The EPA in a 2000 report revisits the 1992 wood stoves (phase II) study.
Long-Term Performance of EPA-Certified Phase 2 WOODSTOVES, Klamath Falls and Portland Oregon: 1998-1999, EPA/600/R-00/100
- The stoves deteriorate with use, emission rates for phase 2 stove models in original tests are not representative of emission levels of the same stove models in homes after extended use. Preliminary analysis of table 3-12 of the report seems to indicate that on average the EPA Certified 'phase II' wood stoves are 175% dirtier than they were certified to be. (See Chart 3-12 below.)
- The study leader said in March of 1990: "In localities where wood is the predominant house heating fuel, wood stoves have been shown to contribute as much as 80% of the ambient PM10 (fine particle) concentrations during winter months. This study shows that the new technology stoves do not achieve the emission reduction expected. Some models were experiencing degraded emission control performance after only a few months use. "the relatively poor showing of the control technologies was very disappointing." ( In-House Performance of New Technology Wood stoves, EPA/600/D-90/026, Robert C. McCrillis, EPA/600/D-90/026) Here is the rather cryptic summary.
- Unfortunately this study did not address possible health effects of heating with wood on the participants.
To get the full picture you need to read the long report (1172KB). Tables 3-13 and 3-14 (start on p 48 of the long report) as they are particularly interesting and are reproduced below. These tables are the Organic Compound Emission Factors and Rates with lists of the most significant carcinogens and addictive substances produced per hour.