Emissions comparison

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sparke

Minister of Fire
Jul 6, 2006
564
Maine
What would it take to be able to compare emissions? I suspect forced draft units burn cleaner then other type gassifiers. What would it take to get some analysis going. Obviously we would all need measuring equipment and a method so we are all collecting the same data...
 
Emissions come in many types, some easy to measure and some really hard. Some are 'bad', and some are not. For the sake of the argument, I assume you're thinking of emissions that are harmful or disagreeable.

Here's my take on emissions:

Troublesome emissions are primarily the result of incomplete combustion, and would include CO, methane, assorted polyaromatic hydrocarbons (PAH), and particulate emissions (soot, creosote, and so on).

PAH emissions are easy to detect if not quantify - it's the woodsmoke smell. If you can't smell smoke, then those emissions are low. Particulate emissions above a certain point are visible.

The gear to quantify these is expensive, but for any given boiler, higher delivered efficiency almost certainly means lower emissions.

I agree that it would be nice to have hard comparative data on different boiler designs. I have seen independent test data for an EKO 80, and the results looked like this:

O2 8%
CO2 12%
CO .04%
N2 80%

There were some other trace combustion byproducts:

NOx 95 ppm
hydrocarbons 200 ppm

Overall boiler efficiency was 90%, including heat loss to the environment from the boiler, though not from any other system components.
 
I look at chimneys as I drive around the countryside, and I've noticed some interesting characteristics and compared those with my own experience. I think that in general, blue smoke indicates wood that isn't dry enough. Brown smoke indicates dry wood but incomplete combustion, usually early in the cycle. White early in the loading cycle smoke is mostly steam. White smoke late in the cycle is brown smoke getting somewhat better combustion. No smoke either suggests an efficient appliance getting secondary burn, or a non-epa appliance near the end of the cycle.

The other day I had no visible emissions, but I did get some smokey smell. Typically, that's a kind of a toasted wood smell, but the other day it was a bit acrid, so I guess I was getting PAH.

This morning, with temps down around zero, both nozzles were blasting yellow and orange flame. I had some wispy white vapor coming out of the chimney when I loaded it up, but it dissipated almost immediately. Just steam, I suspect.
 
Since the equipment is expensive, it rules out having some real world data from the different models. That leaves us with the smell, visual approach. I was hoping for some scientific data (from this forum - not company reps) to prove or disprove manufacturer data...
 
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