The Boldr Kelvin heater looks cool and promises energy savings and far-infrared heat. Too bad it also heats backward.

Cool looking, in an iPhone way. Draws less energy than most heaters. Gentle, even warmth. A smart-home app promises near-infinite customization and energy monitoring.

The Boldr Kelvin is unlike other space heaters I've tested. It is a blank mirrored panel, 3 feet across on its longest side, meant to hang on a wall. It comes in any color you want, as long as it's white or black.

The Kelvin looks a bit like a TV without a border, or the monolith in Stanley Kubrick's 2001: A Space Odyssey. Instead of driving apes crazy, this particular monolith emits far-infrared heat (a type of radiant energy) that its maker promises will make me feel toasty-warm while consuming a fraction of the power of a standard heater. Unlike resistance heaters with fans, it's blessedly silent. And there's an app that tracks basically everything, from room ...