Should we worry about winter chimney haze in rural towns?

Winter in many Australian country towns is accompanied by a pall of smoke from wood-fired heaters that lasts from late afternoon to the following morning. In larger towns and cities burning wood has been limited by laws to reduce the impact of smoke on respiratory health.

This is not a significant concession, given that other sources of heat, with much lower emissions, are available.

The majority of heat and electrical energy we use is recovered from oxidizing compounds of mainly carbon or carbon hydrogen and oxygen, usually by combustion of fuel in a furnace. When fuel is burned, a variety of compounds are released with the energy. These include organic molecules of varying molecular weights, carbon, carbon dioxide, carbon monoxide, hydrogen, water, oxides of nitrogen and sulphur, ammonia, and others. Of course the products of combustion are dependent on the fuel composition.

Burning wood produces all the compounds listed above with the exclusion of sulphur oxides. These are more commonly a product of coal or, to a lesser extent, gas combustion, and are noted to produce acids in the atmosphere that fall as rain. Natural gas is a primarily a mix of gaseous alkanes (CnH2n+1) and some minor compounds such as hydrogen sulphide. Burning natural gas produces larger amounts of lower molecular weight compounds compared to wood, and because these can quickly distribute with the same compounds in the atmosphere, burning gas is considered to be cleaner. In addition, burning wood produces heavy compounds as liquids and solids. Smoke, as an example, is particulate carbon and minerals.

The Conversation

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5 responses to “Should we worry about winter chimney haze in rural towns?

  1. The real issue with smoke and respiratory health is “Don’t sit in the fire.”
    Until the 12th century indoor domestic fireplaces were unvented, and people suffered and died young. When chimneys were invented, the smoke left the house, taking all the CO, NOx, oils, soot, ash, unburned lignin, etc with it.
    Health improved, families thrived, and the population grew.
    If you believe Lisa Jackson and her Green Helmet Army, even the slightest hint of smoke is fatal, and our pre-Medieval ancestors should all have died in infancy.
    Wood fires smell good and are very relaxing (stress-reducing) to watch.

  2. I saw an earlier post about “traditional” cookstoves in Bangladesh causing 50,000 deaths a year, and 2 million worldwide. Apparently, the Bangladeshites (Bangladeshis, Bangladeshians?) are stuck in the 12th century even when the government encourages more modern types (they would rather spend the money on food). I wondered if they count accidental deaths from burns inflicted by falling into the fire, or house fires caused by the stoves as part of the 50K deaths. As far as the worldwide death rate, that’s just another belly laugh from the Lisa Jackson school of statistics and fantasy.

  3. Corning, Inc. used to make a catalytic converter which fitted in the flue of your woodstove, and completed the combustion process, so that the effluent was non-toxic. It also recovered a lot of combustion energy otherwise wasted.

    What happened to this? Is it still on the market?

  4. I was raised using wood for heat and cooking up in the WV Mountains. We used hand operated cross-cut saws and axes to harvest the firewood. I’d like to see a green key pounder try THAT for a year. Later, we used chain saws, log splitters and tractors. It made life much easier for us, but they run on gasoline.

  5. Eric Baumholder

    There’s a good case to be made for *not* having chimneys: much of the heat goes up the chimney with the smoke. There are of course consequences to this sort of ‘energy conservation’. However, a well-made hearth and chimney will absorb a great deal of heat from combustion and continue radiating it into the dwelling well after the fire has gone out. Somehow I doubt the Bangladeshis have brick hearths and chimneys. Or at least not very many of them. Might not even need the home-heating aspect, in their neck of the woods.

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