Wednesday, October 26, 2011

Multi-Fuel Stove Tips & Tricks part 1 of 4


Multi-Fuel Stove 
Tips & Tricks 
for economy and efficiency
part 1 of 4

1.    The Stove Itself.

If you don’t have a well-designed stove in good condition - you simply won’t get good heat output or fuel efficiency.

Apart from superficially looking nice and pretty, a stove must have certain well-designed and properly functioning technical features in order to work efficiently and have a reasonable working life.

Fire Grates.

The fire grate/s should be cast in high chromium iron in order to sustain high temperatures without burning out and warping. Check this carefully before you buy any stove, or you could find yourself replacing the grates after a couple of years, this is especially true if you use smokeless coals which can burn at very high temperatures. The grates are quite an expensive part of a stove. They are complex in shape and come in several parts. This is because they are usually remotely activated by an external lever to move them in order to shake down excess ash from the fire.

The Importance of Air.

Any stove should essentially be an airtight box, so having good door seals and well-jointed sections etc. is of the essence. A stove should have precise controls on both the primary and secondary air inlets. It is the mixture of fuel and air that causes combustion. Control the air and you control the level of combustion.

The Primary Air Inlet.

The primary air inlet or control is the one underneath the firebox that allows air to come up under and permeate through the burning fuel. This is the most important control to regulate the rate of burn. It should be capable of controlling the air supply to the fire in a quick and accurate way.

With some fuels, especially smokeless coals, it can be almost closed down completely. This will give slow burn and will keep the stove going for up to 9 hours or so over night or while you are at work. Slow constant heat 24 - 7 will keep a house very comfortable and stop fluctuations in temperature. When a house cools down, it can take up to half a day or more to get it fully warm again.

It takes a bit of practice to get the right settings. Basically, open the primary air right up when lighting a fire, as the fire gets going, begin to turn down the air. When the fire is good and hot further reduce the air until the fire starts to dim down. At that point gradually - over a few minutes - open the valve a fraction at a time, until you reach a point of burn that you require.

Secondary Air Inlet.

The secondary air inlet allows an air supply in above the burning fuel in order to allow burn-off of the gasses released from the fuel. I personally do not ever open this inlet, as I use mainly smokeless coal which tends to glow rather than create a flame. Opening the secondary air supply, where gasses don’t need to be flame burned, can reduce the efficiency of the burn. When wood is burned, the secondary air supply needs to be opened a crack in order to get full and proper combustion of the gasses released.

Subsequent posts on this subject will be spaced out over a few weeks - so keep a look out for them.


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