Abstract:
Embodiments disclosed provide a sunshade apparatus that integrates a solar collector into an attractive architectural sunshade, and a system for deriving energy, and in particular heat, from such an apparatus. The sunshade is comprised of between one and several solar collector panels. Each panel has an infrared clear pass face and contains tubing. The panel may also contain a layer of insulation underneath the tubing. The tubing contains a fluid and is connected to a solar water system. The clear face extends for most but not all of the upper surface of the panel, such that the ends are solid to provide structural support for the panel. The panels are designed in advance for use in connection with an architectural feature, such as a window on a building, with angles for each of the panels and in some cases the shade as well. Aesthetic architectural options including interior beam colors and clear face coatings are contemplated.

Description:
BACKGROUND 
       [0001]    The present disclosure relates to the field of shades. 
         [0002]    Shades are intended to provide protection from the sun. In addition to providing shade, shade structures enhance the visual appeal of buildings, platforms, patios, and other outdoor areas. Shade structures are available in a wide variety of designs, including, for example: awnings, brise soleil, canopies, fences, guardrails and decorative screens. Shade structures may be attached to a structure, or may be free-standing. Existing shade structures are manufactured from materials such as wood, metal, plastic, and fabric. 
       SUMMARY 
       [0003]    The systems, methods, and devices disclosed herein have innovative aspects, no single one of which is indispensable or solely responsible for their desirable attributes. Without limiting the scope of the claims, some of the advantageous features will now be summarized. 
         [0004]    The present disclosure relates to a sunshade with an integrated solar thermal collector. In some embodiments, a sunshade is comprised of at least one panel that doubles as a solar thermal collector. The panels may be fixed in place, or may be rotatable. The panels may all be arranged in the same orientation to form an attractive sunshade. The panels may be tilted in order to maximize sun exposure on the top face of the panels. The optimal tilt of the panels is determined by the location&#39;s latitude, the orientation of the shade structure (for example south-west facing), and by the location of the shade relative to surrounding structures that determine the sun exposure on the shade throughout the day. 
         [0005]    Each panel of the shade is a solar thermal collector. In some embodiments, a panel is comprised of an elongated U-shaped (in cross section) beam (also referred to as a “C” beam) on which a clear face is mounted on top of the U-shape to enclose a cavity. Further, insulation may be mounted inside the cavity to rest in the bottom of the U-shaped beam. Further, a tube may be disposed behind the clear face and on top of the insulation. Further, a fin may be disposed in the cavity between the clear face and the tube. Preferably, the fin is situated in contact with the tube for a length substantially equal to the length of the cavity that is contacted by sunlight. 
         [0006]    Each panel may advantageously be capped at its ends with sleeves. The sleeve at each end may be attached to an outrigger beam. Two outriggers may hold a series of panels in place in the same orientation to form an attractive sunshade. Sleeves are advantageous because they increase the strength of the panel and also the strength of the overall sunshade structure. The sleeves are also advantageous because they secure the clear face, which extends under the sleeve, to prevent it from falling off the panel. This is especially important where the sunshade acts to shade a window that is several stories high. Generally, longer panels require longer sleeves to ensure the sunshade&#39;s integrity. 
         [0007]    The clear face of a panel allows sunlight to pass into the interior of the panel. After the sunlight passes into the panel, it strikes the absorbing material, for example, metal or insulation, comprising the panel&#39;s interior. The material of the clear face (which may be tempered glass, for example) must be “clear” to the infrared rays of the Sun and allow these rays to freely pass through. Because the sunshade is visible from the outside of the architectural structure (such as a multi-story building, for example), coatings can be used as an architectural feature, adding a mirror look or even color where appropriate. The material within each panel absorbing the sunlight converts the sunlight into heat. The clear face and the U-shaped beam prevent the heat from escaping. 
         [0008]    The present disclosure also includes a solar thermal collector system that derives energy from the sunshade. The sunshade may comprise at least one solar thermal collector panel. Further, tubing disposed in the panels is connected such that the sunshade has one inlet and one outlet tube. 
         [0009]    In some embodiments, the tubing is tied into a water supply. In these embodiments, the water supply passes through the solar thermal collector panels before being fed back into a hot water supply or a water heater. In other embodiments, a solar thermal collector system enables energy absorbed by fluid in the solar thermal collector panels to be transferred to and heat a hot water supply for a building, household, or pool by means of a heat exchanger, In these embodiments, the tubing is closed circuit. The sunshade is connected to a heat exchanger and a pump with tubing. The heat exchanger transfers heat from a system fluid to a water supply. 
         [0010]    In some embodiments, the tubing is connected to a space heating system. The tubing may be connected to a thermal radiator. Alternatively, the tubing may be connected to a radiant floor. 
         [0011]    The sunshade structure detailed below is operable in a wide climate range, and over a broad geographic area. The sunshade structure detailed below may qualify for government or utility-sponsored renewable energy incentives, and, dependent on its location, may provide energy cost savings that may equal or exceed the cost of the shade within as soon as 4-5 years. Thus, sunshade structures with integrated solar thermal collectors and solar thermal collector systems using such structures, as described herein, are desirable. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    Various embodiments are depicted in the accompanying drawings for illustrative purposes, and should in no way be interpreted as limiting the scope of the inventions. In addition, various features of different disclosed embodiments can be combined to form additional embodiments, which are part of this disclosure. Throughout the drawings, reference numbers may be reused to indicate correspondence between reference elements. 
           [0013]      FIG. 1  is a depiction of an illustrative solar collector panel holding two clear faces. 
           [0014]      FIG. 2  is a depiction of an illustrative solar collector panel containing one run of tubing. 
           [0015]      FIG. 3  is a depiction of an illustrative solar collector panel containing two runs of tubing. 
           [0016]      FIG. 4  is a depiction of an illustrative sunshade in a partially exploded view. 
           [0017]      FIG. 5  is a depiction of members used to connect solar collector panels to an outrigger beam. 
           [0018]      FIG. 6  is a flow diagram for an illustrative one-pass sunshade. 
           [0019]      FIG. 7  is a flow diagram for an illustrative two-pass sunshade. 
           [0020]      FIG. 8  is a flow diagram for an alternative two-pass sunshade. 
           [0021]      FIG. 9  is a schematic diagram showing the fluid flow circuit in the heat exchanger embodiment. 
           [0022]      FIG. 10   a  is a depiction of an illustrative sunshade attached to a building and extending over a window. 
           [0023]      FIG. 10   b  is a depiction of an alternative sunshade attached to a building and extending over a window. 
       
    
    
       [0024]    The various features illustrated in the drawings may not be drawn to scale. Accordingly, the dimensions of the various features may be arbitrarily expanded or reduced for clarity. In addition, some of the drawings may not depict all of the components of a given device. 
       DESCRIPTION 
       [0025]    The embodiments of the disclosure and the various features and details thereof are explained more fully with the reference to the non-limiting embodiments and examples that are described herein and/or illustrated in the accompanying drawings. It should be noted that the features of one embodiment may be employed with other embodiments as the skilled artisan would recognize, even if not explicitly stated herein. Descriptions of well-known construction techniques may be omitted so as to not unnecessarily obscure the teaching principals of the disclosed embodiments. The examples used herein are intended merely to facilitate an understanding of ways in which the disclosure may be practiced and to further enable those skilled in the art to practice disclosed embodiments. The examples and embodiments herein should not be construed as limiting. 
         [0026]    Referring now to the drawings, in some embodiments as depicted by  FIG. 1 , the panel  10  is rectangular in shape when viewed from the top. The panel  10  may also be square, circular, oval, zigzag, arched, or any other shape needed to achieve a desired appearance of the sunshade. 
         [0027]    A panel  10  may have a length of about 3 ft. to about 7 ft. Further, a panel  10  may have a length of about 1 ft. to about 3 ft. Further, a panel  10  may have a length of about 7 ft. to about 12 ft. Heating capacity improves with panels of greater length because a longer stretch of tube  11  is heated. However, the length of a panel  10  is limited by increasing fragility of longer clear faces  13  that form the top face of the panel  10 . Longer clear faces are also disadvantageous because they are more expensive. To address this problem, where longer panels are necessary to accommodate a design need, the long panel may be comprised of segments of shorter panels, as depicted in  FIG. 1 . The shorter panels may be connected by a sleeve that fits around and is affixed to the ends of the two panels to be connected. Alternatively, where longer panels are necessary to accommodate a design need, a single longer elongated U-shaped beam  16  may hold more than one clear face. In these embodiments, the longer elongated U-shaped beam  16  may need to be thicker to provide more structural strength. Additionally, sleeves  40  may be necessary where the clear faces meet, to provide a more aesthetic shade, and/or to keep the clear faces separated to prevent breakage. 
         [0028]    A panel  10  may have a width of about 3″ to about 4″. Further, a panel  10  may have a width of about 1″ to about 3″. Further, a panel  10  may have a width of about 4″ to about 8″. Further, a panel  10  may have a width of about 8″ to about 1 ft. Further, a panel  10  may have a width of about 1 ft. to about 3 ft. Further, a panel  10  may have a width of about 1.5 ft. to about 3 ft. A greater width increases the amount of solar energy capture; however, greater widths are often less desirable from an architectural appearance and functional standpoint because greater widths result in fewer panels  10  comprising the overall sunshade structure  20 , as depicted in  FIG. 4 , and fewer panels  10  lead to a single larger panel (which may require a revised structural design to support the larger expected weight per panel, for example, by attaching U-shaped beams side-by-side) and a less attractive overall sunshade structure  20 . 
         [0029]    A panel  10  may have a depth of about 1.5″ to about 2″. Further, a panel  10  may have a depth of about 1″ to about 1.5″, Further, a panel  10  may have a depth of about 2″ to about 3″. Further, a panel  10  may have a depth of about 3″ to about 5″ Further, a panel  10  may have a depth of about 5″ to about 1 ft. Generally, shallower panels are more beneficial because of their lower weight which requires less structural support. The versatility of the design is important in order to accommodate and permit the creation of different desired architectural aesthetic impressions. 
         [0030]    A panel  10  may be comprised of an elongated U-shaped beam  16 , as shown in  FIG. 2 . The elongated U-shaped beam  16  may be formed of extruded aluminum. Alternatively, the elongated U-shaped beam  16  may be comprised of other materials, such as steel, galvanized steel, stainless steel, plastic, Trex decking material, or any other hard, and weatherproof or weather resistant material. 
         [0031]    The elongated U-shaped beam  16  includes a bottom panel  21 , side panels  22 , and support lips  25 , as shown in  FIGS. 2 and 3 . Each of side panels  22  has a support lip  25  extending parallel to the bottom panel  21  and inwardly towards another support lip  25  on the opposing side panel. The support lip  25  extends about ⅜″ from the interior side of the side panels  22 . Alternatively, the support lip  25  may extend from the interior side of the side panels  22  a length of about 2% to about 5% of the total width of the elongated U-shaped beam  16 . Alternatively, the support lip  25  may extend from the interior side of the side panels  22  a length of about 5% to about 10% of the total width of the elongated U-shaped beam  16 . Alternatively, the support lip  25  may extend from the interior side of the side panels  22  a length of about 10% to about 20% of the total width of the elongated U-shaped beam  16 . 
         [0032]    The top of the support lip  25  may be located about 3/16″ from the top edge of the side panel  22 . Alternatively, the top of the support lip  25  may be located about 5/16″ from the top edge of the side panel  22 . Alternatively, the top of the support lip  25  may be located about 9/16″ from the top edge of the side panel  22 . Alternatively, the top of the support lip  25  may be located about 13/16″ from the top edge of the side panel  22 . Generally, the position of the support lip  25  is determined by the thickness of the clear face  13 , and is such that top of the clear face is either flush with or not more than ½″ lower that the top of side panels  22 . 
         [0033]    A clear face  13  is secured to rest inside the U-shaped beam  16  and on top of the support lips  25 , as shown in  FIGS. 2 and 3 . The clear face  13  may have a length substantially equivalent to the length of the elongated U-shaped beam  16 , as shown in  FIG. 1 . Alternatively, the clear face  13  may have a length extending between about 90% and about 95% of the length of the elongated U-shaped beam  16 . Alternatively, the clear face  13  may have a length extending between about 85% and about 90% of the length of the elongated U-shaped beam  16 . Alternatively, the clear face  13  may have a length extending between about 80% and about 85% of the length of the elongated U-shaped beam  16 . Alternatively, the clear face  13  may have a length extending between about 75% and about 85% of the length of the elongated U-shaped beam  16 . Alternatively, the clear face  13  may have a length extending between about 65% and about 75% of the length of the elongated U-shaped beam  16 . 
         [0034]    The clear face  13  may be secured to the support lips  25  with double-sided tape. Alternatively, the clear face  13  may be secured to the support lips  25  with glue or adhesive. Alternatively, the clear face  13  may be secured to the support lips  25  by tabs extending from the elongated U-shaped beam  16  to extend over the clear face. Alternatively, the clear face  13  may be situated on the support lips  25  without securing it in any fashion. Preferably, there is some form of cushioning between the clear face  13  and the support lips  25 . Double-sided tape can provide adequate cushioning. Persons having skill in the art know of common means for providing an adequate cushion between the clear face  13  and the support lips  25 . The interface of the clear face  13  and the elongated U-shaped beam  16  may be sealed with sealants commonly known in the art. 
         [0035]    The clear face  13  may be about 0.125″ thick. Alternatively, the clear face  13  may be about 0.1″ thick to about 0.2″ thick. Alternatively, the clear face  13  may be about 0.2″ thick to about 0.4″ thick. Alternatively, the clear face  13  may be about 0.4″ thick to about 0.6″ thick. The clear face  13  may be comprised of one or more glass panels. Alternatively, the clear face  13  may be comprised of one or more plastic panels. Acceptable plastic, such as polyethylene, polypropylene, and vinyl, is commonly available and known to persons having skill in the art. 
         [0036]    In some embodiments, the panel  10  could have two clear faces  13  (for example, one of the side panels  22  could also be a clear face), an arrangement which lets in more sunlight. In other embodiments, the panel  10  has three clear faces  13 . In other embodiments, the panel  10  is formed entirely of clear faces  13 . In embodiments with more than one clear face  13 , the clear faces may be formed of an extruded plastic. 
         [0037]    In some embodiments, at least one clear face  13  of the panel  10  is tempered glass. Tempered glass, which is processed by controlled thermal or chemical treatments to increase its strength, is beneficial because its durability leads to a lower likelihood that the clear face will break during transport and installation or when exposed to outdoor elements including, for example, rain, hail, birds, squirrels, and flying debris. The tempered glass may include a thin plastic film inside forming a sandwich structure to prevent the glass from shattering and breaking into sharp separated pieces. There are many types of “safety” glass and many ways to accomplish this safety result that are well known in the art. It is understood that the material selected for the clear face may include any of these well-known glass types and others that may become known in the future. The tempered glass face  13  may be about 0.125″ thick. Alternatively, the tempered glass face  13  may be about 0.1″ thick to about 0.2″ thick. Alternatively, the tempered glass face  13  may be about 0.2″ thick to about 0.4″ thick. Alternatively, the tempered glass face  13  may be about 0.4″ to about 0.6″ thick. Tempered glass is widely available and appropriate varieties of tempered glass are well known to those skilled in the art. 
         [0038]    In some embodiments, at least one face of the panel  10  is low-iron tempered glass. Low-iron tempered glass is preferable because of its widespread availability, its durability, and its ability to transmit a high percentage of solar radiation. A standard sheet of 0.1″ thick to 0.2″ thick low-iron tempered glass typically has a transmittance of greater than about 90% of total solar radiation. The low-iron tempered glass face  13  may be about 0.125″ thick. Alternatively, the low-iron tempered glass face  13  may be about 0.1″ thick to about 0.2″ thick. Alternatively, the low-iron tempered glass face  13  may be about 0.2″ thick to about 0.4″ thick. Alternatively, the tempered glass face  13  may be about 0.2″ to about 0.4″ thick. Alternatively, the low-iron tempered glass face  13  may be about 0.4″ to about 0.6″ thick. 
         [0039]    In some embodiments, at least one face of the panel  10  is glass or plastic with an anti-reflective coating. Anti-reflective coating is preferable because less light is lost to reflection, thereby increasing the heat transfer efficiency. Those skilled in the art know of appropriate anti-reflective coatings. In some embodiments, at least one face of the panel  10  is glass or plastic with a self-cleaning coating. Self-cleaning coating is preferable because less dirt and dust accumulates, allowing more light to pass through, thereby increasing the heat transfer efficiency. Those skilled in the art know of appropriate self-cleaning coatings. In some embodiments, at least one face of the panel  10  is glass or plastic with a coating or glazing that advantageously allows the passage of infrared light but reflects all or part of the visible light. In other embodiments, at least one face of the panel  10  is glass or plastic with a coating that affects the color of the glass or plastic. Such coatings are widely available and commonly known. 
         [0040]    Sleeves  40  may be fitted around the ends of the elongated U-shaped beam  16 , as shown in  FIG. 4 . Alternatively, a U-shaped support bracket  47 , as shown in  FIG. 5   a , may secure only the bottom two corners of the elongated U-shaped beam  16 , leaving the top half of the elongated U-shaped beam ends uncovered by the U-shaped support bracket. Alternatively, a support bracket  48 , as shown in  FIG. 5   b , providing support to only the bottom two corners of the elongated U-shaped beam  16 , leaving an open space between the two corners, may be used. Alternatively, a support bracket  49 , as shown in  FIG. 5   c , providing support to only the four corners of the elongated U-shaped beam  16 , leaving open spaces between the four corners, may be used. The sleeves  40  or brackets may be spot welded to the outside or inside of the elongated U-shaped beam  16 . Alternatively, the sleeves  40  or brackets may be seam welded to the outside of the elongated U-shaped beam  16 . Other welding processes may also be used. Alternatively, sleeves  40  or brackets may be affixed to the ends of the elongated U-shaped beam  16  by other means such as glue, crimping, or friction fit, which are commonly known to those skilled in the art. 
         [0041]    Sleeves  40  may entirely surround the elongated U-shaped beams  16  to cap off their ends. Sleeves  40  may be made substantially of aluminum, or any other appropriate metal or alloy, Trex decking or building material, or any other appropriately hard, weatherproof or weather resistant material. The sleeves  40  or the brackets may be welded or otherwise attached to an outrigger  42  on the outward-facing side of the outrigger. Alternatively, the elongated U-shaped beams  16  may be affixed directly to the outrigger  42  without the use of sleeves or brackets. The outrigger  42  has openings to accommodate for a plurality of panels  10  to be situated in a common orientation to form a sunshade  20 . An outrigger cover  45  may be secured to the outrigger  42  to hide the tubing  11  and the welded connection between the outrigger  42  and the sleeves  40  or brackets. An fascia panel  43  may be secured to an either end of the outriggers  42 . 
         [0042]    In some embodiments, the elongated U-shaped beam  16  is formed with the top portions at the ends of the beam being enclosed (for example, the top portions of the beam may be part of the extruded metal structure). This eliminates the need for sleeves  40 , where the beam can be directly affixed to the outriggers  42 . 
         [0043]    A layer of insulation  18  may be mounted inside the elongated U-shaped beam behind the clear face  13 , as shown in  FIGS. 2 and 3 . The insulation layer improves efficiency by helping to trap heat inside the panel  10  and by preventing external elements such as wind and cold air from cooling the panel  10 . The insulation layer  18  is advantageously non-reflective, thereby allowing more energy to be absorbed inside the panel  10 . The insulation layer  18  may be positioned to be flush with the bottom panel  21 . The insulation layer  18  may extend to cover a substantial portion or the entire bottom panel. The insulation layer  18  may be about ½″ thick, and therefore may extend upward to be flush with bottom ½″ of the side panels  22 . The insulation layer  18  may be comprised of foam. Alternatively, the insulation layer  18  may be comprised of a polystyrene foam block material, for example or a fiberglass matting-type insulation material of the type often used in attics. Other embodiments may include insulation layers  18  comprised of any other appropriate insulation product, known by those skilled in the art. 
         [0044]    Other embodiments may not include an insulation layer, as shown in  FIG. 3 . The inside of the elongated U-shaped beam  16  may be painted a dark color to enhance its absorbing capability. 
         [0045]    Tubing  11  is disposed in the panel  10  behind the clear face  13 . At least one tube  11  extends the length of the panel  10 . In some embodiments, as depicted in  FIG. 6 , the tube  12   a  enters a first panel  10 , passes through the panel  10 , exits the panel  10 , then is provided with a U-turn by bending or fittings so that it extends through the adjacent panel in the opposite direction of the flow passing through the first panel. The tube weaves through all panels  10  that comprise a sunshade  20  in this fashion. Alternatively, as depicted in  FIG. 7 , the tube  11  can pass through the panels twice, as shown in  FIG. 3 . The tube  11  would first weave though all panels, and after passing through the final panel, would reenter the next-to-last panel, flowing in the opposite direction as the first tube disposed in that panel. Tubing  12   a  and  12   b  outside the panel  10  carries cool fluid into the sunshade  20 , and also carries heated fluid out of the sunshade  20 . An alternative two-pass tubing arrangement is depicted in  FIG. 8 . In other embodiments, such as those with a single panel  10 , the tubing  11  may weave to pass through the single panel several times to allow for optimal heat collection. 
         [0046]    Preferably, the tube  11  weaving through the panels  10  is comprised substantially or entirely of copper and is spaced from the walls of the U-shaped beam. Copper is a good conductor and thus allows for faster heat absorption in the tubing  11 . In other embodiments, the tube  11  may be made from other conductive materials well known in the art such as, for example, aluminum and even glass where the glass is coated such that it absorbs heat. In other embodiments, the tube may be comprised of a glass outer tube and a concentric inner tube wherein the cylindrical space between the inner and outer tube acts as an insulator so that the heat does not escape. This space can be a vacuum or air or another gas. The appropriate coatings to be used are well known to one of ordinary skill in the art. The tubing  11  may be about ½″ in diameter. Alternatively, the tubing  11  may be about ¼″ in diameter. Alternatively, the tubing  11  may be about ⅜″ in diameter. Alternatively, the tubing  11  may be about ¾″ in diameter. Alternatively, the tubing  11  may be about 1″ in diameter. Further it is contemplated that, in addition to round tubes, the portions of the tubes  11  that are exposed to sunlight within the elongated U-shaped beam  16  may be shaped in cross-sectional shapes that may be flatter in order to allow for easier heat collection. These contemplated shapes may include oval or rectangular shapes with the wider portion of the tubing  11  facing the clear face  13 . The tubing  11  within the elongated U-shaped beam  16  may also be structured to spread the fluid out as fat and as thin as reasonably possible while it passes through the elongated U-shaped beam  16  and is exposed to sunlight so as to more quickly collect the available heat. This may advantageously be accomplished by, for example, dividing the water flow into a series of thin tubes laid flat across the width of the elongated U-shaped beam  16  or by using a flat thin tube with baffles inside and extending substantially across the width of to the beam to keep the water flow relatively slower as it passes through the panel  10 . 
         [0047]    As shown in  FIG. 2 , a fin  14  may disposed behind the clear face  13  and on top of the tube  11 , the fin  14  having a length substantially equal to the length of the elongated U-shaped beam  16 . The fin  14  is advantageously comprised of copper. Alternatively, the fin may be made from any conductive material known by those having skill in the art. Preferably, the fin  14  is rectangular in shape and sized to cover the entire area that sunlight contacts when passing through the clear face  13 . The fin  14  may be arched, such that the area of the fin contacting the tube  11  is maximized. As the system fluid passes through the tubing  11 , it absorbs heat and cools the tubing and the area of the fin that it in contact with the tubing. Thus, a thermal gradient forms across the fin, wherein the portions of the fin further from the tubing are hotter. The gradient creates a transfer of thermal energy to the tubing and to the system fluid, thereby increasing heat transfer. 
         [0048]    The side of the fin  14  facing the clear panel  13  may be colored to affect the outward appearance of the panel  10 . For example, the fin  14  may be painted red which gives the top of the sunshade  20  a reddish appearance. As another example, the fin  14  may be painted green which gives the top of the sunshade  20  a greenish appearance. 
         [0049]    In some embodiments, the tubing  12   a  and  12   b  located outside the sunshade  20  is PEX tubing. PEX tubing is manufactured from cross-linked polyethylene. PEX tubing is a flexible tube commonly used in heating systems. PEX tubing is preferable because it is widely available and because it meets all major plumbing/heating codes and bends easily, making it more versatile than copper tubing. Manufacturers of PEX generally provide a 20-25 year warranty, but PEX is known to have a much longer lifespan. PEX comes in ⅜″, ½″ ⅝″, and ¾″ are also available. 
         [0050]    The tubing  12   a  and  12   b  located outside the sunshade  20  may be made of other materials known to persons of ordinary skill in the art to be appropriate for this application given the relatively high expected temperature levels. 
         [0051]    The system may be designed to use water in the tubing  11 ,  12 . When the system is a closed circuit system as shown in  FIG. 9 , where a system fluid is needed, water is preferable because it is inexpensive and non-toxic. Drawbacks of water include its high freezing point, its low boiling point, and its acidity which can cause corrosion. Also, over time minerals in the water can deposit inside the system creating blockages. Alternatively, non-toxic types of antifreeze may be used. For example, polypropylene glycol, usually mixed with purified or distilled water at a ratio no greater than 1:1, is a beneficial system fluid because it has a low freezing point and inhibits corrosion. 
         [0052]    Some embodiments include a plurality of panels  10  arranged in the same orientation to form an attractive sunshade  20 , as shown in  FIGS. 10   a  and  10   b , suitable for providing shade. The shade may extend over the window of a building. Alternatively, the shade may be free standing and extend over a patio. The panels may be fixed in place. Fixed panels are advantageous because rotatable panels can lead to mechanical issues, becoming stuck in position. The panels may be designed in advance to be tilted in order to maximize sun exposure on the top face of the panels given the expected location where the shade will be placed. The optimal tilt of the panels is determined by the location&#39;s latitude, the orientation of the shade with respect to the expected path of the Sun across the sky, and by the location of the shade relative to surrounding structures that determine the sun exposure on the shade throughout the day. Alternatively, the panels may be rotatable. Rotatable panels are advantageous because they can be adjusted to capture more sun throughout the day. 
         [0053]      FIG. 9  depicts a solar thermal collector system that enables solar energy absorbed by fluid in the solar thermal collector panels  10  to be transferred by a pump  52  to heat a household&#39;s or building&#39;s water supply  53  by means of a heat exchanger  51 . The tubing is closed circuit and contains a fluid (which may advantageously be the polypropylene glycol and water mixture referred to above). The sunshade  20  is connected to a heat exchanger  51  and a pump  52  with tubing. The heat exchanger transfers heat from a system fluid to a water supply. 
         [0054]    Conditional language used herein, such as, among others, “can,” “might,” “may,” “e.g.,” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or states. Thus, such conditional language is not generally intended to imply that features, elements and/or states are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without author input or prompting, whether these features, elements and/or states are included or are to be performed in any particular embodiment. The terms “comprising,” “including,” “having,” and the like are synonymous and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list. 
         [0055]    While the detailed description herein has shown, described, and pointed out novel features as applied to various embodiments, it will be understood that various omissions, substitutions, and changes in the form and details of the devices illustrated can be made without departing from the spirit of the disclosure. As will be recognized, certain embodiments of the inventions described herein can be embodied within a form that does not provide all of the features and benefits set forth herein, as some features can be used or practiced separately from others.