U.S. patent application number 14/758982 was filed with the patent office on 2016-10-13 for evaporative cooling system.
The applicant listed for this patent is POLYMERIUM, LLC. Invention is credited to Paul W. Schmalzl, Robert L. Warren.
Application Number | 20160298866 14/758982 |
Document ID | / |
Family ID | 51167309 |
Filed Date | 2016-10-13 |
United States Patent
Application |
20160298866 |
Kind Code |
A1 |
Schmalzl; Paul W. ; et
al. |
October 13, 2016 |
Evaporative Cooling System
Abstract
A novel system for using a high water content polymer and its
various implementations to provide a means of evaporative cooling
and temperature regulation for buildings and structures. This
invention will provide benefits at much lower initial and ongoing
costs than competing solutions and will bring other benefits and
extensions inherent in its design and implementation.
Inventors: |
Schmalzl; Paul W.;
(Greenville, SC) ; Warren; Robert L.; (San Diego,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
POLYMERIUM, LLC |
Cheyenne |
WY |
US |
|
|
Family ID: |
51167309 |
Appl. No.: |
14/758982 |
Filed: |
January 6, 2014 |
PCT Filed: |
January 6, 2014 |
PCT NO: |
PCT/US2014/010313 |
371 Date: |
July 2, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61749969 |
Jan 8, 2013 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B32B 27/08 20130101;
E04D 7/00 20130101; B32B 2307/726 20130101; Y02B 30/54 20130101;
F24F 5/0035 20130101; B32B 2419/06 20130101 |
International
Class: |
F24F 5/00 20060101
F24F005/00; E04D 7/00 20060101 E04D007/00 |
Claims
1. An evaporative cooling system comprising a high water content
polymer capable of holding water to a surface in order to enable
heat removal from the surface via phase change of the water being
held by said polymer.
2. The evaporative cooling system of claim 1 further comprising an
adhesive layer on the surface.
3. The evaporative cooling system of claim 1 wherein the polymer
comprises multiple layers.
4. The evaporative cooling system in claim 1 further comprising a
water system.
5. The evaporative cooling system of claim 1 wherein said polymer
has sufficient hydrophilicity to allow rehydration from ambient
humidity.
6. The evaporative cooling system of claim 1 in which the polymer
includes an adhesive monomer to enable said polymer to bond to the
surface.
7. The evaporative cooling system of claim 1 in which the polymer
is mixed with a separate adhesive component to enable the polymer
to bond to the surface.
8. The evaporative cooling system of claim 1 in which the polymer
includes a UV-resistance component.
9. The evaporative cooling system of claim 1 in which the polymer
includes an agent to minimize plant growth including one or more of
mold, fungus, algae or bacteria.
10. An evaporative cooling system comprising a high water content
polymer that holds water to a surface in order to enable heat
removal from the surface via phase change of the water being held
in by said polymer and an element providing structural support to
the polymer.
11. The evaporative cooling system of claim 10 in which the polymer
is integrated with the structural support element prior to
application.
12. The evaporative cooling system of claim 10 in which the polymer
is integrated with the structural support element at the time of
application.
13. The evaporative cooling system of claim 10 in which the
structural support element is a mesh.
14. The evaporative cooling system of claim 13 wherein the mesh
comprises synthetic materials.
15. The evaporative cooling system of claim 13 wherein the mesh
comprises natural materials.
16. An evaporative cooling system comprising a high water content
polymer that holds water to a surface in order to enable heat
removal from the surface via phase change of the water being held
in by said polymer with said polymer being polymerized in place on
the structure.
17. The evaporative cooling system of claim 16 wherein the
polymerization is effected by ultra-violet radiation.
18. The evaporative cooling system of claim 16 wherein the
polymerization is effected by heat.
19. An evaporative cooling system comprising a high water content
polymer that holds water to a surface in order to enable heat
removal from the surface via phase change of the water being held
in by said polymer that is created in forms.
20. The evaporative cooling system of claim 19 wherein said forms
include tiles or shingles.
21. The evaporative cooling system of claim 19 wherein said forms
include rolled surface coatings.
22. The evaporative cooling system of claim 19 wherein said forms
enable liquid application techniques.
23. A method for evaporative cooling comprising: applying a polymer
to a surface; supplying water to said polymer to form a high water
content polymer with a water content of 85-99.9 wt%; and cooling
said surface by a phase change of said water.
24. The method for evaporative cooling of claim 23 wherein said
phase change is evaporation.
25. The method for evaporative cooling of claim 24 further
comprising replenishment of water removed from said polymer by said
evaporation.
Description
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/749,969, entitled "Evaporative Cooling System,"
filed Jan. 8, 2013, the contents of which are hereby incorporated
by reference.
BACKGROUND OF INVENTION
[0002] Conserving energy is important for many economic and
environmental reasons. New technologies and approaches are being
developed to help reduce energy needs and improve efficiencies.
These technologies range from relatively simple to very complex,
with a mix of cost-benefit ratios. Because of the claimed value of
some of these technologies, cost-benefit ratios can be skewed to
greater favorability by various incentives like specific tax
breaks, funding grants and others.
[0003] Often a real breakthrough comes from an unexpected source,
including a different industry or material application. Such is the
case of the invention disclosed herein: a novel polymer compound
invented for other purposes finds substantial suitability to the
application of energy conservation. It will be shown in this
document that this polymeric compound allows for a means of
biological mimicry for energy conservation. When combined with
various enhancements, some of which are also disclosed herein, the
benefits can be dramatic.
SUMMARY OF THE INVENTION
[0004] The invention described in this disclosure provides a novel
system for using a high water content polymer and its various
implementations to provide a means of evaporative cooling and
temperature regulation. This invention will provide benefits at
much lower initial and ongoing costs than competing solutions and
will bring other benefits and extensions inherent in its design and
implementation.
[0005] In the preferred embodiment, a polymer is used to retain
water on a building roof in order to enable phase change of the
water, thereby removing substantial amounts of heat from the roof
surface. This heat removal will reduce heat load to the building
and reduce energy required to mitigate the heating and cooling of
the building.
[0006] Several application implementations are described. These
various application implementations enable application of the
invention to different types of surfaces, including flat and
pitched roofs and sidewalls. Moreover, the invention includes
various enhancements that increase usability, longevity and
maintenance.
DETAILED DESCRIPTION OF THE INVENTION
[0007] The field of energy research has grown tremendously in
recent decades. From the most basic, including simple means of
conservation, to fairly complex generation systems, like fusion,
the quest to extend energy availability is at the forefront of much
interest. Sometimes breakthroughs come from approaches different
from existing solutions and appear on the surface to be quite
logical or natural. It is, however, recent developments of
technology that allow for such seemingly natural approaches to
become viable. This invention is such a case.
[0008] Polymer compounds have been synthesized for decades and have
a wide range of applications. Each developed for specific
characteristics necessary for a primary application, polymers are
unique combinations of chemicals (monomers) in specific
formulations and conditions to enable creation of the polymer.
Often, however, the application of a particular polymer to
something other than its primary application can yield very
interesting results.
[0009] The Polymeric Evaporative Cooling (PEC) is just such an
application. Of particular interest for PEC is the removal of heat
from structures like buildings and houses. Effective heat removal
can have demonstrable effects on energy requirements for cooling,
and thereby reducing costs. Widespread reduction in energy
requirements as a result of heat removal from buildings can have
significant impact in the production of energy and a commensurate
benefit to the environment.
[0010] In some respects the PEC mimics various biological systems
in that it enables a phase change (i.e., evaporation) to remove
heat from a surface much like perspiration cools a human body. The
key attributes and novel aspects of PEC are found in the materials
used and the applications of those materials.
[0011] For the purposes of this description, a high water content
polymer is considered. Such a polymer may be found in U.S. Pat. No.
6,201,089 ("Example Polymer") and myriad other formulations. This
example patent describes hydrophilic polymers with 95-99.9% water
content. While developed for other applications, the
characteristics of the polymers described are very suitable to the
application of the PEC. Among these, the small pore size (nominally
90-100 .ANG.) allows for ready flow of water while blocking the
flow (or intrusion) of unwanted materials. Additionally, as will be
described later, the formulation of the polymer provides features
that enhance the benefits beyond simple evaporative cooling.
[0012] The PEC is best considered in terms of a layer of polymer on
the roof of a building or house as shown in FIG. 1. This layer 102,
which can be varied in thickness, will conform to the roofing
surface 101 in order to maximize the heat transfer from the
structure. Properly hydrated, the PEC will be predominately water
that, as the temperature rises, will change phase from a liquid to
a gas. That is, it will evaporate. It will be obvious that, while
water is suitable for PEC and used throughout this document, other
fluids or fluid mixes may be used as well.
[0013] Those versed in basic physics will understand that phase
change--from one state of matter to another--involves far greater
energy exchange than simple temperature change. For example, when
water temperature rises a single degree it requires .about.4180
J/kg (1 BTU/lb), but changing from liquid to gas (with no
temperature rise necessary) requires approximately .about.2260
kJ/kg (.about.972 BTU/lb). Similarly, the same amount of energy is
given off when reversing that phase change.
[0014] With the evaporation of the water in the PEC, significant
heat removal is possible. Many variables can be manipulated to gain
maximum advantage for the location or specific use. Some of these
variables may include thickness of the layer, format of the layer,
and enhancements.
[0015] In the preferred embodiment, the PEC polymer is applied to
an existing roof structure. Sprayed on to the roof surface, as one
would consider a standard coating like paint or roofing sealant,
the PEC polymer can be applied either dry or pre-hydrated.
[0016] In the preferred embodiment, in a spray-on application, the
hydrated polymer will be part of a liquid mix that includes an
adhesive component. The adhesive component provides for a mean to
keep the polymer layer attached to the roof surface in addition to
any natural adhesion found in the polymer itself The correct
mixture of polymer to adhesive can be varied depending on the
target surface type, expected thickness of the polymer layer,
environment and other variables.
[0017] Alternatively, a layer of adhesive may be applied prior to
the spray-on of the polymer as shown in FIG. 2. In this case,
polymer layer 102 is affixed to structure 101 with adhesive layer
203.
[0018] An additional alternative is the inclusion of an adhesive
monomer in the polymer formulation. Such may be selected for
application to specific roof coating materials in order to maximize
adhesion, longevity or other characteristics.
[0019] Some applications may not be amenable to a spray-on
treatment. In such cases, the ability to spread the polymer
material with a brush, mop or other device becomes preferable. It
may also be forced into existing flexible roof surfaces like tar or
membranes. Further, it may be allowed to settle into porous
surfaces, like stone or gravel coatings. This is particularly
useful in some flat roof applications like those common in
industrial structures.
[0020] The advantage of the spray-on application is that specific
roof design does not matter. For example, pitched-roof houses can
be comprised of asphalt or wood shingles, tile and gravel, all of
which are compatible with a spray-on coating. In fact, in some
cases, the spray-on polymer layer may enhance the overall
appearance and viability of the roof surface. This may be the case,
for instance in the case of wood shingles that have become aged and
brittle over time but that are effectively sealed with the polymer
mix.
[0021] Alternative means of application of the polymer are also
considered in this invention. In one alternative, the polymer may
be cast in a form very similar to tiles such that each are
individually applied to the surface. Such may be more suitable in
cases that require more precise polymer thickness or other special
considerations. In the case of such a tiling arrangement, adhesive
may be applied prior to application or may already be integrated
into one or more surfaces of the polymer tile. Here again, the
specific implementation may guide the choice.
[0022] Yet another alternative is to integrate the polymer into
existing structural elements. For example, the polymer may be
applied to the surface of or integrated into the composition of
various roof treatments like tiles. The advantage of such an
implementation is that it becomes a standard part of a workflow
during construction or refurbishment. A further advantage of such
an implementation is that it allows for a sporadic or patterned
distribution to allow for access to portions of the structure
without potential damage from stepping on the polymer itself.
[0023] For applications to surfaces like roofs that require
repeated access, an enhancement to this invention is the
incorporation of channels, gaps or superstructures interspersed in
the polymer coating layer. These will allow for access ways without
risking damage to the layer itself. It is important to note that
direct exposure to the sun is not necessary for performance, which
allows for application below existing structures like catwalks and
access paths.
[0024] Still another implementation of the PEC is the formation of
the polymer into a rollable form that is similar to other roofing
materials. As such, the polymer may be fully or partially hydrated
or unhydrated at any time prior to installation and rolled onto the
surface. As with other implementations, an adhesive may be
integrated or may be added at the time of PEC installation.
[0025] It is important to consider that a hydrated polymer may be
quite fragile. Polymer fragility may be mitigated somewhat with
increased thickness but may also incorporate additional means to
provide structural stability. A simple example to be considered, as
shown in FIG. 3, is a mesh 301 around which the polymer 102 is
cast. Such casting may an active part of the polymerization process
or it may be post-polymerization stages and include adhesive to
provide connection to the mesh. The mesh may be flexible or
rigid.
[0026] An alternative to the mesh integration is the application
approach similar to that used when applying stucco to buildings. In
this case, a mesh is installed and the material is applied to the
mesh either by spraying, trowelling, some other method or a
combination of these. The key to the application is to rely on the
mesh as a structure with the polymer engulfing the mesh.
[0027] Whether formed directly around a mesh or applied on a mesh,
the structure provides additional benefit during periods of
dehydration. One would reasonable expect a drying polymer to
separate during shrinkage. With a properly designed and sized mesh,
the shrinkage will take place in the mesh gaps while allowing the
polymer to remain attached to the mesh. An example of this is shown
in FIG. 4, in which polymer 102 is affixed to mesh 401 such that
any shrinkage occurs in the gaps of the mesh 401, thereby
maintaining the integrity of the polymer layer upon
rehydration.
[0028] Additionally, the polymer may be encapsulated in some porous
layer as shown in FIG. 5. The porous layer 501 will allow for water
to enter and escape the polymer 102 but will also provide for some
protection of the polymer itself. The porous layer 501 may be that
of a fabric material or rigid and may be on a single side or both
top and bottom. An advantage of this implementation is the ability
for the polymer layer to be installed temporarily or moved and
adjusted to fit the specific and/or changing needs.
[0029] Another advantage of the PEC being encapsulated in a porous
layer 501 is that it can help contain the polymer if it becomes
completely dehydrated. In a case of complete dehydration, a
nominally 95% water content polymer can shrink, become brittle and
fracture into small pieces.
[0030] It is with possible shrinkage in mind that the selection of
a flexible adhesive may be beneficial. With sufficient elasticity
in the adhesive component, during dehydration the PEC remains in
place and will upon rehydration return to its desired form. This
capability can be enhanced by applying in a very specific manner
such that the polymer is applied in the dry state and in a pattern
that allows for rapid expansion upon rehydration.
[0031] Another approach to mitigate issues resulting from
dehydration is the ability to process in the polymer in a means
that allows for expansion upon hydration in only the vertical
direction. Such an enhancement will mitigate concerns of expansion
and contraction during wet and dry periods, respectively, and any
resulting mechanical separation.
[0032] Yet another alternative implementation of the invention is
the ability to actually polymerize the polymer upon application to
a UV-exposed source. For example, the incorporation of a UV
initiator for polymerization may be sufficient to enable the UV
delivered by the sun to actually cause polymerization after the
polymer's monomer mix has be applied to a surface.
[0033] It will be well understood that this PEC may also be applied
to other than roof structures and that application format may vary.
Such an alternative application may be for the sidewalls of
buildings and structures or integrated into other heat exchanger
systems that can take advantage of the phase change cooling
system.
[0034] In the preferred embodiment, the polymer used will have
sufficient hydrophilicity that rehydration will be easily
accomplished. In some high humidity areas, such rehydration may
occur naturally during low-heat periods like at night. An
alternative is to provide water to rehydrate the polymer. As shown
in FIG. 6, providing water 601 may be accomplished in a manner
similar to that provided to lawns and landscaping plants with
sprinklers, misters or trickle water systems 602. Fortunately, such
a system can be tied directly into a landscape system such that it
operates during non-peak heat times. The use of non-potable water,
used in many locations specifically for irrigation, is readily
compatible with this embodiment of PEC.
[0035] It is important to note that proper polymer selection for
PEC may have additional benefits. The incorporation of specific
elements into the polymer may help provide cold-weather performance
benefits. For example, the Example Polymer requires initial
hydration using a particular buffered solution. This buffered
solution interacts with the organic acids in the polymer
composition and provides a sodium (Na) atom to become part of the
polymer. This sodium atom provides some amount of freeze point
depression, which can be advantageously used to mitigate ice
build-up from roofs and other structures. An additional benefit to
this implementation is that the phase change from liquid to solid
(i.e., water to ice) releases energy that can be absorbed by the
structure. It will be easily understood that other fluids, like
glycol solutions, may be used to enhance cold weather
performance.
[0036] An advantage of using water as the working fluid for PEC is
that it also provides a high degree of reflectivity at higher
angles and transmissivity at smaller angles, allowing for
additional reflectivity from underlying surfaces. This is
beneficial in that it further helps reduce heat energy that may be
absorbed by a structure. Such transmissivity and reflectivity may
be enhanced with the addition to the polymer of specific elements
or pigments or the selection of one or more adhesive
components.
[0037] As with the anti-icing attributes of PEC, various means may
be incorporated to enhance cold weather performance. For example,
absorbing elements or pigments may be added to the polymer
specifically to provide additional heat absorption during cold
weather periods. Any adhesive element may also contribute to this
quality.
[0038] Ideally a temperature-responsive element may be incorporated
in PEC such that during warm periods reflectivity is enhanced,
perhaps by appearing white in color, and during cold periods
absorbance is increased, perhaps by appearing darker in color.
[0039] An alternative to providing such opposing functions for PEC
is to implement it in some mechanical fashion that takes advantage
of the sun's angle of incidence during different parts of the year.
The ability to effectively change exposed colors to enhance
reflectivity and absorbance is conceptually straightforward and is
shown schematically in FIG. 7 with mechanical element 701
installed. Such mechanical element can take many forms but would
nominally have a surface optimized for absorbing heat energy when
the source, like the sun 702, is at a seasonally low position but
does not obscure heat energy when the source, like sun 703, is
seasonally at a high angle. Such optimization may include coloring
or mechanical features. It is understood that mechanical element
701 may also include additional reflective surface to enhance
performance when the source is at a high angle as in 703. The
combination of this approach with a hydrophilic polymer that also
incorporates enhanced anti-icing qualities is beneficial to
many.
[0040] Yet another alternative for enhancing heat reflectivity or
absorbance is the incorporation of electro-active chromophoric
elements into the polymer material. Similar to those found in
liquid crystal displays (LCDs) or organic light emitting diodes
(OLEDs) these electro-active elements may provide for an active
color change element upon the application of a small electrical
charge.
[0041] One can easily envision, for example, the incorporation of
an element that become bright upon charging. Not only does the
reflectivity increase because of the brightness, but heat issues
are greatly minimized if not eliminated altogether from the glowing
elements because of the water content of the material. In the same
manner, an element that turns dark in the winter may greatly
enhance the retention of heat energy absorption. The electrical
source may be a small solar panel, house current, battery or other
source.
[0042] It will be easily understood that while a suitable polymer
may have sufficiently small pore size to prevent plant and other
intrusions into the polymer matrix, the water content may invite
surface or under-layer growth. An enhancement to this invention is
the inclusion of elements or compounds into the mix to further
enhance the inability for plant, fungi and bacterial matter to
grow.
[0043] Similarly, another enhancement is to address the possibility
that exposure to the sun's UV rays may degrade the polymer over
time. To mitigate this, at least partially if not completely, UV
inhibitor means and compounds may be incorporated into the polymer
formulation or the polymer mix.
EXAMPLE
[0044] Existing high water content polymers like that disclosed in
U.S. Pat. No. 6,201,089 provides a straightforward basis for an
example implementation of this invention.
[0045] A hydrated polymer, combined with a liquid adhesive
component is mixed with a working fluid to provide the proper
application viscosity. Viscosity requirements may be based on
several factors, but at a minimum will have to allow compatibility
with application means. For the sake of this example, the
application means is a spray system commonly used in the
construction trade for applying paints or expandable foam
insulation and other surface coatings.
[0046] After clearing an existing roof from debris and easily
removed dirt and residue, an operator uses the spray system to
apply a layer of the polymer mix. Environmental factors like
temperature and humidity may impact the speed at which the operator
can apply the material. As is often the case in applying paint,
multiple applications may be necessary to provide the desired
thickness. While the desired thickness is likely determined well
before application, it is understood that it may be increased at a
later time. After the desired area is coated to the desired
thickness of the polymer mix, the operator simply lets it set and
the adhesive cure in place.
[0047] For this example, one may assume that during peak summer
seasons the polymer will likely face periods of extended dryness.
To maintain the polymers beneficial actions, during the relatively
cooler nighttime a sprinkler system tied to the non-potable
landscape water source sprays water on the polymer-covered roof.
This will ensure optimal performance during the next days heat
cycle. Such a sprinkler cycle will not be necessary if there is
rain or sufficient moisture available in the atmosphere.
[0048] In an area of high humidity there is always a concern about
the growth of mold, mildew, algae and other unwanted plant life.
For the example polymer mix, this is easy dealt with by periodic
application of a simple sodium bicarbonate and water or similar
mixture. Not only does this provide moisture to the polymer but the
nature of the mixture will kill any surface growth. Such an
application may be ideally performed at least once per year. Should
additional action be required against molds, mildews, algae or
other unwanted growth--commercially available biocides, algicides
or other treatments can be applied, including as part of the water
rejuvenation feed through the sprinkler system.
[0049] Should there be any work done on the roof system,
ventilation system maintenance for example, any damage to the
polymer layer is easily fixed with a simple spray of more polymer
mix. There is not issue of compatibility with the existing polymer
layer.
[0050] While specific polymer types and embodiments are cited in
this description, it will be well understood by those schooled in
the art that variations are possible. Nothing in this description
is to be read as limiting with respect to such potential
variations. Moreover, while synthetic polymers are used for example
purposes, the invention disclosed herein may be applicable to the
use of naturally derived or hybrid natural/synthetic
formulations.
* * * * *