The information on this website regarding the Greenwood Furnace Series is provided for reference only and to assist prior dealers with their non-warranted inventory. Please note, these products have not and are not being sold by Greenwood Clean Energy.
The Greenwood Furnace Series has been replaced by the next-generation Greenwood wood boiler, the Frontier Series hydronic wood furnace. Please visit here for more information on this revolutionary product.
As a public service, Greenwood Clean Energy is providing information for products sold by Greenwood Technologies here: support.greenwoodusa.com.
The Greenwood Hydronic Wood Furnace represents the latest innovation in wood burning boilers. Based on a tested design developed more than 20 years ago, the Greenwood wood boiler is the most efficient, wood burning boiler you can buy for your home. It is safe to operate, burns smoke- and creosote-free, and saves you up to 70% on your home heating bills. Our wood boiler is also easy on the environment -- the fuel you burn is a renewable resource and does not contribute to global warming. Finally, the Greenwood hydronic wood furnace is easy to install and works with a variety of heating systems and applications.
How the Greenwood is Different
Most wood burning furnaces and wood boilers on the market today are unable to sustain a temperature of 1100º F or higher. They are built with a firebox made of steel which is surrounded by a jacket of water. This water jacket serves two purposes: it transfers heat from the firebox to the home heating system, and it cools the steel firebox and keeps it from melting. The problem is, by keeping the firebox cool, the water jacket also cools the fire and prevents it from burning at temperatures needed for complete combustion. That's why these units produce irritating smoke and potentially dangerous creosote.
Greenwood's hydronic wood furnace is built in an entirely different way. Our firebox is made of super-duty ceramic refractory, cast four to six inches thick, and surrounded by outer layers of insulation designed to keep the heat in. The natural draft system pulls air into the furnace which fans the flames and creates a roaring fire with sustained temperatures of 1800º to 2000º F. Heat from the fire is captured by a water tube heat exchanger located above the firebox in the path of the escaping superheated gases. The furnace extracts heat from these escaping gases, not the fire below.
This innovative design enables the Greenwood wood boiler to burn cleanly and operate at a very high level of efficiency. By the time the escaping gases leave the furnace, they have cooled to around 300º F. The 1700º F difference in temperature between firebox and the vent represents the amount of energy captured to heat your home. The Greenwood hydronic furnace burns clean and delivers up to 85% of the wood's thermal energy to your home heating system.
The Features of Greenwood's Hydronic Wood Furnace:
Combustion efficiency (how much of the wood mass is converted to energy?): nearly 100%
Thermal efficiency (how much of the wood's energy is transferred to the home heating system?): up to 85%
Ceramic refractory fire chamber, cast up to 6 inches thick and capable of withstanding temperatures of 2500° F
Highly efficient water tube heat exchanger charged with a propylene glycol solution to avoid freezing and prevent corrosion
Updraft flame path and downdraft thermal transfer
Aquastats: one to control operation of the furnace and a strap-on aquastat to interface the furnace with your home heating system
Heat exchanger: (optional add-on) to transfer heat from the furnace to your home heating system
Simple, direct-acting, electro-mechanical controls
Burns unsplit logs -- dry or seasoned wood
|100,000 BTUH||200,000 BTUH||300,000 BTUH|
|up to 4,000 SF||up to 8,000 SF||up to 12,000 SF|
|32" x 52" x 48"||42" x 52" x 48"||52" x 52" x 48"|
|Max Log Length
(feed door width)
|Max Log Diameter
(feed door height)
|Approximate Weight||2,400 lbs||3,000 lbs||3,800 lbs|
|19" x 32" x 24"
8.4 cubic feet
|29" x 32" x 24"
12.9 cubic feet
|39" x 32" x 24"
17.3 cubic feet
|Limited Warranty||Greenwood provides a 10-year limited warranty on internal furnace components and a 1-year warranty on components.|