A chimney flue heater for selectively inducing an updraft within a chimney flue generally includes a body releasably hanging from a flue liner and a heating assembly to heat air and induce an updraft within the chimney flue. The body includes a hanger assembly having (i) a top member extending outwardly from an upper portion of the planar support and (ii) a side member extending downwardly from the top member and overlapping an outer surface of the flue liner. The planar support extends downwardly from the hanger assembly and along an inner surface of the flue liner. The heating assembly is mounted on the planar support opposite the hanger assembly. A method of using the chimney flue heater is also disclosed.

Methods and apparatus to thermally destruct volatile organic compounds are disclosed. An example thermal oxidizer for a furnace includes: an oxidation chamber comprising an inlet configured to receive exhaust gases from a furnace and an outlet configured to output resultant gases; and a plurality of heating elements within the oxidation chamber configured to heat the exhaust gases to oxidize one or more components of the exhaust gases between the inlet and the outlet to result in the resultant gases, the plurality of heating elements comprising resistive heating elements forming coils having respective axes, the plurality of heating elements being oriented within the oxidation chamber such that the axes of the coils are transverse to an exhaust gas flow direction from the inlet to the outlet of the oxidation chamber.

Methods and apparatus to thermally destruct volatile organic compounds are disclosed. An example thermal oxidizer for a furnace includes: an oxidation chamber comprising an inlet configured to receive exhaust gases from a furnace and an outlet configured to output resultant gases; and a plurality of heating elements within the oxidation chamber configured to heat the exhaust gases to oxidize one or more components of the exhaust gases between the inlet and the outlet to result in the resultant gases, the plurality of heating elements comprising resistive heating elements forming coils having respective axes, the plurality of heating elements being oriented within the oxidation chamber such that the axes of the coils are transverse to an exhaust gas flow direction from the inlet to the outlet of the oxidation chamber.