Radiant and circulating heaters
Radiant and circulating heaters have firechambers which may be airtight 1 or non-airtight and are available in a number of sizes, shapes, and designs. The firechamber is closed in use, but there may be a window of specially formulated glass for viewing the fire. Drafts and dampers are used to control the burning process. There may be a secondary combustion chamber, baffles, a thermostat, a blower, or other components which function to improve combustion efficiency or to control heat output. The primary function of these appliances is as space heaters. However, some have lift-off cooking pothole lids, and the top surface of most can be used for cooking. The fuel may be wood, coal, or both. Radiant heaters transmit heat primarily by direct radiation. Circulating heaters have an outer jacket surrounding the fire chamber. Air enters from the bottom, is warmed by passing over the fire chamber, and exits at the top. Movement is by natural convection or forced air circulation.