Question: Dear Sirs: My client has Multiple Chemical Sensitivities. Exposure to gases and emissions is detrimental to her health. I need information which specifically assures us that the emissions from wood pellets stoves are zero with proper ventilation. What constitutes proper venting for the gases and combustion by-products from wood pellet stoves? Also, in the event of a major power outage, is it possible for the wood pellet stove to operate? Answer: I would guess that any home with a woodstove, pellet stove or any other biomass burner will have increased trace amounts of gases, dusts, etc. Even the raw pellets, when poured into the stove, will emit certain compounds such as wood tar vapors, etc. Ash must also be removed from the units, sometimes when operating, so zero emissions are not possible. There are battery back-ups that allow Pellet Stoves to run for hours or days with no electricity.