Room heating apparatus and methods

Abstract

A room heater comprising a housing having an lower opening at the bottom of the housing forming an inlet to admit a gas into the housing and an upper opening positioned above the lower opening forming an outlet through which the gas exits the housing, and a thermally sprayed heater that provides heat to the gas inside the housing. A method of fabricating the room heater is also disclosed.

1 . A room heater, comprising:
 a housing having an lower opening at the bottom of the housing forming an inlet to admit a gas into the housing and an upper opening positioned above the lower opening forming an outlet through which the gas exits the housing; and   a thermally sprayed heater that provides heat to the gas inside the housing.   
     
     
         2 . The room heater of  claim 1 , wherein the heater comprises a baseboard heater. 
     
     
         3 . The room heater of  claim 1 , wherein the thermally sprayed heater comprises a resistive heating layer having a substantially lamellar structure. 
     
     
         4 . The room heater of  claim 1 , wherein the resistive heating layer comprises a first material and a second material, wherein the first material is an electrically conducting material and the second material is an electrically insulating material. 
     
     
         5 . The room heater of  claim 3 , further comprising a support substrate, the heating layer being provided on the support substrate. 
     
     
         6 . The room heater of  claim 5 , wherein the support substrate comprises a surface of the housing. 
     
     
         7 . The room heater of  claim 5 , wherein the support substrate comprises a separate substrate that is bonded to a surface of the apparatus. 
     
     
         8 . The room heater of  claim 5 , further comprising an insulating layer, the insulating layer being provided on the support substrate and the heating layer being provided over the insulating layer. 
     
     
         9 . The room heater of  claim 8 , wherein the insulating layer comprises a thermally-sprayed layer comprising a substantially lamellar structure. 
     
     
         10 . The room heater of  claim 9 , wherein the support substrate comprises an electrically insulating material, and the heating layer is provided in contact with the support substrate. 
     
     
         11 . The room heater of  claim 5 , wherein the support substrate comprises a mica material. 
     
     
         12 . The room heater of  claim 11 , wherein the mica material comprises a mixture of mica with an electrically insulating material, the mixture having a higher thermal coefficient of expansion than pure mica. 
     
     
         13 . The room heater of  claim 5 , wherein the support substrate comprises a polymer. 
     
     
         14 . The room heater of  claim 5 , further comprising a protective layer, the protective layer being provided over the heating layer and the support substrate. 
     
     
         15 . The room heater of  claim 14 , wherein the protective layer comprises an insulating material. 
     
     
         16 . The room heater of  claim 3 , wherein the resistive heating layer is patterned to provide an electrical circuit, and at least two electrical connectors are in electrical contact with the resistive heating layer to provide a voltage across the circuit. 
     
     
         17 . The room heater of  claim 4 , wherein the content of the electrically insulating material in the resistive heating layer comprises at least about 40% by volume. 
     
     
         18 . The room heater of  claim 4 , wherein the content of the electrically insulating material in the resistive heating layer comprises between about 40-80% by volume. 
     
     
         19 . The room heater of  claim 4 , wherein the electrically conductive material comprises a metallic material. 
     
     
         20 . The room heater of  claim 19 , wherein the metallic material comprises at least one of titanium (Ti), vanadium (V), cobalt (Co), nickel (Ni), magnesium (Mg), zirconium (Zr), hafnium (Hf), aluminum (Al), tungsten (W), molybdenum (Mo), tantalum (Ta); silicon (Si), a metal alloy, a metal composite, and a metalloid. 
     
     
         21 . The room heater of  claim 20 , wherein the electrically conductive material comprises aluminum. 
     
     
         22 . The room heater of  claim 21 , wherein the electrically insulating material comprises a reaction product of the metallic material. 
     
     
         23 . The room heater of  claim 22 , wherein the reaction product comprises at least one of an oxide, a nitride, a carbide and a boride. 
     
     
         24 . The room heater of  claim 23 , wherein the electrically insulating material comprises aluminum oxide. 
     
     
         25 . The room heater of  claim 19 , wherein the electrically insulating material comprises a thermally-sprayed insulating material and a reaction product of the electrically conducting material. 
     
     
         26 . The room heater of  claim 1 , wherein the thickness of the thermally sprayed heater is less than about 0.030 inches. 
     
     
         27 . The room heater of  claim 1 , wherein the thermally sprayed heater is characterized by a material resistivity of greater than about 10 −4  Ω-cm. 
     
     
         28 . A method of fabricating a room heater, comprising:
 providing a housing having an lower opening at the bottom of the housing forming an inlet to admit a gas into the housing and an upper opening positioned above the lower opening forming an outlet through which the gas exits the housing;   thermally spraying a material to form a resistive heating layer;   positioning the resistive heating layer within the housing for heating the gas flowing in the housing.   
     
     
         29 . The method of fabricating a room heater of  claim 28 , wherein the resistive heating layer is thermally sprayed by at least one of an arc wire, flame spray, high-velocity oxy-fuel, arc plasma, and kinetic spray process. 
     
     
         30 . The method of fabricating a room heater of  claim 28 , further comprising providing a feedstock material comprising a metallic material and a reaction gas, and thermally spraying the metallic material in the presence of the reaction gas, the metallic material reacting with the reaction gas to produce a reaction product, the reaction product comprising an insulator. 
     
     
         31 . The method of fabricating a room heater of  claim 30 , wherein the feedstock material comprises a metallic material having a core and an insulator within the core, the metallic material and the insulator being thermally sprayed to form the resistive heating layer. 
     
     
         32 . The method of fabricating a room heater of  claim 28 , further comprising providing an insulating material and forming the resistive heating layer over the insulating material.