What are the differences in emissions for the various wood burning appliances?
Natural gas fireplaces are the cleanest air quality option. Natural gas fireplaces generate a fraction of a gram of PM per hour. EPA certified wood heaters, with a particulate emission standard of 7.5 grams per hour, incorporates combustion controls — generally a secondary combustion zone, or use catalysts akin to the catalytic converters used in motor vehicles. Pellet-fueled wood heaters burn cleaner because they control the mixing of fuel and air more tightly than conventional woodstoves. Emissions of virtually all pellet stoves are substantially lower than EPA standards. Fireplaces certified by EPA. EPA does not have a certification program for hearth-type fireplaces. Currently no fireplace manufacturers have submitted data to indicate they can meet the 7.5-gram per hour PM standard set for wood heaters.
