What is airwash?
Tar and other deposits will condense onto any cold surface inside a stove, especially when burning wood. This can leave a black/brown deposit on the window of the stove that blocks the view of the fire.
A stove with an airwash system has air vents that direct a flow of air down across the glass which helps to stop tar being deposited on the glass.
Burning your stove relatively fast can also help to cut down on deposits as the firebox temperature stays high which means that much less tar is deposited. This can even burn off tar deposited earlier.
What is cleanburn?
When wood burns most of the visible flames are in fact due to gases released by the hot wood. Inside the firebox of a stove the oxygen can quickly become used up and in the absence of oxygen some of these gases remain unburnt and exit up the chimney.
A cleanburning stove generally introduces another supply of air into the firebox, preheated so as to maintain the firebox temperature. This supply of air is often introduced to the firebox through a series of holes which results in jets of air entering the firebox - this means that the air and gases mix well and encourages more complete combustion.
Once a wood stove is running nice and hot you may see jets of burning gas hanging in the firebox where the supply of air enters. It is often quite beautiful.
What is a baffle?
A baffle plate is a plate usually made of metal that sits inside the stove over the firebox. This plate blocks off the direct exit to the chimney which means that the hot flue gases have to travel further before they get out of the stove. This means that there is more time for the flue gases to be mixed with air and fully combust in the firebox and that more heat can be transferred from the firebox to the stove and/or water in the boiler.
So a flue baffle makes the stove more efficient and can increase it's heat output.
In some boiler stoves the boiler forms all or part of the baffle such as the Stratford boiler stoves.
What are firebricks?
Firebricks are found in the firebox of a stove and protect the insides of the stove from the intense heat of the fire. Modern firebricks are often made from vermiculite a light highly insulating material that not only protects the inside of the stove but also increases the temperature in the firebox thus increasing efficiency.
Many boiler stoves have a wraparound boiler which forms the back and sides of the firebox so firebricks are often unnecessary in these boiler stoves.
In boiler stoves with clip in boilers the boiler replaces the firebricks at the back of the stove and the firebricks at the sides remain in place.