How to operate a still air box (SAB) for home and commercial mushroom cultivation
Still air is the name of the game in a still still-air-box (SAB). A still internal atmosphere allows for microscopic contaminant particles to rest on the floor of the SAB, turbulence generated by movements within the "box" will disrupt the settled particles, potentially resulting in contamination.
Never modify a SAB with gloves, blowers, or fans, filtered or otherwise. Do not fill your SAB with flammable vapors or operate a torch within the SAB, certainly never combine flammable alcohol vapor with open torch flames.