Abstract: The natural fuel heating system includes an elongate firebox covered by a cowling. The firebox includes means for accessing the interior thereof for fuel placement and vents at opposite ends. The cowling surrounds a majority of the firebox and forms an air circulating barrier between the firebox and the cowling. Outside air is introduced into the barrier through an intake shroud extending from the back of the firebox. The natural fuel heating system includes a heat exchange system for efficiently heating the cooler outside air circulating within the barrier. The heated air is drawn through an exhaust shroud extending from the air barrier into a building ventilation system to heat the building via natural thermal convection and negative air pressure caused by oxygen consumption from combustion within the firebox. A waste gas exhaust vent protrudes from the firebox to deliver harmful exhaust gas back outside.

Abstract: The natural fuel heating system includes an elongate firebox covered by a cowling. The firebox includes means for accessing the interior thereof for fuel placement and vents at opposite ends. The cowling surrounds a majority of the firebox and forms an air circulating barrier between the firebox and the cowling. Outside air is introduced into the barrier through an intake shroud extending from the back of the firebox. The natural fuel heating system includes a heat exchange system for efficiently heating the cooler outside air circulating within the barrier. The heated air is drawn through an exhaust shroud extending from the air barrier into a building ventilation system to heat the building via natural thermal convection and negative air pressure caused by oxygen consumption from combustion within the firebox. A waste gas exhaust vent protrudes from the firebox to deliver harmful exhaust gas back outside.

Abstract: A system for administering gas to a patient during an endoscopic or medical procedure includes elements for regulating the temperature, pressure, and volumetric flow rate of the gas. A gas source operating with a heated pressure regulator and filter provide a smoothly regulated flow of any medically necessary gas, such as CO.sub.2, to a main body of the gas delivery system. The main body comprises a primary heater for control of the temperature of the gas administered to the patient, a fine pressure regulator for controlling its pressure in a safe manner, and a flow regulator for controlling its volumetric flow rate. Temperature, pressure, and volumetric flow rate indicators allow the physician continuous monitoring of the quantitative status of each of these important physiologic parameters; this data may also be recorded for documentation purposes.