AU701134B2

AU701134B2 - Floor heating system

Info

Publication number: AU701134B2
Application number: AU61912/98A
Authority: AU
Inventors: Terry Wayne Alsberg
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-03-15
Filing date: 1998-04-15
Publication date: 1999-01-21
Anticipated expiration: 2015-03-15
Also published as: AU6191298A

Description

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AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT *1

ORIGINAL

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Namne of Applicant: Actual Inventor: Address of Service: Invention Title: TERRY WAYNE ALSBERG Terry Wayne ALSBERG BALDWIN SH-ELSTON WATERS MARGARET STREET SYDNEY NSW 2000 "FLOOR HEIATING SYSTEM" Details of Original Application No. 21037/95 dated 15th March, 1995 The following statement is a full description of this invention, including the best method of performing it known to me:-- *i-A,AlWkMI tSN SSJ .fIMIAwz* n ias n a aina.

FLOOR HEATING SYSTEM BACKGROUND OF THE INVENTION 1. Fiead of Invention T his invention relates to hydronic or electric radiant panel beating or cooling sysms.m 2. Description of the Prior Art Prnor ant in the cork-pt of heating a space by heating the floor surface within the spa=c :goes Toack as far as the Romran Empire. Hydramic floor panel heating systems currently in use emaploy mnetal or plastic tubing embedded in a conaret slab or tubing with alumninum plate amat.-hed through va rious man. There art systems (for example, as distributed by the Wirsbo Comepany of Apple Valley. Minnesota) wheir after a floor is constructed, the alumninum plates are attached underneath the plywood subfloor. between the floor joists.

There have been systems were the aluminumn plates and tubing are supported by light framing (see for example Shiroki, US patent number 4,865,12()), gioorved foamn plastic sheets or grooved plywood (for example as distributed by L-agerstcdt and Krantz A.B of Sweden) placed above the subfloor and covered by an additional she=t of nailable material- Tere have been some foarn plastic systemns (for examplr as distributed by Wirsbo A-B olf Sweden) and somoe tile systems (See for example German patet number DE3411 339A I and Williamns,, US patent number 3,037,746) that utilize modular groove geomnty to facilitate the layout of the arrays of tubing.

~i~~UUi~aol6t~t~ ll~ a~e~,~~lmT,~L~I~WI~ -3- There have been a number of systems that are comprised of indi'idual panels which contain tubing already embedded in the panels and which are then joined together to create a larger radiant panel array (see for example Rapp, US patent number 2,681,796 and Japanese patent numbers 57-108531, 59-158919, 59-95321, 59-225228) which is placed upon a previously constructed subfloor system.

There is no evidence of systems where there is a combination of a structural subfloor panel, with a top surface comprised of a heat conductive sheet embossed with grooves laid out in a modular geometry, which implements the full range of features described herein. It is this unique combination of elements into a system which greatly 10 simplifies the installation of rad:aant panel heating that distinguishes the present invention from the prior art.

All radiant panel heating systems have tended to provide superior comfort among other benefits and yet current systems have had mixed acceptance in part because of: Excessive Cost. Prior systems typically involve highly customised designs to fit each building design and as a result are largely site built. They often require additional structural design and cost due to the weight of the panels. Their installation is labor intensive and is accomplished by specialists. These systems disrupt the timing of the construction process and often interfere with the easy installation of finish floor materials.

Reliability. In most current systems the tubing is concealed from the installers of finish floor materials and it is not unusual for a tube to be damaged by a fastener during this process. During a remodel, relocating interior walls also poses a great risk of tubing damage. When tubes are damaged the location of the damage may not be readily detected and the repairs often require substantial dismantling of the floor panels.

Response time. Because of high thermal mass and/or high thermal resistance, current systems are typically slow to respond to changing heating loads with response times measured in hours or days.

It is an object of the present invention, at least in the preferred embodiment, to overcome or substantially ameliorate one or more of the disadvantages of the prior art.

I jL SUMMARY OF THE INVENTION According to a first ispect of the invention there is provided a thermal transfer system for a building story including: a plurality of load-bearing panels, each panel composed of a structural material which can be sawn, nailed, screwed, glued and otherwise utilized in a manner consistent with the requirements for unheated subfloors employed in conventional frame construction, each of the load-bearing panels having a grooved surface to which a heat conducting layer is adhered to form a thermally conductive surface and which substantially conforms to said grooved surface, 10 said grooved surface of each of said load bearing panels positioned to abut said :grooved surface of an adjacent load bearing panel, the plurality of load-bearing panels being positioned together to form a subfloor that is substantially continuous for the story, is sccured to support members, and the thermally conductive surfaces of the secured load-bearing panels provide a continuous 15 pathway of grooves substantially throughout the subfloor, said grooves opened at a top surface of the subfloor, for incorporating a thermal exchange means to form a substantially continuous, substantially planar, thermally conductive surface over substantially all of the subfloor, prior to and independent of erecting walls or partitions.

20 According to a second aspect of the invention there is provided a method for constructing a thermal exchange system for a building story of a structure including support members, from a plurality of load-bearing panels, each panel composed of a structural material which can be sawn, nailed, screwed, glued and otherwise utilized in a manner consistent with the requirements for unheated subfloors employed in conventional frame construction, each of said load-bearing panels having a grooved surface and a thermally conducting panel surface on which is formed a modular grooved pattern that substantially conforms to said grooved surface, the method including the steps of: securing the plurality of load-bearing panels to the support members to form a subfloor that is substantially continuous for the story wherein the modular groove l l l IW,^ patterns of the plurality of load-bearing panels form a continuous network of grooves substantially throughout a top surface of the subfloor; and depositing a thermal exchange means in the network of grooves after forming said sub floor and prior to and independent of erecting walls or partitions.

A preferred embodiment of this invention provides for: A modular geometry, subfloor system, installed using conventional construction methods, timing and skills, which in one step provides a structural subfloor and the basis of a heating system.

Reduced dead weight for a radiant panel heating system which will 10 reduce lateral and vertical loading of a building's structural systems.

A system which allows for and therefore is largely independent of wall ~placement and application of finish floor materials, is not easily damaged either during the primary construction or any subsequent remodelling phase and which is more readily repaired if damaged.

15 A reduction in response time to changing heating leads.

In combination with all of the above objectives: a reduction in the cost of materials and labor along with an increase in user satisfaction sufficient to make the overall cost/benefit comparison of radiant panel heating to other heating systems, more favourable.

20 In a typical embodiment of the invention, the subflooring membrane of a building is constructed of special sub-floor panels made typically of plywood, oriented strand board or other structurally suitable material which like plywood is easily sawn, nailed, glued and otherwise utilized in a manner consistent with prevalent practices in the construction industry. The sub-floor panels have been manufactured with a pattern of grooves formed into their surface; a heat conductive sheet has been embossed to match the pattern of the grooves; and this sheet has been bonded to the sub-floor panels.

After the panels are in place, an elastomeric compound is placed in the grooves and tubing is pressed into the grooves, following the pattern provided by the modular geometry. The compound holds the tubes in place; fills in any air voids between the tubing and the heat conductive surface and is trowelled flush with the top surface of the panels thereby providing a smooth surface to which finish floor materials are easily

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*~Ckn-,rlBw -6attached. The heat conducting surface is in direct contact with the finish floor covering and provides for a more rapid thermal response than conventional systems.

In one step, prior to walls being constructed, the structural subfloor and heating system is installed, thereby providing great cost savings. The clear visibility of the tubing paths makes damage of the tubing while fastening walls and finish flooring materials to this subfloor, unlikely. In the event of damage, leaks are easily located and repairs are easily made.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more fully comprehended from the following detailed 10o description and accompanying drawings in which: FIG. is an isometric view of this invention utilized within a typical floor framing, subfloor and wall framing system.

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7- FIG. 2 is a schematic top view of the modular assembly of the heating panels into an array which provides a continuous unjointed tubing path.

FIG. 3 is a top view of the grooves in a typical modular sub-floor panel used for the end tubing runs.

FIG. 4 is a top view of the grooves in a typical iri adular sub-floor panel used for straight tubing runs.

FIG. 5 is a cross section view of the assembled sub-floor panel heat conductive sunrace and hydronic tubing.

FIG. 6 is a top view of the grooves in a single modular sub-floor panel which is an 10 rsggregate of the geometies depicted in Figs. 3&4.

FIG. 7 is a top view of the grooves in a group of related modular sub-floor panels, which are disaggregated from the geometries of Figs. 3&4.

DETAILED DESCRIPTIION Referring now to Fig. 1. a typical application of the present invention within at floor framiing system is depicted. Conventional floor joists 1 comprise the support system Panels 2 (such as am depicted in Fig. 3) and 3(such as aedepicted in Fig. 4) are fastned to thc floor joists; in a manner typical of conventional subflooring membranes. A tube 4 of the type employed in radiant panel heating is pressed into the modular pathway of grooves.

In this example, the inlet is at 5 and the outlet is at 6. The spacing of the grooves allows for exterior walls 7 to be fastened directly to the panels without damaging the tubes.

Interior walls 8 can cross the grooves without bearing on and therefore, without damaging the tubes. The clear visibility of the tubing paths allows for walls or finish floor materials to be fastened to the subfloor membrane with nails 9, without damage to the rubes.

make a lecaks neesrtoesm isblt htmkspucuenieywl mke lakseasy tolocate.Onytapatodifiihforcvigoerheeetwul haeto be removed rather than removing whole sections of the subfloor.

The heat conductive surface is in direct contact with the floor covering such as for example carpcr, hardwood floor or tile. The thermal impedance provided by the finish floor covering slows down heat dissipation from the surface sufficiently to reduce the- heat gradient berwec adjacent hydronic tube elements.

In existing hydronic systems the warm up time or thermal lag is governed by thec thermal mass and/or resistance of the concrete slab or the plywood subfloor. This can be many hours or even days in existing systems. In the subject invention. low mass plus low resistanice permits a change of surface temperature to become measurable in minutes.

~56~E~slcla9aulW~nru~b /~i~lP~i~dlr~nYr~ -8- Fig. 2 is a top view of a typical array of heating panels which shows an example of how hydronic tubing is placed in an array. The hoc water input 5 is routed along the grooves tangential to the arcs of end section panels 2. Then it is routed to a 90 degree curved groove 11. It is then routed as shown in Fig. 2 through end panels 2 turning 180 degrees 12 typically at each end panel, and through straight panels 3 finally turning in a 90 degree groove 11 to the toutput 6 thereby completing a circuit.

Fig. 3 is a top view of an end section panel utilizing three longitudinal grooves per panel. The size and aspect ratio is typical of subfloor panels currently in use. The spacing between the centers of three grooves 13,14, 15 is one third of the width of she panel. The centers of grooves 13 and 15 are spaced one sixth of the width of the panel 2 from the long edge of the panel 2. On one end of the panel 2 the ends of grooves 13, 14 and 15 are Terminated by semi circular arc grooves 12. In addition, grooves 13, 15 connect to quarter arc circular grooves 1L Lastly a straight groove 10 is placed tangential and connecting to arcs 11 and 12. The center of this tangential groove is spaced the same distance from the short edge of a panel as grooves 13 and 15 are spaced from long edge.

S. This spacing, which is based on three primary tubing paths per panel, is optimum for typical construction in the U.S. based on English units of measure. It allows for the erection of exterior walls of conventional thickness while providing sufficient space between the interior surface of an exterior wall and the nearest tubing path for attachment of carpet tack 20 strips. Nonetheless, it may be advantageous to manufacture panels with one, two, four, five or six tube modules per sheet of subfloor, but still in accord generally with the geometry and modularity depicted herein. These units may be selected where, for example, case of carpet installation is less important than various other considerations such as surface temperatmre and tubing density. Where metric based lumber and subflooring materials are 'sed, the exact 25 spacing may need to be modified based on the metric sizing of conventional construction materials, but still in accord with the geometry and modularity depicted herein.

Fig. 4 is a top view of a straight section panel utilizing three longitudinal grooves per paneL The spacing between the centers of the three grooves 16, 17, 18 is one third of the width of the panel 3. The centers of grooves 16 and 18 are spaced one sixth of the width of the panel from the long edge of the panel 3. The variations arising from differing numbers of tubing pathways per panel or metric units of measure envisioned ia the description of the panels in Fig. 3 apply to these straight run panels as well.

Fig. 5 is a cross section view applicable to all panels depicted herein. A groove 19 is formed in a sub-floor panel. In one embodiment, panels may be manufactured of a homogenous material such as plywood or oriented strand board. In that embodiment, the layer of a panel 23 in which the groove is formed is structurally compromised by the groove 9 and therefore the remaining layer 24 which is ungrooved must have sufficient structural characteristics to span the typical spacing of floor joists 1 found in standard construction.

Alternatively, the most cost effective embodiment of this invention may be a hybrid panel with a layer 23 of a material such as chip board or particle board whose primary characteristics are compressive strength and a layer 24 of a material such as plywood or oriented strand board whose characteristics are optimized for structure across a span.

A heat conducting sheet 20 is pre-formed to have a contour matching the sub-floor panel topography and is then bonded to the panel. After installation of the panels in the array of FIG. 1 2, elastomer 21 is placed into groove 19. Then the hydronic tubing 22 is 10 pushed tightly into the bottom of the elastomer lined groove 19 to make good th-mal contact with the heat conducting surface 20. Any elastomer 21 not filling voids between the heat conductive surface of groove 19 and the hydronic tubing 22 will be squeezed to the top of the hydronic tubing 22. This excess is then trowelled flush with the top surface of the panel.

This provides a flat surface on which floor covering can be installed directly.

The elastorner 21 serves three functions. It improves the heat transfer between the hydronic tubing 5 and the conductive surface 20 by reducing or eliminating air filled voids. It provides a smooth surface and support for pliable floor coverings such as carpet, linoleum or tile. It holds the tubing in place. In the case of a rigid floor covering such as hardwood, a tight press fit between the hydronic tubing 22 and the heat conductive lined groove 19 may 20 permit complete omission of the clastomer 21 and may be the economically most attractive construction method.

The two panel types depicted in Figs. 3&4 are sufficient to produce all of the desired benefits envisioned for this invention with only occasional on site modification. However, in order to allow just two types of panels to accommodate a wide variety of panel layouts, it is 25 obvious that in a given panel there may be arced paths 11 and 12 and tangential paths 10 that are not utilized in a given panel Eliminating these unused paths by disaggregating the basic geometry of the system into a number of differentiated panels might reduce some of the costs of manufacture and installation with the trade off that more types of panels may be required thereby ihcreasing the tooling and inventory costs associated with this invention. Figs. 7a, 7b, 7c, 7d, 7e depict an example of a system of panels which is a disaggregation of the geometries of panels 2 and 3.

Alternatively, cost savings due to simplified manufacturing and stocking requirements, may override any need to reduce the number of unused paths and may, to the contrary, dictate that a single panel which aggregates the geometry of the panels depicted in Figs. 3&4 will be most cost effective. Fig. 6 is an example of single panel which is an aggregation of the geometries of panels 2 and 3 into a single panel.

The invention has other potential applications and those skilled in the art can find other fields of use. The prescnt invention may be utilized as a wall panel or ceiling panel which can be easily be made smooth in a manner typical of Gypsum Board surfaces. Instead of heating, the invention could be used for cooling by circulating a cooling liquid- In another example electric panel heating may use a similar modular panel with smaller grooves to receive the smaller diameter wires typical of these systems. Electric cooling could be accomplished by using coulomb cooling, Ther may be other electronic or thernodynamic applications where standardized modular panels can facilitate the easy assembly of arrays of wires, tubes or fibers as part of a conductive surfae.

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Claims

3. The thermal transfer system of claim 2, wherein the grooves of the load-bearing panels are aggregated into a single load-bearing panel. -12-
4. The thermal transfer system of claim 1, wherein said subfloor that is formed from said plurality of load-bearing panels supports point loads, horizontal shear loads, and uniform loads in accordance with conventional wood frame construction requirements and said subfloor replaces a standard subfloor used in conventional wood frame construction. The thermal transfer system of claim 4, wherein said subfloor provides the structural qualities essential to the transfer of the variety of loads borne by a conventional subfloor membrane including said point loads, said horizontal shear ilads, and said uniform loads in accordance with conventional wood frame construction requirements and said subflocr replaces a standard subfloor used in conventional wood 0 frame construction. S6. The thermal transfer system of claim 5, wherein said load bearing papel can be shaped and fastened to the support members in a manner typical of standard subfloor panels used in conventional wood frame construction.
7. The thermal transfer system of claim 6, wherein a location of said thermal exchange means is visible throughout the top of the subfloor.
8. The thermal transfer system of claim 1, wherein said thermal exchange means is embedded in a hardenable composition.
9. The thermal transfer system of claim 8, wherein the hardenable composition has an appearance that is distinct from that of the heat conducting layer to identify locations of the thermal transfer means and reduce damage to the thermal transfer means. The thermal transfer system of claim 1, wherein the plurality of load-bearing panels further includes an additional groove extending between edges of each second rectangular panel perpendicular to the first and second edges and tangential to the arced grooves.
11. The thermal transfer system of claim 1, wherein the thermal exchange means is used for heating a room in contact with the thermal transfer system. I
13- 12. The thermal transfer system of claim 1, wherein the thermal exchange means includes tubing for carrying a thermal exchange medium throughout the plurality of load-bearing panels. 13. A method for constructing a thermal exchange system for a building story of a structure including support members, from a plurality rf load-bearing panels, each panel composed of a structural material which can be sawn, nailed, screwed, glued and otherwise utilized in a manner consistent with the requirements for unheated subfloors employed in conventional frame construction, each of said load-bearing panels having a grooved surface and a thermally conducting panel surface on which is f-nred a modular grooved pattern that substuLtially conforms to said grooved surface, the method including the steps of: securing the plurality of load-bearing panels to the support members to form a subfloor that is substantially continuous for the story wherein the modular groove patterns of the plurality of load-bearing panels form a continuous network of grooves substantially throughout a top surface of the subfloor; and depositing a thermal exchange means in the network of grooves after forming said subfloor and prior to and independent of erecting walls or partitions. C *14. The method of claim 13, wherein said subfloor that is formed from said plurality of S* :load-bearing panels supports point loads, horizontal shear loads, and uni':rm loads in C 20 accordance with conventional wood frame construction requirements and said subfloor replaces a standard subfloor used in conventional wood frame construction. The method of claim 14, wherein said subfloor provides the structural qualities essential to the transfer of the variety of loads borne by said unheated single layer subfloor membranes including said point loads, said horizontal shear loads, and said unifbrm loads in accordance with conventional woe i frame construction requirements and said subfloor replaces a standard subfloor used in conventional wood frame construction.
16. The method of claim 15, wherein said load bearing panel can be shaped and fastened to the support members in a manner typical of standard subfloor panels used in conventiona!, wood frame construction. I-- -14-
17. The method of claim 16, wherein a location of a said thermal exchange means is visible throughout the top of the subfloor.
18. The method of claim 13, further including the step of: depositing a hardenable composition in the network of grooves after forming said subfloor and prior to and independent of erecting walls or partitions.
19. The method of claim 18, further including the steps of: smoothing the hardenable composition to form a substantially planar surface with the thermally conducting panel surface; and curing the hardenable composition to form a load-bearing, thermal exchange 10 surface in the subfloor of the story.
20. The method of claim 13, wherein the depositing step includes the steps of: depositing a hardenable composition in the network of grooves; embedding the thermal exchange means in the deposited hardenable composition so that the hardenable composition forms a heat conducting path between the thermal exchange means and the plurality of load bearing panels; and depositing additional hardenable composition over the thermal exchange means.
21. The method of claim 20, wherein the step of depositing a hardenable composition includes the steps of: selecting the hardenable composition that is visually distinguishable from the conducting panel surface when cured for identifying the locations of the thermal transfer means; and depositing the selected hardenable composition in the network of grooves.
22. The method of claim 21, wherein said load bearing panel can be shaped and fastened to the support members in a manner typical of standard subfloor panels used in conventional wood frame construction.
23. A thermal transfer system for a building story substantially as herein described with reference to the accompanying drawings.
24. A method for constructing a thermal exchange system for a building story of a structure including support members substantially as herein described with reference to the accompanying drawings. DATEDthis 12th Day of October 1998 TERRY WAYNE ALSBERG Attorney: JOHN B.;REDFERN Fellow Institute of Patent Attorneys of Australia of BALDWIN SHELSTON WATERS e eo -P I S. ABSTRACT The present invention provides in combination, a radiant panel heating system, configured for ease of installation and maintenance which also provides the structural characteristics required of a subflooring panel within a floor framing system. The 5 system consists of structural subflooring panels with grooves arrayed in a modular geometry. The panels are overlaid with a heat-conducting surface embossed with a matching groove pattern. The panels are capable of being fastened to a variety of floor support structures in a manner typical of subfloor panels, which fulfil a structural requirement only while simultaneously interacting to create an array of approximately 10 evenly spaced grooves into which tubing or wire of the type used in hydronic or *ooele a• 0electric radiant panel heating is installed. c-