U.S. patent application number 13/320063 was filed with the patent office on 2012-04-19 for tile systems with enhanced thermal properties and methods of making and using same.
This patent application is currently assigned to Mohawk Carpet Corporation. Invention is credited to Wesley A. King.
Application Number | 20120090812 13/320063 |
Document ID | / |
Family ID | 43085536 |
Filed Date | 2012-04-19 |
United States Patent
Application |
20120090812 |
Kind Code |
A1 |
King; Wesley A. |
April 19, 2012 |
TILE SYSTEMS WITH ENHANCED THERMAL PROPERTIES AND METHODS OF MAKING
AND USING SAME
Abstract
The various embodiments of the present invention are directed to
tile systems and to methods of making and using the tile systems.
The tile systems provide improved thermal properties to floor and
wall coverings in either heated or unheated applications. The tile
systems generally include a tile and a discrete phase change
material.
Inventors: |
King; Wesley A.; (Rockwall,
TX) |
Assignee: |
Mohawk Carpet Corporation
Calhoun
GA
|
Family ID: |
43085536 |
Appl. No.: |
13/320063 |
Filed: |
May 11, 2010 |
PCT Filed: |
May 11, 2010 |
PCT NO: |
PCT/US10/34390 |
371 Date: |
November 11, 2011 |
Current U.S.
Class: |
165/53 |
Current CPC
Class: |
Y02E 60/14 20130101;
F28D 20/023 20130101; E04F 13/142 20130101; E04F 13/0812 20130101;
Y02E 60/145 20130101; F24H 7/00 20130101; E04F 15/08 20130101 |
Class at
Publication: |
165/53 |
International
Class: |
F28F 7/00 20060101
F28F007/00 |
Claims
1. A tile system, comprising: a tile; and a phase change material
in thermal communication with the tile, wherein the phase change
material does not comprise a portion of the tile, and wherein the
phase change material is configured to increase the heat capacity
of the tile system.
2. The tile system of claim 1, further comprising a heating element
in thermal communication with the phase change material.
3. The tile system of claim 1, further comprising a thermally
insulating layer disposed between the tile and a surface of a floor
or wall on which the tile system is disposed.
4. The tile system of claim 1, wherein the tile is a ceramic
tile.
5. The tile system of claim 1, wherein the phase change material is
a solid state phase change material.
6. The tile system of claim 1, wherein the phase change material is
a liquid phase change material encapsulated in a thermally
conductive container.
7. The tile system of claim 1, wherein the phase change material is
disposed in a cavity within a backside surface of the tile.
8. The tile system of claim 1, wherein the phase change material is
disposed directly on a backside surface of the tile.
9. The tile system of claim 1, wherein the tile comprises a portion
of a floating floor or wall tile unit.
10. The tile system of claim 9, wherein the floating floor or wall
tile unit further comprises a substrate, wherein the tile is
disposed on, or within a cavity within, the substrate.
11. The tile system of claim 10, wherein the phase change material
is interposed between a backside surface of the tile and a top
surface of the substrate.
12. The tile system of claim 10, wherein the phase change material
is disposed at least partially within a cavity within a top surface
of the substrate.
13. The tile system of claim 10, wherein the phase change material
comprises a portion of the substrate and is entirely encapsulated
by the substrate.
14. The tile system of claim 10, wherein the phase change material
is disposed on, or within a cavity within, a backside surface of
the substrate.
15. A tile system, comprising: a tile unit, comprising a substrate
and a tile that is disposed on, or within a cavity within, the
substrate; and a phase change material in thermal communication
with the tile; wherein the phase change material does not comprise
a portion of the tile; wherein the phase change material is
configured to increase the heat capacity of the tile system; and
wherein the phase change material is disposed in a cavity within a
backside surface of the tile, directly on the backside surface of
the tile, between the backside surface of the tile and a top
surface of the substrate, at least partially within a cavity within
the top surface of the substrate, entirely within the substrate, on
a backside surface of the substrate, within a cavity within the
backside surface of the substrate, or a combination comprising at
least one of the foregoing.
16. The tile system of claim 15, further comprising a heating
element in thermal communication with the phase change
material.
17. The tile system of claim 15, further comprising a thermally
insulating layer disposed between the tile unit and a surface of a
floor or wall on which the tile unit is disposed.
18. The tile system of claim 15, wherein the phase change material
is a solid state phase change material.
19. The tile system of claim 15, wherein the phase change material
is a liquid phase change material encapsulated in a thermally
conductive container.
20. The tile system of claim 15, wherein the substrate comprises a
thermally conductive element in thermal communication with the
phase change material and the tile, wherein the thermally
conductive element facilitates heat transfer between the phase
change material and the tile.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims the benefit of U.S.
Provisional Patent Application Ser. No. 61/177,224 filed 11 May
2009, and entitled "Tile Systems with Enhanced Thermal Properties
and Methods of Making and Using Same," which is hereby incorporated
by reference in its entirety as if fully set forth below.
TECHNICAL FIELD
[0002] The various embodiments of the present invention relate
generally to tile systems. More particularly, the various
embodiments of the invention relate to tile systems with improved
thermal performance and to methods of making and using such tile
systems.
BACKGROUND
[0003] Ceramic tiles are prized for their aesthetic and
wear-resistant properties for applications such as floor and wall
coverings. One disadvantage that ceramic tiles have relative to
other decorative covering materials (e.g., solid wood, plastic
laminates, and carpeting) is that surfaces covered with ceramic
tiles tend to feel colder. During winter months, interior spaces
are actively heated, and the significant temperature difference
between outside and inside drives the heat loss through the floor
and walls. There is a need to reduce the heat lost through the
floor and walls by increasing the thermal insulating ability of
ceramic tile products.
[0004] Often there is the desire to warm floors by installing
radiant heating systems underneath the flooring; and, if the
flooring is to be actively heated, then ceramic tile is often
preferred due to its superior ability to conduct heat to its upper
surface, where the heat can be used to heat the room and its
occupants via radiative, convective, and conductive means. Thermal
energy from a floor heating system flows away from the heating
elements in all directions. Heat transferred up through the
flooring is used for heating, while heat flowing towards the
sub-floor is lost. The overall system efficiency will be at least
partly determined by the relative rates of heat transfer towards
and away from the floor's top surface. As such, in addition to
reducing heat lost to the sub-floor, there is a need to increase
the ability of ceramic tile to conduct heat from heating elements
towards the room. Additionally, whether the floor is directly
heated or not, the sub-floor and foundation act as a heat sink, and
so the overall system efficiency can be increased if the flooring
is constructed to prevent or reduce heat loss to the sub-floor. As
was described above for floors, heating systems also can be
installed either onto walls or as a part of the wall, and the
desire to improve the flow of heat into the space adjacent to the
wall outer surface while also reducing the loss of heat in the
opposite direction is governed by the same considerations.
[0005] Accordingly, there is a need for tile systems having
improved thermal properties. It is to the provision of such
systems, and the associated methods of manufacture and use that the
various embodiments of the present invention are directed.
BRIEF SUMMARY
[0006] Various embodiments of the present invention are directed to
improved floor and wall tile systems with enhanced thermal
properties. The tile systems provide enhanced thermal properties to
floor and wall coverings. The improved tile systems, which can be
implemented in either heated or unheated applications, generally
include a tile and a phase change material (PCM). The PCMs can
provide heat capacity via sensible and latent heat storage
methods.
[0007] According to some embodiments, a tile system includes a tile
and a PCM that is in thermal communication with the tile. The PCM
does not comprise a portion of the tile, and is configured to
increase the heat capacity of the tile system. The tile system can
also include an optional heating element in thermal communication
with the PCM and/or a thermally insulating layer disposed between
the tile and a surface of a floor or wall on which the tile system
is disposed.
[0008] In some cases, the PCM is a solid state PCM. In other cases,
it is a liquid PCM encapsulated in a thermally conductive container
(e.g., a metal container). Similarly, in some situations, the tile
is a ceramic tile.
[0009] The PCM can be positioned in a variety of locations. For
example, the PCM can be disposed in a cavity within a backside
surface of the tile. It can also be disposed directly on a backside
surface of the tile.
[0010] In some embodiments, the tile comprises a portion of a
floating floor or wall tile unit. Such a tile unit can include a
substrate, such that the tile is disposed on, or within a cavity
within, the substrate. In these situations, in addition to the
above-described locations, the PCM can be disposed: between a
backside surface of the tile and a top surface of the substrate; at
least partially within a cavity within a top surface of the
substrate; entirely within the substrate (e.g., when the PCM
comprises a portion of the substrate); on, or within a cavity
within, a backside surface of the substrate; or a combination of
one or more of the foregoing locations.
[0011] According to some embodiments of the present invention, a
tile system can include a tile unit that includes a substrate and a
tile that is disposed on, or within a cavity within, the substrate;
and a PCM in thermal communication with the tile. The PCM does not
comprise a portion of the tile, and it is configured to increase
the heat capacity of the tile system. The PCM can be disposed in a
cavity within a backside surface of the tile, directly on the
backside surface of the tile, between the backside surface of the
tile and a top surface of the substrate, at least partially within
a cavity within the top surface of the substrate, entirely within
the substrate, on a backside surface of the substrate, within a
cavity within the backside surface of the substrate, or a
combination comprising at least one of the foregoing.
[0012] The tile system can also include a heating element in
thermal communication with the phase change material and/or a
thermally insulating layer disposed between the tile unit and a
surface of a floor or wall on which the tile unit is disposed. In
certain situations, the thermally insulating material can be
located below the heating element, while the tile is located above
the heating element and the PCM can be between the tile and
thermally insulating material.
[0013] In some implementations, the substrate can have a thermally
conductive element that is in thermal communication with the PCM
and the tile. In this manner, the thermally conductive element can
facilitate heat transfer between the PCM and the tile.
[0014] Other embodiments are directed to methods of making the tile
systems. The improved tile systems can be readily manufactured,
having both a modest manufacturing cost and a relatively
non-complicated geometry and construction.
[0015] Still other embodiments are directed to methods of using the
tile systems. The tile systems can be installed using techniques
that are either standard in the traditional tile industry or, for
groutless tile products, an easier alternative that allows a
do-it-yourself installation. The tile systems provide for
relatively simple installation of tile surfaces having both the
enhanced thermal properties, which are not normally found in tile
systems.
[0016] Other aspects and features of embodiments of the present
invention will become apparent to those of ordinary skill in the
art, upon reviewing the following detailed description in
conjunction with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 includes schematic illustrations of (a) the backside
of a conventional high-temperature ceramic tile, and (b) a
cross-sectional side-view of the same tile with a phase change
material (PCM) disposed in certain cavities on the posterior of the
tile according to some embodiments of the present invention.
[0018] FIG. 2 is a schematic illustration of a groutless ceramic
floor tile according to some embodiments of the present
invention.
[0019] FIG. 3a is a schematic plan-view illustration of the
underside of a groutless ceramic floor tile wherein PCMs are
disposed within the cavities within the underside of the substrate
according to some embodiments of the present invention.
[0020] FIG. 3b is a schematic illustration of a cross-sectional
side-view of a groutless ceramic floor tile wherein PCMs are
disposed within the cavities within the topside surface of the
substrate according to some embodiments of the present
invention.
[0021] FIG. 4 includes schematic illustrations of the underside of
a groutless ceramic floor tile wherein PCMs are disposed (a)
directly on the underside surface of the substrate and (b) within a
cavity within the underside of the substrate according to some
embodiments of the present invention.
[0022] FIG. 5 is a schematic illustration of a groutless ceramic
tile floor system with two groutless tiles mated together, wherein
the PCMs are disposed between the ceramic tile decorative component
and the substrate according to some embodiments of the present
invention.
[0023] FIG. 6 is a schematic illustration of a groutless ceramic
tile floor system with two groutless tiles mated together, wherein
the PCMs are positioned in defined cavities in the substrate itself
according to some embodiments of the present invention.
[0024] FIG. 7 is a schematic illustration of a groutless ceramic
tile floor system with two groutless tiles mated together, wherein
the PCMs are incorporated into the polymeric frame itself as an
additive according to some embodiments of the present
invention.
[0025] FIG. 8 is a schematic illustration of a groutless ceramic
tile floor system with two groutless tiles mated together, wherein
the PCMs are positioned onto the backside of the polymeric frame
according to some embodiments of the present invention.
[0026] FIG. 9 is a schematic illustration of (a) a side
cross-section, (b) a bottom view, and (c) a top view of a groutless
wall tile unit according to some embodiments of the present
invention.
[0027] FIG. 10 is a schematic illustration of (a) rear view and (b)
a top view of an installed groutless wall tile system according to
some embodiments of the present invention.
DETAILED DESCRIPTION
[0028] Referring now to the figures, wherein like reference
numerals represent like parts throughout the several views,
exemplary embodiments of the present invention will be described in
detail. Throughout this description, various components may be
identified having specific values or parameters, however, these
items are provided as exemplary embodiments. Indeed, the exemplary
embodiments do not limit the various aspects and concepts of the
present invention as many comparable parameters, sizes, ranges,
and/or values may be implemented. The terms "first," "second," and
the like, "primary," "secondary," and the like, do not denote any
order, quantity, or importance, but rather are used to distinguish
one element from another. Further, the terms "a," "an," and "the"
do not denote a limitation of quantity, but rather denote the
presence of "at least one" of the referenced item.
[0029] Disclosed herein are improved tile systems and methods of
making and using the tile systems. For either heated or unheated,
floor or wall applications, the improved tile systems described
herein provide increased efficiency of heating and/or cooling a
building by enhancing the ability of tiles to store and release
thermal energy, thereby minimizing the dynamic temperature
differences that normally develop and are the driving force behind
unwanted heating or heat loss. Further, the methods used to obtain
these advantages are consistent with established manufacturing and
installation processes considered normal for tiles and other
flooring or wall decor. The various embodiments of the present
invention allow for products having thermally enhanced properties
without the deleterious effects on other, normally desired
properties, namely wear resistance, appearance, and ease of
installation.
[0030] Heat transfers from a hotter region or object to a cooler
region or object, and the transfer of heat over time (i.e., the
"rate") is determined by the temperature difference between the
"hot" and "cold" objects (i.e., the "temperature gradient") and the
radiative, convective, and conductive thermal properties of the
objects of interest. For buildings, significant amounts of heat are
lost via radiation; particularly through windows and roofs.
Buildings in colder climates are normally well-insulated to reduce
the conductive, convective, and radiative transfer of building heat
from the interior walls to the exterior surfaces. Heat can also be
lost from a building through the floor, where it passes through the
sub-floor and into the foundation; or heat can be lost through the
wall, where the heat is lost to radiative or convective transfer
from the external wall. The costs associated with heating and
cooling a building can be reduced if the transfer of heat can be
reduced and/or the temperature gradient between conditioned spaces
and their immediate surroundings (e.g. floor, walls, and ceiling)
can be reduced.
[0031] To achieve this goal, the tile systems disclosed herein
generally include a (i.e., at least one) tile and a phase change
material (PCM) that does not comprise a portion of the tile itself.
The tile can be any type of tile, including a ceramic tile, marble
tile, granite tile, quartz tile, natural stone tile, porcelain
tile, glass tile, a variety of metal or polymer tiles, wood plank,
laminate floor tile (i.e., floating floor unit), and the like. In
addition, the tiles can be conventional (i.e., non-floating) floor
or wall tiles, or they can be incorporated into a floating floor or
wall tile system, as will be described in more detail below.
[0032] For convenience, and not by way of limitation, reference
will now be made to ceramic tiles. It should be recognized by those
skilled in the art to which this disclosure pertains that other
types of tile, such as those listed above, can be used in place of
ceramic tiles in the embodiments described below.
[0033] Table 1 provides the thermal properties of traditional
ceramic tiles compared with other flooring and wall material types.
Relative to most other building and construction materials (e.g.,
wall board, insulation, wood paneling, carpeting, laminated
flooring, polymers, and the like), ceramic tiles generally exhibit
a higher rate of heat conduction (i.e., "thermal conductivity"). In
addition, ceramic tiles normally possess a higher value of thermal
effusivity, a property that combines several material properties
(heat capacity, density and thermal conductivity) into a single
parameter. The thermal effusivity is a measure of how quickly a
cooler object will absorb heat when placed into contact with a
hotter object. The effusivity values in Table 1 illustrate why an
unheated ceramic tile floor can "feel" colder than a floor made
using wood, plastic laminates or carpet, because the tile can pull
heat away from the body more quickly.
TABLE-US-00001 TABLE 1 Thermal Thermal Heat Conductivity Effusivity
Capacity Material [Watts/m K] [Watts/ (s m.sup.2 K)] [Joules/Kg K]
Porcelain floor tile 1.484 1675 792 Mosaic floor tile 1.196 1453
750 Porous wall tile 0.969 1255 740 Simulated wood laminate 0.266
595 1380 * Engineered wood laminate 0.210 542 1000 * Polyurethane
elastomer 0.255 623 1371 All measurements are for 25.degree. C. *
denotes the value at 25.degree. C. is extrapolated from data at
slightly higher temperatures.
[0034] Table 2 provides the range of thermal property values
normally seen for various types of standard ceramic tile products.
The limits of these property values can be expanded somewhat with
concerted effort. Achieving very large value increases or
decreases, however, is unlikely, particularly for the heat
capacity. Thus, methods of increasing the thermal property values,
for example, the heat capacity, of ceramic tile products are
necessary.
TABLE-US-00002 TABLE 2 Thermal Thermal Heat Ceramic Conductivity
Effusivity Capacity Density Tile Product [Watts/m K] [Watts/ (s
m.sup.2 K)] [Joules/g K] (g/cc) High Fire 1.523 1703 0.802 2.376
Porcelain 1 High Fire 1.484 1675 0.792 2.387 Porcelain 2 Mosaic
Tile 1.196 1453 0.750 2.354 High Fire 1.241 1476 0.740 2.373
Porcelain 3 Low Fire 1.073 1369 0.740 2.363 Porcelain 1 Wall Tile
0.969 1255 0.740 2.195
[0035] Materials typically store heat through an increase in
temperature, and the thermal energy stored this way is termed
"sensible heat." The amount of sensible heat that can be stored by
an object is set by its heat capacity, which is related to the
material(s) of construction as well as the structure (e.g., porous
versus highly dense). There is another heat storage mechanism where
the storage or release of "latent heat" takes place at nearly
constant temperature when a substance changes its physical state.
An example of latent heat absorption is when a solid melts to form
a liquid, whereas an example of latent heat evolution occurs when a
liquid solidifies to form a solid.
[0036] PCMs store sensible heat as their temperature increases.
When a specific temperature is reached, however, the PCM undergoes
a phase transformation and can store a relatively large amount of
latent heat. In transformations involving latent heat, the
temperature does not increase or decrease markedly until the phase
transformation is completed. Most PCMs of interest experience a
solid-liquid phase transformation (i.e., melting). Paraffin waxes
and salt hydrates are traditional PCMs; and, since they melt, the
containment method or design, particularly for the corrosive salts,
is a fundamental issue in employing PCMs.
[0037] Some PCMs experience a second, solid-solid phase
transformation at a temperature below their melting point. Although
the latent heat absorbed or evolved is normally lower than for the
solid-liquid transformation, solid state PCMs (SS-PCMs) are
attractive for some applications because they do not require a
containment method or design. To make better use of PCMs that melt
into liquids, methods have been developed to encapsulate
solid-liquid PCMs inside a shell of some other material that is
phase and shape stable over the temperature range of use.
[0038] The tile systems of the present invention can make use of
both liquid PCMs and SS-PCMs. The liquid PCMs, when used, are
accompanied by a container or shell so as to prevent leakage or
loss of the liquid PCM to the external environment. Such a
container or shell should be made of a thermally conducting
material so as to allow heat to more easily transfer between the
PCM and the tile.
[0039] The PCMs can be incorporated in a variety of locations on,
or adjacent to, the tiles. As stated above, in some cases, the
tiles can be conventional or non-floating tiles, which are
installed directly on a floor or wall using cementitious or
resinous fixatives. In other cases, the tiles are incorporated into
a floating tile system in which the tile itself is indirectly
installed on a floor or wall via some intermediate substrate or
base structure or structures. The individual tile units in a
groutless tile system are composite structures having the means
necessary to effect safe and easy installation of the tiles onto
the floors or walls without using additional fixatives or grouting
materials. Examples of floating tile systems include so-called
"groutless tile" floor or wall systems. Groutless tile flooring
systems, while briefly described below, are described in more
detail in commonly-assigned United States Patent Application
Publication No. 2008/0184646 and International Patent Application
Publication No. WO 2008/097860, which are incorporated by reference
herein in their entireties as if fully set forth below. Similarly,
while described in brief below, groutless tile wall systems are
described in more detail in commonly-assigned International Patent
Application No. PCT/US2009/068113, which is incorporated by
reference herein in its entirety as if fully set forth below.
[0040] In an example of a non-floating floor or wall system, the
ceramic tile, which is manufactured with a cavity-containing back
pattern, has a solid PCM or an encapsulated liquid PCM disposed on
its backside such that the PCM and the ceramic tile are chemically
and/or mechanically bonded. Such a composite tile can be installed
using industry standard methods (e.g., using an adhesive grouting
material). One such composite tile shown in FIG. 1.
[0041] FIG. 1a includes a schematic illustration of the backside of
a conventional high-temperature ceramic tile, generally designated
by reference numeral 100. The backside of the tile 100 includes
hexagonal-shaped hollow spaces/regions or cavities 102. Such
patterns are normally designed into ceramic tiles because these
patterns save on material and facilitate several unit operations
during manufacture. The pattern shown is one of many such patterns
a ceramic tile may have on its backside that can accommodate the
PCMs. In the pattern shown in FIG. 1a, for a conventional
12-inch.times.12-inch ceramic tile, about 30 to about 40
milliliters (mL) of a PCM can be placed into the about 0.7
millimeter (mm) deep cavities via a number of methods, and the
volume capacity of the back pattern could be increased
substantially.
[0042] FIG. 1b provides a schematic illustration of a side view of
such a PCM-containing ceramic tile 100. In this illustration, the
PCMs 104 are incorporated into a portion of the plurality of
cavities 102. It should be noted that the number of cavities 102
into which the PCMs 104 are disposed can vary based on the
application and the level of heat storage desired. Thus, if greater
heat storage is desired, a larger number of PCMs 104 can be placed
in the cavities 102 of the ceramic floor or wall tile 100. The
particular location where the PCMs are placed can be also be
tailored for the particular application.
[0043] In another non-floating floor or wall system example, the
ceramic tile can have a flat or substantially-flat backside, such
that one or more PCMs are disposed directly on the backside surface
of the tile. A solid PCM or an encapsulated liquid PCM can be
chemically and/or mechanically bonded to the backside surface of
the tile. Just as with the tiles with the cavity-containing
backsides, such a composite tile can be installed using industry
standard methods.
[0044] In contrast to non-floating tiles, when a groutless tile
floor or wall system is used, the PCM can be incorporated in a
number of locations. As will be described and illustrated, the PCM
can be incorporated either: 1) in the back-pattern of the ceramic
tile (this is already described above for non-floating tile
systems); 2) in a continuous layer between the bottom surface of
the ceramic tile and a top layer of the groutless tile's base or
substrate layer; 3) in cavities formed inside the groutless tile's
base or substrate layer; 4) as a filler/component of the groutless
tile's base or substrate layer; 5) in the back-pattern of the
groutless tile's base or substrate layer; and/or 6) as one or more
of the previous five situations in combination.
[0045] For convenience, and not by way of limitation, reference
will now be made to groutless tile floor systems where each tile is
encased by a polymeric frame or substrate to provide a so-called
"groutless tile" unit. Again, such groutless tile units and systems
are described in more detail in commonly-assigned United States
Patent Application Publication No. 2008/0184646 and International
Patent Application Publication No. WO 2008/097860. In addition to
having a ceramic tile encased by a polymeric frame, the tile units
of these floor systems generally include mechanical joints for
connecting adjacent groutless tiles.
[0046] FIG. 2 illustrates an exemplary groutless floor tile, which
can be used in the tile systems disclosed herein. The groutless
tile is generally designated by numeral 200. The groutless tile 200
includes a durable, decorative component 202 (e.g., ceramic tile,
marble tile, granite tile, quartz tile, natural stone tile,
porcelain tile, hardwood planks, engineered wood planks, glass
tile, a variety of metal or polymer tiles, and the like) that is
disposed on a substrate 204. The decorative component 202 will be
described as a ceramic tile in this illustration of a tile unit for
convenience.
[0047] The decorative component 202 can be affixed to the substrate
204 using a wide variety of methods. The substrate 204 can be
constructed of a suitable material that is chemical resistant,
stain resistant, at least partially non-porous, and formable to
within sufficient precision. In exemplary embodiments, the
substrate 204 is formed from a polymeric material. While the
groutless tile unit 200 is depicted as square-shaped in FIG. 2, it
will be clear that alternatively shaped groutless tiles (e.g.,
circles, rectangles, diamonds, hexagons, octagons, triangles, and
the like) are also contemplated.
[0048] The substrate 204 shown in FIG. 2, is designed to have
larger dimensions than the decorative component 202 such that the
decorative component 202 can be disposed within a groove defined
within the substrate 204. The top surface of the decorative
component 202 and the top surface of the substrate 204 can form a
continuous surface, if desired. The substrate 204 includes a flange
portion 206 disposed along the side edges or walls of the substrate
204. The flange portion 206 provides the location of a mechanical
joint, which is designed such that it is operable for coupling
together one or more adjacent groutless tiles 200. When two or more
adjacent groutless tiles 200 are coupled using the mechanical joint
of the flange portion 206, it is the top surfaces of the substrates
204 of the coupled tile units 200, which are adjacent to the top
surfaces of the decorative components 202, that can provide the
appearance of a grouted finish.
[0049] FIG. 3 schematically illustrates the backside and side
cross-section of one type of design for a groutless floor tile as
shown in FIG. 2. In the backside view of FIG. 3a, the groutless
tile 300 includes the substrate 304 and the decorative component
302 (of which the back side is shown in the cut-away circle). The
substrate 304 includes the flange portions 306, which are disposed
along the side edges or walls of the substrate 304 and are used to
form the mechanical joints to couple adjacent groutless tiles. The
substrate 304 also includes a plurality of cavities 308. These
cavities 308, which can be formed when the substrate 304 is molded
or by removing portions of the substrate 304 after the substrate
has been manufactured, can be designed to accommodate the PCMs
310.
[0050] In the side cross-section of the groutless floor tile 300
shown in FIG. 3b, the ceramic tile decorative component 302 is
disposed within a groove or channel within the substrate 302, as
described above, with the exception that the substrate 304 has
additional cavities on the topside surface that can provide
locations for the PCMs 310. It should be noted that, instead of (or
in addition to) placing them in cavities within the substrate 304,
one or more PCMs 310 can be placed directly on the topside surface
of the substrate such that a sandwich is formed between the ceramic
tile decorative component 302 and the substrate 304.
[0051] To manufacture such a design, a cohesive layer or discrete
portions of PCMs 310 could be adhered to the ceramic tile component
302 or simply placed against the ceramic tile component 302. Next,
the combined ceramic tile component 302 with the PCM 310 can be
molded around using the polymeric material that forms the substrate
304. Alternatively, after molding the substrate 304, the PCMs 310
can be melted and inserted into the cavities molded into the
polymeric substrate 304.
[0052] FIG. 4 schematically illustrates the backside of another
type of design for a groutless floor tile as shown in FIG. 2. In
the backside view of FIG. 4a, only the substrate 404 is shown. The
substrate 404 includes the flange portions 406, which are disposed
along the side edges or walls of the substrate 404 and are used to
form the mechanical joints to couple adjacent groutless tiles. The
substrate 404 further includes a plurality of protruding legs 412,
which can be used to at least partially support the groutless tile
on the flooring surface on which it is installed. In this design,
the PCM 410 can be disposed directly on the backside surface of the
substrate 404.
[0053] Alternatively, in the backside view of FIG. 4b, wherein only
the substrate 404 is shown again, the PCM 410 can be disposed
within a cavity 408 within the backside of the substrate 404,
similar to the design of FIG. 3a. The cavity 408 in this design
(like the cavities 308 of the design shown in FIG. 3a can be
configured to penetrate through the entire thickness of the
substrate 404 such that the PCM 410 makes direct contact to the
back of the ceramic tile decorative component (not shown).
[0054] Thus, the cavities shown in FIGS. 3 and 4 can be designed to
accommodate PCMs such that the PCMs are directly in contact with
the backside of the ceramic tile and/or with the thermally
insulating polymer substrate between the ceramic tile and the
sub-floor. Regardless of whether the PCMs are incorporated in the
cavities on the bottom or top of the substrate, the mechanical
integrity or strength of the composite tile structure is not
degraded. Thus, an adequate underlying structural support is
provided to the ceramic tile component on top.
[0055] FIGS. 5 through 8 provide additional views of various
embodiments making use of a groutless floor tile system, with PCMs
shown in various locations. These illustrations all show two
groutless tiles mated together. For example, in FIG. 5, the PCMs
510 are placed between the ceramic tile component 502 and the
substrate 504, making contact to both the ceramic tile component
502 and the substrate 504. In FIG. 6, the PCMs 610 are placed in
defined cavities within the substrate 604, but do not contact the
ceramic tile component 602. In FIG. 7, the PCMs 710 are
incorporated into the substrate 704 itself as an additive. Again,
the PCMs 710 of FIG. 7 do not contact the ceramic tile component
702. Finally, In FIG. 8, the PCMs 810, which do not contact the
ceramic tile component 802, are placed onto the backside of the
substrate 804.
[0056] For convenience, and not by way of limitation, reference
will now be made to groutless tile wall systems that comprise a
tile unit, a mounting unit, a wall-fastening device that is
configured to fasten the mounting unit to a wall, and a tile
unit-fastening device that is configured to fasten the tile unit to
the mounting unit. In general, the mounting unit occupies a small
fraction (e.g., less than 30 percent) of an area of the wall. When
the tile unit is fastened to the mounting unit, and the mounting
unit is fastened to the wall, at least a portion of the tile unit
does not contact the wall directly. This portion corresponds to at
least the portion that is fastened to the mounting unit, but can
include up to the entire surface of the tile unit. Again, such
groutless tile units and systems are described in more detail in
commonly-assigned International Patent Application No.
PCT/US2009/068113.
[0057] The tile units used in these groutless wall tile systems can
be designed similar to the groutless floor tile units. That is,
these tile units can include a decorative tile component disposed
within a groove or channel of a polymeric frame or substrate. These
tile units, however, do not necessarily require any mechanical
joints for connecting adjacent groutless tile units because they
are held in place by the tile unit-fastening devices.
[0058] One example of such a tile unit is shown in FIG. 9. FIG. 9
includes side-, top-, and bottom-views of a groutless wall tile
unit 900. In this illustration, the groutless wall tile unit
includes four decorative ceramic tiles 902 disposed in a channel
within a substrate 904. The substrate can include a recessed
mounting point 918 for mating with the tile unit-fastening device
(not shown). If the edges of the ceramic tiles 902 are not mated
together, then a sealant 912 can be placed in the spaces between
the ceramic tiles 902 in a given tile unit 900. Optionally, the
ceramic tiles 902 can be fixed into place using an adhesive or
fixative 914.
[0059] Another example of a groutless wall tile system is shown in
FIG. 10. FIG. 10 includes front and rear views of an installed
groutless wall tile system, wherein the groutless wall tile units
1000 are mounted to a wall (not shown) by means of a mounting unit
1020 that adopts a rail-like structure. The rail-like mounting
units are fixed to the wall by means of mounting unit-fastening
devices (not shown) that can be screws, nails, bolts, or the like.
The groutless wall tile units 1000 include a decorative ceramic
tile component 1002 that is disposed on a substrate or platform
1004. The substrate 1004 includes tile unit-fastening devices 1018
in the form of clips or hooks that can attach to the rail-like
mounting unit 1020. As indicated in the rear view of the installed
tile system of FIG. 10a, there is a gap or design space between the
surface of the ceramic tiles 1002 of the tile units 1000 and the
wall surface (which would be in direct contact with the backside
surface of the rail-like mounting units 1020.
[0060] Just as was the case for the groutless tile floor units, the
PCMs can be placed in a variety of locations on or within the
groutless tile wall units. Specifically, the PCMs can be placed
between the top surface of the substrate and the bottom surface of
the decorative ceramic tile component, within cavities on the
topside and/or backside of the substrate, within the substrate as a
filler material, and/or in any cavities on the backside of the
decorative ceramic tile component itself. In addition to these
locations, when the tile system allows for it, the PCMs can be
placed in the gap or design space between the tile units and the
wall itself. In this manner, a larger continuous layer of a PCM can
be used because there is less concern for space than there would be
in trying to place a PCM in the substrate of a groutless tile
unit.
[0061] The wall or floor tile systems that make use of so-called
groutless tiles, which do not require cementitious or resinous
grouting material for installation, confer additional advantages
relating to the greater ease of installation as well as the ability
to non-destructively/temporarily remove (e.g., for inspection and
repair) and reinstall the tile systems. In addition, it is possible
for the material used to form the substrates for the ceramic tiles
to be formed from one or more distinctive materials or components
that can provide specific intrinsic thermal properties. For
example, when the substrate is formed from a polymeric (e.g.,
polyurethane, polystyrene, polyvinylchloride, or the like) foam,
the substrate can confer a thermally insulative property to the
tile behind the backside surface of the tile. This can serve to
decrease the flow of heat to or from the space towards which the
tile's decorative top surface is facing. In another example, the
substrate can be designed to facilitate the conduction of heat
between the tile and the PCM. For example, components comprising a
thermally conductive material (e.g., metal, graphite, or the like)
can be disposed between the ceramic tile and the PCM, thereby
permitting heat to be transferred more readily between the ceramic
tile and the PCM. Yet another example involves designing the
substrate to have a thermally conductive material disposed between
the ceramic tile and PCM, while a thermally insulative material is
disposed around those surfaces of the PCM that are not in
conductive thermal contact with the ceramic tile. Such a design can
slow or prevent the transfer of heat between the PCM and the wall
or floor onto which the tile systems are installed, while
simultaneously facilitating the conduction of heat between the
ceramic tile and the PCM.
[0062] In some cases, the improved tile systems described herein
can include a heating element, which is placed in thermal
communication with the PCM. For non-floating wall or floor tiles,
this heating element can be disposed between the tile and the floor
or wall. For floating wall or floor tile systems, the heating
element can be included as part of the substrate or can be separate
from the tile unit. This optional heating element can serve to
activate the PCM by contributing heat to the PCM, which can then
transfer such heat more efficiently to the ceramic tile. The
heating element can be controlled using known techniques used in
conventional radiant heating systems. Such techniques would be
understood by those skilled in the art to which the various
embodiments of the present invention pertain.
[0063] The tile systems described herein can also implement an
optional thermally insulating layer to further reduce heat loss.
For example, with non-floating floor or wall tiles, this can be a
thin fabric or foam underlayment that is placed between the ceramic
tiles (which contain PCMs on their backside surfaces and/or within
any cavities on their backside surfaces). With floating floors, the
optional thermally insulating layer can be placed between the
substrate and the wall or floor surface, between the PCM and the
substrate surface in cases where the PCM is placed between the
ceramic tile and the topside surface of the substrate, in the
cavities within the backside surface of the substrate such that the
PCM is between the thermally insulating layer and the bottom of the
cavity within the substrate, and/or the like.
[0064] In certain embodiments, regardless of whether a ceramic tile
or groutless tile is used, the ceramic tile itself may possess a
chemical formula and structure such that its intrinsic thermal
properties are enhanced relative to standard ceramic tiles.
[0065] During operation, the tile systems described herein will be
able to store latent heat or absorb thermal energy from their
environment (i.e., the "space" in which the tile system is
installed) without as large a concomitant increase in their
temperature as would be seen in the absence of a PCM. As the
driving force for thermal conduction, convection, or radiation
between surfaces is the difference in temperature, the ability to
obtain thermal storage with a reduced temperature increase leads to
a reduction in unwanted heat transfers (i.e., heat "losses"). It is
these unwanted heat transfers that lead to more energy consumed in
the process of heating or cooling a living space. Thus, the use of
PCM as a passive means for improved heat storage and energy
efficiency is effected using the tile systems described herein.
[0066] Similarly, for tile systems that also include the optional
heating elements, the PCM can further increase the thermal heat
capacity of the floor or wall, thereby allowing more heat from the
heating elements to be transferred to, and stored in, the floor or
wall. Further, this additional heat is transferred and stored in
the floor or wall at a lower heating element temperature than would
be required without the use of a PCM. As a result, there is greater
overall efficiency in the heating system. The reason for this
phenomenon is that the transfer of heat in the direction opposite
the tile surface (i.e., into the floor or wall) is considered lost
heat, and the amount of lost heat generally increases as the
heating element temperature increases. Thus, if a lower heating
element temperature is used to achieve the same or better result
(i.e., the same amount of, or more, heat transferred to the tile,
and ultimately into the room in which the tile system is
installed), then the overall efficiency of the system is
increased.
[0067] The tile systems disclosed herein can be used in a variety
of manners. For example, the tile systems can be used simply to
transfer heat to and from the tile surface, which will result in a
transfer of heat to and from the room or environment in which the
tile system is installed. In addition, the tile systems can be used
to decrease the consumption of energy, for example in heating,
ventilation and air conditioning costs. This can be accomplished by
matching the heat flow dynamics(e.g., including the actual storage
and release of heat, the rate of heat transfer, and the like) of
the PCM-containing tile system such that the release of heat can be
off-set to a desired time of day. For example, the tile system can
be configured, with the appropriate choice of PCM, tile material,
and other optional components as described above, such that heat is
collected by the PCM during the day, and released in the evenings
when the sun is down, the load on the air conditioning system is
lowered and its efficiency is increased, and the electric rates are
lower. Similarly, the tile system can be configured such that heat
is transferred to the tile surface (and, ultimately, to the room or
environment in which the tile system is installed) by the PCM
during the day, and collected in the evenings, as may be desired
for the particular application.
[0068] The various embodiments of the present invention are further
illustrated by the following non-limiting example.
EXAMPLE 1
Calculated Benefits of PCM Incorporation
[0069] This example illustrates the effect that adding PCMs to
ceramic tile products can have. In this analysis, the latent heat
storage capability for a number of PCM candidates, which undergo
their transition over the temperature range around room temperature
(i.e., about 20.degree. C. to about 40.degree. C.), was compared
with the sensible heat storage capacity of a typical porcelain
ceramic tile, having a dimension of 12 inches by 12 inches and
weighing about 1.5 kilograms, and a composite tile comprising the
same typical porcelain ceramic tile encapsulated with about 350
grams of polyurethane over that same temperature range.
[0070] Assumptions made include volume available to accommodate
PCMs in both tile types and the temperature range of interest. The
volume of the back-pattern of the back side of a typical ceramic
tile was set at 30 cubic centimeters. The heat storage capacity of
such a tile was set at 24,060 Joules at the temperature range of
interest. Similarly, the volume of available space in the groutless
tile polymeric frame was set at 100 cubic centimeters; and the heat
storage capacity of such a groutless tile was set at 33,657 Joules
at the temperature range of interest.
[0071] The known properties of the PCM candidates are provided in
Table 3.sup.1. These properties include transition temperature,
heat of fusion, and density. .sup.1Douglas C. Hittle ["Phase Change
Materials in Floor Tiles for Thermal Energy Storage", October 2002;
Award No. DE-FC26-00NT40999]
[0072] Based on the properties of the PCM candidates and the
assumed volume and heat storage of the tile component, the data in
Table 4 was calculated. As shown by the data of Table 3, the use of
PCMs results in a latent heat storage capability that is a
substantial fraction of the original heat storage capacity for both
tiles, particularly for the composite, or groutless, tile, where
one could expect to incorporate more PCM into the structure. The
data in Table 4 does not account for the increase in sensible heat
storage due to the capacity of the PCM, but this storage component
would further increase the overall heat storage capacity and
effectiveness for tiles containing the PCMs.
TABLE-US-00003 TABLE 3 Transition Heat of Density (gram Temperature
Fusion (Joules per cubic Material (.degree. C.) per gram)
centimeter) Solid state PCM Pentaerythritol (PE) 188 269 1.390
Pentaglycerine (PG) 89 139 1.220 Neopentyl Glycol (NPG) 48 119
1.060 60% NPG + 40% PG 26 76 1.124 Normal Paraffin/Waxes
Tetradecane C14 5.5 228 0.825 Hexadecane C16 16.7 237 0.835
Octadecane C18 28 244 0.814 (Technical grade) Eicosane C20 36.7 244
0.856 Commercially Available PCMs from Outlast Technologies Kenwax
18 31.2 165 0.765 Kenwax 19 36.8 151 0.811 Technical Grade 28 244
0.814 Octadecane
TABLE-US-00004 TABLE 4 Additional Heat Storage (Joules per square
foot) Ceramic % Groutless % Material Tile Gain Tile Gain 60% NPG +
40% PG 2563 11% 8542 25% Octadecane C18 5958 25% 19862 59%
(Technical grade) Eicosane C20 6266 26% 20886 62% Kenwax 18 3787
16% 12623 38% Kenwax 19 3674 15% 12246 36% Technical Grade 5958 25%
19862 59% Octadecane
[0073] The embodiments of the present invention are not limited to
the particular components, process steps, and materials disclosed
herein as such components, process steps, and materials may vary
somewhat. Moreover, the terminology employed herein is used for the
purpose of describing exemplary embodiments only and the
terminology is not intended to be limiting since the scope of the
various embodiments of the present invention will be limited only
by the appended claims and equivalents thereof.
[0074] Therefore, while embodiments of this disclosure have been
described in detail with particular reference to exemplary
embodiments, those skilled in the art will understand that
variations and modifications can be effected within the scope of
the disclosure as defined in the appended claims. Accordingly, the
scope of the various embodiments of the present invention should
not be limited to the above discussed embodiments, and should only
be defined by the following claims and all equivalents.
* * * * *