Recent Tests:

Graphical Data Summary

Correlation Between Condar PM number and Opacity Curve

Data Analysis

February 23/08 - HK-J30

This is the last run in the HK-J series.

Largest fuel load of 30 run series.

Maple, 18% moisture, 78.0 lbs
5 round pieces of maple, with 3 pieces of white birch on top, 2 on bottom, 10pieces
Warm heater (162F firebox temp), cold fuel
Side ignition
Cold kindling, 4.0 lbs

Similar to run HK-J29, 1/2 lb more kindling, larger load.
Nice clean start, then fire overamped at 27 minutes, creating large opacity spike for 10 minutes.
Dark grey smoke from stack. However, PM number still reasonably low, indicating that this was pure soot with no tar, as would be expected at this stage in the burn.
This is an interesting demonstration of the high opacity, low mass nature of the soot component of PM.

1.0 g/kg PM (Condar)
21.5 g/kg CO
74.2% overall efficiency

February 22/08 - HK-J29

Lowest surface/volume (largest pieces) of 30 run series

Mixed hardwood, 18% moisture, 70.3 lbs
Round pieces, 2 small pieces of white birch on top, 9 pieces
Stack sloped slightly towards kindling
Warm heater (132F firebox temp), cold fuel
Side ignition
Cold kindling, 3.5 lbs (not enough)

Almost identical load to run HK-J26 (very clean), except a borderline start, requiring one additional piece of kindling.
Interesting example of non-linear system -- high sensitivity to initial conditions.

1.1 g/kg PM (Condar)
19.3 g/kg CO
70.1% overall efficiency

February 21/08 - HK-J28

Highest CO of 30 run series

Maple, 16% moisture, 50.3 lbs
Small pieces, smaller on top, 11 pieces
Stack sloped towards kindling
Warm heater (144F firebox temp), cold fuel
Side ignition
Cold kindling, 4.0 lbs (too much)

Highest PM and CO of any of the "Maple, warm firebox, side ignition" runs.
Also highest surface to volume ratio (smallest pieces), very dry.

1.7 g/kg PM (Condar)
43.7 g/kg CO
71.3% overall efficiency

February 20/08 - HK-J27

Lowest instantaneous CO/CO2 ratio of 30 run series

White birch, 20% moisture, 70.0 lbs
Medium pieces, smaller on top, 10 pieces
Stack sloped towards kindling
Cold heater (90 F firebox temp), Cold fuel (-5 F)
Side ignition.
Cold kindling, 3.5 lbs with 2.25 lbs extra added at 18 minutes (see gas curves)
Lowest instantaneous CO/CO2 ratio of 30 run series - 0.0002 at 84.5 minutes (10 ppm)

1.4 g/kg PM (Condar)
16.7 g/kg CO
72.3% overall efficiency

February 18/08 - HK-J26

Maple, 17% moisture, 68.5 lbs
Medium pieces, all round pieces, smaller on top, 10 pieces
Stack sloped towards kindling
Warm heater (180F firebox temp), warm fuel
Side ignition.
Cold kindling, 3.5 lbs.

0.6 g/kg PM (Condar)
14.7 g/kg CO
74.5% overall efficiency

February 17/08 - HK-J25

Maple, 17% moisture, 69.6 lbs
Large pieces, smaller on top, 8 pieces
Stack sloped towards kindling
Warm heater (167F firebox temp), warm fuel (40F)
Side ignition.
Cold kindling, 3.5 lbs. -- 4 lbs would have been better.

0.9 g/kg PM (Condar)
35.9 g/kg CO
73.3% overall efficiency

February 16/08 - HK-J24

White birch, 20% moisture, 61.3 lbs
Large pieces, smaller on top, 8 pieces
Stack sloped towards kindling
Warm heater (145F firebox temp), cold fuel (0F)
Side ignition.
Cold kindling, small kindling, large amount, very rapid start.

0.9 g/kg PM (Condar)
21.2 g/kg CO
72.7% overall efficiency

February 15/08 - HK-J23

Lowest CO of 30 run series

White birch, 20% moisture, 70.5 lbs
Very large pieces, smaller on top, 7 pieces
Stack sloped towards kindling
Warm heater (137F firebox temp), warm fuel
Side ignition.
Cold kindling, false start, needed boost with torch
Last 10 minutes of gas data lost - substituted with estimated data.
Very low CO.

0.8 g/kg PM (Condar)
13.7 g/kg CO
73.0% overall efficiency

February 14/08 - HK-J22

White birch, 20% moisture, 59.3 lbs
Large and small pieces, 10 pieces, 3.0 lbs kindling
Warm heater (160F firebox temp), warm fuel.
Start was too fast with the birch bark catching right away.

Side ignition.
1.6 g/kg PM (Condar)
36.3 g/kg CO
73.0% overall efficiency

February 13/08 - HK-J21

White birch, 20% moisture, 65 lbs
Large pieces, 8 pieces, 3.5 lbs kindling
Cold heater (80F firebox temp), cold fuel (10F)

Side ignition.
1.0 g/kg PM (Condar)
19.4 g/kg CO
76.8% overall efficiency

February 11/08 - HK-J20

Maple, 17% moisture, 58 lbs
Large pieces, 8 pieces, 4.2 lbs kindling
Cold heater (50F firebox temp), cold fuel (0F)
Compare with HK-J19 (below) -- this is one
scenario where the faster start from bottom
may have an advantage.

Side ignition
2.3 g/kg PM (Condar)
27.6 g/kg CO
74.1% overall efficiency

February 6/08 - HK-J19

Maple, 17% moisture, 55 lbs
Large and small mixed, 8 pieces, 1.5 lbs kindling
Cold heater (48 hrs, 100F firebox temp), cold fuel

Bottom ignition.
1.1 g/kg PM (Condar)
27.9 g/kg CO
74.6% overall efficiency

February 4/08 - HK-J18

White birch, 19% moisture, 55 lbs
13 pieces, 1.5 lbs kindling
Warm heater, warm fuel, small fuel. Bottom ignition, regular air slot
Kindling went out, restarted with torch.

3.3 g/kg PM (Condar)
39.7 g/kg CO
73.8% overall efficiency

February 3/08 - HK-J17

Mixed hardwood, 21% moisture, 64 lbs
8 pieces, 3.2 lbs kindling
Warm heater, warm fuel

0.9 g/kg PM (Condar)
26.8 g/kg CO
73.8 % overall efficiency

February 2/08 - HK-J16

Highest moisture of 30 run series
Highest kindling weight of 30 run series

Wet hardwood, maple and oak, 35% moisture, 84 lbs
12 pieces, 12 lbs kindling
Cold heater (66F), side kindling

Difficult to start. Had to add more kindling twice.

1.9 g/kg PM (Condar)
41.4 g/kg CO
71.9 % overall efficiency

January 30/08 - HK-J15

Large and small maple, 16% moisture,
53 lbs, 9 pieces, 3.3 lbs kindling
Warm heater, cold fuel, side kindling

Clean run. Piece #1 on bottom was too large, difficult to manage coals at end.

0.7 g/kg PM (Condar)
24.3 g/kg CO
74.8 % overall efficiency

January 29/08 - HK-J14

Large and medium maple, 16% moisture,
65 lbs, 8 pieces, 5.5 lbs kindling
Warm heater, cold fuel, side kindling

Mis-start, extra newspaper added.
Also, fuel pile was slow to catch and required 1.5 lbs added kindling.

1.5 g/kg PM (Condar)
23.8 g/kg CO
74.4 % overall efficiency

January 28/08 - HK-J13

OMNI ASTM fuel crib, 10% moisture 44.6 lbs
12 pieces, 2 lbs kindling
Room temp fuel. Warm heater (24 hrs)
Kindling from the side.
Regular air slot in front - 1"

1.0 g/kg PM (Condar)
19.9 g/kg CO
75.1 % overall efficiency

Compare with crib tests
HK-J12, HK-H13, and HK-H12

January 27/08 - HK-J12

Highest PM number of 30 run series
Highes Surface/Volume of 30 run series
Lowest moisture of 30 run series

OMNI ASTM fuel crib, 10% moisture 47.2 lbs
12 pieces, 6 lbs kindling
Room temp fuel. Warm heater (24 hrs)
Kindling from the bottom (underneath pile)
Modified air - front slot reduced 50%

3.6 g/kg PM (Condar)
36.5 g/kg CO
74.7 % overall efficiency

Compare with crib tests
HK-H13, and HK-H12

January 26/08 - HK-J11

White birch, small pieces, 19% moisture, medium load 41 lbs
12 pieces, 1.8 lbs kindling
Cold fuel. Cold heater (66F)
Kindling from the bottom (underneath pile)
Modified air - front slot reduced 50%

1.0 g/kg PM (Condar)
22.1 g/kg CO
78.3 % overall efficiency

January 23/08 - HK-J10

Maple, large pieces, 16% moisture, large load 70 lb.
6 pieces, 2.5 lbs kindling
Cold fuel (0F). Cold heater (66F)
Kindling from the bottom (underneath pile)

1.5 g/kg PM (Condar)
38.6 g/kg CO
74.3 % overall efficiency

January 21/08 - HK-J09

White birch, large and small pieces, 20% moisture, medium load 48.7 lbs
9 pieces, 3.25 lbs kindling
Cold fuel (0F). Cold heater (50F)
Kindling from the bottom (underneath pile)

1.6 g/kg PM (Condar)
19.0 g/kg CO
78.0 % overall efficiency

January 16/08 - HK-J08

Lowest PM number of 30 run series

Hard maple, medium and large pieces, 16% moisture, large load 64.6 lbs
10 pieces, 3.5 lbs kindling
Cold fuel, stacked in warm firebox for 90 minutes. Warm heater (24 hrs)

0.5 g/kg PM (Condar)
27.2 g/kg CO
74.8 % overall efficiency

January 15/08 - HK-J07

White birch, large pieces, 21% moisture, large load 79.1 lbs
8 pieces, 4.5 lbs kindling
Cold fuel, stacked in warm firebox for 90 minutes. Warm heater (24 hrs)

0.9 g/kg PM (Condar)
26.0 g/kg CO
74.7 % overall efficiency

January 14/08 - HK-J06

White birch, medium pieces, 20% moisture, 62.1 lbs
10 pieces, 3.5 lbs kindling
Cold fuel, stacked in warm firebox for 90 minutes. Warm heater (24 hrs)

0.8 g/kg PM (Condar)
23.6 g/kg CO
74.9 % overall efficiency

January 13/08 - HK-J05

Hard maple, medium pieces, 16% moisture, 52 lbs
8 pieces, 3.6 lbs kindling
Cold fuel, stacked in warm firebox for 4 hours. Warm heater (24 hrs)

0.8 g/kg PM (Condar)
27.0 g/kg CO
75.8 % overall efficiency

January 12/08 - HK-J04

Hard maple, medium pieces, 16% moisture, 56.2 lbs
8 pieces, 3 lbs kindling
Cold fuel. Warm heater (24 hrs)

0.9 g/kg PM (Condar) Note: estimated value, due to a gas leak. See page for details.

January 11/08 - HK-J03

Highest piece count (cordwood) of 30 run series

Small white birch, 20% moisture, 51 lbs
Cold heater, cold fuel

Small wood, 15 pieces, stacked tight, 2.75 lbs kindling
2.34 g/kg PM (Condar)
38.75 g/kg CO
76.5 % overall efficiency

January 5/08 - HK-J02

Mixed hardwood, 16% moisture, 61 lbs
Previous fire: 24 hours
Large wood, 8 pieces, 2.5 lbs kindling

0.7 g/kg PM (Condar)
37.9 g/kg CO
74.1% overall efficiency

January 4/08 - HK-J01

White birch, 20% moisture, 51 lbs.
Cold heater, cold wood
Medium wood, 8 pieces, 2.1 lbs kindling

2.0 g/kg PM (Condar)
23.4 g/kg CO
77.5% overall efficiency

October 21 - 31, 2007
Calibration of 4 Condar portable dilution tunnels

Test Results

October 16/07 - HK-I07

FGM series.
White birch, 20% moisture
Previous fire: 24 hours.
Medium wood, evenly sized, 8 pieces. 2.5 lbs kindling. Rear corner teepee side ignition.
Very controlled collapse - even sizing, all half pieces facing down.
Last test in series. Next testing is at CCHRC in Fairbanks, Alaska

October 15/07 - HK-I06

FGM series.
White birch, 20% moisture
Previous fire: 24 hours.
Small wood, 12 pieces. 2 lbs kindling. Top ignition.

October 14/07 - HK-I05

FGM series.
White birch, 20% moisture
Previous fire: 20 hours.
Medium to large wood, large load of kindling (7 lbs)
Very dirty burn - too much kindling, overamped the fire, couldn't get enough air.
Large bottom piece on left partially blocked both front and rear air supplies.
Reference dirty burn.

October 13/07 - HK-I04

FGM series.
White birch, 23% moisture
Previous fire: 24 hours.
Repeat with large fuel, except one extra tier.
Reasonably opacity.

October 12/07 - HK-I03

FGM series.
White birch, 24% moisture
Previous fire: 24 hours.
Very large pieces, still with some moisture inside.
Not quite enought kindling to get "over the hump" of the temperature curve

October 11/07 - HK-I02

FGM series.
White birch, 20% moisture
Previous fire: 24 hours.
Repeat run of KHI-01, with warm heater.
Notice difference in opacity curve

October 10/07 - HK-I01

First test of FGM series.
White birch, 20% moisture
Cold heater, cold fuel
Difficult startup.

March 11/07 - HK-H20

Reference run.
This run was a best guess as to an optimum fuel loading and optimum air.
Very clean, low PM, low CO, very good efficiency.
This run will serve as a benchmark for comparison for future tests.
This concludes the HK-H test series. Next testing will be at 2007 MHA Meeting,
April 13th - 19th, 2007

Jan 9/08: Condar summary added.
CO was 15.6 g/kg

March 10/07 - HK-H19

An interesting run.
It was a repeat of HK-H18, except with a hot heater (10 hrs since last burn),
and with the grate open and the ashbox door closed (air control open).
In other words, hot heater, new HeatKit air, vs. lukewarm heater, old Heatkit air,
with a medium load of large wood - 50 lb.
We captured an accidental chimney draft reversal at the beginning.
The clue is the 35F initial flue temperature reading on the analyzer.
Since the heater exits directly to an outside insulated metal chimney at floor level, this condition is easy to produce. Also, easy to reverse.

March 10/07 - HK-H18

Medium load of large maple. 6 pieces. 19% moisture. 49 lb.
Lukewarm heater (36 hrs since last fire).
Old air system (grate closed, ashbox door open)
Low particulates (smoke), medium CO, medium efficiency.

March 08/07 - HK-H17

Very small maple. 12 pieces. 19% moisture. 47.5 lb
Warm heater. More air than HK-H16 (ashbox door open).
Higher stack temp peak, lower peak to the characteristic crib opacity hump
at the middle of the burn.
Attempt to simulate ASTM crib with hardwood cordwood.

March 07/07 - HK-H16

Very small maple. 12 pieces. 19% moisture. 39 lb
Warm heater. Standard air.
Attempt to simulate ASTM crib with hardwood cordwood.

March 06/07 - HK-H15

Small maple. 8 pieces. 19% moisture. 54 lb
Warm heater. Standard air.
Very clean run.

March 05/07 - HK-H14

Mixed size maple. 7 pieces. 19% moisture. 60 lb
Warm heater. Standard air.
Clean run with a slow start - kindling got hung up and needed extra newspaper.

March 04/07 - HK-H13

ASTM crib test. White spruce 4x4's, 16% moisture. 34 lbs.
Repeat run of HK-H12, yesterday.
Semi-warm heater. Standard air.
Very consistent with HK-H12, considering the warmer heater.

March 03/07 - HK-H12

ASTM crib test. White spruce 4x4's, 17% moisture . 34 lbs.
Cold heater. Standard air.
Very different burn, as evidenced by the gas and opacity curves.
Compare with HK-H10, regular hardwood, cold heater.

March 01/07 - HK-H11

Small hardwood , 9 pieces. 19% moisture. 52 lbs.
Cold heater. Cold fuel.
Experimental air system switched in for selected intervals.
Noted mainly for its ability to produce huge opacity spikes at the beginning!

February 28/07 - HK-H10

Large mixed hardwood , 6 pieces. 19% moisture. 50.5 lbs.
Revised opacity system
Cold heater.

February 25/07 - HK-H09

Large mixed hardwood , 7 pieces. 19% moisture. 55.5 lbs
Cold heater.

February 22/07 - HK-H08

Very large white birch, 6 pieces. 21% moisture. 62 lbs

February 21/07 - HK-H07

Very large maple, 7 pieces. 19% moisture. 64 lbs

February 20/07 - HK-H06

Small maple, 9 pieces. 19% moisture. 49 lbs

February 19/07 - HK-H05

Large maple, 7 pieces. 19% moisture. 51 lbs

February 18/07 - HK-H04

Load of medium maple, 8 pieces. 19% moisture. 49 lbs
Animation posted. Fueling data posted
Other data to follow.

February 17/07 - HK-H03

Load of large maple, 6 pieces. 19% moisture. 57.5 lbs
Animation posted. Data to follow.

February 16/07 - HK-H02

A dry run using white birch. Animation posted. Data to follow. 39.7 lbs

February 15/07: Update

We have our new gas analyzer and other new equipment installed, and did a dry run test last night. Look for more data soon.

April 3/06: Update

After the Feb 21 test, about 25 repeat burns were observed anecdotally in a heater with a similar air setup that heats our house. Formal testing has been suspended until we take delivery of a new TESTO 330-2 gas analyzer. It will be shipped directly to the annual MHA meeting in North Carolina (April 13 - April 20), where we plan to build and test an experimental heater.

February 21/06 - 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 20/06 - HK-G13

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

February 19/06 - HK-G12

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

February 18/06 - 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