U.S. patent application number 12/527757 was filed with the patent office on 2010-05-06 for apparel with heating and cooling capabilities.
Invention is credited to Kranthi K. Vistakula.
Application Number | 20100107657 12/527757 |
Document ID | / |
Family ID | 39710723 |
Filed Date | 2010-05-06 |
United States Patent
Application |
20100107657 |
Kind Code |
A1 |
Vistakula; Kranthi K. |
May 6, 2010 |
APPAREL WITH HEATING AND COOLING CAPABILITIES
Abstract
A process and system for heating or cooling comprising a
ihermoelectric unit having a cooling surface and a heating surface,
the cooling surface being thermally insulated from the heating
surface is provided. A heat sink is thermally coupled the
thermoelectric unit and a wicking material operatively coupled to
the heat sink. The wicking material may be substantially saturated
with a mixture of water and DNA to dissipate energy. An apparel
item incorporating the system for heating and cooling is also
provided.
Inventors: |
Vistakula; Kranthi K.;
(Hyderabad, IN) |
Correspondence
Address: |
BROWN RUDNICK LLP
ONE FINANCIAL CENTER
BOSTON
MA
02111
US
|
Family ID: |
39710723 |
Appl. No.: |
12/527757 |
Filed: |
February 20, 2008 |
PCT Filed: |
February 20, 2008 |
PCT NO: |
PCT/US08/54438 |
371 Date: |
August 19, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60903231 |
Feb 23, 2007 |
|
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Current U.S.
Class: |
62/3.5 |
Current CPC
Class: |
F25B 2321/025 20130101;
F25B 21/02 20130101; A41D 13/0056 20130101; A41D 13/005
20130101 |
Class at
Publication: |
62/3.5 |
International
Class: |
F25B 21/02 20060101
F25B021/02; F25D 23/00 20060101 F25D023/00 |
Claims
1. A system for heating or cooling comprising: a thermoelectric
unit having a cooling surface and a heating surface, the cooling
surface being thermally insulated from the heating surface; a heat
sink thermally coupled the thermoelectric unit; and a wicking
material operatively coupled to the heat sink.
2. The system according to claim 1, wherein the wicking material is
substantially saturated with water, DNA or a mixture of water and
DNA or any other material that consumes energy during a phase
change or increase in temperature.
3. The system according to claim 1, wherein the heat sink and
wicking material maximize the surface area for evaporation.
4. The system according to claim 2, further comprising a breathable
layer disposed on the wicking material to allow evaporation of the
water to the environment.
5. The system according to claim 2, further comprising a phase
change material operatively coupled to the thermoelectric unit.
6. The system according to claim 2, further comprising a unit to
resaturate the wicking material with water, DNA or the mixture of
water and DNA mixture or any other material that consumes energy
during a phase change or increase in temperature.
7. The system according to claim 2, further comprising a battery
unit to power the thermoelectric unit.
8. The system according to claims 2 incorporated into an apparel
item.
9. The system according to claim 8, wherein the apparel item is
selected from jackets, vests, helmets, shows, hats, undergarments,
pants, socks.
10. The system according to claim 1, wherein the heat sink is a
layer of aluminum.
11. The system according to claim 1, wherein the heat sink is
selected from a layer of aluminum, metal or composite material.
12. An apparel item for heating or cooling comprising; a
thermoelectric unit having a cooling surface and a heating surface,
the cooling surface being thermally insulated from the heating
surface: a heat sink material thermally coupled the thermoelectric
unit; a wicking material operatively coupled to the heat sink; and
a battery unit to power the thermoelectric unit.
13. The apparel item according to claim 12, wherein the wicking
material is substantially saturated with water, DNA or a mixture of
water and DNA or any other material that consumes energy during a
phase change or increase in temperature.
14. The apparel item according to claim 13, further comprising a
breathable layer disposed on the wicking material to allow
evaporation of the water to the environment.
15. The apparel item according to claim 13, further comprising a
phase change material operatively coupled to the thermoelectric
unit.
16. The apparel item according to claim 13, further comprising a
unit to resaturate the wicking material with water, DNA or the
mixture of water and DNA mixture or any other material that
consumes energy during a phase change or increase in
temperature.
17. The apparel item according to claim 13, wherein the apparel
item is selected from jackets, vests, helmets, shows, hats,
undergarments, pants, socks.
18. The apparel item according to claim 13, wherein the heat sink
is a layer of aluminum.
19. A process for heating or cooling comprising the steps of:
providing an apparel item including a thermoelectric unit having a
cooling surface and a heating surface, the cooling surface being
thermally insulated from the heating surface; providing a heat sink
material thermally coupled the thermoelectric unit; providing a
wicking material operatively coupled to the heat sink; and
providing a battery unit to power the thermoelectric unit.
20. The process according to claim 19, wherein the wicking material
is substantially saturated with water, DNA or a mixture of water
and DNA or any other material that consumes energy during a phase
change or increase in temperature.
Description
RELATED APPLICATION INFORMATION
[0001] This patent application claims priority from U.S.
Provisional Application No. 60/903,231, filed on Feb.23, 2007
wherein the entire contents of which are incorporated herein by
reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure generally relates to a system and
process for heating and cooling the body or a portion of the body
and more particularly to apparel with heating and cooling
capabilities incorporating the system and process for heating and
cooling the body.
[0004] 2. Description of the Related Art
[0005] There are presently two groups of personal thermo-regulated
apparel. These two groups are active and passive. Active
thermo-regulated apparel is designed to maintain the temperature
that the user has selected while passive thermo-regulated apparel
is not capable of maintaining the selected temperature over time.
Currently available products in the active thermo-regulated apparel
group are only capable of single applications such as heating or
cooling. Current active heating technologies generally incorporate
resistive heating. For example, Polartec.RTM. has integrated
electrically resistive heating technology into a jacket. Similarly,
compressive cooling is typically used in most currently available
cooling apparel items.
[0006] Passive heating systems are generally chemical reaction
heating systems. Likewise, passive cooling systems have included
cooling with a phase change material, however, the systems
currently available have not provided a system and process for
heating and cooling that can be incorporated in wearable apparel
for a wide variety of uses.
[0007] For example, U.S. Pat. No. 4,856,294 to Scaringe et al.
describes a Micro-Climate Control Vest which contains a phase
change material with a solid-to-liquid phase change as a cooling
medium. The vest may also have an optional second phase change
material layer of ice and an optional outer insulation layer. The
inner liner containing the phase change material is divided into
individual compartments due to the rigidity of the phase change
material in its solid state. Thus, the apparel is rigid and
inflexible making it uncomfortable to wear. Another example of
apparel incorporating phase change material is described in U.S.
Pat. No. 4,894,931 to Senee et al. Senee describes a battery
powered electric heating device incorporating phase change material
such as salt for warming various body parts. The salt serves as a
heat storage medium and as a temperature regulator for the
resistance heater since it can absorb a lot of heat without rising
above its melt temperature. As in many other devices of this
nature, the rigidity of the system along with the rigidity of the
salt make the system difficult to incorporate into various apparel
items.
[0008] U.S. Pat. No. 4,572,158 to Fiedler describes a heating pad
for warming body parts that use a supercooled phase change material
salt solution for heat storage. The phase change material is
liquefied and then can be cooled to room temperature without
solidifying. A trigger is used to activate the salt, causing an
exothermic crystallization. This device is sold with a cloth or
neoprene cover to prevent burns when it is placed against the skin.
Furthermore, this system is difficult to incorporate into apparel
for heating and cooling the body.
[0009] U.S. Pat. No. 4,851,291 to Vigo et al. describes another
method of making fibers with thermal storage properties by filling
the core of a hollow fiber with a phase change material or
absorbing a phase change material onto the surface of a non-hollow
fiber. The phase change materials described include cross-linked
polyethylene glycol and plastic crystals that have a solid-to-solid
crystalline phase change. These fibers do not allow absorption of
enough phase change material into the containment material to be of
practical use in heating or cooling.
[0010] U.S. Pat. No. 6,763,671 to Klett et al. describes a
closed-cycle cooling and protective apparatus. The apparatus
includes a thermal battery cooling source. Unfortunately, this
system is rigid and must be completely closed. Furthermore, even a
small amount of damage to the system would render the system
non-functional making it unsuitable for harsh working
conditions.
SUMMARY OF THE INVENTION
[0011] Accordingly, the current disclosure relates to a system and
process for heating or cooling the body that can be incorporated
into a variety of apparel items. The user may direct a small
electronic interface to either supply or remove heat to the insert,
thus cooling or heating the individual.
[0012] The current system according to the current disclosure
incorporates the novel design of a heat sink and relates to heat
removal from hot side of the thermoelectric unit in cooling
applications. Alternatively, it is envisioned that the system may
be configured for heating applications.
[0013] The current disclosure incorporates a combination of
thermoelectric devices and evaporative cooling in form of a novel
heat sink attached to thermoelectrics. Additionally, a heat pipe or
similar heat transfer system can be used in locations where
evaporation cannot happen immediate to hot side of thermoelectric.
In one embodiment, the system for heating or cooling includes a
thermoelectric unit having a cooling surface and a heating surface,
the cooling surface being thermally insulated from the heating
surface, a heat sink thermally coupled the thermoelectric unit and
a wicking material operatively coupled to the heat sink. The
wicking material can be substantially saturated with a mixture of
water and DNA to dissipate energy. A breathable layer is disposed
on the wicking material to allow evaporation of the water to the
environment. Furthermore, a phase change material may be disposed
between the body and the cold side of the thermoelectric unit for
storage of cold energy to increase the system functioning time. The
system may include a unit that can be filled so as to allow a user
to resaturate the wicking material with the water and DNA mixture.
A battery unit or any other power source may power the
thermoelectric unit.
[0014] The system according to the present disclosure can be
incorporated in a wide variety of apparel items as further
described below. Some apparel items include jackets, vests,
helmets, shows, hats, undergarments, pants and socks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The objects and features of the present disclosure, which
are believed to be novel, are set forth with particularity in the
appended claims. The present disclosure, both as to its
organization and manner of operation, together with further
objectives and advantages, may be best understood by reference to
the following description, taken in connection with the
accompanying drawings as set forth below:
[0016] FIG. 1 depicts an exemplary heat pipe that may be used in
accordance with the present disclosure;
[0017] FIG. 2 depicts a schematic of an exemplary system in
accordance with the present disclosure;
[0018] FIG. 3 depicts a cross-sectional view of one embodiment in
accordance with the present disclosure;
[0019] FIG. 4 depicts a perspective view of an exemplary heat sink
in accordance with the present disclosure;
[0020] FIG. 5 depicts a perspective view of one embodiment of the
system in use in accordance with the present disclosure;
[0021] FIG. 6 depicts a cross-sectional view of another embodiment
in accordance with the present disclosure;
[0022] FIG. 7 depicts a perspective view of an exemplary embodiment
of the system incorporated into a jacket in accordance with the
present disclosure; and
[0023] FIG. 8 depicts cross-sectional view of an exemplary
embodiment of the system incorporated into a helmet according to
the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The present disclosure will be described in connection with
certain preferred embodiments, with reference to the following
illustrative figures so that it may be more fully understood. With
reference to the figures, it is stressed that the particulars shown
are by way of example and for purposes of illustrative discussion
of the preferred embodiments of the present invention only, and are
presented in the cause of providing what is believed to be the most
useful and readily understood description of the principles and
conceptual aspects of the invention. In this regard, no attempt is
made to show structural details of the invention in more detail
than is necessary for a fundamental understanding of the invention,
the description taken with the drawings making apparent to those
skilled in the art how the several forms of the invention may be
embodied in practice.
[0025] Within the context of the present disclosure, the following
definitions are used for the terms listed below. It should be noted
that some of these terms have other definitions when used in other
contexts.
[0026] The term "apparel" broadly refers to any article of clothing
or similar garment such as jackets, biking shorts, biking shoes,
biking jerseys, exercise suits, sport bras, spandex pants, under
garments, shorts, tops, shirts, gloves, shoes, boots, ski boots,
roller skates, ice skates, roller blades, socks, wrist bands, heart
monitors, wrist watches, uniforms, baseball caps, golf caps,
visors, head bands, hats, glasses, sunglasses, headphones,
medallions, pendants, jewelry, necklaces, bracelets, anklets,
chemical suits, bio suits, space suits, space helmets, bullet-proof
vests, fire protective suits, motorcycle leathers, goggles, hard
hats, construction helmets, welding masks, motor racing helmets,
motor cycle helmets, motor racing suits, motor racing under
garments, bicycle helmets, football helmets, batting helmets,
cricket batting helmets, baseball batting helmets, softball
helmets, skiing helmets, skiing suits and under garments, riding
helmets, equestrian riding helmets, fencing masks, fencing tunics,
shin guards, knee pads, military equipment hats, and military
helmets.
[0027] The term "phase change material" refers to any material with
a high heat of fusion which, melting and solidifying at certain
temperatures, is capable of storing or releasing large amounts of
energy. One skilled in the art will appreciate that a variety of
phase change materials (both inorganic and organic) may be
incorporated into the present disclosure such as PCM Latest.TM.
from PCM Energy Pct Ltd. or calcium chloride hexahydrate. Other
examples include Heptanone-4, n-Undecane, TEA-16, Ethylene glycol,
water, Thermasorb 65 and Thermasorb 43.It is envisioned that a
large variety of phase change materials can be incorporated into
the system of the present disclosure.
[0028] The term "wicking material" refers to any material that has
the ability to draw another substance into it. In accordance with
the present disclosure, wicking materials include, for example,
cotton, wicking fibers such as 4DG fibers, candle wick, super
absorbents and sponges.
[0029] The term "coolant" generally refers to a fluid which flows
through the system according to the present disclosure in order to
transferring the heat because produced by the system to other areas
of the system to utilize or dissipate the heat. Examples of
coolants that may be employed according to the present disclosure
include ammonia, water, ethlyl alcohol, polyethylene glycol among
others
[0030] The term "liquid" refers to a fluid that can freely form a
distinct surface at the boundaries of its bulk material. The
surface is a free surface where the liquid is not constrained by a
container. Liquids that can be used in saturate the wicking
material according to the present disclosure include water and
ethyl alcohol. It is also envisioned that fluids such as urine may
be used in accordance with the present disclosure.
[0031] In accordance with the present disclosure, the system and
process are based on the thermoelectric effect, which is the
simultaneous cooling of one junction and heating of another
junction in a thermocouple. The thermoelectric effect occurs when
current is passed through two dissimilar metals or semiconductors
(N-type and P-type) that are connected to each other at two
junctions. Current thermoelectric devices are a network of
thousands of P-N junctions with all P-type material facing one side
and N-type facing the other side. Depending of the direction of the
current, either P-type or N-type surface becomes hot or cold.
Accordingly, the thermoelectric units incorporated into the system
according to the present disclosure are highly efficient heat pumps
that directly convert electricity into heating and cooling power.
When power is supplied to the thermoelectric units, the current
causes one side of the units (the cool side) to absorb heat.
Meanwhile, the other side of the thermoelectric unit (the hot side)
releases heat (the hot side). Thus, the thermoelectric unit causes
heat to flow from the cool side to the hot side. Reversing the
current causes the heat to be moved in the opposite direction
thereby reversing the hot side and the cold side. Consequently, the
heating and cooling according to the present disclosure may be
selected by the user. One of ordinary skill in the art will
recognize the various possible reconfigurations of the system
according to the present disclosure to provide a variety of heating
and cooling effects to a user of the system.
[0032] Heat pipes may be used in certain embodiments in accordance
with the present disclosure. Heat pipes are thermally conductive
tubes that can quickly transfer heat from one point to another by
evaporating water at the hot side of the pipe and condensing it at
the cold side. A general example of a heat pipe is shown in FIG. 1.
Working fluid evaporates to vapor absorbing thermal energy as
depicted at 2. Vapor migrates along vapor cavity 4 shown at 6 to
the lower temperature end 8. At 10, vapor then condenses back to
fluid and is absorbed by the wick 12, releasing thermal energy.
Working fluid flows back to higher temperature end 14, shown
generally at 16.
[0033] Now referring to FIG. 2, a schematic of a one embodiment of
the thermoelectric system is shown. In this embodiment, a flexible
heat pipe is incorporated in the system. Cooling plate 20 with
embedded thermocouples rests against a portion of a person's body.
The heat pipe vapor conduit 22 is connected to the heat pipe
condenser unit 24. This heat pipe condenser unit may be clipped to
the hip region of an individual or other area to allow for
effective use of the system. A battery pack 28 supplies energy to
the thermoelectric system and allows an operator to turn the system
on or off. Thus, if for example, a person wishes to cool a body
part, liquid will evaporate at cooling plate 20 and exit to heat
pipe vapor conduit 22. The vapor will travel to condenser unit 24
where the condenser unit will condense the vapor and release
thermal energy. The heat pipe liquid return 26 returns liquid to
cooling plate 20.
[0034] In this particular embodiment, the core of the heat pipe can
be made of a polycarbonate or similar material such as polyvinyl
chloride, Kevlare composite or a variety of other flexible
composite materials and carbon nanotubes or similar material with
high thermal conductivity such as silver, carbon fibers and
graphite. The heat pipe can be coated with silver nanoparticle
paste or carbon nanofibers with thermal conductivity of
approximately 200 W/m-K. The ends of the heat pipe can have a high
concentration of graphite incorporated into the material and carbon
nanotubes with conductivity of 400 W/m-K. Other possible material
combinations can be used such as carbon fibers and gold
nanoparticles.
[0035] The system can, for example, be worn against the torso. A
cross sectional view of such a system is shown in FIG. 3. A cooling
plate 30 incorporating a thermoelectric module 32 is worn against a
torso 34 of a person. A cushioning gel 36 can be placed between
cooling plate 30 and torso 34 to provide support and comfort for a
user of the system. As the body is cooled, for example, vapor in
the heat pipes 38 will travel to a condenser unit located away from
torso 34. A Velcro attachment 40 can provide an attachment
mechanism between the heat pipes 38 and body armor 42. Furthermore,
thermal insulation 44 provides for insulation between the heat
pipes and cooling plate 30. In addition to cushioning gel 36, a
layer of conductive fabric may be placed between the thermoelectric
unit and a user's skin.
[0036] Once heat is drawn away by the thermoelectric system
described above, it must be dissipated. Direct dissipation by means
of a heat sink attached to the hot side of the thermoelectric may
be difficult to incorporate in this embodiment as the system may be
worn beneath a bulky, armored vest. Thus, heat pipes as described
above are incorporated to carry the heat away from the
thermoelectric to a place where it can be safely and effectively
vented to the outside environment.
[0037] A heat sink block or strip, which can be a thin aluminum pad
(or similar conductive alloy, metal, or material, such as
magnesium, carbon-fiber, and/or carbon-carbon materials or
composites)of approximately 0.25 inches thick can be attached to
the hot side of each thermoelectric unit through which heat pipes
will be run. Various sizes of the heat sink block or strip can be
selected based on the application and size of the system. A
thermally conductive adhesive, such as double sided tape, epoxy
cement, a highly thermally conductive heat film adhesive, or the
like, may be used to mount the heat sinks onto the thermoelectric
units. The coolant in the heat pipes will absorb the heat and carry
it to the dissipater or condenser unit by means of the natural
wicking action of the heat pipes.
[0038] The heat pipes can be adiabatically insulated to prevent
transfer of warmth to the body, and will be flexible to allow for
comfort of the user. For example, insulator that can be used
include, for example, wool, Thermal Ceramics 400 Mineral Fiber
Paper, Thermal Ceramics Min-K Type LW Insulating Tape and Zirconia
ZYK-15 Ziconia Cloth. When the system is shut off, the remaining
energy must either be stored or dissipated so that the heat isn't
transferred back to the individual using the system. The primary
purpose of implementing a heat capacitor is to dissipate energy.
The heat energy transferred from the thermoelectric should be
constantly dissipated into the outside environment or stored in
another form of energy, which will increase the efficiency of the
total system. The total system is designed to add or remove about
173 kcal/hour (200 Watts) from a human body. However, by small
changes in the design, this capacity can be significantly increased
or decreased.
[0039] According to the present disclosure, a heat capacitor can be
implemented, which is shown in FIG. 4. The heat capacitor may be
placed by the hip of the user or another location that is
convenient for the particular application and use. As shown in FIG.
4, the heat capacitor can be a vacuum-sealed container 50 with
internal fins 52 that holds water filled with artificially
synthesized deoxyribonucleic acid (DNA). Heat pipes 54 runs through
fins 52 and heat capacitor 50 such that the heat capacitor
dissipates the heat being removed from the individual. The amount
of water, the amount of DNA, and the number of fins will depend on
the size of the heat capacitor. The heat is dissipated by the
evaporation of water and the breaking of the hydrogen bonds within
the DNA. To evaporate 10 g of water, approximately 6 kcal of energy
is required. To break a mole of hydrogen bonds, the system requires
10 kcal. Preferably the heat capacitor will contain 200 g of water
with 10 moles of hydrogen bonds present in the DNA.
[0040] As described above, heat pipes 54 will run through heat
capacitor 50, so heat exchange can occur between the heat pipes and
the coolant, which is water and DNA in one embodiment. The use of
the heat capacitor, with its large surface area, allows for vastly
improved heat transfer from the heat pipes to the coolant. A
variety of coolants may be used.
[0041] In one exemplary embodiment, the heat capacitor has 1/16''
thick square fins that are 1'' long. There can be 64 fins per
square inch layered over a 2'' sq box. This gives 1280 fins per
heat capacitor. Laying a thin cover over the fins may help prevent
damage and/ or snagging.
[0042] This embodiment provides a surface area of
1.6.times.10.sup.-4 per fin, or a net finned surface area of 0.205
m.sup.2. If a convection constant of 70 is assumed and a AT of
5.degree. C. ambient is 40.degree. C. and T.sub.hot side of
thermoelectric is 45.degree. C.), 72 W of heat is dissipated from
the box via forced air convection.
[0043] The fluid in the heat capacitor box can absorb a net heat of
5434 J. In conditions when the box is taking in the ideal 200 W and
losing 143.5 W, there is a net difference of 56.5 W. Thus, the 56.5
W of heat will be stored by a combination of the breaking of the
hydrogen bonds and through the evaporation of the water.
[0044] An exemplary embodiment of the system incorporated into a
vest according to the present disclosure is shown in FIG. 5. In
this embodiment, a thermoelectric array 70 covers a large portion
of the user's torso. Flexible heat pipes 72 are coupled to
thermoelectric array 70 as to carry heat away from the user's body.
Each thermoelectric unit in the thermoelectric array may be
constructed with the heat sink or strip as described above. The
heat pipes carry the vaporized liquid to heat capacitor 74.
Flexible heat pipes 72 may be attached to heat capacitor 74 with a
detachable plug or other means to operatively connect the heat
pipes to the heat sink such that heat is dissipated. A battery pack
76 is attached to the system. The battery pack can provide variable
temperature control and can attached to body armor, vest or other
clothing or apparel a user may be wearing.
[0045] The batteries can be selected for the largest possible
Ampere/hour (ah) value and minimum weight. Preferably, they will be
rechargeable and as lightweight as possible. The back of the vest
can contain pockets which snugly hold the batteries. Types of
batteries that may be incorporated into the present system include
Lithium Ion, Lithium metal hydride, lithium polymer among others.
Other power sources may be envisioned. For examples, other sources
may be used to power the system such as wind, solar and mechanical
sources.
[0046] The thermoelectric array can consists of approximately 6 to
9 thermoelectric units. This number can be increased or decreased
to accommodate for persons of various sizes. In one embodiment,
each thermoelectric is attached to a steel pad approximately 1/1641
thick steel. The steel pad thermally couples the heat sink and the
thermoelectric unit on one side and on the other side it acts to
increase conductivity between the torso and the thermoelectric
unit.
[0047] Each thermoelectric unit can be attached to the surface of a
user's vest, on top of aluminum mesh, for example, to act as the
heat sink or strip, with the base of the aluminum cup, which is an
encasing for the thermoelectric unit. Preferably, each
thermoelectric unit is thin and is approximately no more than 0.5
inches this. Similarly, the aluminum cup can have very thin walls
to reduce thermal resistance as well as weight. A previously
described, other suitable materials that may be used in place of
the aluminum mesh such as steel mesh or carbon fiber fabric. Carbon
nanotubes can also be used as heat sink replacing aluminum. A
composite material made of CNT, Polymers and fibers can also be
used to perform the heat transfer and also act as the heat
sink.
[0048] These thermoelectric units provide effective and direct heat
transfer away from the body. Thermal backwash is solved through a
timing circuit. Thus, when the system is turned off, the power
supply is not disconnected immediately. which prevents thermal
backflow until the temperatures are in equilibrium.
[0049] By way of example, when the system according to the present
disclosure is incorporated into a vest, the system may include a
snug-fitting, natural cotton vest onto which a metal blend `fabric`
panel is attached such that it sits across the user's chest. This
panel can be made of aluminum-dipped cotton thread to allow for
effective heat exchange between the thermoelectric and the body.
Aluminum, with its thermal conductivity (k) value of 222 W/m-K,
provides essentially negligible thermal resistance so the user will
feel the same temperature as that on the cold side of the
thermoelectric, while the cotton core provides additional strength
in tension.
[0050] This vest can also be constructed without the fabric, using
thin aluminum contact pads connected directly to the cotton fabric
of the vest, though the fabric may provide more comfort to a
user.
[0051] The thermoelectric system according to the present
disclosure, may have a large possible range of operating
temperatures, which are also current dependent. The heat transfer
rate is directly proportional to the current that passes through
the thermoelectric. A current regulator control can be attached to
the thermoelectric array so that the user can control the
temperature of the vest to suit their situation. A current
regulator will also prevent battery waste, because thermoelectric
units are not self-regulating in their draw of current from a
battery.
[0052] In a preferred embodiment, while heat pipes may be used,
they are not necessary. An example cross section of this embodiment
is shown in FIG. 6. At least one thermoelectric unit 80 sits
against the body of a user. A cushioning gel may be placed between
a thermoelectric unit and the user for additional comfort. In
addition to cushioning gel, a layer of conductive fabric or other
conductive material may be placed between the user and the
thermoelectric. A phase change material can be thermally coupled to
the side of the thermoelectric facing the torso for storing heat or
acting as a heat absorbent material to increase the singe use life
lifetime. These lays may be connected by way of an adhesive or
other connective material. A battery 82 is attached to the
thermoelectric unit such that is provides electricity to the
thermoelectric unit. On the hot side of the thermoelectric unit 80
is an aluminum, or similar conductive alloy, metal, or material,
such as magnesium, carbon-fiber, and or carbon materials or
composites heat sink 84, which may be partially or fully exposed on
a hot side of the thermoelectric unit. As previously discussed,
when power is supplied to the thermoelectric unit or units, the
current causes on side of the thermoelectric unit to absorb heat,
which the other side releases heat (the hot side). The
thermoelectric unit causes heat to flow from the cool side to the
hot side. If the current is reversed the heat will move in the
opposite direction, allowing a person to heat rather than cool a
body part. As the cool side of the thermoelectric cools the body,
the heat is drawn to the hot side of the thermoelectric and through
the aluminum or other alloy heat sink 84.
[0053] A wicking material 86, such as cotton is disposed on the
aluminum heat sink. Wicking material 86 can have water and DNA such
that heat is dissipated by the evaporation of water and the
breaking of the hydrogen bonds within the DNA. In the heat sink the
water can be mixed with DNA to act as heat capacitor. DNA has
hydrogen bonds and when the water with DNA is heated the hydrogen
bonds break by absorbing heat. The DNA is recharged when the system
is switched off such that is supply of heat to the heat sink is
stopped. This makes the DNA a good self recharging material to be
used in the system according to the present disclosure. Wicking
material 86 absorbs energy and facilitates and the dissipation of
the energy. A breathable fabric or as another alternative, a porous
material coupled to the wicking material allows the water to
evaporate into the atmosphere.
[0054] If it is not feasible or is impracticable to allow for
evaporation to the outside from certain areas of an apparel item,
heat pipes may be used to carry the heat to a heat capacitor
located at the hip, armpit or other area conveniently located to
allow for heat dissipation and evaporation of water from the
wicking material.
[0055] Furthermore, as the water evaporates, it may become
desirable to add more water to the system. An optional pack may be
operatively connected to the system to refill the system as
desired. This pack may be carried on a users body and connected at
all times or be carried separately and attached when needed. It is
desirable to use water as the evaporating liquid, however, other
liquids such as ammonia or ethyl alcohol can be used.
[0056] Another example is shown in FIG. 7. A temperature controller
92 is located on a user's jacket to allow for easily accessible
control of the system. Temperature controller 92 is operatively
connected a battery pack 94 to provide energy to a thermoelectric
units 96. The thermoelectric units can be selected such that the
cold side is closest to the body or the hot side is closest to the
body depending on the desired use of the system according to the
present disclosure. An aluminum or other acceptable material as
described above is disposed about the thermoelectric unit to act as
a heat sink 98. A wicking material 100 having water and DNA is used
as previously describe to dissipated energy into the atmosphere. A
breathable layer operatively disposed on wicking material 100
allows the water or similar material to evaporate outside of the
jacket 102.
[0057] A helmet incorporating the system is shown in FIG. 8. The
thermoelectric 110 may sit directly again a user's hear or have a
gel or cushioning material between the user and the thermoelectric.
A battery 112 supplies power to the thermoelectric. A heat sink
material 114 is operatively connected to the thermoelectric. A
wicking material 116 is operatively connected to the aluminum heat
sink. Wicking material has water and DNA or other liquid which
evaporates and dissipates energy. A phase change material 118
allows for evaporation to the environment from the helmet.
Alternatively, if there it is not feasible to allow for evaporation
at the point of the thermoelectric, the heat may be carried to
another portion of the helmet or body to allow for evaporation in a
different area. Furthermore, the entire helmet can act as a heat
sink and allow water or another liquid to evaporate from the entire
surface.
[0058] It is envisioned that the system according to the present
disclosure can be incorporated into a large variety of apparel
items as listed above.
[0059] In all embodiments as described above components that make
up the personal heat-control device may include an operational
switch, a control circuit board (printed or otherwise), one or more
thermoelectric units, one or more batteries and one or more water
(or other suitable material) supply. The components may be
distributed within and/or permanently or temporarily attached to an
item of apparel incorporating the system according to the present
disclosure. Depending upon the particular application or garment,
two or more of the components may be co-located or combined. These
components may be broken down into smaller sub-components, for
example, one or more thermoelectric units may be located remotely
from one or more other thermoelectric units to provide a more
distributed cooling effect. Likewise, batteries may be distributed
throughout the apparel or in one located depending on the
application and desire of the user.
[0060] An operational switch may be communicatively coupled to a
control circuit board and the control circuit board operatively
coupled to the to the thermoelectric units to receive temperature
information such that the duration of the heat transfer cycle or
other adjustments may be made by the user.
[0061] The operational switch can be a solid-state electronic
timing switch operable by a user to activate and deactivate heat
transfer cycles modulated by optional electronics, such as a timer
and/or other monitoring or control circuitry. According to one
embodiment, the optional electronics provide timed cycling
(pulsing) of the thermoelectric units to extend operational time
per battery charge, to avoid overcooling, to increase the comfort
of the user, and/or accommodate battery recovery. According to some
embodiments of the present invention, control circuit board may be
a programmable logic device such that they may be programmed to
pulse of cycle the thermoelectric units in certain patters. These
patterns may be programmed via an external computing source, such
as a laptop computer. According to some embodiments of the present
invention, the control circuit board may also include a radio
receiver or transceiver and be programmed and/or reprogrammed via
radio signals.
[0062] The transmission of one or more of control signaling and/or
status information among several of the distributed components is
can be via wireless means. In other embodiments, the transmission
of one or more of power, control signaling and/or status
information among several of the distributed components is via one
or more fine conductive wires formed as part of the material of an
apparel item.
[0063] It will be understood that various modifications may be made
to the embodiments disclosed herein. Therefore, the above
description should not be construed as limiting, but merely as
exemplification of the various embodiments. Those skilled in the
art will envision other modifications within the scope and spirit
of the claims appended hereto.
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