Recent Tests:

February 21/07 - HK-G14

A repeat of the "side burn" from yesterday, except with a large load of large, cold wood.
Again, no opacity spike and an almost smokeless burn.
Although it requires more detailed testing to confirm, this appears to be a significant result.

February 20/07 - HK-G13

A very interesting test. First test with no opacity spike.

February 19/07 - HK-G12

Restricted air, very large load, large wood stacked tight, extra kindling.

February 18/07 - HK-G11

Restricted air, large load, large wood

February 17/06 - HK-G10

A repeat of HK-G07, with unrestricted air

February 16/06 - HK-G09

Cold heater, cold fuel, small load.

February 13/06 - HK-G08

Restricted air (ashbox door closed, air slider open)

The last two tests were very interesting. Some of the kinks have finally been resolved with the opacity measurements.

February 12/06 - HK-G07

Unrestricted air (ashbox door open)

Previous Tests:

This test was a dry run.

The heater was not preheated.
Test fuel was cold (brought in from outside)
Fuel was not weighed, it was approximately 1/2 a load (35 lbs)

Fuel load stacked in firebox.

Graph of stack temperature and light extinction.

Photo taken at the opacity peak at 5 minutes.

Photo taken 3 minutes later, when the opacity reading was near zero.
Stack temperature is low.
Steam can be seen condensing as it exits the chimney.
This has to be distinguished from smoke, and makes visual assessment more complicated.

Comments:

The light extinction in the test section of flue seems to be a
good predictor of visible smoke from the chimney.

Past particulate matter (PM-10) testing experience at Lopez indicates
that visible smoke is a very good predictor of grams per kilogram
particulate emissions.

At this point, no calibration of the CdS sensor has been done,
so the next step is to determine whether we are in the linear
range of the sensor's light response.

Further Results :

February 6/06:

Paul Tiegs, principal at OMNI-Test, has commented that opacity testing was tried in the 1980's with coventional woodstoves, and did not find strong correlation with particulates.

Paul adds that EPA has a standard method, (U.S. EPA Method 9), that requires readings to be made at various distances downstream of the chimney exit, depending on the dissipation of moisture particles. There is another test method that is in-stack, but requires the gas stream to be higher than 350F or so, so that volatile organics remain uncondensed.

In view of Paul's comments, we have done elementary testing of the CdS sensor for linearity, but decided to concentrate first on determining if this method as a whole is useful for the particular case of masonry heaters.

Since we are measuring at the chimney entry, we do not appear to be getting water condensation in the flue stream, but can't be certain at this point. This requires some further investigation. Since we are mainly investigating the cold start, it takes some time before gas temperatures reach 350F.

This is a view through the ceramic glass end cap on the horizontal flue, illuminated by a flashlight beam, during combustion.

The far end (left side) downdraft channel is clearly visible. Small particles of ash caught in the flashlight beam provide a good visualization of the gas path and speed (not visible from the photograph).

The thermocouple/draft probe is inserted through the damper frame and visible.

February 8/06

We have conducted 2 more burns (G02 and G03). Both times, there were some glitches with the CdS sensor setup, which should be resolved for the next test.

You can view a 5 Mb animation of test G-03 here. It shows the startup at 30 second intervals for the first 20 minutes, and 5 minute intervals for another 40 minutes or so. Note: the flames appear redder in the photos than they do to the eye. Fuel load was 62 lbs.

The Excel data for G03 (Feb 8) is posted: here

February 10/06

Here's a 4Mb animation of test G-04, with less air. Fuel load was 55 lbs. All runs are with 8 pieces of fuel.

February 11/06

Here is an experimental animation page of test G-05 and G-06, comparing the two burns.

February 12/06

An interesting test

February 13/06

An interesting test to compare with February 12