Having spent a lot of time in rondavel huts (round huts with conical thatch roof) as a kid growing up on a farm, I can also attest to some benefits of wood smoke in such huts - the smoke keeps mosquitoes at bay! Also, the trick is how the top of the roof is made. In the older traditional huts there was a gap at the top of the roof to allow smoke to leave. Modern designs close this off with a cement cap on the top of the cone - no smoke release. It is this type of design where the smoke is retained inside the building that is a problem.
Rex From: David [mailto:[email protected]] Sent: 28 December 2013 06:29 PM To: Discussion of biomass pyrolysis and gasification Subject: Re: [Gasification] Wood heating in the UK - whole log gasification Jason, On 12/28/2013 12:57 AM, Jason wrote: PS. I have one aquaintance in New Zealand that is challenging the science around respiratory disease and emissions from wood smoke. He says the link is tenuous and the early bogus studies keep getting repeated and used as justification to ban wood stoves. Water is necessary for life and too much can drown you. Similarly with some things, a little can be of benefit. I recall a study of woodcutters that showed they had increased resistance to colds, and this was attributed to intermittent exposure to wood smoke. On the other hand, the WHO says that 1.6 million people die every year from exposure to indoor air pollution, i.e. also (for the most part) wood smoke. (Coal smoke is far more deadly.) The epidemiology is pretty well established. The term of art is hormesis, for which wikipedia offers the definition: Hormesis is the generally favorable biological response to low exposures to toxins and other stressors. A pollutant or toxin showing hormesis thus has the opposite effect in small doses as in large doses. ... http://en.wikipedia.org/wiki/Hormesis As far as the most common contributors to air pollution, it may end up that airborne particulate matter of a certain size range, particularly where the makeup of the particles includes irritants leading to inflammation, will be seen to be most at fault for negative impacts on health. Not wood smoke, exactly, in other words, but some things found in wood smoke, may well be identified as the key bad actors. That would be my current best guess, where I am solidly grounded in nearly perfect ignorance. It may be hard to get around the better safe than sorry approach that many might be inclined to take. The future promises to have more regulation, from almost any point of view. d. -- David William House "The Complete Biogas Handbook" www.completebiogas.com Vahid Biogas , an alternative energy consultancy www.vahidbiogas.com "Make no search for water. But find thirst, And water from the very ground will burst." (Rumi, a Persian mystic poet, quoted in Delight of Hearts , p. 77) http://bahai.us/ _____ <http://www.avast.com/> Image removed by sender. This email is free from viruses and malware because avast! Antivirus <http://www.avast.com/> protection is active. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com
<<~WRD000.jpg>>
_______________________________________________ Gasification mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org for more Gasifiers, News and Information see our web site: http://gasifiers.bioenergylists.org/
