None.
1. Field of the Invention
This invention relates generally to energy efficient, safe, high tech, in-the-wall building and room heaters that are intended to promote personal comfort and health, and particularly to such heaters that are electrically powered and emit infrared radiation. In a first embodiment, the invention can be unobtrusively installed within the confines of a standard interior wall space that is at least 3½ inches (8.9 cm) deep and between two 16 inch (40.6 cm) on center (or more) wall studs. In a second, alternative embodiment, the invention can be placed upon the floor of a room and electrically powered from an a.c. wall or floor outlet. Preferably, the second embodiment is also made portable by resting on caster wheels.
2. Description of Related Art
In-the-wall room heaters have mainly comprised apparatus for delivering centrally heated air ducted from an electrical or gas central heater, of an inefficient nature, located outside the building or in a cellar, furnace room or garage. Heating and maintenance costs for such heaters have run unacceptably high. Other in-the-wall heaters have comprised apparatus entirely confined to a single room that is to be heated, but have depended upon relatively low temperature heating elements and high volume fans to prevent fire hazard. Heaters mountable upon an interior wall surface of a room (on-the-wall heaters) have also incorporated relatively low temperature heating elements and high volume fans. Each of these kinds of heaters is relatively noisy, inefficient, expensive to operate and, in the case of propane and kerosene wall-mounted heaters, also consume room oxygen to the potential detriment of the health of room occupants. Portable room heaters have been constructed similarly to the above-mentioned stationary room heaters and have also been relatively inefficient to run, sometimes have been fire prone, and consume room oxygen.
Accordingly, there remains a need for a room heater that overcomes the above-described disadvantages of the previously known room heaters.
It is, therefore, and object of this invention to provide an electrically-powered room heater that, in a first embodiment, can be mounted entirely within the interior wall space of a room of a building and emit infrared radiation to heat the air in the room, and, in a second embodiment, to provide such a heater than can be placed upon, and easily be moved across the surface of, a floor of a room.
It is a further object of this invention to provide such a heater that efficiently converts electrical energy consumed by the heater into heat energy within the room, thereby making the heater relatively inexpensive to operate.
It is still a further object of this invention to provide such a heater that will not consume room oxygen or room air moisture.
It is another object of this invention to provide such a heater that includes one or more electric fans to draw air in from a room and expel heated air back into the room, but nevertheless operates quietly.
It is still another object of this invention to provide such a heater that includes effective heat shielding to prevent excessive build up of heat in any wall into which it may be installed, thereby avoiding a fire hazard.
It is a further object of this invention to provide for the user easy access, maintenance and cleaning of internal components thereof, which components include a removable heat exchanger assembly and a mesh, electrostatic air filter.
These and other objects of the invention will become apparent from the figures and detailed description of the invention, and are accomplished through first and second embodiments of the invention, which embodiments principally have in common that they employ the same method to heat by infrared radiation room air drawn into the interior space of a heater system housing, thereafter expelling heated air back out into the room.
According to the method of the invention, air is drawn into a substantially closed interior space of a heater system that includes a housing. The housing has first and second, spaced apart sidewalls and contains means for electrically powering the system, and a heat exchanger assembly that emits infrared radiation whenever sufficient electric current from the means for electrically powering the system passes through a resistive conductor encased within one or more ceramic heating elements attached to a first copper plate. Attached to each of the sidewalls are first heat insulating means to impede flow of heat from the heat exchanger into the housing sidewalls. Air within the housing interior is forced through parallel first, second and third air transit channels. The first air transit channel is defined by space between a first copper plate and the first insulating means. A second copper plate is mounted to the heat exchanger assembly adjacent to, but spaced apart from, a first insulating means attached to the second sidewall, and the second air transit channel is defined by the space between the second copper plate and said first insulating means. A third air transit channel is defined by the space between the first and second copper plate. Inlet air traversing the first and second air transit channels has the beneficial effect of cooling the housing sidewalls while at the same time absorbing heat directly from the sidewalls and indirectly from the first and second copper plates. The inlet air traversing the third air transit channel is heated directly by infrared radiation emitted from the one or more ceramic heating elements and from the first and second copper plates. Each ceramic heating element encases a resistive conductor, which is preferably configured in a sinuous path within the body of the ceramic heating element. In the below-described embodiments of the system, electric current passes through a resistive conductor of the one or more ceramic heating elements and a fan assembly draws room air into the housing interior and forces the air through the heat exchanger assembly and back out into the room as heated air whenever the temperature of the room falls below a user-selected temperature setting in a thermostat. In the case of the first embodiment, the thermostat is preferably mounted on a wall of the room that is to be heated; in the case of the second embodiment, the thermostat is mounted on the room heater itself.
Means for electrically powering the system include a first d.c. power circuit that energizes a first electric fan within the fan assembly and energizes a solid state relay. A low temperature sensor limit switch attached to the heat exchanger assembly is wired in series with the first electric fan; this switch is open when the sensed temperature of the heat exchanger assembly is below 36° C. and closes, turning on the first fan, when the temperature rises above that level. When energized, the relay provides a conductive path for 120 volt a.c. power to be applied to a second d.c. circuit and to the one or more ceramic heater elements. The second d.c. circuit powers two additional electric fans within the fan assembly. A high temperature sensor limit switch wired in series with the heater elements is attached to the heat exchanger and opens whenever the temperature of the heat exchanger exceeds 76° C., thereby de-energizing the heater elements.
The housing for the first embodiment is preferably configured for installing the system within a standard room wall of depth 3½ inches (8.9 cm) and between wall studs spaced 16 or more inches (40.6 cm) on center apart, with an air inlet grate attached to the housing and disposed above the heat exchanger assembly, and with an air outlet grate attached to the housing and disposed below the heat exchanger assembly. The means for electrically powering the system is disposed within a lower interior space of the housing and is heat insulated from the rest of the interior space of the housing by an isolation wall. Interposed between the air inlet grate and the air outlet grate is a front panel that attaches to front edges of the housing sidewalls. By removing the front panel and the air outlet grate, the entire heat exchanger assembly can be removed from the system for cleaning and/or for replacement of ceramic heating elements within the assembly.
The housing for the second embodiment, intended for placement on the floor of a room that is to be heated, is substantially closed except for an air inlet cutout on a rear wall of the housing, and an air outlet cutout, and a control panel cutout on a front wall of the housing. Air inlet and outlet grates are mounted over the air inlet and air outlet cutouts, respectively, and a control box is installed within the control panel cutout. A front wall of the housing also has a heat exchanger assembly cutout, which permits the assembly to be slid in and out of the housing between horizontal upper and lower tracks. The heat exchanger assembly is disposed for horizontal flow of air from the rear interior of the housing through the heat exchanger assembly and toward the front interior of the housing, and thence back out into the room through the air outlet grate. A portion of the room air that enters the system 10′ through the air inlet grate, however, first flows forward under a lower surface of the lower track, then rearward between an upper surface of the lower track and the heat exchanger assembly, thence is drawn through the fan assembly and forced through the heat exchanger assembly. Similarly, another portion of the room air that enters the system 10′ through the air inlet grate first flows forward over an upper surface of the upper track, then rearward between the upper track and the heat exchanger assembly, thence is drawn through the fan assembly and forced through the heat exchanger assembly. In this manner, the upper and lower tracks are air cooled, as is the housing and the means for electrically powering the system 10′ that is disposed within the housing above the upper track. Preferably, the housing is supported by caster wheels that permit the system to be wheeled about a room floor surface.
The operating temperature within the heat exchanger assemblies of the first and second embodiments is about 243° C., which means that both embodiments are germicidal and fungicidal. Both embodiments produce about 35 percent greater heat output compared to conventional infrared quartz heater technology for the same electrical power input.
Similar numerals denote similar components throughout the several views.
Referring to
As may best be seen in
The system further includes a fan assembly 130 and a heat exchanger assembly 100 disposed below the fan assembly for heating room air as it flows downward through a lower, interior portion of the system 10. As may best be seen in
By removing the front panel 22 and the air outlet grate 142, the heat exchanger assembly 100 is removably insertable through the open front of the housing 12, as denoted by arrow 189 in
Referring to
Means are provided to prevent heat from leaking out of the interior of the housing 12 into the housing 12 itself or into the means 150 for electrically powering the system 10, and thereby avoid creating a fire hazard, as well as to improve the energy efficiency of the system 10. To that end, first insulating means 114 is interposed between the side panels 102 of the heat exchanger assembly 100 and the sidewalls 14 of the housing 12 to impede flow of heat from the heat exchanger assembly side panels 102 to the housing 12. Second heat insulating means 116 is disposed to impede the flow of heat from a lower portion of the interior of the housing 12 through the isolation wall 151, which heat flow otherwise might overheat the means 150 for electrically powering the system 10. Third heat insulating means 118 is interposed between the first copper plate 106 and the rear heat exchanger panel 104. Fourth heat insulating means 202 is disposed to impede the flow of heat from the second copper plate 120 to the housing 12. Referring to
The space between the first copper plate 106 and the rear panel 20 of the housing 12 defines a first air transit channel, denoted by arrow 251; the space between the second copper plate 120 and the front panel 22 of the housing 12 defines a second air transit channel, denoted by arrow 253; and the space between the first copper plate 106 and the second copper plate 120 defines a third air transit channel, denoted by arrow 255. The relatively cool air inlet air 52, when traversing through the first and second air transit channels, 251, 253, cools the front and rear panels 20, 22 of the housing 12, and is itself warmed thereby. Heated air 53 from all three air transit channels 251, 253, 255 is combined and mixed as the heated air exits the system 10.
Referring to
Referring now to the second direct current circuit 192, the primary winding of a second step-down voltage transformer 360 is wired in series with the first a.c. input 196 and with an a.c. power output terminal 310 of the relay 266. An a.c. power input terminal 312 of the relay 266 is wired to the other a.c. power input 195. Accordingly, whenever the thermostat 268 closes due to room temperature falling below the user-selected temperature setting, the relay 266 is energized and permits a.c. current to flow through the primary winding of the second transformer 360. A second diode bridge rectifier 364 is wired to the secondary winding of the second transformer 364. A second 1000 μF capacitor 364, and second and third fans 132 are also wired in parallel with the second diode rectifier bridge 362. The upstream heater element 108 and the downstream heater element 110 are wired in parallel with each other, and their parallel combination is wired in series with a high temperature limit sensor switch 158 and in series with the first a.c. input 196 and with the output terminal 310 of the relay 266. The high temperature limit sensor switch 158 is normally closed, but opens when the temperature of the heat exchanger assembly 22, as sensed by the switch 158, exceeds 76° C. Accordingly, the second and third fans, and the heater elements 108, 100 are only energized when the relay 266 is energized—namely, when the room temperature falls below the user-selected temperature setting of the room thermostat 268. To achieve high efficiency of conversion of electrical energy to infrared radiant energy, the ceramic heating elements 108, 110 are preferably obtained from Main Key Trading Co., Ltd., Taipei, Taiwan, R.O.C., part number SL-1100400 (120 Volt, 400 watt) or SL-2200400 (220 volt, 400 watt). A pair of laterally spaced-apart, depending, resilient spacer clips 122 are attached to, and extend below, a lower flange portion 107 of the first copper plate 106 in order to engage an upper surface of the isolation wall 151 and thereby maintain a gap between the heat exchanger assembly 100 and the isolation wall; see
The first embodiment of the system 10 can be combined with an air purifier and the entire combination installed within a room wall. Referring to
In a second, alternative embodiment suitable for placement on the floor of a room, as depicted in
From the foregoing description, it will be clear that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. For instance, although the first embodiment of the system 10 is depicted in
This application claims the benefit of a provisional patent applications by the same applicants for a first embodiment of the same invention filed on Nov. 1, 2006, application No. 60/855,661 and a provisional application by the same applicants for a second embodiment of the same invention filed on Jan. 8, 2007, application No. 60/879,084.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US2007/022846 | 10/29/2007 | WO | 00 | 3/16/2009 |
Publishing Document | Publishing Date | Country | Kind |
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WO2008/057321 | 5/15/2008 | WO | A |
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