This could be 'ultimate' wood stove

Jim and Holly Harley heat their home most effectively with wood. But they scorn the quantities of conventional and increasingly expensive cord wood normally associated with this form of heat.

Instead, when winter clamps its icy grip on this corner of Maine, they reach each day for a few bundles of twigs, tree prunings, etc. -- everything, in fact, that the woodsman leaves in the forest after he has hauled out the tree. In the process the Harley's burn the equivalent of about two cords of wood a year. That is because they have what they see as "the most efficient wood-burning system known to man."

That "system" is the Russian or Finnish fireplace, a multi-flued brick stove that is known to have been in use throughout the colder regions of Europe for 500 years -- possibly twice that length of time. In brief, it collects and stores 90 percent of the available heat from a wood fire in its own brick construction and then releases it steadily to the surrounding air, hence its remarkable effeciency. It is so efficient, in fact, that all gases are thoroughly burned off. This results in little or no creosote buildup in the chimney and very little smoke as well.

In effect, the fireplace becomes a radiating brick wall that frequently ranges from 3 to 5 feet wide and up to 7 feet high.

Early immigrants brought the technique to Canada, the northeast US, and ultimately to the Midwest where straw, fed into the stove minutes, would produce enough stored heat to warm a prairie farmhouse for 12 hours. In fact, any rapidly burning fuel (wood shavings are another option) is effective. This is the reason the Harleys burn small tree branches. Anything above 2 1/2 to 3 inches in diameter should be split because the need is to create an even, fast fire that burns itself out in under an hour.

This is how the Russian fireplace (stove is a more accurate description) works:

* The firebox is fully charged with slender sticks or similar fuel and lit. With the damper wide open the fire roars away without restraint. A rapidly burning fire extracts far more Btus (units of heat) from a fuel than a slow-burning one. As a result, the heat inside the combustion chamber readily builds up to between 1,200 and 1,500 degrees F. at which temperature all gases, given off by the burning wood, are also ignited. (Only unburned gases, escaping the fire, condense in a chimney to form the sticky tarlike substance known as creosote.)

* Heat and smoke leaving the fire are forced to pass, unnaturally, up and down a series of 3 or 5 flues before finally exiting up the chimney (some stoves , generally those used for cooking, have horizontal flues instead). This slows down the exiting heat enabling the surrounding masonry to absorb all but 10 percent of it.

* When the fire has died down, generally after about 30 minutes, leaving only glowing coals covered with ash, the damper between the flues and the chimney is shut. This prevents any further hot air from escaping up the chimney. Note: Do not shut the damper while there is evidence of a blud flame (an indication of carbon monoxide) in the fire. Some Russian fireplace users recommend a double firing -- refueling the stove after 30 minutes, closing the damper only after the second fire has died down.

It takes about five hours before the surrounding bricks reach their peak temperature (about 150 degrees F.), Mr. Harley says. That is too hot to rest a hand on for more than a few secons but is not hot enough to burn the skin. The hot bricks retain considerable heat for more than 12 hours radiating out a steady warmth over a distance of some 20 feet.

According to Mr. Harley, an architect who also teaches at bowdoin College, the Russian fireplace dovetails perfectly with passive solar heat. When the sun shines his own home collects much of its heat from a sunroom or greenhouse that faces directly south.

If there is a disadvantage to the Russian fireplace, according to Mr. Harley, it is this: If, some five hours after you have fired up the stove, the wind should suddenly switch direction and a hot breeze come blowing up from the south , the warm weather will have arrived just when the brick stove has reached its heat peak.

The Harleys learned of the Russian fireplace from Basilo Lepuschenko, a resident of neighboring Richmond, and had theirs built by the Russian immigrant. Mr. Lepushenko, a Byelorussian by birth, spent World War II in Nazi labor camps before making his way to the United States in the late 1940s.

almost as soon as he settled in Maine he built a Russian fireplace in his first home (two in fact -- one at each end of the house). But in the face of cheap heating oil, they weren't worth the trouble of firing, so he took them down. Now that the situation has changed dramatically, he has built one in his present home and now is in the full-time business of building these stoves for others. His expertise is also being widely sought by those, far from this region, who want to go the economical "twig-heating route."

Because of this, Mr. Lepuschenko has prepared plans for three-flue, and five-flue fireplaces. These are available for $10. His address is: Alexander Road, Richmond, Maine 04357. If you merely seek information from Mr. Lepuschenko, please enclose a samped self-addressed envelope. In the past so much mail has flooded the Lepuschenko home that the postage all but bankrupted him.

According to Mr. Lepuschenko, the design is such that the bricks would hold together without any mortar. He doesn't recommend that however. Any moderately handy person should be able to build his own stove from the plans. Or a mason could construct it for something in the region of $1,400, depending on the price of bricks in your region.

Another source of Russian fireplace information is: The Maine Wood Heat Company, Father Rasle Monument Road, Norridgewock, Maine 04957.