Preheating is by glow plugs with automatic control of preheating time. The process has three stages&colon; preheating, blanching, and cooling. After preheating and pressurizing, H is added. Preheating of the air is shown to greatly enhance desiccant regeneration. These are converted during kiln feed preheating and become oxidized to form CO and CO. Unglazed transpired collectors are perforated sun-facing walls used for preheating ventilation air. Number 6 fuel oil is a high-viscosity residual oil requiring preheating to . Aermet is weldable with no preheating needed. Unglazed transpired collectors (UTC) are perforated sun-facing walls used for preheating ventilation air. Systems can avoid frosting by modulating wheel speed, preheating the air, or stop/jogging the system. Austenitic stainless steels do not require preheating, but martensitic and ferritic chromium stainless steels do. Preheating and proper joint formation is a must for eliminating these types of defects. This can be achieved by preheating the material.