We built this compact room heater around a 300mm shortwave halogen tube—spec’d to hit 2500W at 400V. The whole idea? Cram serious infrared power into a small footprint, so you can warm up a spot fast or support a process, without wrestling with a giant enclosure. Here’s the thing: running 2500W at 400V pushes a lot of current through a short tube. That compact shape concentrates the heat, which means you get a quick warm-up and a strong blast of infrared—right where you need it. But that kind of power density also makes the inside of the heater run hot. So plan your cooling and clearances with that in mind. The electrical and thermal loads are both real, not theoretical. The halogen element keeps the filament steady and hot, while the quartz envelope handles the sudden temperature swings without blinking. We add a coating to shape the IR output and keep the quartz free from contaminants, so performance stays consistent over time. And the R7s connector? It’s a direct, solid fit. Wire it once, and it stays put—no wobble, no loose contacts, even when things get shaky. When you need heat on demand, this setup shines. No slow ramp-up—just fast infrared response for localized warmth, equipment pre-heating, or a quick comfort zone. The 300mm length and R7s termination make it an easy drop-in replacement in existing fixtures. You get a lot of output in a small space. Just make sure your wiring, fusing, and ventilation are sized for the 400V, 2500W load.