Finally, figure 4 BEFORE and AFTER illustrates a common installation. The ash dump cleanout door is replaced with a screen. This is to prevent access to pests. The firebox ash dump door is replaced by an operable vent. The firebox opening is covered by glass fireplace doors. If there is not a built in "heat-o- later", I recommend the installation of one in conjunction with the glass doors. I have used this method on several fireplaces and everyone is continually amazed by the dramatic improvement in performance. The glass doors not only block smoke contamination, but also provide a positive barrier to flying sparks and embers.

The second requirement for a safe wood heat system is heat storage. This can be accomplished using water, masonry, or eutectic salts. If storage is not available to capture the excessive heat released in the early burn stages, the operator might waste heat by over ventilation (opening a door) or fall back on the dangerous and inefficient practice of starving the fire for oxygen by closing the dampers. Starving the fire for air does three things:

1. It lowers the temperature differential between the heat source and the heat absorber. This results in less efficient energy transfer.
2. Wood is a complex collection of fuels with various combustion temperatures that range from approximately 200 to 1,200 deg. F. Therefore, the higher the firebox temperature, the more fuels that will be consumed. Additionally, if the fire is allowed to reach 500 to 600 deg. F. the wood alcohol will be burned and no significant creosote will form in a properly sized chimney. I have never had to sweep the chimney of an appliance I operate, though I give them regular inspections.
3. When a wood-burning appliance is operated safely and efficiently, there is a significant reduction in outdoor air pollution. This is in direct contradiction to page 4.6 paragraph 5 of the E.I.S. This assertion is supported by the research of Prof. Richard C. Hill of the University of Maine.