GENERAL INFORMATION
Woodchuck furnaces represent the ultimate in solid fuel and dual fuel heating appliances. From the massive model 4000 to the economy model 526, each unit is de- signed to be attractive, durable and efficient while pro- viding the safety and comfort you and your family deserve.
HIGH QUALITY CONSTRUCTION
Constructed of high grade, heavy gauge, hot rolled steel plate, the firebox is continuously welded for an air- tight seal and structural strength. The heavy duty cast iron doors are equipped with a positive latching device for your safety. The loading door has a
Woodchuck furnaces are subjected to the most strin- gent test criteria applicable by an independent third party testing laboratory and listed/labeled as having met or exceeded those standards. Finally, any ma- chine, even this Woodchuck, is only as safe as the per- son operating it. This is why we have compiled this comprehensive manual to assist you in operating your Woodchuck properly and safely. Please read and follow all instructions.
EFFICIENCY
The total efficiency of a unit is broken down into com- bustion efficiency and transfer efficiency. We know that when woodburning, 20% of it burns as fixed carbon. The other 80% is in the gaseous state as it burns. Therefore, to obtain efficient combustion of the wood it is necessary to introduce 20% of the oxygen “under” the fire to promote combustion of the solid material and 80% “over” the fire where it can readily react with the gaseous material. Coal burns just the opposite of wood. 80% of it burns as fixed carbon and 20% burns in the gaseous state. Therefore, before a furnace can burn coal or wood efficiently, it must provide the 80/20 ratio of combustion air and allow the operator to reverse the ratio depending on the fuel being used. Combustion air must be warm when it enters the firebox to further pro- mote complete combustion. Your Woodchuck furnace provides all these features and more. Here is how: when combustion air enters a Woodchuck furnace it en- ters into a “draft
channel." Here it comes into contact with the hot fire- box front and is warmed before entering the firebox. The draft channel is equipped with adjustable orifices which provide for the 80/20 distribution of the com- bustion air. A lever on the front of Models 2900/4000 allows for quick and easy adjustment of these orifices to correspond to the fuel being used. As the air enters the firebox it strikes a deflector which creates a turbu- lence and causes the oxygen to mix thoroughly with the gases for complete combustion.
Finally, Woodchuck Model 2900/4000 furnaces are designed to accept a catalytic combustor. This device will cause the small amount of unburned fuel to ignite before entering the secondary heat exchanger. The benefits of all this are threefold:
A.) You obtain very high combustion efficiencies, meaning you use less fuel.
B.) You reduce the amount of unburned fuel that can collect in your chimney as creosote and hence reduce the hazard of a chimney fire.
C.) You virtually eliminate pollution of the air we all breathe.
Transfer efficiency refers to how effectively we trans- fer the heat generated inside the firebox to the rooms we want to heat. Insufficient blower capacity will result in poor transfer allowing the unused heat to escape up the chimney. This is why we utilize a blower with such large air handling capacity. The large surface area of the firebox and secondary heat exchanger provide for efficient transfer.
COMFORT
Comfort and efficiency are closely related. The more efficient the heating system is, the more comfortable you and your family are. Not only are the Woodchuck furnaces efficient, they can actually increase the effi- ciency of your home.
On a furnace with a conventional single speed blower, the speed of the blower is a compromise between comfort and efficiency. If the blower has a large enough capacity to heat the home in the cold- est weather it will cycle rapidly in milder weather so the system air is not as warm. If this air is moved too rapidly it can actually feel cool. Air that is mov- ing at 3 ft. per second will feel 4° cooler than sta- tionary air at the same temperature. If the blower capacity is enough to operate properly in mild
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