Austrian Eco Firebox Testing

Background

The heater in the lab has a replaceable firebox liner. The standard liner of firebricks on edge was replaced with this one.
After the second course, the horizontal joints are shimmed open to create 5mm air slots.
See PDF for Austrian specifications for firebox: MB_10_eco-friendly combustion chamber_20120424Version2.pdf

For this testing, the grate air was shut off.
Underfire air could be used to burn up the coals at the end, to allow the chimney damper to be closed earlier.
In the Austrian system, the stove is airtight. Chimney shut off dampers are not permitted. 
The air is shut off when the load is reduced to a charcoal bed.

Cross section of supply channels is 26.25 sq. in.
Cross section of horizontal firebox air slots 27 sq. in.

Air enters air frame from below and is fed out the sides into the horizontal firebox 5mm air slots. There are also 3 mm air slots cut into the 4 inside corner edges of the air frame, aimed 45 degrees towards the firebox.

View from firebox, showing air horizontal and vertical air slot in air frame, aimed 45 degrees at the fire. Air frame is 3"x4" tubing. Total cross section of both legs is 20.6 sq. in.

View of top horizontal slot on air frame, aimed down at the fire at 45 degrees.

Video URL: https://vimeo.com/88009913

Video Download:

Test Results

Runs GH-01 - GH-18 were by Homestead Heat, see below

Update from Lopez Labs member Boris Kukolj

Spreadsheet 1: Condar-BK1-09 June11.xls

Spreadsheet 2: Condar-BK1-09 June12.xls

Homestead Heat Testing

Double bell heater with eco-firebox, Homestead Heat
See testing summary, above

Test GH-18

Video URL: https://vimeo.com/91749931

Video Download:

Heat-Kit Testing

HK-M34 (March 20, 2014)

Red oak cordwood, big pieces
Side ignition.  Newspaper 3/4 up the kindling pile.
58.3 lbs including 5.0 lbs kindling
19.7% moisture.

HK-M33 (March 19, 2014)

Red oak cordwood, big pieces
Side ignition.  Newspaper 3/4 up the kindling pile.
60.7 lbs including 5.5 lbs kindling
16.4% moisture.

HK-M32 (March 18, 2014)

Sugar maple cordwood. 
Side ignition.  Newspaper 3/4 up the kindling pile.
59.5 lbs including 5.0 lbs kindling
19.0% moisture.

HK-M31 (March 17, 2014)

Sugar maple cordwood. 
Side ignition.  Newspaper 3/4 up the kindling pile.
68.2 lbs including 5.5 lbs kindling
18.3% moisture.

HK-M30 (March 16, 2014)

White birch cordwood. 
Side ignition.  Newspaper 3/4 up the kindling pile.
50.6 lbs including 5.00 lbs kindling
15.5% moisture.
2 dry pieces on top caused too fast a start.

HK-M29 (March 13, 2014)

White birch cordwood. Small wood, cold fuel
Side ignition.  Newspaper 3/4 up the kindling pile.
42.4 lbs including 3.75 lbs kindling
15.5% moisture.

HK-M28 (March 10, 2014)

Data loss due to power failure. Photographic record only.

HK-M27 (March 9, 2014)

Red oak cordwood. Small wood, higher moisture than HK-M26
Side ignition.  Newspaper 3/4 up the kindling pile.
67.8 lbs including 6.0 lbs kindling
22.9% moisture.

HK-M26 (March 8, 2014)

Red oak cordwood. Large wood.
Side ignition.  Newspaper 3/4 up the kindling pile.
60.1 lbs including 5.2 lbs kindling
18.7% moisture

HK-M25 (March 7, 2014)

White birch cordwood. Large wood, mix of wet and dry (see fueling details in Condar Spreadsheet below)

Spreadsheet Excel File: Condar-HK-M25.xls

Side ignition.  Newspaper 3/4 up the kindling pile.
61.7 lbs including 5.2 lbs kindling
22.4% moisture
Cleanest burn to date on this heater.

HK-M24 (March 6, 2014)

White birch cordwood.
4 lbs kindling on left side. Newspaper 2/3 up the kindling pile.
49.6 lbs including 4.00 lbs kindling
20 % moisure (estimated)
Very staged start.

HK-M23 (March 5, 2014)

White birch crib. Crib turned 90 degrees from HK-M22
3.75 kindling on left side, as opposed to kindling on both sides, on HK-M22
37.1 lbs including 3.75 lbs kindling
15.1% moisure

Compare with HK-M22, below. It used the same crib and kindling, except the crib was turned 90 degrees and the side kindling was on one side instead of both sides.

This test series has established the excellent repeatability of cribs for masonry heater testing, and
this is a good demonstration of how fuel and ignition geometry in the firebox affects emissions.
In particular, there is a dramatic effect on particulate (PM) emissions, but only a very small effect
on CO emissions in this example.

Repeatability PDF: Heatkit and Stovemaster_Crib testing PM lb_MMBtu 7125-2.pdf

Compare with HK-M22, below

HK-M22 (March 4, 2014)

White birch crib. Ignition from both sides.
40.6 lbs including 3.75 lbs kindling
15.7% moisure

Compare with HK-M23, above

HK-M21 (March 3, 2014)

White birch cordwood. Large wood, top ignition
57.2 lbs including 4.0 lbs kindling
15.5% moisure
Stack temperature corrected for height.

Top ignition

HK-M20 (March 2, 2014)

White birch cordwood
46.0 lbs including 4.0 lbs kindling
15.2% moisure
Stack temperature corrected for height.

Too much newspaper, too fast a start