© 2008 Greenwood Technologies, LLC Page 5
INTRODUCTION
Congratulations on your purchase of this wood-fired hydronic furnace from Greenwood Technologies. With
proper installation and maintenance, this US Environmental Protection Agency (EPA) Phase 1 emissions
compliant furnace will provide years of low cost heat for your home.
To insure correct installation and safe operation of your Greenwood hydronic furnace, you should:
1. Hire a Greenwood approved licensed heating contractor to install the furnace and integrate it
with your heating system. This contractor should have experience with installation and operation of
gas, oil, and solid fuel heating appliances and be familiar with local building codes, fire codes and
other regulations.
2. Read this manual and learn how to safely operate and maintain your Greenwood furnace.
How the Greenwood furnace works
The Greenwood furnace produces few emissions and achieves a high level of heating efficiency because of
its unique design. The ceramic firebox supports an internal temperature that allows the furnace to convert
every bit of wood fuel into thermal energy. Then, the unique up and down draft flame path allows the heat
exchanger to absorb the maximum possible energy from the superheated air. This simple, yet sophisticated
design results in a highly efficient, clean burning furnace that will provide years of reliable, low cost heating
for its owner.
To understand how the Greenwood hydronic furnace works, we need to look at the flow of air and wood
gases through the furnace and the transfer of heat from the superheated gases to the thermal transfer fluid
circulating in the internal heat exchange manifold.
Air Flow through the Furnace
1. Heat from the burning fire draws fresh air into the furnace through a mechanically operated air
intake manifold. An aquastat (a thermostat that works in water) opens and closes the damper to
regulate the air entering the firebox and control the rate of burning.
2. As air flows through the firebox, its temperature rises to nearly 2000ºF.
