Moving towards gentler, more effective machines

The common modern compost machines are estimated to spin a shaft at 300 - 600 rpm with flails that hammer and disaggregate the compost course structural texture. The core intentions are to break up larger clumps that may retain anaerobic pockets inside the pile and introduce more air, supplying oxygen for aerobic decay.

The Institute performed early work to measure the air refresh rate after pile turning using such high-rate machines and found surprisingly little “aeration effect”. In fact, within 10 minutes of turning it, the compost would often revert to near its original status - low oxygen content. This abrupt effect dissipated over-time as the pile advanced in quality so that - ironically - eventually, the turning machines seemed to help.

The work that the Institute performed led to an original design for a machine that blew air into the pile with lifting the compost- with amazing effects.