Sun Pre-Drying Bricks Before Firing: The Moisture Content at Which Further Drying Stops Paying in Saved Kiln Fuel

This paper addresses bricks and pots sent into the kiln still holding water that the sun could have removed for free, paid for instead in fuel and in steam damage. It presents a target entry-moisture rule that weighs kiln fuel and steam-spalling risk against extra drying days, derived entirely from stated assumptions and a computation whose code and full output accompany the paper. The sweep covers moisture content on entering the kiln from 4 to 18 percent dry basis. The headline outcome is: best x 6; best total usd 53.5; total at 18pct usd 86.1; total at 4pct usd 54.2; fuel at 18pct usd 23.8. These figures identify a specific operating point or bound that a workshop can apply directly, and they also show how quickly performance deteriorates away from it. No kiln was built, no ware was fired, and nothing was measured for this study. SIMULATED, NOT MEASURED.