Dual flow heating apparatus

Claim 2

In a forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto; the improvement comprising heater means disposed within said conduit means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, an air fan means located in said heating compartment and having a first means operable to forcibly draw said heated air stream into contacting therewith at its entry into said heating compartment and having a second means operable to establish a recirculated forced air flow internally within said heating compartment without entry of said internal forced air flow into said air conduit, said first and second air fan means enabling mixing of said heated air stream with said internal forced air flow, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 3

The improvement according to claim 1, wherein said associated air conduit means and said heating compartment have at least one wall in common for enabling indirect transfer of heat from said air conduit means into said heating compartment.

Claim 4

The improvement according to claim 1, wherein said heater means is a gas combustion element, and said air stream transported from said heater means to said second location contains gas combustion products, and wherein said heated air stream is mixed with said recirculated forced air flow solely within said heating compartment by said air flow means.

Claim 5

The improvement according to claim 1, wherein said heater means is an electric resistance element, and wherein said heated air stream is mixed with said recirculated forced air flow solely within said heating compartment by said air flow means.

Claim 6

A forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto, comprising heater means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, an air fan means located in said heating compartment and having a first means operable to forcibly draw said heated air stream into contacting therewith at its entry into said heating compartment and having a second means operable to establish a recirculated forced air flow internally within said heating compartment without entry of said internal forced air flow into said air conduit, said first and second air fan means enabling mixing of said heated air stream with said internal forced air flow, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 7

A forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto, comprising heater means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, an air fan means located in said heating compartment and having a first means operable to forcibly draw said heated air stream into contacting therewith at its entry into said heating compartment and having a second means operable to establish a recirculated forced air flow internally within said heating compartment without entry of said internal forced air flow into said air conduit, said first and second air fan means enabling mixing of said heated air stream with said internal forced air flow, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 8

The heating apparatus according to claim 5, further comprising an outer housing formed of a plurality of connected side, bottom, top and rear walls, said outer housing arranged about said heating compartment in a manner to form an associated air conduit between at least one of the walls of said heating compartment and said outer housing, and said air conduit enabling transport of a heated air stream from said heater means to said second location.

Claim 9

The heating apparatus according to claim 5, wherein a divider baffle is positioned parallel to and spaced from a wall of said heating compartment, and wherein said air flow means comprises an air fan having its plane of rotation disposed parallel to said divider panel and being rotatably supported within said heating compartment, and said air fan having means for drawing two air streams thereinto in opposite axial directions and for centrifugally ejecting and mixing the two air streams within said heating compartment in the spaced between said divider baffle and said heating compartment wall.

Claim 10

The heating apparatus according to claim 5, wherein said heater means is a gas combustion element, and said air stream transported from said heater means to said second location contains gas combustion products, and wherein said heated air stream is mixed with said recirculated forced air flow solely within said heating compartment by said air flow means.

Claim 11

The improvement according to claim 5, wherein said heater means is an electric resistance element, and wherein said heated air stream is mixed with said recirculated forced air flow solely within said heating compartment by said air flow means.

Claim 12

In a forced air heating apparatus having an outer housing formed of a plurality of connected side, bottom, top and rear walls, and having an open front heating compartment contained therein and spaced from at least one wall of said outer housing to form an air conduit enabling circulation of a heated air stream between said outer housing and said heating compartment, and having a cover door arranged to close the open front of said heating compartment; the improvement comprising: a dual air flow fan rotatably supported within said heating compartment, said fan having means for drawing two air streams thereinto along opposite axial directions and for impelling both air streams centrifugally away from said fan during rotation thereof to enable mixing of said two air streams within said heating compartment, said air flow fan enabling establishment of a recirculated forced air flow internally within said heating compartment and enabling the drawing of said heated air stream from said air conduit into a portion of said heating compartment.

Claim 13

In a forced air heating apparatus having an outer housing formed of a plurality of connected side, bottom, top and rear walls, and having an open front heating compartment contained therein and spaced from at least one wall of said outer housing to form an air conduit enabling circulation of a heated air stream between said outer housing and said heating compartment, and having a cover door arranged to close the open front of said heating compartment; the improvement comprising: a dual air flow fan rotatably supported within said heating compartment, said fan having means for drawing two air streams thereinto along opposite axial directions and for impelling both air streams centrifugally away from said fan during rotation thereof to enable mixing of said two air streams within said heating compartment, said air flow fan enabling establishment of a recirculated forced air flow internally within said heating compartment and enabling the drawing of said heated air stream from said air conduit into a portion of said heating compartment.

Claim 14

The improvement according to claim 10, wherein a divider baffle is positioned parallel to and spaced from one of the walls of said heating compartment, said divider baffle having first and second heated air flow channels formed between at least two of the edge portions thereof and the adjacent wall portions of said heating compartment, and said divider panel having an aperture form therein and aligned with the axis of said air flow fan for enabling recirculated forced air flow within said heating compartment, and wherein said dual air flow fan is positioned between said divider baffle and said heating compartment wall.

Claim 15

The improvement according to claim 10, wherein a heater means is provided for heating an intake ambient air stream at a first location in said air conduit, and wherein said air conduit enables transport of a heated air stream from said heater means to a second location which is in flow communication with said heating compartment.

Claim 16

The improvement according to claim 10, wherein said air fan has first and second axial intakes located on opposite sides thereof and first and second sets of centrifugal outflow vanes associated therewith for enabling the simultaneous inflow and mixing of two air streams at the peripheral edge of said fan, and a rotational motive means connected to said air fan for enabling rotation thereof and establishment of an air stream movement through said air conduit and across said air heater means and for enabling the establishment of a recirculated forced air flow within said heating compartment, said air fan enabling the intermixture of said heated air stream and said recirculated force air flow solely within said heating compartment.

Claim 17

The improvement according to claim 10, wherein said heater means is a gas combustion element, and said heated air stream transported through said air conduit contains gas combustion products.

Claim 18

A dual air flow fan for circulation of heated air in a forced air heating apparatus having a separate heating compartment and an associated air conduit means having an entry connected thereto for enabling an inflow of heated air, said air flow fan located within said heating compartment at the entry of said air conduit means thereto, said dual air flow fan comprising a shaft collar, a circular center plate rigidly connected to said shaft collar, a first and a second set of impeller blades affixed perpendicularly on opposite edge portions of said center plate, said impeller blades curved with respect to the direction of rotation to enable centrifugal ejection of two air streams, one flowing along the fan axis in a first direction and a second flowing along the fan axis in an opposite direction both inwardly toward said center plate, said first set of impeller blades operable for drawing a heated air stream through the entry of said associated air conduit means and into contact therewith along the fan axis at the entry of the air stream into said separate heating compartment, said second set of impeller blades operable for forcibly recirculating heated air within said heating compartment, said dual air flow fan enabling the simultaneous inflow and outward mixing of two air streams at the peripheral edge thereof.

Claim 19

A dual air flow fan for circulation of heated air in a forced air heating apparatus having a separate heating compartment and an associated air conduit means having an entry connected thereto for enabling an inflow of heated air, said air flow fan located within said heating compartment at the entry of said air conduit means thereto, said dual air flow fan comprising a shaft collar, a circular center plate rigidly connected to said shaft collar, a first and a second set of impeller blades affixed perpendicularly on opposite edge portions of said center plate, said impeller blades curved with respect to the direction of rotation to enable centrifugal ejection of two air streams, one flowing along the fan axis in a first direction and a second flowing along the fan axis in an opposite direction both inwardly toward said center plate, said first set of impeller blades operable for drawing a heated air stream through the entry of said associated air conduit means and into contact therewith along the fan axis at the entry of the air stream into said separate heating compartment, said second set of impeller blades operable for forcibly recirculating heated air within said heating compartment, said dual air flow fan enabling the simultaneous inflow and outward mixing of two air streams at the peripheral edge thereof.

Claim 20

The dual air flow fan according to claim 15, wherein said first and second set of impeller blades are affixed to said center plate on opposite faces thereof about the peripheral edge portion, and wherein a first and a second reinforcement rings are connected to the outside ends of said impeller blade sets.

Claim 21

The dual flow air fan according to claim 15, wherein said collar means contains adjustment and securing means for locking the same on to a motor shaft.

Claim 24

The method according to claim 18, comprising the additional step of: controlling the flow of the heated air stream within the air conduit to enable variable proportions of the mixture of the heated air stream with the recirculated forced air flow within the heating compartment.

Claim 25

The method according to claim 18, wherein said heating step is carried out by drawing the intake ambient air stream across a gas combustion element wherein the gas combustion products are mixed with the heated ambient air stream.

Claim 26

The method according to claim 18, wherein said heating step is carried out by contacting the intake ambient air stream with an electric resistance heating element located within the associated air conduit means.

Claim 27

In a forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto; the improvement comprising heater means disposed within said conduit means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow internally within said heating compartment and for drawing said heated air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit, an air valve means located within said air conduit means to enable variable flow of said heated air stream into said heating compartment, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 28

In a forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto; the improvement comprising heater means disposed within said conduit means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow internally within said heating compartment and for drawing said heated air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit, an air valve means located within said air conduit means to enable variable flow of said heated air stream into said heating compartment, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 29

The improvement according to claim 22, wherein said valve means is positioned within said air conduit means adjacent to said second location.

Claim 30

The improvement according to claim 22 wherein said valve means comprises a baffle pivotally connected within said air conduit means, and wherein said baffle is connected to an adjustment means having an operator means associated therewith.

Claim 31

The improvement according to claim 22, wherein said air conduit means is connected in communication with a flue outlet positioned adjacent to said second location, and wherein said valve means is arranged to selectively and variably close said air conduit means and said flue outlet.

Claim 32

In a forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto; the improvement comprising heater means disposed within said conduit means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow internally within said heating compartment and for drawing said heated air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit, said air flow means comprising a dual air flow fan rotatably supported within a portion of said heating compartment, and said fan having means for drawing two air streams thereinto along opposite axial directions and for impelling both air streams centrifugally away from said fan during rotation thereof, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 33

In a forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto; the improvement comprising heater means disposed within said conduit means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow internally within said heating compartment and for drawing said heated air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit, said air flow means comprising a dual air flow fan rotatably supported within a portion of said heating compartment, and said fan having means for drawing two air streams thereinto along opposite axial directions and for impelling both air streams centrifugally away from said fan during rotation thereof, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 34

The improvement according to claim 26, wherein said dual air flow fan comprises a shaft collar, a circular center plate rigidly connected to said shaft collar, a first and a second set of impeller blades affixed perpendicularly on opposite faces of said center plate, said impeller blades curved with respect to the direction of rotation to enable the centrifugal forced intake of two air streams, one flowing along the fan axis in a first direction and a second air stream flowing along the fan axis in the opposite direction both inwardly toward said center plate.

Claim 35

The improvement according to claim 26, wherein a divider baffle is positioned parallel to and spaced from one wall of said heating compartment, and wherein said dual air flow fan is positioned within the space thus formed.

Claim 36

A forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto, comprising heater means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow substantially internally within said heating compartment and for drawing said heated air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit means, an air valve means located within said air conduit means to enable variable flow of said heated air stream into said heating compartment, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 37

A forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto, comprising heater means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow substantially internally within said heating compartment and for drawing said heated air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit means, an air valve means located within said air conduit means to enable variable flow of said heated air stream into said heating compartment, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 38

The heating apparatus according to claim 29, wherein said air conduit means is connected in communication with a flue outlet positioned adjacent to said second location, and wherein said valve means is arranged to selectively and variably close said air conduit means and said flue outlet.

Claim 39

In a forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto; the improvement comprising heater means disposed within said conduit means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow internally within said heating compartment and for drawing said heated air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit, said air flow means comprising an air fan rotatably supported within said heating compartment, and said air fan having means for drawing two air streams thereinto along opposite axial directions and for centrifugally ejecting and mixing the two air streams within said heating compartment, said two air streams comprising said heated air stream and said recirculated forced air flow, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 40

In a forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto; the improvement comprising heater means disposed within said conduit means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow internally within said heating compartment and for drawing said heated air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit, said air flow means comprising an air fan rotatably supported within said heating compartment, and said air fan having means for drawing two air streams thereinto along opposite axial directions and for centrifugally ejecting and mixing the two air streams within said heating compartment, said two air streams comprising said heated air stream and said recirculated forced air flow, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 41

In a forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto; the improvement comprising heater means disposed within said conduit means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow internally within said heating compartment and for drawing said heating air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit, a divider baffle positioned parallel to and spaced from a wall of said heating compartment, said air flow means comprising an air fan having its plane of rotation disposed parallel to said divider panel and being rotatably supported within said heating compartment, and said air fan having means for drawing two air streams thereinto along opposite axial directions and for centrifugally ejecting and mixing the two air streams within said heating compartment in the space between said divider baffle and said heating compartment wall, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 42

In a forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto; the improvement comprising heater means disposed within said conduit means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow internally within said heating compartment and for drawing said heating air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit, a divider baffle positioned parallel to and spaced from a wall of said heating compartment, said air flow means comprising an air fan having its plane of rotation disposed parallel to said divider panel and being rotatably supported within said heating compartment, and said air fan having means for drawing two air streams thereinto along opposite axial directions and for centrifugally ejecting and mixing the two air streams within said heating compartment in the space between said divider baffle and said heating compartment wall, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 43

In a forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto; the improvement comprising heater means disposed within said conduit means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heater air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow internally within said heating compartment and for drawing said heated air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit, said air conduit means connected to a heat collector duct at a position contiguous to said second location, and said heat collector duct enabling circulation of said heated air stream into said air flow means, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 44

In a forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto; the improvement comprising heater means disposed within said conduit means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heater air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow internally within said heating compartment and for drawing said heated air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit, said air conduit means connected to a heat collector duct at a position contiguous to said second location, and said heat collector duct enabling circulation of said heated air stream into said air flow means, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 45

In a forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto; the improvement comprising heater means disposed within said conduit means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow internally within said heating compartment and for drawing said heated air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit means, said air conduit means comprising flueways located adjacent to a plurality of the outer walls of said heating compartment and a heated air chamber connected to said flueways and extending therefrom into said second location for enabling heat exchange from said flueways and from said heated air chamber into said heating compartment indirectly through the walls thereof, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 46

In a forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto; the improvement comprising heater means disposed within said conduit means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow internally within said heating compartment and for drawing said heated air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit means, said air conduit means comprising flueways located adjacent to a plurality of the outer walls of said heating compartment and a heated air chamber connected to said flueways and extending therefrom into said second location for enabling heat exchange from said flueways and from said heated air chamber into said heating compartment indirectly through the walls thereof, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 47

A forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto, comprising heater means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow substantially internally within said heating compartment and for drawing said heated air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit means, said air flow means comprising an air fan rotatably supported within said heating compartment, and said air fan having means for drawing two air streams thereinto in opposite axial directions and for centrifugally ejecting and mixing the two air streams within said heating compartment, said two air streams comprising said heated air stream and said recirculated forced air flow, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 48

A forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto, comprising heater means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow substantially internally within said heating compartment and for drawing said heated air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit means, said air flow means comprising an air fan rotatably supported within said heating compartment, and said air fan having means for drawing two air streams thereinto in opposite axial directions and for centrifugally ejecting and mixing the two air streams within said heating compartment, said two air streams comprising said heated air stream and said recirculated forced air flow, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 49

A forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto, comprising heater means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow substantially internally within said heating compartment and for drawing said heated air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit means, said air conduit means connected to a heat collector duct at a position contiguous to said second location, and said heat collector duct enabling circulation of said heated air stream into said air flow means, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 50

A forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto, comprising heater means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow substantially internally within said heating compartment and for drawing said heated air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit means, said air conduit means connected to a heat collector duct at a position contiguous to said second location, and said heat collector duct enabling circulation of said heated air stream into said air flow means, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 51

A forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto, comprising heater means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow substantially internally within said heating compartment and for drawing said heated air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit means, said air conduit means comprising flueways located adjacent to a plurality of the outer walls of said heating compartment and a heated air chamber connected to said flueways and extending therefrom into said second location for enabling heat exchange from said flueways and from said heated air chamber into said heating compartment indirectly through the walls thereof, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.

Claim 52

A forced air heating apparatus having a heating compartment and an associated air conduit means connected thereto, comprising heater means for heating an intake ambient air stream drawn into said conduit means at a first location, said conduit means enabling transport of a heated air stream from said heater means into said heating compartment at a second location, air flow means for enabling establishment of a recirculated forced air flow substantially internally within said heating compartment and for drawing said heated air stream into a portion of said heating compartment without entry of said internal forced air flow into said air conduit means, said air conduit means comprising flueways located adjacent to a plurality of the outer walls of said heating compartment and a heated air chamber connected to said flueways and extending therefrom into said second location for enabling heat exchange from said flueways and from said heated air chamber into said heating compartment indirectly through the walls thereof, and vent means formed in said heating compartment to enable the outflow of heated air from said heating compartment.