“Natural” is the tannish gray of the base material. The other colors are our proprietary ceramic stain coloration. We recommend darker colors (Black, Dark Gray, & Brown) as the burner will create soot from the natural, luminous yellow flame. The black soot is more noticeable against the lighter colors (White, Natural, Adobe Red, Beige, & Light Gray); with the darker colors there is less contrast, so the soot is not as pronounced.

All ALTERNA vent free sets are certified to two standards: ANSI Z21.11.2 (Unvented Room Heaters) and ANSI Z21.60 (Vented Decorative Appliance). For use in wood-burning fireplaces or approved vent-free firebox enclosures. They may be used with the damper open, closed or anyplace in between. Vent-Free sets are supplemental zone heaters, they are not intended for continuous use or whole house heating. Has 30,000 BTU/hr maximum inputs.