Wood Heater Pollution and CO2

[glend (Glen)]

Winter has seen yet another growth period in wood heaters. Rising electricty prices are causing more and more people to install these hideous devices. Have we made no progress in the last 100 years? Last night i was out at my observatory and could see the pall of smoke hanging over the neighborhood, around the street light up the hill, and drifting down to the Lake. This obviously affects astronomy, imparting a haze like filter, and potentially settling on optics. In the early morning from up the back of my place i can see the ever growing numbers of smoke columns rising into the sky. The local council newspaper ran a story early this winter asking people to stay away from these nasty heaters, sighting, health issues, and the release of CO2 sequested in the timber they burn - and still the numbers grow.

I have to be very careful about when i can hang out my laundry, my next door neighbor has one of these heaters, and it spews out smoke whenever they are home.
This has to be controlled in some way. Local wood cutters are driving around public reserve space cutting up any dead wood they can find. Tree loppers sell off green wood to unsuspecting consumers. I dread the delivery of yet another trailer load next door. And this stuff is not as cheap as people may think.
A nice electric blanket uses no more than 100w of power, the same with the electric throws for lounges, chairs, or just used as wraps. I would like to see the Greens get behind a campaign to stop the growth of these heaters.. What is the situation in your area?

[xelasnave]

Cutting it yourself or buying it is actually not that cheap.

Smoke here late yesterday from a burn off which will be the first of many.
But minimum lot around here in one hundred acres so people problems are less.
I think the problem is make much worse by using poor wood ...
Still look on the bright side I think in India they still use cow manure to cook.
Alex

[torana68 (Roger)]

here were happily burning wood....our heater doesnt spew smoke except when initially lit, we dont pay for the wood either....... its not really a viable choice in urban areas but unless the cost of electricity is controlled what are people to do? I imagine there is gas available in towns/cities but its not cheap either, have you spoken to your neighbour? help them understand your problem?

[Atmos (Colin)]

A good wood heater with nice dry wood and the correct amount of air flow should not create any smoke at all. Even a good heater with good wood but poor airflow will smoke horribly, this is likely a big culprit. People not knowing HOW to manage a wood heater.

[xelasnave]

Your are right Colin my open fire at the other place ...all you notice out the chimney is a heat haze.
I built and refined it over years an it breaths perfect.
There is a lot to making a good fire place and chimney.
Alex

[Wavytone]

Glen unfortunately greenies generally think wood is god as it is in principle renewable. My sister is a tree hugger in Tas.

The snag is if you do the maths, hardwoods (eucalypts) grow too slowly to be used in plantations so the reality is we're burning far more than the replacement rate.

Secondly these things are not environmentally friendly - the exhaust gases are well known as a major source of airpollution and contribute to asthma and other respiratory diseases.

This is why there was a major campaign in the 1980 to stop people burning wooden stuff - everything from fireplaces to wood heaters, incinerators anb BBQs.

If it was encouraged the air quality in Sydney for example would be on par with that in Beijing.

[sheeny (Al)]

Being a country dweller, I am all for wood heaters. However, I understand your irritation, especially when you see the down side and not the benefits, but they have their place. In the city or built up areas where you need to buy your firewood, and gas is readily available I think they are a luxury and not terribly appropriate.

Before I go any further, however, wood fires are no more polluting than gas heaters in terms of CO2 produced per MJ of energy, and they are way more efficient than electrical heating from fossil fueled generators due to the efficiency losses of transferring chemical energy to heat to steam to mechanical energy to electrical energy and back to heat again. Wood heaters bypass all this and go straight from chemical energy to heat where it is needed.

The smoke you see from a wood fire is a blend of steam, incomplete combustion and fly ash. The steam is also produced by gas heaters, as is the CO2. The fly ash (which is incombustible particles too small to settle in the heater) is usually invisible in the flue gas as evidenced by the flue gas being clear if the fire has sufficient excess air for combustion. The incomplete combustion is unfortunately the down side of a wood heater. For good clean combustion, the fire needs around 100-120% excess air.

Unfortunately, 100-120% excess air means the majority of the heat from the fire is lost up the chimney. The wood heaters you buy from the shops today, have this built into them. You cannot turn down the air in a modern wood heater as much as an old one. So they are not as efficient as heaters, but superficially cleaner. The smoke from incomplete combustion results in larger particles than the fly ash from complete combustion. That's why you see the smoke. And these settle. In a country environment, this adds to humus in the soil, and so is not a bad thing. In the city, with a lot of paved surfaces, that smoke goes from visible air pollution to invisible water pollution.

Now, I said modern wood heaters are superficially cleaner. Yes, you cannot turn the air down so much, so the fire burns hotter and cleaner and produces less smoke per kilogram of wood burned, but because the excess air is higher, you actually need to burn more wood to get the same heat since more of it is wasted up the chimney. Yet another case of green spin unfortunately, not real world benefit. In actual fact, the smoke pollution works out about the same as an old heater, but the CO2 pollution is greater, the waste heat (heat pollution) is greater, and the amount of wood you have to burn is greater. Collectively we humans are often not as smart as we think we are.

We run a wood heater, as we have no natural gas available, electricity is exorbitant and inefficient. I grow my own firewood on my property in a sustainable way. I haven't had to get wood from off our property since moving hear 10 years ago and I don't cut trees down. Ultimately, I want to change to solar and reverse cycle air con as this is the next most efficient heating after direct burning of wood, and I am getting older and don't want to be cutting and splitting and stacking and handling wood as I get older.

We collect our drinking water in tanks fed from the roof. It is sweet and clean and there is no taste or smell from our drinking water (though we have had it from bush fires and dust storms). We do not have any problem with smoke smell in our clothing from the washing line, though it is rare we run the wood heater during the day.

Al.

[xelasnave]

A side issue...remember the plant trees fad...plantations overtaking excellent farmland.

Tax scams grew better than the trees..

Well last month for two days the plane flew over to the South poisoning a plantation...but funny farmers and greenies alike are happy to see it go...
Alex

[xelasnave]

Hi Al
That was most interesting and informative. Thank you.
Alex

[sheeny (Al)]

Thanks Alex.

Wood heaters are an excellent example of the latest technology not always being better. Caviat Emptor - new technology is someone trying to sell you something, so you need to do the homework to work out what they are NOT telling you.

Al.

[w0mbat (Ian)]

I agree that poorly run fires burning poor quality firewood are probably not a good idea in city areas. However we live in a sparsely populated area and collect our own firewood from our own and neighbours properties. We only collect wood from already dead trees. So by burning already dead wood all we are doing is speeding up the return of the CO2 in the wood to the atmosphere that would naturally happen anyway due to the decay of the wood.
With the one fire we heat the whole house and heat our water. The costs are chainsaw fuel and maintenance and physical work which is really good for us to do. We only use electricity for lighting, electronics, refrigeration, water pumping and air conditioning on the rare very hot days in eastern Victoria. This averages out at around 7kwh per day.
I am pretty sure that if we were to replace the energy from wood with electricity that the CO2 emitted would be greater considering transmission losses and other inefficiencies.
Ian

[torana68 (Roger)]

Originally Posted by xelasnave

....................
I built and refined it over years an it breaths perfect.There is a lot to making a good fire place and chimney. Alex

can you expand on that pls, perhaps with a drawing? ( studied brick chimneys once as I had to restore one)

[xelasnave]

Hi Roger
Thank you for your interest.
It would take years of training to impart all I know about the art however I will explain a few things that may help.
I don't think I can draw a picture but as the old saying goes "a thousand words is worth a simple picture".

When I say breath this thing puffs when fueled up..the air rushes in burns pauses and more rushes in...whoosh, pause, whoosh, pauses...the heat is unbelievable and when run like this uses a.trailer load of wood before midnight...
There is about five ton of rock in the unit which means after it runs for a while the rock heat up and retain the heat...I usually have only a very small fire going to keep the rocks up.

There is a relationship between the opening and the exit to the chimney not sure what the book says but I guess it would be 4 or 6 to 1.
The most important feature is a shelf between the main combustion area and where it narrows to meet the chimney, it is called a smoke shelf and positioned such that any smoke thinking about escaping into the house is thrown back into the updraft and goes up the chimney.
I see the whole thing, mine anyways, like the expansion chamber on a two stroke race bike ..I like to think I have developed a back pulse or downward blast onto the fire to force all incoming air onto the fire..that is why it pulses when fully fueled, and the pulse is like a bellows action...
There are books, probably utube stuff but if you have another question ask away.
I placed an aluminium sheet at the entrance once when it seemed to come alive and to prevent the radiant heat doing damager to things and it melted a third of that sheet ...
Alex

[xelasnave]

Another feature is a plate steel back plate to help absorb heat before the rocks get hot and to somewhat assist it radiating heat.
I have not done this but I was going to run pipes in.at the bottom and exiting back into the room so as to draw in colder air from the floor and exhaust it back as hot into the room.
There was also a tank built I to the rock to take off hot water to run under the floor but never got to do that and unfortunately the water did not really get very hot..the tank was separated by only sic inches or so of rock but that was enough to stop the water getting very hot.
Alex

[torana68 (Roger)]

the smoke shelf and the bit below that I was told is the reflector wall had been removed from mine, took a lot of talking to older builders and finding older construction books to get all the details. then there was the fun of putting it back where it should have been.

[el_draco (Rom)]

Originally Posted by Wavytone

Glen unfortunately greenies generally think wood is god as it is in principle renewable. My sister is a tree hugger in Tas.

The snag is if you do the maths, hardwoods (eucalypts) grow too slowly to be used in plantations so the reality is we're burning far more than the replacement rate.

Secondly these things are not environmentally friendly - the exhaust gases are well known as a major source of air pollution and contribute to asthma and other respiratory diseases.

This is why there was a major campaign in the 1980 to stop people burning wooden stuff - everything from fireplaces to wood heaters, incinerators anb BBQs.

If it was encouraged the air quality in Sydney for example would be on par with that in Beijing.

Nothing quite like a balanced, informed viewpoint.

1/ Tasmania has massive eucalyptus plantations, and they are expanding, both here and on the mainland.

2/ If dry wood is burning in a good fire place, the pollutants are negligible and certainly less than mining and burning the megatons of coal/oil/gas used to heat most cities.

3/ There was a big campaign in the 1980's towards eliminating burn-off's as a means of rubbish disposal because the rubbish contained toxics, like rubber, plastic, paint and everything else deemed "junk"... ie, not dry wood in a clean fireplace.

4/ Sydney is largely surrounded by mountains which form a bowl for smoke haze to accumulate. Its very similar in Launceston, (Northern Tas), where smoke also accumulates. Big, localised problem.

5/ Wood is not, "in principle", renewable; it is IN FACT renewable.

The basic reality is if you burn wood and leave the fossil rubbish in the ground, where it belongs, and plant more forest that you burn, there should be a decrease in air pollution... Of course, it is not that simple because people are stupid, ignorant or irresponsible with their fires.

I live in a cold part of Tassie, (snow territory), I burn good clean dry wood which I source from my own forest and I use it sparingly. I take steps to insulate my home and avoid wasting wood. As a consequence, I contribute about 2.5 tonnes of carbon dioxide to the atmosphere p.a. , (many people burn 4 times this... and usually leave the doors open); I use the carbon ash and feral cats, (), to enrich my soil and my forest generates about 100 tonne of new wood p.a.. Net carbon sink...

This "tree hugger" says, You are How big is your Carbon foot print?

Tired, boring, Green bashing rhetoric is really irritating and obsolete if you care to do a little research. Someone has to stand up for the environment whilst we have economic & ecological terrorists in power.

Good luck breathing if the oceans are dead and forests are gone.

[cruxo (Craig)]

G'day all, could nuclear power the answer? I often hear how clean and clear the skies of countries who use it are. And it is as cheap to produce as coal fired power. The waste is a massive issue though, as i'm lead to believe there is still no way to dispose of it properly. (my first post by the way)

[glend (Glen)]

I would like to remind respondents that burning wood in a device inside your house depletes oxygen from your air supply ( a wood fire needs oxygen to burn, as do gas heaters in homes). These devices also emit carbon monoxide as part of the combustion process, which can be deadly in itself. A properly designed flue system is needed to vent the combustion gases but it does not help with input air supply quality, you need to have outsude air coming in to sustain aur quality. So unless your wood heater has its own outside air source you are going to need to keep a window open. It scares me that people with young kids use these things, as these kiddies are much more susceptible to oxygen depletion and carbon monoxide buildup.

People turning to wood burning in response to electricity, or gas, price increases, is perhaps a natural response in a country without any sort of national energy policy. The lack of leadership is incredible. Having lived in Sydney, i know how pollution can hang in that bowl east of the Blue Mountains, and bush fire smoke can linger there. Is there actually a no burning policy in Sydney? I seem to recall a ban on back yard incinerators, don't wood heaters fall into the same category?

Craig i am a big fan of Australian nuclear power.. we are self sufficent in uranium. Modern reactor designs insure no possibility of accidents like those in Japan. Canada has been doing some great design work in this area. If total cost is considered nuclear is expensive due to build cost. Fusion is the ultimate answer, as i was reminded of watching " Back to the Future" last night, sign me uo for a Mr Fusion unit.

[xelasnave]

Originally Posted by cruxo

G'day all, could nuclear power the answer? I often hear how clean and clear the skies of countries who use it are. And it is as cheap to produce as coal fired power. The waste is a massive issue though, as i'm lead to believe there is still no way to dispose of it properly. (my first post by the way)

Welcome to iceinspace.
Unfortunately I am anti NP so I will disagree.
I think it is more expensive than anything else if one was realistic about long term costs.

Accidents...yes this or that wont happen again.
Accidents are so named because they are unforseen...what unforseen events does NP hold.

Thorium maybe but its biggest drawback is that it does not produce weapons grade bi product...so it won't fly.

Alex

[UniPol]

http://www.health.nsw.gov.au/environ...ood-smoke.aspx