CA1191059A

CA1191059A - Fireplace insert

Info

Publication number: CA1191059A
Application number: CA000454200A
Authority: CA
Inventors: Ted. Witzel Jr.
Original assignee: Onward Hardware Ltd
Current assignee: Onward Hardware Ltd
Priority date: 1984-05-11
Filing date: 1984-05-11
Publication date: 1985-07-30

Abstract

ABSTRACT OF THE DISCLOSURE

An improved double walled prefabricated fireplace apparatus insertable into a pre-existing masonry fireplace in a building for heating a room. The apparatus is provided with an air manifold within the apparatus adjacent the combustion cham-ber and having opposite mutually spaced walls through one of which an inlet for room air is provided and through the other of which an inlet for fresh outside air is provided. The manifold is further provided with an outlet for enabling air to flow to the air heating chamber between the double walls. A
manually adjustable air flow control means is provided slidable within the manifold between two positions, one blocking the flow of air through the room air inlet and leaving open the fresh air inlet, and the other blocking the flow of air through the fresh air inlet and leaving open the room air inlet. The air flow control means is of a size and construction to permit, when air enters the manifold through either of the inlets, that air to flow to the air outlet to the air heating chamber. The manifold is preferably also provided with an outlet which communicates with the combustion chamber, which outlet manually adjustable independently from the air flow control means for the manifold air inlets, when open permitting flow of air from the manifold to the combustion chamber and when closed preventing such flow. This apparatus permits controlled direction of cold room air or fresh outside air to its air heating chamber and then to the room, and/or controlled direction of such air to the combustion chamber.

Description

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The present inven~ion relates to a prefabricated fireplace apparatus in~ertable into a pre-existing masonry fireplace in a building for heating a room, and more particularly to a zero clearance, double walled fireplace having impro~ed air flow characteristics.

BACKG~OUND OF THE INVENTION

Double or multiple walled fireplaces and ~ireplace inserts, in which air is heated between the walls prior ~o delivery to the room to be heated, are known in the art. For example, Kelley et al U.S. Patent No. 2,297,776 i~sued October 6, 1942; Austin U.S. Patent No. 2,362,526 issued November 14.
1944; Brown U.S. Patent No. 2,642,859 issued June 23, 1953:
Fogel et al U.S. Patent No. 2,703,566 issued March 8, 1955:
Andrews U.S. Patent No. 3,762,391 issued October 2, 1973;
Nel~on U.S. Patent No. 3,965,886 issued June 29, 1976; Nelson U.S. Patent No. 3,995,611 issued December 7, 1976; Buckner U.S.
Patent No. 4,185,610 issued Januaey 29, 1980; Martenson U.S.
Patent No. 4,015,581 issued April 5, 1977; Shaw U.S. Patent No.
4,059,090 issued November 22, 1977; Jensen U.S. Patent No.
4,074,679 i~sued February 21, 1978; Shaw U.S. Patent No.
4,169,458 i~ued October 2, 1979 (Canadian Patent No. 1,061,207 i6sued Augu~t 28, 1979); Buckner U.S. Patent No. 4,185,610 issued January 29, 1980; Well~ U.S. Patent No. 4,254,756 i~sued March 10~ 1981; Hempel U.S. Patent Ns. 4,280,473 issued July 28, 1981; Brown Canadian Patent No. 500,427 i~sued March 2, 1954; Petrescue Canadian Patent No. 1,09~,902 issued February 3, 1981 Buckner et al Canadian Paten~ No. 1,139,624 issued January 18, 1983 all describe various constructions of such double or multiple walled fireplaces. In most of these constructions, convection or fan assisted circula~ion of room or outside air through the double walls is provided, the air bein~ heated while between the double walls as it passes over the surface of the combustion chamber wall. In certain of these constructions, such as Shaw U.S. Pa~ent No. 4,059,0~0, Jensen U.S. Paten~ No. 4,074,679, Shaw U.S. Patent No.
4,169,458 and ~ells U.S. Patent No. 4,~54,756, as well as Petrescue Canadian Patent No. 1,094,9~2, there is limited control of the flow of alternatively fresh air from outxide, or room air, through the double walls and/or the combustion chamber.
Of general background interest are additionally Brooks U.S. Patent No. 2,359,197 issued September 26, 1944; Bauer U.S.
Patent No. 3,190,282 issued June 22, 1965: and Kamstra et al U.S. Patent No. 4,143,638 issued March 13, 1979.
It is an objec~ of the present invention to provide an improved and novel construction for controlling the flow of room air and outside air through the air heating chamber between the walls of a double wall fireplace. It is a further object of the present invention to provide a cons~ruction for such a fireplace which will, as required, divert flow of some of that air to the combu~ion chamber.

SUM~ARY OF THE INVENTION

According to ~he pre~ent invention there i6 provided a prefabricated fireplace apparatu~ insertable as an in~ert into a pre-exi~ting masonry fireplace, or usable as a fireplace or ma60nary heat form~ in a building for hea~ing a room. The apparatus comprise~ a combustion chamber defined and enclosed by heat conducting side wall~, a ba~k wall, a floor and a top.
The top i8 provided with an opening to communicate with a flue to exhaus~ product~ of combustion in the chamber to the flue.
The combu~tion chamber ha~ a front access opening and doors mounted thereon to cover the opening so that when the door~ are clo~ed, air will not be admitted to the chamber through the opening. An outer wall circum~cribes the combu~tion chamber, walls, floor and top to define ~herebetween an air heating chamber. The air heating chamber i~ provided with interior walls extending acros~ the space between the air heating chamber wall~ and the outer wall to define a continuou6 air pas6ageway through the air heating chamber over the major portion of the area o~ the walls, floor and top of the combustion chamber from the floor of the combustion chamber to it~ top. An outlet at the ~op of the air heating chamber is provided to permit passage of heated air from the air heating chamber to the room. The invention further provide~ an inlet 5~

at ~he bottom of the air heating chamber to permit entry of unheated air from the air heating chamber. The appara~u6 has an air manifold wi~hin the apparatus adjacent the combustion chamber. The manifold has opposite, mutually spaced walls through one of which an inlet for room air is provided and through the other of which an inlet for fresh, outside air is provided. The manifold is further provided with an ou~let communicating with the air heating chamber to enable air from the manifold to pass into the air heating chamber a~ its bo~tom. A manually adjustable air flow control means is slidable between two positions, one closing ~he flow of air through the room air inlet and leaving open the fresh air inlet, while the other closing the flow of air through the fre~h air inlet and leaving open the room air inlet. Both inlets are left open when the air flow control means is in an intermediate posi~ion. The air flow control means is of a æize and construction to permit, when air en~ers the manifold through either of ~he inlets, that air to flow to the air outlet to the air heating chamber.
In a preferred embodiment the manifold i8 further provided with an outlet which communicate6 with the combustion chamber. The outlet is provided with air flow control means manually adjustable independently from the air flow control means for the manifold air inlets. The air flow control means is adjustable between open position, which permits flow of air from the manifold to the combustion chamber, and clo~ed position, which prevents 6uch flow.
The fireplace or fireplace insert according to the present invention provides accurate control of fre~h and/or room air through the heating chamber between the walls thereof in an efficient, effective manner. While the apparatus ha~
simple construction, it permits the uer to ea~ily manually control the makeup of the heated air supplied to the room by sliding the air flow control means of the manifold into the appropriate po~itioning for fresh outside air or cold room air or a combination ~hereof to be heated between the walls of the apparatus. A~ well, in the preferred embodiment thereof, in which an air outlet i~ provided from the manifold, communicating with the combustion chamber, multiple options of air flow de~tination and room/out6ide air proportions directed to such destinations are effectively provided.

BRI~F D~SCRIPTION OF THE DRAWINGS

These and other objects and advantages of the present invention will become apparent upon reading the following detailed description and upon referring to the drawings in which:

FIGURE 1 is an exploded perspective view, from the front, of a fireplace in ert according to the present invention;
YIGURE 2 is a per6pective view of the device according to FIGURE 1, from th0 rear:

FIGURES 3 and ~ are respectively schema~ic top and side views illustrating air flow through the double walls of the device with the air flow control means being set for supply of fresh air;
FIGURES 5 and 6 respectiYely are schematic top and side views of the device illustrating air flow through the double walls of the device with the air flow control means being set for supply of inside air;
FIGURES 7 and 8 are respectively side section partial views of the manifold according to the invention illustra~ing in detail the air control mechanism of the embodimen~ of FIGURES 1 to 6; and FIGURE g iB a side section partial view in detail of an alternative, preferred embodiment of air control mechanism in accordance with the invention.
While the invention will be described in conjunction with an example embodiment, and in particular a fireplace insert, it will be understood that it is not intended to limit the invention to such embodiment. On the contrary, it is in~ended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE INV~NTION

In the following description, similar ~eatures in the os~

drawings have been given similar reference numerals.
Turning to FIGURE 1 there is shown a double walled fireplace insert 2 according to the present invention, the insert being insertable into a pre-existing masonry fireplace in a building for heating a room.
The apparatus comprises a combustion chamber 4 defined and enclosed by heat conducting side walls 6, back wall 8 (FIGURE 2), a floor 10 and a top 12. The comhustion chamber has a front access opening as illustrated, with doors 14 mounted on the apparatus ~o cover the opening so ~ha~ when the doors are closed air will not be admitted to the chamber through the opening. The top is provided with an opening 16 to communicate with a flue (not shown) through which products of combustion in the combustion chamber are passed ~o the flue.
The apparatus is double walled, in that an outer wall 18 circumscribes side walls 6, back wall 8, floor 10 and top 12 of the combustion chaber 4, to define therebetween an air hea~ing chamber 20. This chamber is provided with interior walls or vanes 22 which define a continuous air pas~ageway ~hrough air heating chamber 20 over a major portion of the area of the walls 6 and 8, and floor 10 and top 12 of combu~tion chamber 4. This passageway extends from below the floor of the combustion chamber upwardly, in circuitous fashion as illustrated, to above its top. The vertically oriented interior walls 23, shown at the rear of the apparatus in FIGURE

2, serve to divide air heating chamber 20 into two halves, with 5~

air flow upwardly progressing as illustrated therein, independently through each half. At the top of air heatin~
chamber 22 is a vent 24 which serves as an ou~let to enable passage of air heated within chamber 20, to the room. In the bottom front portion of the fireplace insert apparatus 2, at the front of combustion chamber 4 is manifold 26. This is a chamber formed in part by opposite walls 28 and 30, wall 30 being perforated to provide inlets 3Z to permit passage of room air into the manifold 26. Wall 28 is provided with an inlet 34. Duc~ 36 communica~es with inlet 34, at one end, and with a supply of fresh air, for example, from outside the building in which the fireplace insert 2 is located, at the other, to feed fresh air into manifold 26. At either side of this wall 28 are provided a pair of outlets 38 communicating with opposite halves of air heating chamber 20. Appropria~ely controlled fans 40 are positioned in or near outlets 38 to force air from ~he manifold 26 into the corresponding side of air heating chamber 20.

To control the flow of air into manifold 26, there is provided an air flow control mechani~m 42 which consists of panels 44, as illustrated, secured to rod 46 for slidable movement within manifold 26. As can be seen from the schematic views of FIGURES 3 and 4 and the section view of FIGURE 7, when the air flow control mechanism 42 is in its ou~er position, with the outer panel 44 adjacent wall 30, inlets 32 are sealed off preventing room air from entering manifold Z6. In thi~

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po~itionhowever, fresh air inlet 34 i~ open~othat fre~hair may be drawn through duct 36 into manifold 26. As can be seen in the top and side views respectively shown in schematic FIGURES 5 and 6 and the section ~iew of FIGURE ~, when air flow control mechani6m 42 is in the illustrated position with the narrower vane 44 in against wall 28 sealing inlet 34 again~t the flow of fresh outsida air into manifold 26, the wider of the vane6 44 is ~paced from wall 30 enabling room air to enter manifold 26. Of course, ~hen the vanes or panel6 44 are in an intermediate position, fre6h air from duct 36 as well as room air through inlet 32 may enter manifold 26.
It will be appreciated that cold room air or frefih outside air, entering the apparatu& as it doe6 from a low po~ition, is forced by fan 40 into air heating chamber 20 beneath floor 10 where it proceed to pa~s, as illustrated in the FIGURES, a~d particularly FIGURES 1 and 2, in circuitous, ri~ing fa~hion, acro6s side walls 6 and back wall 8 until it arrives at top wall 12. During combu6tion in combuætion chamber 4, thi~ air i6 gradually heated as it passes in ri6ing fa~hion through air heating chamber 20 until, at ~he to~

thereof, it i~ pas6ed into the room through outlet~ 24 a6 heated air.
A~ can be 6een in FIGURE 7, it i8 preferred to have one or more outlet6 50 may be provided in manifold 26, communicating directly therewith or, a6 illustrated, communicating with intermediate chamber 54, which in turn s~

communicate~ through combustion chamber inlets 52 with the combu~tion chamber itself. An appropriate independently adjusta~le mechanism 56 tFIGURE 1) is provided to enable control of the flow of air from manifold 26 to combustion chamber ~ through this intermediate chamber. This adjustmen~
means enable~ complete closing of f the f low of air ~rom manifold 26 to combustion chamber 4, or, in open position, an unobstructed flow of air from the manifold to the combus~ion chamber. This feature, in combination with the air flow control mechani~m 42 and fans 40, enables control of the source and rate of flow of air entering manifold 26, as well as control of the air in the manifold to the combustion chamber and to the air heating chamber 20.
Turning to FIGURE 9 there i~ illustrated in section an alternative, preferred air control mechanism 60 according to the pre~ent invention. Rod 46 again ~lides within manifold 26, between one position, as shown in bold line, and another, as ~hown in phantom. In the first (bold line) position, panel 4 is adjacent wall 30 to close inlets 32 and thereby prevent room air from entering manifold 26. Rod 46 extends towards the rear of duct 36 near the fresh air inlet where, in ~his position, its upwardly extending end 62, acting as a valve control means, holds open flap 64 which, when closed as illustrated in phantom~ serves as an air flow shu~ off valve to seal off duct 36 and prevent cold, outsid0 air from entering. As this end 62 is moved from i~s other po~ition, shown in phantom, to this ~L~9~ ;i;9 first position, it bears against the flap 64 to pivot the flap at pivot point 66 from closed ~o open position. To clo~e flap 64, rod 46 is moved to the left into the posi~ion illus~rated in phantom. As it approache~ this position, bearing surface 68 secured to the end of rod 46 bears aga;nst the forward or bottom part of flap 64 to force it downwardly. A~ well, this bearing surface 68 holds flap 6~ in closed position when rod 46 has reached the limit of its movement to the left (phantom~.
At the manifold end, when rod 46 has been moved to ~he left, again as shown in phantom~ panel 44 has been moved away from wall 30 freeing room air to enter through inlets 32 into manifold 26. Air control mechanism 60 thus differs from mechanism 4Z, illus~rated in the preceding drawings, in tha~
the control of fresh air from duct 36 into manifold 26 is controlled, rather than by panel 44 closing off and opening duct 36 near the manifQld, by means of end 62 of rod 46 controlling the opening and closing of flap 64. The advantage of mechanism 60 i8 that fresh air is shut off closer to the source, ehereby redusing cold air transfer when the apparatus is not in operation.
~s previou&ly indicated, the apparatus of the present invention has application not only as a fireplace insert, but also as a factory built zero clearance fireplace or a masonary fir~place heat form.
Thus it is apparent that there has been provided in accordance with the invention an improved double walled 5~3 pre-fabricated fireplace apparatus that fully satisfies the objects, aims and advan~ages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparant to those skilled in the art in light of ~he foregoing de~cription. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within tha spirit and broad scope of the appended claims.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOW:

1. In a prefabricated fireplace apparatus for heating a room, comprising a combustion chamber defined and enclosed by heat conducting side walls, a back wall, a floor and a top, the top having an opening to communicate with a flue to exhaust products of combustion in the chamber, the combustion chamber having a front access opening and doors mounted thereon to cover the opening so that when the doors are closed air will not be admitted to the chamber through the opening; an outer wall circumscribing the combustion chamber walls, floor and top to define therebetween an air heating chamber; the air heating chamber being provided with interior walls extending across the space between the air heating chamber walls and the outer wall to define a continuous air passageway through the air heating chamber over the major portion of the area of the walls, floor and top of the combustion chamber from the floor of the combustion chamber to its top; an outlet at the top of the air heating chamber to permit passage of heated air from the air heating chamber to the room: and an inlet at the bottom of the air heating chamber to permit entry of unheated air to the air heating chamber: the improvement comprising an air manifold within the apparatus adjacent the combustion chamber and having opposite, mutually spaced walls through one of which an inlet for room air is provided and through the other of which an inlet for outside air is provided, the manifold being further provided with an outlet communicating with the air heating chamber to enable air from the manifold to pass into the air heating chamber at its bottom, manually adjustable air flow control means being slidable between two positions, one closing the flow of air through the room air inlet and leaving open the fresh air inlet, and the other closing the flow of air through the fresh air inlet and leaving open the room air inlet, the flow of air through these inlets being permitted when the air flow control means is in an intermediate position, the air flow control means being of a size and construction to permit, when air enters the manifold through either of the inlets, that air to flow to the air outlet to the air heating chamber.

2. An apparatus according to claim 1 wherein the manifold is further provided with an outlet communicating with the combustion chamber, the outlet being provided with air flow control means manually adjustable independently from the air flow control means for the manifold air inlets, between open position permitting flow of air from the manifold to the combustion chamber and closed position preventing such flow.

3. An apparatus according to claim 1 or 2 wherein the air flow control means for the manifold comprises a panel structure slidable between one position closing the flow of air through the room air inlet to air flow into the manifold while at the same time opening the fresh air inlet to air flow into the manifold, and the other position closing the fresh air inlet to the flow of air while at the same time opening the room air inlet to the flow of air.

4. An apparatus according to claim 2 wherein a fan means is provided at or near the outlet communicating with the air heating chamber to draw air from the manifold into the air heating chamber.

5. An apparatus according to claim 4 wherein an outlet communicating with the air heating chamber is provided at each side of the manifold, a fan being provided at or near each said outlet to direct the flow of air from the manifold into the air heating chamber through each outlet, interior walls of the air heating chamber dividing the air heating chamber into two parts, one on each side of the apparatus, having similar continuous air passageways.

6. An apparatus according to claim 2 wherein the air manifold is positioned within the apparatus, in front of the combustion chamber.

7. An apparatus according to claim 6 wherein an outside air passageway is provided within the apparatus, the passageway at one end communicating with the outside air inlet of the manifold, and to communicate at its other end with a source of fresh air outside of the room.

8. An apparatus according to claim 7 wherein the passageway for the outside air is a duct for outside air passing through the air heating chamber under the floor of the combustion chamber.

9. An apparatus according to claim 7 wherein the outside air passageway is provided with an air flow shut off valve near its end communicating with the source of fresh air outside the room, and wherein a panel structure is linked to a shut off valve control means for simultaneous movement, the panel structure and valve control means being simultaneously movable between one position in which the panel structure closes the flow of air through the room air inlet while the shut off valve control means holds the air shut off valve open, and another position in which the panel structure permits the flow of air through the room air inlet while the shut off valve control means holds the air shut off valve closed to prevent flow of air through the fresh air duct.