Radiant Heater

Abstract

A radiant heater with a panel forming corrugations and having at least one heating element mounted on one of the corrugations. The panel is mounted at a distance from a surface partially defining a space to be heated for permitting fluid circulation between the panel and the space. The heating element is arranged in a groove defined at the apex of a convex surface defined by the corrugation, and is arranged facing the space defining surface. When a plurality of heating elements are provided, a thermostat having a set of contacts for each heating element is provided for actuating at least a portion of the elements at a predetermined temperature different from that for the other heating elements.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to radiant heating, particularly a radiant electric panel heater intended to be suspended from a ceiling.

2. Description of the Prior Art

Radiant heating panels are known which are suspended from, for example, a ceiling with their heating elements directed downwardly. Their flat panels, however, are very directional and do not cover a large area. Radiant heaters are also known that use corrugated panels. An example of such a heater may be found in U. S. Pat. No. 2,469,963. This type of heater, however, is intended to be mounted in, for example, a ceiling with insulation provided for preventing the radiated rays from going upwardly. The known heaters using corrugated panels locate the heating elements in concave portions of the corrugations for focusing the rays into the space to be heated. This arrangement has the disadvantage of not providing uniform temperature distribution in the space to be heated.

A further problem encountered with the known radiant heaters is that although they generally are maintained at high temperatures in the range of, for example, 2,200.degree. Fahrenheit to 4,000.degree. Fahrenheit, it has been found that they must operate at least 80 percent of the time for efficiency and optimum comfort when used in an area having an outside design temperature, of, for example, 0.degree. Fahrenheit. The known radiant heaters have the disadvantage that they are not suitable for operation of up to 80 percent of the time.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a radiant heater which will heat evenly a space to be heated. It is a further object of the present invention to provide a radiant heater which will have at least one heating element operating at least 80 percent of the time.

These and other objects are achieved according to the present invention by providing a radiant heater with a panel forming corrugations and having a heating element mounted on one of the corrugations, means for mounting the panel at a distance from a surface partially defining a space to be heated for permitting fluid circulation therebetween, and arranging the heating element for facing the surface.

A preferred embodiment of the present invention has the one corrugation form a convex surface with an apex defining a groove, and the heating element mounted in the groove.

It is possible, especially to realize the feature of almost continuous operation, to provide a plurality of heating elements and an equal number of corrugations defining grooves, each heating element mounted in a respective groove.

A preferred embodiment according to the present invention for realizing the almost continuous operation of the the radiant heater has means provided for actuating at least one of the heating elements at a predetermined temperature different from that for the other element. When this feature is used, the panel preferably has a plurality of sections, each section associated with a heating element, and means are provided for connecting the sections together for permitting thermal expansion of one of the sections independently of an adjacent section. This construction effectively prevents warping of the panel due to uneven heating.

The radiant heater according to the present invention is preferably suspended from a ceiling by at least two longitudinal elements, such as chains, each having a pair of spaced ends connected to the panel.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a radiant heater according to the present invention suspended from a ceiling.

FIG. 2 is a schematic, vertical longitudinal sectional view through a space to be heated, and showing an end view of a radiant heater according to the present invention.

FIG. 3 is an end sectional view showing a detail of a radiant heater according to the present invention.

FIG. 4 is a top plan view, partly cut away, showing a radiant heater according to the present invention.

FIG. 5 is a sectional view, on an enlarged scale taken generally along the line 5--5 of FIG. 1.

FIG. 6 is a vertical longitudinal sectional view taken generally along the line 6--6 of FIG. 5.

FIG. 7 is a fragmentary sectional view taken generally along the line 7--7 of FIG. 5.

FIG. 8 is a schematic diagram showing a control system for modulating the heating elements of a radiant heater according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 of the drawings shows a radiant heater 10 according to the present invention suspended from a ceiling 12 by means of chains 14, and supplied with electric power through a conduit 16. It is to be understood that radiant heater 10 could be spaced by rigid members (not shown) from, for example, a wall 18 (FIG. 2) if desired.

Radiant heater 10 has a panel 20 forming corrugations 22. A plurality of heating elements 24, four being shown in the drawings, are mounted on corrugations 22. Panel 20 is arranged at a distance from ceiling 12 for permitting fluid , such as air, to circulate between panel 20 and ceiling 12, and heating elements 24 are arranged facing ceiling 12.

FIG. 3 shows a corrugation 22 which forms a convex surface 26 with an apex 28 having a wall defining a groove 30. A heating element 24 is mounted in groove 30 in a known manner, such as by a suitable, known adhesive material. Heating elements 24 may be tubular, as shown, or in the form of heating strips (not shown). Suitable, known heating elements which will operate in the range of 1,000 to 2,000 watts at 120 or 240 volts may be used. The material for mounting heating element 24 may be an epoxy material bonding the element to a, for example, aluminum panel 20. The heating element 24 may be, for example, an aluminum tube three-eighths of an inch in diameter with resistance wire arranged in the center thereof.

FIGS. 4 to 7 show the construction of panel 20. Panel 20 is preferably made up of a plurality of sections 32, two being shown in the drawings. Sections 32 are joined together as at 34. Means 26 for joining sections 32 together has a clamp 36 for forming a guide channel. This arrangement permits thermal expansion of one section 32 independent of an adjacent section 32. The significance of this construction will be set out below. Clamp 36 is made up of a longitudinally extending wedge piece 38 and a pair of plate members 40 secured to piece 38 by a plurality of bolts and nuts 42.

End covers 44 may be mounted on the longitudinal ends of plate 20 by means of, for example, bolts and nuts 46. Covers 32 finish off panel 20 and provide for mounting a connection box 48 and mounting lugs 50. The two spaced ends 52 of longitudinal chain 14 are connected to lugs 50. Chains 14 can be fastened to a ceiling 12 as by, for example, screw hooks 54.

Connection box 48 houses the distribution system for the various heating elements 24.

FIG. 8 shows a circuit for two-stage modulation of a pair of heating elements 60. A modulating thermostat 56 is connected between a line 58 of a power line 59 which may be a standard 110 or 240 volt line, and a pair of heating elements 60. Elements 60 are in turn connected to one line 62 of power line 59. For a 240 volt system, elements 60 may be connected to ground instead of line 62. Thermostat 56 may be a suitable known type such as that sold under the designation "Mears M7M" One contact, for example, contact 64, is set close at a predetermined temperature. The other contact, for example, contact 66, is set to close at a temperature slightly below that for contact 64. This temperature difference, may be, for example, 1 degree F. Thus, heating element 60 in series with contact 60 may be selected to satisfy the normal heating requirement with at least 80 percent operation. This permits element 60 to operate in an efficient manner, and to maintain a steady heat in the space to be heated 68 (FIG. 2). While only one contact 66 is closed, heater 10 uses only one-half the total rated wattage. Each element 60, which may be, for example, two heater elements 24, is associated with a section 32 so that thermal expansion of only the one section takes place. Only when the heating load becomes too great for one heating element 60, does contact 64 close and bring the other heating element into operation.

It is known that every point of a surface emits a visible infra-red heat ray which travels away from that point in a straight line in any direction, but with greater intensity perpendicular to the surface, decreasing to zero intensity parallel with the surface, and decreasing intensity with distance. Corrugated aluminum panel has been found to provide most all points with maximum intensity, thus achieving optimum radiant comfort.

As can be seen from FIG. 2, panel 20 radiates the rays in both directions from corrugations 22 and spreads them evenly over space 68, which may be a room. The rays will tend to bounce-off floor 70 and wall 18 for additional diffusion. Panel 20, and thus heater 10, should be spaced about, for example, three inches from the lowest extending portion of ceiling 12 for optimum results. The portion of ceiling 12 adjacent panel 20 may be covered with a reflective medium for increasing the distribution of rays reflected toward ceiling 12 (FIG. 2) and the ceiling itself becomes a radiant panel. Thermostat 56 and/or an off-on switch (not shown) may be provided and arranged at a suitable location in a surface defining the space 68.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

Claims

What is claimed as new is as follows:

1. A radiant heating panel for mounting on a wall surface of a space to be heated, comprising, in combination:

a. a corrugated, heat radiating panel;

b. means for mounting said panel adjacent to and spaced from a wall surface for permitting fluid circulation between the panel and wall surface, the corrugations of said panel including alternate concave and convex surfaces arranged facing a space to be heated partially defined by the wall surface, an apex of at least one of the concave surfaces being provided with means for defining a shallow, elongated groove open toward the wall surface; and

c. an elongated heating element mounted in the groove and arranged facing and radiating directly onto the wall surface.

2. Structure as defined in claim 1, wherein there are a plurality of heating elements, and at least an equal number of corrugations defining grooves, each heating element mounted in a respective groove.

3. Structure as defined in claim 2, wherein means are included for actuating at least one of the heating elements at a predetermined temperature different from that for the other heating elements.

4. Structure as defined in claim 2, wherein said panel includes a plurality of sections having edges arranged side-by-side, each section having associated therewith at least one heating element, and means including clamp means forming a guide channel connecting said sections together at said edges for permitting independent thermal expansion thereof.

5. Structure as defined in claim 2, wherein the space defining wall surface is a ceiling, and said means for mounting includes at least two longitudinal elements, each having a pair of spaced ends connected to said panel for suspending said panel from the ceiling.

6. Structure as defined in claim 1, wherein said panel includes a plurality of sections having edges arranged side-by-side, each section having associated therewith at least one heating element, and means including clamp means forming a guide channel provided for connecting said sections together at said edges for permitting independent thermal expansion thereof.

7. Structure as defined in claim 1, wherein the space defining surface is a ceiling, and said means for mounting is at least two longitudinally extending elements, each having a pair of spaced ends connected to said panel for suspending said panel from the ceiling.