2019 MHA Research Heater Tests

Test MHA-1907
February 3, 2019

Random loading, red oak, log cabin stacking, top ignition. Cold firebox.
Pieces loaded in order of increasing weight. 2344 stacking.
71.9 lbs including 2.0 lbs kindling
Estimated moisture 15%.
Start of a cold firebox test series. Heater fired every 2nd day.
This is the first test that was fully automated - once the Condar and Testo were set up
and turned on, there was no intervention until the Condar was turned off at 90 minutes.
The Testo data was started 15 minutes before the test and run for 2 hours past the 90 minute test.
This allowed data at 120 minutes to be calculated, and data to be captured after the combustion air
supply was closed, and then with the Testo probe in free air.

Pisla HTT 602 door, 22" wide
Austrian eco firebox, see http://www.heatkit.com/research/lopez-2014-03-01.html

This was the fifth full run using the new automated Condar controller

Condar spreadsheet results at 90 minutes.

Condar Spreadsheet

Condar spreadsheet results at 120 minutes.

Condar Spreadsheet calculated at 120 minutes

Testo Raw Data

Lab Notes

Flue gas graph to 90 minutes.

Flue gas graph to 120 minutes.

Testo gas graph. Blue line is stack temperature and purple line is oxygen.
The Testo data was started 15 minutes before the test and run for 2 hours past the 90 minute test.
This allowed data at 120 minutes to be calculated, and data to be captured after the combustion air
supply was closed, and then with the Testo probe in free air.
If you look at the stack temperature (red line), at 1:00 PM the combustion air supply is closed, and there is no more gas flow in the flue. 10 minutes later, the probe is removed from the stack and run in free air.

12 Fuel loads were prepared ahead of time for this test series.
The lab technician is away for the month of February, so we will be using the new Condar controller to try fully automated
testing on a cold firebox series (firing every second day).

Burn sequence. Time lapse taken at 2 minute intervals.
The red square marks the normal 90 minute mark for end of test. However, with a large load in a cold firebox, the pile is not burned down at this point. Full sequence shown is 120 minutes.
At 120 minutes, calculated PM is 7% higher than calculated at 90 minutes (same filter catch). CO is 92% higher, and efficiency is 3.2% lower.
With the Austrian eco-labelled air system, coals are not normally burned up, and the air is turned off at 90 minutes. For this load in actual use, air would be turned down at 90 minutes, and turned off around 120 minutes.

This page was updated on February 7, 2019
This page was created on February 3, 2019