EP0006897B1 - Forced air heating unit - Google Patents

Forced air heating unit Download PDF

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Publication number
EP0006897B1
EP0006897B1 EP78900095A EP78900095A EP0006897B1 EP 0006897 B1 EP0006897 B1 EP 0006897B1 EP 78900095 A EP78900095 A EP 78900095A EP 78900095 A EP78900095 A EP 78900095A EP 0006897 B1 EP0006897 B1 EP 0006897B1
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EP
European Patent Office
Prior art keywords
heating unit
air
forced air
unit according
chamber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP78900095A
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German (de)
English (en)
French (fr)
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EP0006897A1 (en
Inventor
Carrol E. Buckner
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Individual
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Individual
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Filing date
Publication date
Priority claimed from US05/828,206 external-priority patent/US4185610A/en
Priority claimed from US05/828,107 external-priority patent/US4147153A/en
Priority claimed from US05/828,207 external-priority patent/US4230093A/en
Priority claimed from US05/828,208 external-priority patent/US4207861A/en
Application filed by Individual filed Critical Individual
Publication of EP0006897A1 publication Critical patent/EP0006897A1/en
Application granted granted Critical
Publication of EP0006897B1 publication Critical patent/EP0006897B1/en
Expired legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24B—DOMESTIC STOVES OR RANGES FOR SOLID FUELS; IMPLEMENTS FOR USE IN CONNECTION WITH STOVES OR RANGES
    • F24B1/00—Stoves or ranges
    • F24B1/18—Stoves with open fires, e.g. fireplaces
    • F24B1/185—Stoves with open fires, e.g. fireplaces with air-handling means, heat exchange means, or additional provisions for convection heating ; Controlling combustion
    • F24B1/188—Stoves with open fires, e.g. fireplaces with air-handling means, heat exchange means, or additional provisions for convection heating ; Controlling combustion characterised by use of heat exchange means , e.g. using a particular heat exchange medium, e.g. oil, gas  
    • F24B1/1885—Stoves with open fires, e.g. fireplaces with air-handling means, heat exchange means, or additional provisions for convection heating ; Controlling combustion characterised by use of heat exchange means , e.g. using a particular heat exchange medium, e.g. oil, gas   the heat exchange medium being air only
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24B—DOMESTIC STOVES OR RANGES FOR SOLID FUELS; IMPLEMENTS FOR USE IN CONNECTION WITH STOVES OR RANGES
    • F24B7/00—Stoves, ranges or flue-gas ducts, with additional provisions for convection heating 
    • F24B7/02—Stoves, ranges or flue-gas ducts, with additional provisions for convection heating  with external air ducts
    • F24B7/025—Stoves, ranges or flue-gas ducts, with additional provisions for convection heating  with external air ducts with forced circulation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24C—DOMESTIC STOVES OR RANGES ; DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION
    • F24C1/00—Stoves or ranges in which the fuel or energy supply is not restricted to solid fuel or to a type covered by a single one of the following groups F24C3/00 - F24C9/00; Stoves or ranges in which the type of fuel or energy supply is not specified
    • F24C1/14—Radiation heating stoves and ranges, with additional provision for convection heating

Definitions

  • the invention relates to a forced air heating unit comprising a chamber for holding a source of heat; and opening in the front wall of said chamber for providing access; a flue port in said chamber for removing fumes; a forced air channel surrounding a back wall, side walls and a bottom wall of said chamber, said air channel having a back and a bottom portion and two side portions including substantially the entire back wall, the two side walls and the bottom wall of said chamber; a baffle system interior said back, two side and bottom portions of said air channel for directing forced air over substantially the entire back, side and bottom walls of said chamber; and a blower for forcibly introducing air through an inlet into said back portion of said air channel and over substantially the entire surface of said back wall of said chamber.
  • This heating unit is a free standing heater.
  • the US-A-1 490 135 and 3 094 980 make use of the flue heat in a stove and fireplace respectively to heat a second column of forced air which is introduced into the room in which the stove or fireplace is located.
  • Prior art space heaters have also been used or converted to fireplaces to provide a pleasing and second mode of heating.
  • An example of this is shown in the US-A-1 944 626.
  • a forced air heating unit of the type mentioned at the beginning of this description is known from the CH-A-585 878.
  • this heating unit there are provided several separate boxes with an air channel, and each box is separately connected to a blower and has a separate exit.
  • this heating unit has a complicated and unpractical structure and it's production is time consuming.
  • Heating units of the prior art have either used the natural upward flow of heating air by drawing cold air in at the bottom of a heating unit to exit heated from the top.
  • forced air systems have been used to augment the natural upward flow by moving more air past the exterior of the fire box. Although the forced air systems have increased the capture of available heat, the prior art devices have not optimized the heat transfer from the burning material in the fire box to the air circulated about the exterior of the fire box.
  • a forces air heating unit of the above mentioned type which is characterized by vertically oriented vents in the front wall of said side portions of said air channel, said vertically oriented vents being positioned adjacent each side of said access opening; and a horizontally oriented vent in the front wall of said bottom portion of said air channel; the back portion of said forced air channel communicates with said two side and bottom portions of said forced air channel, and said bottom portion communicates with said two side portions; said baffle system directing forced air from said back portion to said two side portions and to said bottom portion and from said bottom portion to said side portions, said forced air emitting from said heating unit through said horizontally and vertically oriented vents.
  • the invention provides a heating unit which is simple in it's construction but very effective in it's operation.
  • FIG. 1 which illustrates a preferred embodiment of the forced air heating unit 10, shows a housing having top, front, bottom, two sides, and back walls 12, 14, 16, 18, 20, and 22 respectively.
  • Top wall 12 which is a single walled portion of the housing, extends past the front, back, and side walls, and includes a collar 24 surrounding an orifice or flue port 26.
  • a flue (not shown) to remove the fumes from a source of heat or combustible material is connected to flue port 26 through the collar 24.
  • the heating unit 10 is supported by four legs 28 providing space between the floor and the bottom wall 16.
  • Front wall 14 has a pair of elongated vertical vents 30 and 32, each covered by a screen 31 which is secured to the front wall 14 by a bracket or lip 33.
  • An access opening 34 in front wall 14 is covered by a closure including a pair of doors 36 and 38.
  • the vertical vents 30, 32 extend a portion of the height of the opening 34 and are spaced from the bottom and top of the opening 34.
  • the door 38 has a strip 40 which overlaps door 36 and holds door 36 closed and covers the space between the adjacent edges of the doors.
  • Handle 42 on door 38 is connected to a latch 43 which engages the top interior portion above the opening 34 so as to lock the doors closed. The handle 42 rotates down to close, thus providing a gravity lock of the doors.
  • a pair of posts 41 and 45 on the interior of the doors 38 provides tops for latch 43. Post 41 may be mounted to the interior of front wall 14 if desired.
  • a pair of draft valves 44 and 46 are also provided on doors 36 and 38.
  • the slides 50 and 52 of draft valves 44 and 46 slide within guide members 54 and 56 to adjust the size of a plurality of elongated draft openings 48 in doors 36 and 38.
  • the slides 50 and 52 adjustably vary the draft valves 44 and 46 to regulate the amount of air or draft introduced into the chamber and are locked in the adjusted position by threaded members 51 and 53 e.g. knobs respectively engaging the face of doors 36 and 38 respectively as illustrated in Figure 2. For a wood burning source of combustible material, this would vary the rate of burning as well as the temperature.
  • These valves are used in conjunction with an adjustable flue port 26.
  • the draft valves 44, 46 are shown in the doors 36, 38, they may also be used on a front wall of the fire box below the doors if such a surface is made available.
  • the doors 36 and 38 are mounted to the housing by upper hinges 58 and 60 and lower hinges 62 and 64, respectively.
  • the doors and hinges are dimensional so that the bottom of doors 36, 38 rest flush against the front wall 14 and the top of doors 36, 38 are spaced from the front wall 14 at the top edge of opening 34 as illustrated in Figures 3 and 4. The importance of this separation will be discussed below in reference to Figures 3 and 8.
  • a hood 66 and a platform 68 are mounted to the front wall 14 .
  • the hood 66 traps any smoke pulled from the fire box at the upper edge of access opening 34 when the doors 36, 38 are rapidly opened and directs it back into the fire box as illustrated in Figure 4.
  • the hood 66 includes a center portion 65 and a pair of side portions 67 for capturing the escaping gases and directing them back into the opening 34.
  • the platform 68 provides a surface for supporting a fireplace screen when the heating unit 10 is used as a fireplace without doors.
  • inlet 76 and blower 71 may be located any place which provides them access to the forced air channel.
  • inlet 76 and blower 71 could be on either side wall 18, 20 or on top 12 over the back or either side portion of the forced air channel.
  • they may be on the front wall 14 with access to the two side or bottom portion of the forced air channel.
  • the air channel of the present device includes the exterior sides, back, and bottom walls 18, 20, 22, and 16 respectively and interior sides, back, and bottom walls 78, 80, 82, and 84 respectively.
  • the sides and back walls of the housing and the sides and back interior walls form a generally U-shaped forced air channel with the side walls at an angle other than ninety degrees relative to the back where the forced air from opening 76 is transmitted' towards front vents 30 and 32.
  • the separation of the side walls 18 and 78 and 20 and 80 or the width of the side forced air channel tapers or diminishes from the rear to the front.
  • the increased width of the back air channel and the rear of the side air channel allows blower 71 to pump more air per minute into the forced air channel.
  • the forced air from opening 76 is also provided from the rear forced air channel through an opening 86 into the forced air channel formed by the housing and the interior bottom walls to exit through horizontal vent 88, illustrated in Figure 6, in the front portion of the bottom air channel.
  • the air in the bottom forced air channel also exits into the side forced air channels.
  • baffles within the forced air channels are baffles to create specific air patterns which diverge from the forced air source at opening 76 and converge on the respective vents in the front of the air channels.
  • the rear wall portions of the baffle system includes a horizontal baffle 90 substantially bisecting opening 76 from the forced air system.
  • two upper baffles 92 and 94 and two lower baffles 96 and 98 which diverge from the forced air opening 76.
  • Baffles 94 and 96 direct divergent air flow towards one side wall channel while baffle 92 and 96 in combination direct diverging air flow toward the other side wall channel.
  • Upper baffles 92 and 94 direct an upward flow towards the respective side wall channel portions and baffles 96 and 98 provide a flow towards opening 86 into the bottom forced air channel as well as providing a small flow to the respective side forced air channel.
  • baffles 102, 104, 106, and 108 Located in each side forced air channel are baffles 102, 104, 106, and 108, and in bottom forced air channel are baffles 112, 114, 116, 118, 120, 122, and 124.
  • the inner ends of bottom baffles 114, 116, 118, and 120, 122, 124 are offset relative to the center bottom baffle 112 so as to divert varying portions of the air flowing towards bottom vent 88 and to direct it towards side wall baffles 102 and 104.
  • baffles 114, 116, 118, 120, 122 and 124 are such that the air between baffles 114-116 and 120-122 is directed toward the lower face of side baffle 102; and the air between baffles 116 and 122 and the rear of the bottom is bisected by baffles 118 and 124 respectively and directed between baffles 102 and 104. Since the source of the temperature modification is generally placed adjacent interior bottom wall 84, the communication of the air flow from the bottom forced air channel to the side forced air channel increases the efficiency of the temperature transfer.
  • baffles assures that the air traverses substantially all the interior walls and thereby allows a greater heat transfer from the interior or fire box to the forced air without sacrificing the head of the air emitting from the vents 30, 32, and 88 since it cools a greater surface area.
  • Prior art devices generally substantially increase the length of the air path while sacrificing the head of the air at the vents and thereby reducing the heat transferability of the interior walls.
  • the baffle system in the walls produce streams of air which are not troubled by eddy currents, dead air pockets, localized hot spots, and other disadvantageous freatures of the prior art systems.
  • Blower 71 is chosen to have sufficient capacity to force air in the air channel at a sufficiently high velocity to lower the temperature of the interior walls and thereby increase the transfer of heat from the fire box to the interior walls to be removed by the forced air. Thus less heat from the fire box is available for transmission up the flue.
  • a blower having a capability of pumping 3,96 m 3 of air per minute is sufficient.
  • a blower pushing 13,12 m 3 per minute is adequate for a unit 68,59 cm high by 101,60 cm wide by 50,80 cm deep.
  • thermodynamics of the heating unit 10 will substantiate the efficiency or maximization of heat transfer or capture of the unit.
  • the formula for representing the heat . transferred from the heated air in the fire box through the interior walls to the forced air in the forced air channel is:
  • the overall heat transfer coefficient Q is a function of the resistance to the flow of heat of (a) the air in the fire box, (b) the firebox wall, (c) the forced air, and (d) the fouling on each side of the firebox wall.
  • the blower 71 in combination with thermostat control 73 maintain the back, two sides, and bottom wall of the fire box in a range of temperature to maximize the heat transfer through the fire box walls while heating the forced air to a sufficiently warm temperature.
  • thermostat 73 could turn blower 71 on once the temperature in the forced air channel is 46,11 °C and turn the blower 71 off when the forced air temperature is reduced below 37,78°C.
  • the thermostat control 73 could vary the speed of blower 71.
  • the preferred range is 35°C to 65,56°C.
  • heating unit 10 By forcing air over substantially all the back, two sides, and bottom fire box walls, heating unit 10 substantially maximizes the effective surface area A at the greatest temperature differential. This area could be further increased by extending the forced air channel over the top wall 12 of the fire box, if desired, but is not preferred.
  • the heat flow within the fire box is also based on the above equation except that the temperature differential AT should be expressed as a temperature gradient or the change in temperature per unit distance.
  • the amount of heat flow is illustrated in Figure 7 by the length of the vector. Since the bottom forced air channel, being the closest cool surface, has the largest gradient or vector D.
  • the front wall being a non-forced air wall, can only cool by heat dissipation. Thus, the temperature gradient toward the front wall, and consequently the heat flow F, is substantially less than those toward the forced air cooled walls.
  • the top wall is not forced air cool and thus has a small heat flow U. Since gas ignition occurs adjacent the top (as will be discussed for Figure 8), the surface of the top wall is even hotter than the front wall and consequently vector U is smaller than vector F. With a limited air flow up the flue, there is very little heat left to exit the flue port as illustrated by vector 0.
  • thermostatically controlled blower maximizes the surface area of maximum temperature differential to effectively capture or draw eighty percent of the heat available from the fire box into the forced air channel. This is comparable to the heat efficiency of a residential furnace.
  • a device is provided to reduce the build-up of deposits on the fire box wall by igniting the rising gases from a wood fire. This ignition also increases the amount of heat available from the wood.
  • This device includes a gas baffle 126 extending down from the top wall 12 adjacent the flue port 26 as illustrated in Figure 8.
  • the slide drafts 44, 46 on the doors allow a controlled, even flow of air across the fire.
  • the unburned gases rise from the fire up and slightly forward, to the top wall 12.
  • they circulate to the rear of the fire box, toward the flue port 26 and contact baffle 126 which deflects the gases downward.
  • baffle 126 which deflects the gases downward.
  • a rolling cushion of smoke (partially burned gases) will build up under the top wall 12. This cushion acts to hold the resins and gases in the fire to burn longer and holds the gases in the fire box until they are recirculated and burned as completely as possible.
  • the space between the two doors 36 and 38 and the mounting of the doors 36 and 38 so that the top edges of the doors are spaced from the top edge of the access opening 34 permits the secondary air flow into the area adjacent the top wall 12 aiding the ignition of gas collected there.
  • the air space is provided by the tops of the doors being offset from the plane of the front wall 14, this space may also be provided by making the top of the doors shorter than the access opening 34.
  • the forced air heating unit 10, as illustrated in Figure 9 may be used as a free standing fireplace.
  • the doors 36 and 38 are removed and a screen 128 Is provided underneath hood 66 and resting on platform 68.
  • the screen may be a typical fireplace screen to prevent sparks and ashes from emitting from the fireplace and causing a fire hazard within the room.
  • Adjacent to and surrounding openings 34 is a rim 130.
  • Four pins 132 of hinges 58, 60, 62, 64 are provided on the rim 130 as well as four openings 134 in the rim.
  • the matching hinge element of the closures 36, 38 move in and out of the openings 134 in the rim 130.
  • the rim 130 provides a guide and retainer for the screen 128 which fits within the rim 130. Though not shown, the rim 130 extends above and across the top of the opening 34. A pair of andirons 136 are provided in the interior chamber to support the source of temperature modification. It should be noted that grating or other supports may be used instead of andirons 136.
  • the forced air heating device 10 includes a system of deflectors at the vertical oriented vents 30 and 32 to define a unique air flow pattern in front of the fire box opening 34.
  • the heated forced air dashed lines
  • the heated forced air are directed towards each other to converge in front of the fire box opening 34 a preselected distance.
  • This creates an air pocket 140 in front of the fire box opening 34 in combination with the heated forced air exiting the bottom horizontal vent 88 which is illustrated in Figure 10 but deleted from the pattern of Figure 11 for sake of clarity.
  • the pneumatically created barrier for air pocket 140 limits the amount of air from which the fire can draw and thereby reduces the rate of combustion in the fire box.
  • the outward moving heated air reduces cold air drafts toward the access opening 34.
  • the U-shaped pneumatic barrier is a critical substitute for the open or removed doors 36 and 38.
  • the major source of cool air (solid lines) for the pocket 140 in front of the fire box is the triangular aerodynamic openings 142 between the bottom of the vertical vents 30, 32 and the forced air from the horizontal vent 88.
  • the forced hot air from vertical vents 30, 32 also is directed downward, as well as inward to converge, allowing air to flow into the pocket 140 over the top edge of the freed hot air V.
  • the two vertical air streams converge preferably at about 1,524 m In front of the access opening. To converge much closer would draw smoke from the fire box.
  • Blower 71 on the back wall draws air as indicated by the solid lines around the sides of the unit and over the top.
  • the cool or return air flow is outside the air pattern defined by vents 30, 32 and 88 which pneumatically block cool air flow into the fire box.
  • a preferred device for directing the air exiting the vertical vents 30 and 32 to converge is illustrated in the enlarged view of Figure 12.
  • the side walls 18 and 78 are mounted to the front wall 14 at an opening 144 in the front wall. While side wall 78 lies at the edge of the opening 144, side wall 18 is slightly offset. This offset may be eliminated.
  • the side walls 18, 78 form an angle less than ninety degrees with the front wall 14 to aid the deflection of forced air inward.
  • the bracket or lip 33 is generally L-shaped having a portion extending across the opening 144.
  • the bracket or lip 33 forms an air pocket along the outside edge of opening 144 which is a pneumatically produced deflection surface 146.
  • the pneumatic deflection surface exterior the forced air channel is sufficient to direct the heated forced air to converge in front of the fire box access opening 34.
  • FIGs 13 and 14 Two alternative embodiments are illustrated in Figures 13 and 14.
  • an internal pneumatic deflector could be used.
  • the exterior side wall 18 is substantially offset from the edge of opening 144 providing a pneumatically produced deflection surface 148.
  • Figure 14 shows a vertical deflection plate or baffle 150 mounted between the exterior side wall 18 and front wall 14.
  • the side forced air channels form a ninety degree angle with the front wall, although the non- ninety degree angle alignment is preferred.
  • Each embodiment may also include the pneumatical deflection surface 136 produced by the L-shaped bracket or lip 33.
  • the downward air flow is produced by the mesh 31 secured to the L-shaped bracket or lip 33 across vent opening 144.
  • the mesh 31 includes a plurality of horizontal surfaces 152, at the intersection of adjacent openings, inclined downward from the back to the front to deflect air downward without retarding the air flow through the mesh 31. If the downward deflection is not required, mesh 31 may be mounted with the surfaces 152 vertical to provide the converging air flow. Basically, the mesh 31 may be mounted with any desired orientation of the surfaces 152 to produce a correspondingly directed air flow (e.g. 45° angle relative to the horizontal).
  • the forced hot air patterns convergJng just off the floor in front of the unit push the cool air across the floor.
  • the forced air strikes a wall, it is deflected to either side and up.
  • the blower 71 is pulling return air to either side and down over the top of the unit.
  • This push-pull action results in a high volume of air movement as the blower system forces hot air across the floor and returns coot air around either side and overhead. This is exactly the opposite of normal air movement within a house and results in a more uniform temperature from floor to celling.
  • the air patterns are illustrated in Figure 17 where the solid lines represent cool air and the dashed lines represent warm air.
  • thermostat 154 may be provided in the room to be heated. Whereas thermostat control 73 preferably turns the blower on and off as a function of the air temperature in the forced air channel, thermostat 154 varies the speed of the blower as a function of the air temperature in the room to be heated. The use of a room thermostat increases the comfort in the room, but reduces the efficiency of the unit 10 since the fire box walls may not be kept at the lowest possible temperature.
  • the flow pattern of Figure 17 may also be produced by using only vents in the front of the bottom forced air channel. The pushing of warm air adjacent the floor and pulling cool air from above evenly heats the room.
  • the heating unit 10 is effective for use with coal, oil, gas, or any other heat source in the fire box.
  • Preferred method of assembly of the forced air heating unit 10 is to form the exterior side and back walls 18, 20, and 22, out of a single piece of material and the interior side and back walls 78, 80, and 82 also out of a single piece of material.
  • the baffles are mounted to the exterior side and back walls and the interior side and back walls are mounted to the baffles preferably by welding.
  • the bottom exterior wall 16 is welded to the exterior side and back walls 18, 20, 22, and the baffles of the bottom forced air chamber are mounted to the bottom exterior wall.
  • the bottom interior wall 84 is then joined to interior side and back walls 78, 80, 82.
  • the top and front walls are then mounted to the structure by welding.
  • the welding bead formed between the top and the side and back walls provides a thermal barrier or guard such that the portion of the top 12 which extends beyond the side and back walls is cooler than a portion of the top which is directly over the fire box.
  • the remaining elements are attached or mounted to the front wall and the forced air unit mounted to the rear wall.
  • the interior side and back walls 78, 80, and 82 be made of 4,762 mm thick steel and the exterior side and back walls as well as the top and front walls be made of 3,175 mm thick steel.
  • the bottom exterior and interior walls may be made of 4,762 mm stee).
  • a forced air channel defined by the double sides, back and bottom wall, includes a system of baffles to direct forced air over substantially all of the surface area of the side, back, and bottom fire box walls.
  • the baffles in the back portion of the forced air channel direct forced air between the back portion and the two side and bottom portions.
  • the baffles in the bottom portion direct forced air between the bottom portion and the back and two side portions.
  • the baffles in the side direct forced air between the side portions and the back and bottom portions.
  • a blower is thermostatically controlled to introduce forced air into the air channel for maintaining the back, side and bottom fire box walls in a minimum temperature range to heat the forced air while maximizing the transfer of heat from the burning material to the forced air channel instead of up the flue.
  • the front wall of the heating unit includes an access opening and a pair of doors for covering the access opening.
  • An adjustable draft valve in each door includes a positive screw lock.
  • a gas baffle for directing rising gas to an area of the fire box where the gases are ignited.
  • the gas baffle directs some of the gas downward to the burning material to be ignited and maintains some of the gases adjacent the top of the fire box in front of the gas baffle.
  • the tops of the doors are spaced from the top edge of the access opening to allow air to circulate into the fire box adjacent the top wall for aiding ignition of the gases collected adjacent the top wall.
  • the major source of air is the space between the doors which is covered by a vertical strip mounted to one of the doors.
  • a hood is mounted adjacent the top edge of the access opening for directing gases exiting the top edge of the access opening back into the fire box.
  • a draft system including two vertical forced air channel exit vents adjacent the side edges of the access opening for creating hot air drafts which converge at a selected distance in front of the access opening, limits the draft of air into the access opening.
  • the converging hot air is effected by vertical deflection surfaces including vertical baffles in the side portion of the forced air channel or pneumatic surfaces produced by a lip extending across the vent opening or by the vent opening being offset from the exterior edge of the forced air channel.
  • the less than ninety degree angle that the side walls form with the front of the forced air channel also aids the deflection.
  • a mesh having inclined horizontal surfaces covers the vertical vents and directs the exiting air downward to be combined with heated forced air exiting horizontal vent in the front of the bottom portion of the forced air channel.
  • the heated forced air from the two vertically oriented vents and the horizontally oriented vent pneumatically create a finite cool air pocket in front of the access opening to limit the amount of cool air available for the fire box.
  • the forced air heating unit uniformly heats a room by introducing forced hot air adjacent the floor of the room by the horizontal vent and the downward directing vertical vents.
  • the forced air device mounted to the rear of the freestanding unit draws air from above and around the sides of the unit and around the space defined by the exiting forced hot air.
  • the width of the side portion of the forced air channel tapers from the wider rear portion to the front to increase the air intake.
  • Gravity lock door handles are provided on the access doors.
  • a forces air heating unit is provided which maximizes the use of available heat from a fire box by a unique thermostatically controlled forced air system including pneumatically produced surfaces and barriers.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Ventilation (AREA)
EP78900095A 1977-08-26 1979-03-13 Forced air heating unit Expired EP0006897B1 (en)

Applications Claiming Priority (10)

Application Number Priority Date Filing Date Title
US82818277A 1977-08-26 1977-08-26
US05/828,206 US4185610A (en) 1976-06-07 1977-08-26 Forced air channel baffles
US828207 1977-08-26
US828182 1977-08-26
US05/828,107 US4147153A (en) 1976-06-07 1977-08-26 Fireplace air circulation and draft control
US05/828,207 US4230093A (en) 1977-08-26 1977-08-26 Fireplace door
US05/828,208 US4207861A (en) 1976-06-07 1977-08-26 Fire box gas baffle and hood
US828107 1986-02-10
US828208 1986-02-10
US828206 1992-01-30

Publications (2)

Publication Number Publication Date
EP0006897A1 EP0006897A1 (en) 1980-01-23
EP0006897B1 true EP0006897B1 (en) 1982-09-01

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ID=27542243

Family Applications (1)

Application Number Title Priority Date Filing Date
EP78900095A Expired EP0006897B1 (en) 1977-08-26 1979-03-13 Forced air heating unit

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Country Link
EP (1) EP0006897B1 (xx)
CA (1) CA1115611A (xx)
CH (1) CH625329A5 (xx)
GB (1) GB2036943B (xx)
SE (1) SE7903684L (xx)
WO (1) WO1979000113A1 (xx)

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Publication number Priority date Publication date Assignee Title
DE69326209T2 (de) * 1992-10-16 2000-04-13 Canon K.K., Tokio/Tokyo Bilderzeugungsgerät
CN102721085A (zh) * 2012-07-02 2012-10-10 蒋恩良 民用多功能小热风炉

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GB135415A (xx) *
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Also Published As

Publication number Publication date
SE7903684L (sv) 1979-04-26
EP0006897A1 (en) 1980-01-23
GB2036943A (en) 1980-07-02
CA1115611A (en) 1982-01-05
CH625329A5 (xx) 1981-09-15
WO1979000113A1 (en) 1979-03-08
GB2036943B (en) 1982-11-03

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