THIN-FILM CARBON FORCED WARM-AIR-HEATING UNIT

Abstract

A forced warm-air heating apparatus, a forced warm-air heating system, and method to heat warm-air using an enclosure containing a plurality of thin film carbon-based heating elements configured and arranged to heat a desired heating space driven by a fan assembly, is described. The plurality of thin film heating elements is further ured and arranged to deflect and divide air flow as it flows through the heating enclosure.

Description

FIELD OF THE INVENTION

The invention relates generally to the heating of spaces. More particularly, this invention relates to a forced air heating system to heat space using flat carbon-based resistive elements.

BACKGROUND OF THE INVENTION

Energy usage in homes, particularly the heating of homes, substantially contributes to the usage of fossil fuels. There is a growing need to promote more sustainable living habits by reducing fossil fuel emissions using cleaner forms of energy. Heating energy derived from fossil fuels, such as coal, wood, natural gas, and oil causes atmospheric pollution, and contributes to global warming. Additionally, the supplies of fossil fuels are also becoming increasingly scarce.

Electrical heating provides an alternative to fossil fuels, but lacks the efficiency to be economical. There are generally two forms of electrical heating: vapor-compression based or resistive heating based. Vapor-compression based heating involves circulating a heat transfer medium between a desired heating area and the surrounding environment having a higher heat potential driven by a heat pump. However, when the heat potential in the surrounding environment is low, the efficiency of vapor-compression is diminished, if not rendered inoperable. To illustrate this issue further, the coefficient of performance of a heating system (COP) is generally calculated with the following formula:

$COP=\frac{T_R}{T_R-T_o}$

Where T_R is the room temperature and T_O is the outside temperature. In vapor-compression based heating system, the COP is directly related the heating potential, e.g. the difference in the outside temperature and the room temperature. Thus, in mild conditions where the room temperature is relatively low and the outside temperature relatively high, the COP can be up to 300%. However, once the outside temperature falls below a certain level and/or the inside temperature reaches a sufficiently high value; the COP reduces dramatically below 100%. This means that on a cold winter's day, a heat-pump will struggle to heat a house, and once it get the temperature of the house to a reasonable level, it will be sufficiently ineffective at keeping the temperature at that elevated state.

Conventional filament heaters and resistive air-heaters employ a heating element that heat up as electric current passed though the heating element. Present resistive based heating systems generate heat energy by forcing air over the resistive heating elements that are transferred to the desired heating spaces. Heating elements are typically electric filaments and are generally characterized by their high electrical resistance. Electrical filaments are generally constructed of metal alloys, such as Nichrome, Cupronickel, and Kanthal. The filaments are formed as a fine wire, ribbon, or strip. Electric heat elements convert electric energy into conductive, radiative, and convective heat energy, which have a low efficiency in generating convection heating energy. Convective heat energy is generally the most useful since the energy transfers to the air, which can be transferred to the desired heating area in the house, but are also generally the least produced due to the high temperature resistance between the heating elements and the transferred medium. Conductive heat energy is generally the least useful, but is the most prevalent in the process. Conductive heat energy is considered wasted heat since it heats the ducting of the heating system, which does not generally contribute to heating the desired area of the space or house. Radiative heat energy is also essentially wasted energy since only a small fraction of the radiative energy is transfer to the air to be used to heat the desired heating space.

In most heater applications, heat is transferred to air through convection and to other surroundings through radiation. Most resistive heater elements glow bright red or orange when current is applied, indicating a large portion of the electric energy used by the heater generates radiation. Where this is an efficient way to heat surrounding objects that can absorb the radiation, it is not an efficient heat-transfer mechanism for a ducted air-heating system. In a ducted system, the object is to heat the air and not the surrounding ducting since the ducting transfers a good portion of its heat to the surroundings thus increasing losses. When a filament type heater is used, a good deal of the electric energy that is turned into heat is lost to through radiation that merely heats the ducting and not the air. The only useful part of the heat going into the air is transferred through convection.

SUMMARY OF THE INVENTION

Various embodiments of the present invention overcome the limitations of present resistive heating elements through the use of thin film heating elements, such as thin film carbon fibers. Thin film heating elements, such as thin film carbon fibers, have a superior efficiency of heating air by delivering more heated air to a desired heating space for a given quantity of electric energy used. Three features of the thin film heating elements, such as thin film carbon fibers, contribute to their superior efficiency. Firstly, the thin film heating elements do not reach high temperatures and thus do not generate a large quantity of radiation resulting in more energy available for convection heat transfer to the surrounding air as compared to Nichome, Kanthal, and Cupronickel. Secondly, thin film heating elements, such as thin film carbon fibers, are spread over a large area resulting in larger surface area for heat to be transferred. The surface area of thin film heating elements can also be configured to enable heat transfer without creating substantial disruption to the air flow as conventional coiled resistive elements. Thirdly, since the little radiation that the thin film heating elements do generate is in the far-infrared spectrum, the radiation is extremely well absorbed by the water vapor in the air that has a peak in absorption wavelength at a similar wavelength as transmitted by the thin film heater elements. These three features combine to produce a heater that is ideally suited to heat air in a ducted system at higher efficiencies than filament type heaters. A secondary benefit from the radiation produced by thin film heating elements, such as thin film carbon fibers, is that such radiation further have beneficial anti microbial effects as the far-infrared spectrum emitted results in the heating of water vapors in air-born microbes.

Various embodiments of the invention enable the heating of a desired heated space using a forced warm-air room heating apparatus comprising of an enclosure having an inlet to a supply of air, an outlet to the desired heated space, and a series of panels constructed and arranged to create a series of air channels. A series of thin film heating elements line the series of panels, which are generally arranged to increase the heat exchange characteristics of the thin film heating elements. The series of thin film heating elements generate warm, heated air in its proximity by convection and radiative means. A fan assembly is operatively coupled to the enclosure to force the warm heated air into the desired heating space. In various alternative embodiments, the fan assembly can be mounted in proximity of the inlet, or in proximity to the outlet, or in between the inlet and outlet within the enclosure. It is further contemplated as an alternative embodiment that the fan assembly can be upstream or downstream to the enclosure and can be pushing or pulling the direction of air through the enclosure.

In an illustrative embodiment of the invention, the thin film heating elements are thin film carbon fibers. An exemplary trade name for such thin film heaters is a carbon thin-film. The thin film heaters can be further sandwiched to provide protection from the environment. An example of a suitable material is fiberglass. The thin film heating elements are electrically powered to generate heat when an electric potential is applied across the film heating elements. The electrical current can flow through the thin film heating elements or across the surface of thin film heating elements depending on the characteristic of the electrical current. The electrical current applied can be DC or AC and the electrical potential applied can be constant or oscillating.

The thin film heating elements, such as thin-film carbon-heating elements, efficiently heat up to a relatively moderate temperature, thus allowing the heat to convectively transfer to a medium in the channel with minimal heat loss as radiation or conductive heat. Convection heat transfer is directly related to the surface area of the heating element, thus compressing the heater into a thin-film exposes relatively more air to a larger heating area, thereby increasing the heat transfer to the air. Additionally, thin film heaters emit smaller quantities of radiation, thus less energy is emitted as waste. Additionally, the radiation emitted is generally short wavelength of the infrared (IR) spectrum close to the absorption wavelength of water, thus the thin film heater enables efficient-absorption of energy by the water vapor present in air, further improving the efficiency of the heating.

In various illustrative embodiments, the series of panels are constructed and arranged to divide, deflect, or collectively divide and deflect the airflow within the enclosure. It is further contemplated within the illustrative embodiment that the series of panels can be constructed and arranged in various configurations, including being a solid or a porous. The shape of the panels can be flat or curved, where the curvature is such to gently create gentle laminar flow across the surface of the panels, or curved to aggressively create laminar flow across the surface of the panels as air passes over. In various alternative embodiments, the series of panels are constructed and arranged as air ducts. The air ducts can be shaped in configurations such that the cross section of the air duct can be in the shape of a circle, parabolic, square, rectangular, or other complex curve shapes that allows air to flow through. In the various illustrative embodiments, the thin film heating elements are constructed and arranged as the plurality of panels to deflect, divide, or simultaneously deflect and divide air within the enclosure. It is contemplated in an alternative embodiment that the thin film heating elements can align a portion of the surface of the panel, so long as the thin film heating elements are within proximity of the air flow to allow the air flow to carry the warm air generated by the thin film heating elements to the outlet.

In an illustrative embodiment, the inlet and the outlet of the enclosure are opposed to one another. However, it is contemplated in alternative embodiments that the inlet and outlet can be in any direction and orientation so long as the inlet has access to air supply and the outlet is directed at the desired heating space.

In another illustrative embodiment, the forced warm-air room heater is a warm-air heating system comprising of the enclosure having the inlet, the outlet, the series of panels, and the series of thin film heating elements. The system further comprises of sensors and controllers configured and arranged to measure temperature and flow and control the temperature of the desired heated space. It is contemplated in various illustrative embodiments that standard control, such as proportionate-integrator controller (PI), or proportionate-integrator-differentiator (PID) controller, are used. In various alternative embodiments, more advanced control techniques, which should be clear to those of skill in the art, can be employed, such as Karman filters, adaptive learning or training systems, or model based controls.

In various alternate embodiments, the forced warm-air room heating apparatus can be constructed and arranged in a series, in parallel, or in combinations of series and parallel with other forced warm-air room heating apparatus. The forced warm-air room heating apparatus can be directly coupled to one another. In another alternate embodiment, it is further contemplated that components of the forced warm-air room heating apparatus can be combined such that the air flow in a first forced warm-air room heating apparatus directly couples to air flow in a second forced warm-air room heating apparatus. An illustrative example can be the two or more warm-air heating apparatus operatively coupled to each other in a series and operated by a single fan assembly configured and arranged to force air through the multiple enclosures.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a top cross-sectional view of the enclosure and the fan assembly according to an illustrative embodiment;

FIG. 2 shows a cross-sectional view of a panel assembly comprising of a panel and a thin film heating element;

FIG. 3 shows a top view of the plurality of thin film heating element configured as a panel assembly;

FIG. 4 shows a transparent perspective view of an assembly of the enclosure, the inlet, the outlet, and the plurality of thin film heating elements arranged along the walls of the enclosure according to an alternative embodiment;

FIG. 5 shows a transparent perspective view of an assembly of the enclosure, the inlet, the outlet, and the plurality of panels arranged in an alternating columns V-shaped prism according to an illustrative embodiment;

FIG. 6 shows a transparent perspective view of an assembly of the enclosure, the inlet, the outlet, and the plurality of panels arranged in an alternating columns of V-shaped prism according to an alternative embodiment;

FIG. 7 shows a transparent perspective view of an assembly of the enclosure, the inlet, the outlet, and the plurality of panels arranged in an alternating configuration of parallel horizontal fins according to an alternative embodiment;

FIG. 8 shows a transparent perspective view of an assembly of the enclosure, the inlet, the outlet, and the plurality of panels arranged in an alternating configuration of parallel horizontal fins according to another alternative embodiment;

FIG. 9 shows a transparent perspective view of an assembly of the enclosure, the inlet, the outlet, and the plurality of panels arranged in alternating rows of V-shaped prism according to an alternative embodiment;

FIG. 10 shows a transparent perspective view of an assembly of the enclosure, the inlet, the outlet, and the plurality of panels arranged in alternating rows of V-shaped prism according to another alternative embodiment;

FIG. 11 shows a transparent perspective view of an assembly of the enclosure, the inlet, the outlet, and the plurality of panels arranged in an alternating configuration of parallel vertical fins according to an alternative embodiment;

FIG. 12 shows a transparent perspective view of an assembly of the enclosure, the inlet, the outlet, and the plurality of panels arranged in an alternating configuration of parallel vertical fins according to another alternative embodiment;

FIG. 13 shows a transparent perspective view of an assembly of the enclosure, the inlet, the outlet, and the plurality of panels arranged to divide the air flow with a vertical column according to an alternative embodiment;

FIG. 14 shows a transparent perspective view of an assembly of the enclosure, the inlet, the outlet, and the plurality of panels arranged to divide the air flow with a horizontal column according to another alternative embodiment;

FIG. 15 shows a transparent perspective view of an assembly of the enclosure, the inlet, the outlet, and the plurality of panels arranged to divide the air flow with an X-shape divider according to an alternative embodiment;

FIG. 16 shows a top cross-sectional view of the forced warm-air heating system comprising an enclosure, the fan assembly, and the controller according to an illustrative embodiment;

FIG. 17 shows a flowchart of a method for controls of a forced warm-air room heating system in accordance to an illustrative embodiment;

FIG. 18 shows a cross-sectional view of a building installed with a forced warm-air-room heating system in accordance to an illustrative embodiment;

FIG. 19 shows a flowchart of an alternative method for controls of a forced warm-air room heating system in accordance to an illustrative embodiment;

FIG. 20 shows a cross-sectional view of a building installed with an alternative forced warm-air room heating system in accordance to an illustrative embodiment;

FIG. 21A shows an inlet view of an illustrative embodiment;

FIG. 21B shows an inlet view of an alternate embodiment;

FIG. 21C shows an inlet view of yet another alternate embodiment;

FIG. 21D shows an inlet view of yet another alternate embodiment;

FIG. 21E shows an inlet view of yet another alternate embodiment;

FIG. 21F shows an inlet view of yet another alternate embodiment;

FIG. 22A shows an outlet view of an illustrative embodiment;

FIG. 22B shows an outlet view of an alternate embodiment;

FIG. 22C shows an outlet view of yet another alternate embodiment;

FIG. 22D shows an outlet view of yet another alternate embodiment;

FIG. 22E shows an outlet view of yet another alternate embodiment;

FIG. 22F shows an outlet view of yet another alternate embodiment.

FIG. 23 shows an exposed side view with a side wall of the enclosure removed to reveal the internal supporting structure of the enclosure according to an illustrative embodiment.

DETAILED DESCRIPTION

FIG. 1 shows a top cross-sectional view of an enclosure 102 and the fan assembly 103 according to an illustrative embodiment. The forced warm-air room heating apparatus 100 comprises an enclosure 102 having the fan assembly 103, an inlet 104, an outlet 106, a plurality of panels 108, and a plurality of thin film heating elements 109. The plurality of panels 108 can be constructed of the plurality of thin film heating elements 109 or the plurality of panels 108 can be constructed of a separate material and the thin film heating elements 109 are mounted on the plurality of panels 108.

In the illustrative embodiment, the plurality of panels 108 are constructed and arranged to define a plurality of channels 110 and further arranged to increase the heat exchange characteristics by maximizing exposed surface area 112 of the plurality of panel 108 to the plurality of channels 110. The heat exchange characteristics can be further maximize by the formation of laminar flow 114 in air flow 116 as the air flow 116 passes through the plurality of channels 110. The plurality of panels 108 are constructed and arranged to divide and deflect air flow 102. In another embodiment of the present disclosure, thin film heating element 109 can be constructed and arranged as the plurality of panels 108 to define the plurality of channels 110 and further arranged to increase the heating characteristic of the forced warm-air heating apparatus 100.

The air flow 116 is forced from fan assembly 103 through inlet 104 into enclosure 102. As air flow 116 flows over the plurality of thin film heating elements 109 air flow 116 is heated by convection to form heated air flow 118. In an illustrative example, the apparatus 100 heats an air flow of 84 liters/second from 15.1 degree Celsius to 31.5 degree Celsius using 2.4 kilowatt of power. This is an exemplary data and it should be clear that variations in performance can be observed due to the differing components utilized and the differing arrangements of the components.

In an illustrative embodiment, the apparatus 100 operates in a range of 0.1 liters/second to over 108 liters/second. An illustrative example of the fan assembly 103 is a 200 liter AC centrifugal in-line fan manufactured by Multifen GmGH, which produces a nominal airflow of 1200 cubic meters per hour at 2,650 RPM. It is contemplated that other fans capable of forcing an air flow is adequate, thus different fans of differing volume and/or flow rates can be utilized. Other alternative air forcing technology can be employed, such as axial fans, cross-flow fan, and other centrifugal fan.

It is contemplated in the illustrative embodiment that the plurality of thin film heating elements 109 can be mounted on a single side or both sides of the plurality of panels 108. The plurality of panels 109 or the plurality of thin film heating elements 109 are arranged such that as air flow 116 passes through the plurality of channels 110, the temperature of heated air flow 118 increases incrementally, but not necessarily, by the same increment across each panel. It is further contemplated in the illustrative embodiment that increasing the number of thin film heating elements 109 arranged in series increases the temperature of outlet air flow 120.

In various illustrative embodiments, the plurality of panels 108 or the plurality of thin film heating elements 109 directly couples to the enclosure 102. The plurality of panels 108 or plurality of heating elements 109 is configured and arranged to provide structural support for the enclosure 102. In an alternative embodiment, the enclosure 102 provides structural support to the plurality of panels 108 or the plurality of heating elements 109. In another alternative embodiment, the plurality of panels 108 or the plurality of thin film heating elements 109 is supported by a plurality of support frames 122. The plurality of support frames 122 is constructed of material having low thermal conductive coefficient to minimize the waste from conductive heating. Examples of material used to construct the support frame 122 includes, but is not limited to, wood, ceramic, polymer, composite, and/or other thermally nonconductive materials. It is further contemplated that the structure of support frame 122 can be arranged as a solid or as a series of framework members to minimize conductive heat transfer from the plurality of thin film heating element 109 to the enclosure 102. Likewise any mounts between the wall of enclosure 102 and the plurality of support frames 122 can include insulating connectors (not shown). In an illustrative embodiment, the enclosure 102 and the support frame 122 are manufactured of galvanized steel. However, in various alternative embodiments, other material can be used to construct the enclosure 102, or the support frame 122, including but are not limited to, other heat resistant materials such as Steel, Stainless Steel, Zinkalume, Copper, Super Alloys, Intermetallics, Low Alloy Steels, Carbon-carbon Composites, High Alloy Steels, Cast Iron, High Alloy Cast Iron, Refractory Metals, Ferrous Alloys, Nickel Based Alloys, Cobalt Based Alloys, Zirconis, Ceramics, Titanium Based Alloys, and High Temperature Resistant Polymers.

In various illustrative embodiments, the plurality of thin film heating elements 109 is constructed substantially of thin film carbon fiber. Examples of thin film carbon fibers include, but is not limited to, graphite fiber, carbon graphite, turbostratic carbon fibers, polyacrylonitrile (PAN), rayon, and petroleum pitch.

In various illustrative embodiments, the thin film heating elements 109 generate radiation 126, conductive heat 128, and convective heat 130 as electrical power 132 is applied as shown in FIG. 2. The embodiment further shows one of the plurality of thin film heating elements 109 mounted to one of the plurality of panels 108 by an insulating layer 124. It is contemplated in the present disclosure that other means of mounting can be employed. Further illustrated is an insulating layer 134, which can thermally insulates panel 108 from thin film heating element 109, but also binds the panels 108 and heating elements 109 together. Examples of other mounting can be using mechanical means, such as screws, bolts, or nails, or alternatively using adhesives, such as glue, epoxy, or by attaching the thin film heating element 109 to the panel 110 when the panel 110 is melted.

Heat from the plurality of thin film heating elements 109 is transferred through three different mechanisms that will be apparent to those skilled in the art: conduction, convection and radiation. Conduction is characteristic of heat transfer between two mediums of similar density and phase. Convection is the transfer of heat between two materials of different density and phase. For convection to occur, a transfer medium must be able to flow over the heated medium either naturally or by force. When heat is allowed to flow naturally, that is called natural convection. When heat is forced by, for example, a fan or impeller, that is defined as forced convection. Radiation, conversely, is heat-transfer by photons, where the medium that the photons travel though is not substantially heated, but the object that absorbs the radiation on the other end of the medium does absorb it. Air is generally heated by convection since radiation passes mostly though it and conduction heat transfer between two fluids is considered convection since the fluids move and mix at their interface.

As contemplated in various illustrative embodiments, convection directly relates to the surface area of the heating element, thus compressing the heater into a thin-film exposes relatively more heat transfer medium, such as air or water, to a larger heating area, thereby increasing the heat transfer to the air. By ways of example, a thickness of 0.6 mm to 1.0 mm is sufficiently suitable to generate the moderate heating; however, thinner films can be employed. Moderate temperature increases at the surface of the plurality of thin film heating elements can be from a range of 1 degree Celsius to 80 degree Celsius.

It is contemplated in the various illustrative embodiments that conductive heat 128 is considered wasted heat since the energy expend in generating conductive heat 128 does not result in heating the desired space. Thus, various alternate embodiments employ a variety of mechanisms to minimize conductive heat 128. In an alternative embodiment, the plurality of thin film heating elements 109 are directly mounted to enclosure 102, thus the contact between the plurality of thin film heating elements 109 and enclosure 102 is minimized. In another alternate embodiment, thermal insulating buffers can be installed between the plurality of thin film heating elements 109 and enclosure 102 to further minimize conductive heat 128. Example of such thermal insulating buffer may be plastic or ceramic washer, bolts, or any type of thermal insulating material that can be use in mounting. In yet another alternate embodiment, the outer surface of enclosure 102 is equipped with fins or heat dissipating structure exposed to the desired heating space, thus employing the conductive heat 128 to assist the heating of the desired heating space.

It is contemplated in the various illustrative embodiments that the plurality of thin film heating elements 109 emit smaller quantities of radiation 126, which is closer to the absorption wavelength of water. As a result, firstly, less energy is emitted as waste. Secondly, of the little radiation that is emitted, much is thus absorbed by vapor in the air, which is commonly characterized as humidity, thus improving the efficiency of the heating of the heated air 134. Strong absorbance by water vapor generally occurs at wavelengths of 2500, 1950, and 1450 nanometers (nm). The radiation emitted from thin film heating elements, such as thin film carbon fibers, substantially overlaps with the strong absorbance wavelength of water vapor. It is further contemplated in an alternative embodiment that humidity within the enclosure 102 can be controlled to provide the optimal water vapor absorption of the radiation emitted by the thin film heating elements.

In FIG. 3, a top view of one of the plurality of thin film heating elements 109 is shown mounted in a panel assembly 136. In this illustrative embodiment, the panel assembly 136 is shown comprising of a plurality of thin film heating elements 138, two conductors 140 and 142, a panel frame 144, and protective layers 146. As an illustrative example, the thin film heating elements 138 are sandwiched by two 0.5 mm fiberglass protective layers 146, which are 450 mm by 450 mm to form the panel assembly 136. Encased inside the sandwich construction, four thin film heating elements 138 are connected to the superior copper conductors 140 and one inferior copper conductor 142. The two superior copper conductors 140 and 142 are respectively connected to phase and neutral. The carbon panels are induced with electricity that travels through the thin film heating elements 138, which acts as a resistor and heats up as electric current flows through it. In an example of the illustrative embodiment, a voltage potential of 220-240 VAC is applied across each of the plurality of thin film heating elements 109. It should be clear to those skilled in the arts that voltage potential can variedly accordingly to operate with other voltage potential. In an example of (24) thin film heating elements 109 configured in a parallel configuration consuming 2.4 KW results in a 16.1 degree Celsius increase in the temperature between the inlet 104 and the outlet 120 at an air flow rate of 108 liters/second.

Various alternative embodiments of the invention are shown in FIGS. 4-15, which show various arrangements of the plurality of panels 108 and the plurality of thin film heating elements 109 in the enclosure 102. In FIG. 4, an alternate embodiment is shown, wherein the plurality of thin film heating elements 109 line the walls of the enclosure 102. It should be clear that the inlet 102 and outlet 120 are shown to provide orientation as other components contemplated in the alternate embodiment are omitted to simplify the drawings.

In FIG. 5 and FIG. 6, alternate embodiments are shown, wherein the plurality of thin film heating element 109 and the plurality of panels 108 are arranged as alternating columns of triangularly shaped prism. FIG. 5 illustrates an illustrative configuration of this arrangement and FIG. 6 illustrates a configuration mirroring the configuration of FIG. 5.

In FIG. 7 and FIG. 8, alternate embodiments are shown, wherein the plurality of thin film heating elements 109 and the plurality of panels 108 are arranged as alternating columns of vertical walls. FIG. 7 illustrates an illustrative configuration of this arrangement and FIG. 8 illustrates a configuration mirroring the configuration of FIG. 7.

In FIG. 9 and FIG. 10, alternate embodiments are shown, wherein the plurality of thin film heating elements 109 and the plurality of panels 108 are arranged as alternating rows of triangularly shaped prism. FIG. 9 illustrates an illustrative configuration of this arrangement and FIG. 10 illustrates a configuration mirroring the configuration of FIG. 9. In FIG. 9, the air flow 118 is directed upward first, thus resulting in a differing air flow path to the air flow configuration shown in FIG. 10.

In FIG. 11 and FIG. 12, alternate embodiments are shown, wherein the plurality of thin film heating elements 109 and the plurality of panels 108 are arranged as alternating rows of horizontal walls. FIG. 11 illustrates an illustrative configuration of this arrangement and FIG. 12 illustrates a configuration mirroring the configuration of FIG. 11.

The difference in the air flow path between mirroring configurations of the plurality of thin film heating elements 109 and the plurality of panels 108 is demonstrated in FIG. 13 and FIG. 14. In FIG. 13, the alternate embodiment a vertical divider represents a plurality of panels 108 and the plurality of thin film heating elements 109 that separate the air flow 118 to a left side and a right side of the enclosure 102. Alternatively, in FIG. 14, the alternate embodiment comprises a horizontal divider representing the plurality of panels 108 and the plurality of thin film heating elements 109. Since heat has a tendency to rise, the heating pattern in the upper channel as compared to the lower channel differs.

In FIG. 15, an alternate embodiment is shown, wherein the plurality of thin film heating elements 109 and the plurality of panels 108 are arranged as a horizontal X-shape structure. In another alternate embodiment of FIG. 15, the plurality of thin film heating elements 109 and the plurality of panels 108 are arranged to form a honeycomb shaped structures between the inlet and the outlet of the enclosure 102 (not shown). The honeycomb structure can be configured to have a cross-sectional hexagonal shape, a cross-sectional square shape, a cross-sectional rectangular shape, or a cross-sectional rhomboid shape.

FIG. 16 shows an illustrative embodiment of the warm-air room heating system comprising of the apparatus 100 and a plurality of temperature sensor 152 and a plurality of flow rate sensor 154 operatively coupled with a controller 150. A temperature reading is communicated from the temperature sensor 152 to the controller 150 via a temperature control line 154. It should be clear to those skilled in the arts that temperature control line 154 can contain several voltage line and/or several signal commands and data. The communication can be binary or analog. An example of signal levels employed by the system includes a current signal varying between 4-20 mA where 4 mA represents the minimum temperature read of the system and 20 mA represents the maximum temperature read of the system. It should be clear to those skilled in the arts that the controller 150 operatively couples with the fan assembly 118 and the plurality of thin film heating elements 109 to regulate the air flow through the enclosure 102 and the heating generated by the apparatus 100 respectively. The controller 150 can employ various methods of controls, for example, such as proportionate integrator (PI) control, proportionate integrator differential (PID) control to regulate the temperature in the desired heating space. It is further contemplated in the illustrative embodiment that the controller 150 can further control the humidity level of the desired heating space by controlling an auxiliary system (not shown) that can introduce moisture into the path of air flow 118.

In various alternate embodiments, as further shown in FIG. 16, the system can be configured with a plurality of safety devices, such as an over-temperature probe, and a minimum-flow-rate probe. Each of the plurality of safety devices is serially connected to the controller engaged switch, thus an out-of-bound condition in any of the plurality of safety devices results in a break in the electric supply to the plurality of thin film heating elements 109.

An example of the over-temperature probe in the alternate embodiment consists of a maximum temperature threshold circuit configured to generate an output signal when the sensed temperature in the enclosure 102 exceeds a predetermined threshold. An example of such a pre-determined threshold is 95 degree Celsius. As an example of the alternate embodiment, a normally-closed switch coupled to a thermistor is employed as an over-temperature probe. Multiples over-temperature sensing is desirable since different section of the enclosure 102 heats up at different rate.

An example of the minimum-flow-rate probe consists of a minimum flow rate threshold circuit configured to generate an output signal when the sensed flow rate is below a pre-determined threshold. An example of such a pre-determined threshold is 10 liters/second. As an example of the alternate embodiment, a normally-open switch coupled with a flow-meter is employed as a minimum-flow-rate probe. A single flow-rate sensor is desirable since the flow-rate results in a disturbance of the flow path. Additionally, air flow is the same when differential pressure across the enclosure 102 is the nearly zero. In various illustrative embodiments, the fan assembly 103, the plurality of panels 108, and the plurality of thin film heating elements 109 are configured and arranged to minimized the differential pressure across the enclosure 102 since differential pressure results when there is an significant obstruction to the flow of air and such obstruction would hinder the transferability of the heat air to the desired heating space. It should be clear to those skills in the arts that various techniques exist and can be employed to measure temperature or flow rate.

Additionally, it should be further clear to those skilled in the arts that various control schemes for such safety devices exist and can be employed to protect against over temperature events and under-flow events.

In an alternate embodiment, the plurality of temperature sensors 152 and the flow sensor 158 can be binarized and used within a logic control circuit. FIG. 17 shows an example of the logic control circuit 160 that operates on binarized sensed signal from the plurality of temperature sensor 152 and the flow rate sensor 158. Reading from temperature sensor 162 is fed into maximum-temperature detector 166. The maximum-temperature is a binarized threshold detector. If the maximum-temperature detector 166 does not detect an over-temperature reading, the logic circuit 160 goes to a null waiting state in state 172. However, if the maximum-temperature detector 166 detects an over-temperature reading in one of the plurality of heating elements 109, the logic circuit 160 goes to emergency heating break state 174. In the emergency heating break state 174, the power to the plurality of thin film heating elements 109 is cut. The logic circuit 160 would return to state 162 once the error is cleared by the operation, or sufficient time has passed for the temperature reading of the plurality of heating elements 109 to drop below the trip threshold. In an alternate embodiment, additional signal processing can be employed with the threshold detector, such as a hysteresis circuit, or a low-pass filters to minimize the likelihood of false-trips in the over-temperature detector 166.

Reading from the flow-rate sensor 158 is captured in step 164. The readings are fed to a minimum flow-rate detector 168. If the minimum flow-rate is above the minimum flow-rate threshold, the logic circuit 160 goes to the null waiting state in state 172. However, if the minimum flow-rate detector 164 detects an under flow rate reading, the minimum flow-rate detector 168 signals the logic circuit 160 to check the heating elements activated state 170. If the plurality of thin film heating elements is not energized, the logic circuit 160 does nothing and waits in the null waiting state 172. However, if the thin film heating elements are energized, the logic circuit 160 is directed to enter emergency heating break state 174, thus disabling the thin film heating elements 109. The logic circuit 160 can exit the break state 174 through the various mechanisms discussed above. It is further contemplated that the various embodiments of the illustrative embodiment and the alternative embodiment can operate with out an over-temperature sensor or a minimum-flow-rate sensor.

It is contemplated in this illustrative embodiment that the inputs of the plurality temperature sensor 152 and the flow-rate sensor 158 are continuously monitored by the controller 150. Examples of the placement of the plurality of temperature sensor includes the first thin film heating element of the plurality of thin film heating elements 109 in proximity to the inlet 104, the last thin film heating element of the plurality of thin film heating elements 109 in proximity to the outlet 120, and the thin film heating element of the plurality of thin film heating elements 109 centrally located in the enclosure 102. It is contemplated in the present embodiment and should be clear to those skilled in the arts that output from the plurality of temperature sensors are fed to a plurality of over-temperature detector 166 and an over temperature event results in a tripping state with the logic circuit 160 directed to emergency heating break state 174.

It is further contemplated in the various illustrative embodiments that the electric cables used in the safety and control circuits are rated above 180 degrees Celsius and further are coated in fiberglass for safety.

FIG. 18 shows an alternate embodiment of the control logic 160 for the system depicted in FIG. 17. While the temperature in room 210 is above the set temperature of thermostat 212, the logic does nothing However, as soon as temperature sensor 222 reads below the set point of the thermostat, the fan assembly 218 and then soon after forced warm-air heating apparatus 100 is energized so that air will flow though ducted system 206. As the air flows though forced warm-air heating apparatus 100, it is heated as the plurality of thin film heating elements 109 heat up. This transforms the cool air entering inlet duct 220 into hot air exiting spigot 216 with net effect of increasing the temperature in room 210. When thermostat 212 senses the air temperature in room 210 to be above the thermostat set point, the forced warm-air heating apparatus 100 and then the fan assembly 218 turns off. The above description is by no means the only way to incorporate the forced warm-air heating apparatus 100, the fan assembly 218 and a ducted air system to heat air. The multitude of combinations of push and pull fans, with the ability to utilize valves and multiple duct work is endless as will be evident to those skilled in the art.

A possible control scheme for the configuration of FIG. 17 is shown in FIG. 18. Control system 204 continuously monitors room 210's temperature though thermostat 212, as soon as the temperature in room 210 drops below the thermostat set point, controller 204 switches the fan assembly 218 on. At this point controller 204 reads cavity 202 temperature with temperature sensor 222. If the cavity 202 temperature is above the set point, the system will do nothing and hot air will flow from roof cavity 202 into room 210. However, if the roof cavity 210 temperature is below the set point temperature, controller 204 will engage the forced warm-air heating apparatus 100, turn the plurality of thin film heating elements 109 on and allow the air flowing from roof cavity 202 to be heated before it is releases into room 210.

As an example of the various illustrative embodiments, forced warm-air room heating apparatus 100 is shown installed as part of an internal ducting system of a house 200 in FIG. 19. House 200 consists of room 210 and roof cavity 202. The ducted system 206 of house 200 is a series of components, starting with inlet duct 208, through apparatus 100 past the fan assembly 218 though an outlet spout 216. Room 210 is equipped with thermostat 212, which includes a temperature setting device and a thermometer. Thermostat 212 is connected to controller 204 via communications link 214. It is further contemplated in the present embodiment that the forced warm-air heating apparatus 100 is further equipped with a communication module that enables a user to remotely control the forced warm-air heating apparatus 100 to set the temperature set-point in the desired heating space.

In an illustrative embodiment, the communication module enables one way, or two way communication between the controller 150, which is operatively coupled to the forced warm-air heating device 100, and to the thermostat. It should be clear to those skills in the arts that other user friendly setting and operating set-points can be communicated over the remotely control communicate. It is further contemplated that the communication module can be operated over a wireless communication. Examples of wireless communication system includes, but not limited to, various 900 MHz and 2.4 GHz spectrum wireless system, such as Ethernet 802.11a/g/n, Bluetooth, and Zigbee. Other consumer communication protocols can also be utilized, such as an X-10, and other wireless communication such as infrared, and low power radio.

In an alternate embodiment, FIG. 20 shows another configuration of a ductwork 220 for the forced warm-air heating apparatus 100. The ductwork 220 is exposed to air supply in the roof cavity 202. This configuration enables the room 210 to be heated by the air in roof cavity 202 as long as there is a positive temperature difference between roof cavity 202 and room 210. The present heating embodiment is achieved by operating the fan assembly 218 and forcing the hot air from the roof cavity 202 into the room 210. However, when the temperature in the room cavity 202 is lower than the temperature in the room 210 as sensed by temperature sensor 222 in the room cavity 202, the forced warm-air heating apparatus 100 collectively energizes the plurality of thin film heating elements 109 and the fan assembly 218 to heat air from the roof cavity 202 sufficiently heat the room 210.

In an example of the illustrative embodiment as shown in FIG. 19 and FIG. 20, the inlet duct size 208, 220 is 200 mm in diameter. In various alternate embodiments, the diameter size of the inlet duct can be between 10 mm and 1000 mm. In an illustrative embodiment, the outlet duct size 216 is 300 mm in diameter. In various alternate embodiments, the outlet duct size 216 can be between 10 mm and 1000 mm. It should be clear to those skilled in the arts that the various diameter sizes can vary for the appropriate heating application.

In various illustrative embodiments, the various configurations of the inlet 104 is shown in FIG. 21A-FIG. 21F. It should be clear to those skilled in the arts that the location, size, and number of the inlet 104 can be varied to compel the air flow into the enclosure 102 to generate laminar flow along the surface of the plurality of thin film heating elements 109, while minimizing the formation of turbulent flow throughout the plurality of channels 110 in the enclosure 102. Thus, the inlet 104 can be arranged, sized, numbered in such a way as to affect the airflow characteristic with respect to the plurality of thin film heating elements 109. For example, in FIG. 21B and FIG. 21C, a plurality of inlets 104 is employed to generate an impingement in the air flow as the air flow is flows across the first of the plurality of thin film heating element 109 in the enclosure 102. Various shapes can be employed to generate the same effects as shown in FIG. 21D, where a square shaped inlet 104 is employed. The impingement effects can be further altered by multiple square inlet 104 as shown in FIG. 3E and FIG. 3F.

In an illustrative embodiment, FIG. 23 shows an exposed side view with a side wall of the enclosure 102 removed to reveal the internal supporting structure of the enclosure 102 according to an illustrative embodiment. The plurality of panels 108 is shown as an downward X-shape truss 232 to reveal the supporting interior structure of the enclosure 102. A complementary upward X-shape truss 230 is also shown. The present embodiment provides an example of the plurality of thin film heating elements 109 providing internal support to the enclosure 102.

The foregoing has been a detailed description of illustrative embodiments of the invention. Likewise, the drawings presented herein should be considered as only illustrative of particular examples of the invention. Various modifications and additions can be made without departing from the spirit and scope of this invention. Each of the various embodiments described above may be combined with other described embodiments in order to provide multiple features. Furthermore, while the foregoing describes a number of separate embodiments of the apparatus and method of the present invention, what has been described herein is merely illustrative of the application of the principles of the present invention. For example, while the heating has been shown in a home context, it can be used in various other settings, such as a vehicle setting, a temporary structure, such as a tent, an office and industrial type buildings. The control mechanism employed, are likely variable,

In addition, the heater can be coupled to other in-line heating system to operatively enhance the function of or to supplemental other ancillary functions such as, but not limited to, a cooling system, a humidifier system, a dehumidifier system, air filtration system, an air purification system, and other air conditioning system. Moreover, the system can be packaged in a portable system or a permanent fixed based system. Accordingly, this description is meant to be taken only by way of example, and not to otherwise limit the scope of this invention.

Claims

1. A forced warm-air room heating apparatus comprising:

an enclosure having an inlet, an outlet, and a plurality of panels, wherein the plurality of panels are constructed and arranged to define a plurality of channels that increases heat exchange characteristics as air passes thereover;

a plurality of thin film heating elements lining some of the plurality of panels constructed and arranged to produce warm heated air in each of the plurality of channels; and

a fan operatively coupled to the enclosure to force the warm heated air through each of the plurality of channels to the room.

2. The forced warm-air room heating apparatus of claim 1 wherein some of the plurality of panels are constructed and arranged to at least one of dividing and deflect the direction of flow from the inlet to the outlet through the plurality of channels.

3. The forced warm-air room heating apparatus of claim 1 wherein some of the plurality panels are constructed and arranged as a planar surface, a curve surface to gently generate laminar flow, and a curve surface to aggressively generate laminar flow.

4. The forced warm-air room heating apparatus of claim 1 wherein the plurality of thin film heating elements is constructed of thin film carbon fibers substantially comprised of carbon.

5. The forced warm-air room heating apparatus of claim 1 wherein the plurality of thin film heating elements is electrically powered.

6. The forced warm-air room heating apparatus of claim 1 wherein the plurality of panels is constructed and arranged as a plurality of air ducts.

7. The forced warm-air room heating apparatus of claim 1 wherein some of the panels of the plurality of thin film heating elements align a substantial portion of a panel of the plurality of panels.

8. The forced warm-air room heating apparatus of claim 1 further comprising a thermal insulating layer between the plurality of heating elements and the plurality of panels.

9. The forced warm-air room heating apparatus of claim 8 wherein the thermal insulating layer comprises at least one of galvanized steel, steel, stainless steel, zinkalume, copper, super alloys, intermetallics, low alloy steels, carbon-carbon composites, high alloy steels, cast iron, high alloy cast iron, refractory metals, ferrous alloys, nickel based alloys, cobalt based alloys, zirconis, ceramics, titanium based alloys, and high temperature resistance polymers.

10. A forced warm-air room heating system comprising:

an enclosure having a fan assembly, an inlet, an outlet, a plurality of panels, and a plurality of thin film heating elements, wherein the plurality of panels is constructed and arranged to define a plurality of channels that increases heat exchange characteristics as air passes thereover, wherein the plurality of thin film heating elements line some of the plurality of panels constructed and arranged to produce warm heated air in each of the plurality of channels, and wherein the fan assembly is configured and arranged to operatively couple to the enclosure to force the warm heated air through each of the plurality of channel; and

a controller assembly comprising a plurality of sensors and a processor, wherein the plurality of sensors are arranged within the room to measure thermal properties within room, and wherein the processor operatively couples to the sensor to control at least one of the energizing of at least some of the plurality of the thin film heating elements and the fan assembly.

11. The forced warm-air room heating system of claim 10 wherein the plurality of thin film heating elements is constructed of thin film carbon fibers substantially comprised of carbon.

12. The forced warm-air room heating system of claim 10 wherein some of the plurality of panels are constructed and arranged to at least one of divide and deflect the direction of flow from the inlet to the outlet through each of the plurality of channels.

13. The forced warm-air room heating system of claim 10 wherein some of the plurality panels are constructed and arranged as a planar surface, a curve surface to gently generate laminar flow, and a curve surface to aggressively generate laminar flow.

14. The forced warm-air room heating system of claim 10 wherein the plurality of panels is configured as a plurality of air channel comprises a plurality of air ducts.

15. The forced warm-air room heating system of claim 10 wherein some of the panels of the plurality of thin film heating elements align a substantial portion of a panel of the plurality of panels.

16. The forced warm-air room heating system of claim 10 wherein the plurality of sensor further comprises a flow sensor, wherein the flow sensor measures a rate of air flow data within at least one of the plurality of channels, and wherein the controller further operatively coupled to the flow sensor to receive the rate of air flow data.

17. The forced warm-air room heating system of claim 10 wherein the controller further comprises a communication module configured to receive a desired temperature set-point from a user interface.

18. The forced warm-air room heating system of claim 17 wherein the communication module is configured to receive the desired temperature set-point from the user by electromagnetic waves.

19. A method of heating a desired heating space using warm air comprising:

energizing a plurality of the thin film heating elements arranged to a plurality of channels to generate a warm air mass in the plurality of channels;

forcing an air flow by a fan assembly to at least one of deflect and divide the air flow to compel the warm air mass from at least some of the plurality of channels to the desired heating space.

20. The method of claim 19 wherein some of the plurality channels is constructed and arranged with a plurality of curve surfaces to at least one of gently generating laminar flow and aggressively generating laminar flow as the air flow passes over the surface of at least one of the plurality of thin film heating elements.