design of your house
  • Your desire for the pleasure of the flames or the heat

 

Efficiency

 

The most important factors in terms of efficiency are:

  • The air tightness of the stove
  • The amount of radiating surface
  • The type and dryness of wood
  • The house insulation
  • The way the stove is controlled  

An efficient stove will burn the wood slowly rather than in a flash. Burning is controlled by regulating the flow of air into the firebox.

 

Wood burns in three phases:
  • Water evaporates
  • Wood turns into charcoal and gases
  • The charcoal burns

 

Many stoves lets the gases go up the chimney unburned. These gases can represent 60% of the potential heat of the wood. To avoid this the stoves require oxygen mixed with the gases at a temperature of at least 350 to 600oC. Some stoves have designs that brings secondary air to the combustion chamber to burn gases and particles that would normally go up the chimney unburned and by that they get a higher efficiency. A slow combustion heater is normally driven by primary air. By implementing secondary air you will burn gases and particles more efficient at a lower temperature in the firebox. This is normally called Clean Burn technology and will increase the efficiency by almost 40%.

 

To obtain high efficiency the wood has to be dry. Wet wood will in addition to generating less energy create creosote in the chimney when the combustion is incomplete.Visit woodheat.org for more information about heating with wood.