For the purposes of this rule:

(a) Coal and wood burning appliances means fireplace stoves, room heater/fireplace stove combinations, cookstoves and ranges, and radiant and circulating heaters. It does not include central heating units, masonry fireplaces and chimneys, fireplace inserts, or factory built fireplaces (zero clearance fireplaces).

(b) Central heating units include boilers, furnaces, and furnace add-ons. These appliances are designed to be connected to hot water distribution or ductwork systems for heating several rooms. The furnace add-on converts an existing gas, oil, or electric heating system to one capable of using solid fuel as well as its original fuel.

(c) A chimney is a vertical or nearly vertical enclosure containing one or more passageways called flue passages for conveying combustion wastes to the outside atmosphere.

(d) A chimney connector is the stovepipe which connects the appliance flue with the chimney flue.

(e) Cookstoves and ranges are chimney connected solid fuel burning appliances that are used primarily for cooking. In addition to the firechamber, there may be one or more ovens or warmer compartments and several removable cooking space pothole lids. The intensity of the fire is controlled by damper and draft regulators.

(f) A factory built fireplace is a firechamber and chimney assembly consisting entirely of factory made parts. It is designed for component assembly without requiring field construction. These “zero clearance” units are fabricated for safe installation against combustible surfaces and for burning fireplace fuel.

(g) Fireplace inserts are heating units that fit into a fireplace and connect to the fireplace flue. These units function like radiant and circulating heaters.

(h) A fireplace stove is a freestanding, chimney-connected firechamber which is constantly open to view. It is designed to burn regular fireplace fuel and function as a decorative fireplace.

(i) A masonry chimney is a chimney field-constucted of solid masonry units, brick, stones, or reinforced concrete.

(j) A masonry fireplace is an open firechamber built into a structure along with a chimney and hearth. It is constructed of solid masonry units such as bricks, stones, or reinforced concrete.

(k) Radiant and circulating heaters have firechambers which may be airtight1 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.

(l) A “room heater/fireplace stove combination” is a freestanding, chimney-connected fire chamber with doors. It is designed to be used to burn fireplace fuels with the firechamber either open or closed to view. This appliance functions as a decorative fireplace when the doors are open and as a non-airtight heater when the doors are closed.

[48 FR 21914, May 16, 1983]