Grahn

An Energy Efficient Afterburner Retrofit for Wood Burning Stoves

This technology is the brain child of Dennis Grahn. The afterburner is extremely efficient in removing noxious hydrocarbon emissions from the exhaust stream of any combustion source. The noxious emissions are thermally combusted in a secondary hot spot maintained above the spontaneous combustion temperatures of the hydrocarbon materials contained in the exhaust stream.

Drs. Grahn and Heller, Biologists at Stanford University, study mammalian physiology. The energy efficiency of the afterburner is based on principles of mammalian thermoregulatory physiology - insulation and cn principles of mammalian thermoregulatory physiology - insulation and countercurrent heat n principles of mammalian thermoregulatory physiology - insulation and countercurrent heat exchange to optimize energy utilization. For the wood stove application, the afterburner consumes less energy than a common household appliance. To date, the development of the technology has been a science project.
Dennis Grahn and Afterburner Retrofit
Kevin Haley is a principal of Clearstreme. He is a mechanical engineer with a MBA. Kevin has over 30 years of experience in industry facilitating the transition of prototype designs into functional equipment. Sam Shawe is the founder of Outback manufacturing - a well-established 15 year old precision manufacturing company. Sam has the technical capabilities to design and execute the manufacturing process.

The mission is to transition the technology from a science project platform into production-quality commercially viable merchandise. Critical design considerations will be optimizing function and vastly improving aesthetics.

The Grahn Team


  • Dennis A Grahn | Stanford University | 650-725-8723 | Email
  • H. Craig Heller | Stanford University | 650- 723-1509 | Email
  • Kevin Haley | Clearstreme, LLC | San Jose, CA | 408-833-8188| Email
  • Sam Shawe | Outback Mfg. | Bend, OR | 541-330-1046| Email