Current Heater Testing at Lopez Labs

Today, we did run 6 of a 10 run series with a controlled wood load. All pieces in a given run have the same moisture content, and are split from hardwood boles between 8" and 14" in diameter. The wood load consists of 8 pieces and 2 lb kindling. The pieces are stacked in a 2-3-3 log cabin configuration. The two top rows are stacked tight, with the bark down (see fuel load photo).

We used a Kodak DC-50 digital camera to document the burn progressions. Below are the images from today's test run, which finished at 11:30 a.m. Downloading the images from the camera, processing them, and uploading them to the server takes about 45 minutes.

Today's run went a little more smoothly than yesterday, when there was a slight stacking glitch that prolonged the burn considerably and dropped the efficiency by about 3%. Even though today's wood had 4% more moisture (20.8%) than yesterday (16.8%), overall efficiency was up a little over 1%. Today's load also was smaller (55 lb vs. 70.8 lb).

It is a little early yet to start drawing conclusions, but our basic thesis is that wood sizing and stacking has as large an influence on heater performance as any other factor, including heater brand. Compare today's photos and graph with yesterday, and the day before.