Am experimenting with an Omega Engineering AHP 7561 standard air heater rated for up to 240v. Specs include ability to keep a 20 cfm flow exiting @1000F while pulling about 10A @220v. Nichrome melts around 2400F. I'd like to produce small bursts (lasting a few seconds) of very hot air, like 0.03 cu.ft./sec. (about a liter/sec.), raising its temperature from ambient to 1500F. If I energize the heater with essentially no air flow, it takes about 30 secs to bring the wire from room temp to cherry red (roughly 1400F). At that point several liters of air will exit the heater at about 1000F, rising from ambient to that temperature in a few seconds. How long can I safely heat the nichrome under these conditions before melting it and opening the circuit? I do not want to disassemble the system to replace the air heater so playing on the safe side makes sense; still, I need to raise output temps. What do you think? Any ideas about a safe schedule for longer times, gradually creeping up on the output temps required? By how much will the service life of the heater be reduced under this kind of regime? How valid an estimate of nichrome coil temp can be made from eyeballing its color?