Abstract: The present disclosure provides woodstoves that, optionally, produce low emissions. In certain embodiments, the woodstove includes a housing, a firebox disposed in the housing, an air regulator and a secondary air pipe. The air regulator includes a primary air aperture configured to supply primary air to a fire located in the firebox, a plurality of secondary air apertures configured to supply secondary air to a combustible gas emitted by the fire, and a secondary air damper. The present disclosure also provides methods of operating such a woodstove. As measured according to Method 28 of the U.S. Environmental Protection Agency, the weighted average emission rate of the woodstove of certain embodiments of the invention is no greater than about 4.5 grams of particulate emissions per hour.

Abstract: A power vented fireplace uses a single air inlet to pressurize a staging area from where air is distributed along a passageway between viewing panels to cool them as well as into the combustion chamber as a supply of combustion air. A partial restriction at an inlet to the passageway ensures that sufficient air is directed into the combustion chamber. The inlet to passageway may be adjustable to vary the extent of the restriction. Pressure differential switches may be used to ensure balanced operation of the fireplace.

Abstract: A balanced building ventilation system that employs a fireplace as an element of the ventilation system. The fireplace includes a firebox, and an exhaust gas flue is connected to the firebox for exhausting gas from the firebox to the outdoor ambient. A ventilation channel conveys outdoor ambient air into the building interior. A motor-driven draft inducer is connected to the exhaust gas flue for forcing exhaust gas flow out to the outdoor ambient. A motor-driven blower is provided for forcing ventilation airflow through the channel to replace building interior air lost to exhaust gas flow.

Abstract: Air control apparatus for a fireplace prevents or inhibits the buildup of soot and dirt on the inside surface of the glass doors of the fireplace.

Abstract: The space heating system has a stove (1, 2) with a sealed combustion chamber (3); air is heated in the stove in a heat exchanger (12) therein, and heated air is conducted through hollow blocks (80) of chamotte arranged, for example, as heating panels, heated walls, benches, floors or the like. The hollow blocks are formed, internally, with projections or obstructions (83) to increase heat transfer, and may be faced at the outside with decorative tiles. To seal the combustion chamber, a vertically movable panel, typically of fire-resistant glass, is slidably located in front of a fuel inlet opening (7). In operation, the panel is sealed, so that the combustion chamber (3) will receive air only under controlled conditions, in two air paths; a primary air path supplies air to a narrow space (22) below a fuel support grate (25), after being preheated by passing around an ash receiver (18); and a secondary air flow, passed through ducts (30) within the combustion chamber, and ejecting air towards the panel.

Abstract: Apparatus for ventilating a fireplace having a combustion chamber within the interior of a building comprising an enclosure defining an air volume and a fan unit for generating a constant negative pressure region within the enclosure. A venting passage communicates the enclosure with the combustion chamber of the fireplace such that the negative pressure within the enclosure draws combustion gases from the combustion chamber into the enclosure to ventilate the fireplace. A valve is provided in the venting passage to control the flow of combustion gases to the enclosure. With this arrangement, the fan unit is operated at a constant speed to generate a constant negative pressure within the enclosure. There is no need to install an expensive variable speed fan to provide different levels of ventilation and, as long as the fan installed is sufficiently powerful to ventilate the enclosure, the valve can be used to adjust the ventilation of the fireplace combustion chamber via the enclosure.

Abstract: A fireplace furnace heating system for a structure having a firebox for combustion of fuel, preferably coal. A heating unit is disposed proximately to, and preferably surrounds the firebox. Conduits carry interior air from remote locations to the heating unit. The heating unit is preferably a multi-walled, chambered structure to define numerous air passageways. Air delivered from the conduits to the heating unit must travel through the air passageways. The proximate disposition of the heating unit to the firebox heats the heating unit and the air travelling therethrough. The heating unit has vents for returning the heated air to the interior of the structure. A blower is included for forcible moving the air through the heating unit and back to the interior. Conduits are also provided for supplying fresh air from the exterior to the firebox to fully combust fuel in the firebox. A motorized blower is included to forcibly move the combustion air. Also included is a tempering tank for storing water.

Abstract: A fireplace combustion system in which a sealed firebox contains: a base having apertures connected to a source of combustion air and wherein a hollow grate is connected to one of the apertures to conduct combustion air to a quantity of fuel disposed on the grate; a plurality of baffles and deflectors are utilized to direct the products of combustion above the grate for flow through a quantity of porous refractory material so that the refractory material is heated by the products of combustion to a temperature sufficient to ignite the unburned gases present; and a flue for exhausting the products of combustion. The grate is provided with a plurality of apertures at various levels above the bottom to supply combustion air at varying temperatures at different locations in the burning fuel. Suitable valve means are used to control the amount and direction of the air flow through the apertures in the base to different primary and secondary burning zones in the firebox.

Abstract: The unit restores existing, masonry fireplaces without entailing dismantling of the latter. A heating jacket base, heating jacket, smoke chamber and flue lining are set into the existing firebox, smoke chamber and flue. Ducting is provided to move heating air through the heating jacket, and ducting is provided to pass combustion gases into the smoke chamber and flue. Internal air, or outside air, is accommodated in the unit for heating and combustion. Blowers are provided to move the heating air into the fireplace site (room) and/or to draw in outside air simply to exchange interior, stale air.