Heat-Booster Reclaimer

This highly effective heavy duty flue gas heat reclaimer has been designed for use with wood stoves and coal stoves. Most wood stove operators do not realize how much heat is lost up the chimney. High burning rates result in large losses. The HB2 Heat-Booster can capture most of the heat that is lost up the chimney. In fact, flue gases can be cooled to the point of water condensation. This often happens when green unseasoned wood is used in a smoldering fire. Wet fuel = water = low temperature = condensation. Do not use unseasoned wood with a Heat-Booster!

SpeedControl
To avoid this, inexpensive temperature controllers can be installed. The simplest option is a basic temperature controller that costs approximately $15. Set to cooling start (relay closes) at say 75°C, and differential set to 5°C. A PID type controller can also be used. This is the preferred method. Check Amazon, Auber Instruments and EBay for best deals. Ultimate blower control can be provided by a temperature controller with PID output (4-20 mA or 0-10 mV) that connects to a VFD (Variable Frequency Drive) that controls blower speed in cooling mode. Again, see Amazon.com and EBay for best deals. VariPhase by AirCare Automation is a source of suitable VFDs.
Chimney draft depends on flue gas temperature (warmer gases are lighter than air).
Use a Draft-Booster to compensate for lower flue gas temperatures that result when a Heat-Booster is used.
Heat reclaimers should only be used with clean burning stoves and when seasoned wood is burned at medium to high rates. Older stoves that do not have a secondary air supply will foul the heat exchanger when operated at low fire. Clean burning requires excess air and high temperatures.
The Heat-Booster unit must be installed so that exit stove pipe can be removed to allow cleaning of heat exchanger tubes. A rod with an attached round metal brush works well for this purpose. A jointed rod can be used when available height is restricted.
Our experience is that the temperatures measured are very good indicators of re-fuelling times.

Datalogger
Note how much flue gases are cooled! - Cut wood consumption in half!