From: "Lars Helbro" <lars(at)>
To: "Norbert Senf" <mheat(at)>
Cc: "Alex Chernov" <alex_stovemaster(at)>,
  "Brian Klipfel" <b_klipfel(at)>,
  "Jerry Frisch" <lopezquarries(at)>, <eric(at)>,
  "Paul Tiegs" <paultiegs(at)>, "Dave Misiuk" <misiuk(at)>,
  <fishermasonry(at)>, <stan_homola(at)>,
  "Steve Bushway" <sbushway(at)>,
  "Antoine Guerlain" <wheresantoine(at)>,
  "tristan fortin lebreton" <tristanfortinlebreton(at)>,
  <ch(at)>, "William Davenport" <info(at)>,
  "Mark (at) Gimme Shelter" <mark(at)>,
Subject: SV: SV: SV: Wildacres 2010
Date: Tue, 27 Oct 2009

At 02:41 PM 10/27/2009 +0100, Lars Helbro wrote:

Hi Norbert
B.t.w. Do you know about the accuracy of your Condar dillution tunnel ???
Here in Europe we would have to spend a hell of a lot of money (300,000 US $) to get equipment with just a reasonable accuracy. (And then we would have to clean it every 12 minutes :-(((  No good.
Cheaper equipment can't see the difference between PM10 and PM2,5 and to my knowledge particles smaller than PM2,5 is the most interesting. The rest is probably just dirt that doesn't make much harm to our health, since it cannot get deep into our lungs.

Hi Lars:

From what I know so far, the Condar is very good, for our purpose, which is to get an "equivalent" EPA Method 5 number for masonry heaters.
There are many other ways to measure particulates, and aerosols. However you just want to know what your EPA number will be, beforehand, if you
spend the money and bring your stove to an EPA-accredited lab, such as OMNI, for a test.
Here is a good background paper:

It is from a course that was organized for us by OMNI, and features the late Dr. Stockton (Skip) Barnett, the inventor of the Condar.
It is recognized as an official test method in Oregon, as OM-41. Oregon was the first U.S. state to regulate PM emissions from woodburning.
When EPA had to write a federal regulation, it was based on the prior work done in Oregon, mainly by OMNI.

I doubt that there is very much difference between PM-2.5 and PM-10, in heaters. 90% of woodsmoke is smaller than 2.5, I think.

A few years ago, a researcher from New Zealand contacted me for information on the Condar, and they did a field study on pellet stoves using the Condar method.

They also took the Condar into the lab, and calibrated it against Australia/New Zealand method AS/NZS 4012/3, which is probably a method 5, similar to EPA.
Here is the correlation between the Condar and the laboratory dilution tunnel:

Here is the complete study:

Pellet stoves should be very similar to masonry heaters. Almost all of the particulates that we see are soot.
You can tell something about the organics such as PAH's simply by smelling the filters. Normally, we get no smell.
With airtight stoves (EPA certified stoves), you are also dealing with tar, which adds complication. It is the reason you need to dilute
and cool the exhaust before measuring, so that you make sure the semi-volatiles are condensed similar to real-world.

The only real critique I have heard about the Condar is that it is constant-flow sampling, as opposed to proportional flow.
Also, most of the top lab guys had a bit of experience with the Condar in the old days, with stinky non-certified airtights, and there were
problems with the filters plugging up, etc.

Actual Condar experience with masonry heaters is limited to a very small group of researchers.
However, OMNI has done a bit of calibration work on masonry heaters with the Condar, against Method 5. The results, though limited, are very good.
We are planning to do some additional calibration work at OMNI fairly soon.

A huge advantage of the Condar, aside from low cost and simplicity, is that it allows field sampling.
In fact, some of the cleanest current EPA stoves, such as the Quadrafire, were developed with the Condar.
We are proposing actually to train masonry heater builders to be able to do a field test on a one-off heater,
to verify design and performance. It is a sort of "Plan B", depending on how things go with our current efforts at working something out
with EPA and other regulators.

Best ..... Norbert

Norbert Senf---------- mheat(at)
Masonry Stove Builders  
25 Brouse Rd.
RR 5, Shawville-------          
Québec J0X 2Y0-------- fax:-----819.647.6082
---------------------- voice:---819.647.5092