Ventilated roofing tiles
Ventilated roofing tiles along with other multilayered energy saving and/or producing constructions are disclosed. Also disclosed are insulating bonding constructions having enhanced energy saving attributes. The ventilated roofing tiles employ heat transfer means that may include natural and/or forced air convection.
Latest Patents:
- EXTREME TEMPERATURE DIRECT AIR CAPTURE SOLVENT
- METAL ORGANIC RESINS WITH PROTONATED AND AMINE-FUNCTIONALIZED ORGANIC MOLECULAR LINKERS
- POLYMETHYLSILOXANE POLYHYDRATE HAVING SUPRAMOLECULAR PROPERTIES OF A MOLECULAR CAPSULE, METHOD FOR ITS PRODUCTION, AND SORBENT CONTAINING THEREOF
- BIOLOGICAL SENSING APPARATUS
- HIGH-PRESSURE JET IMPACT CHAMBER STRUCTURE AND MULTI-PARALLEL TYPE PULVERIZING COMPONENT
This non-provisional application claims benefit of the provisional application filed on Dec. 3, 2005 having application number U.S. 60/741,834
BACKGROUND OF THE INVENTION1. Field of the Invention
This invention relates to building materials and more particularly to energy saving and/or producing multilayered construction components. This invention also relates to attachment means that may have thermal insulating properties. More particularly this invention relates to energy saving tiles that may be ventilated and that may employ natural and/or forced air convection.
2. Description of the Related Art
A significant portion of building construction is carried out using relatively fast and easy construction techniques. In addition, much of this construction is done without much emphasis being placed on the energy efficiency. This often results in buildings requiring significant heating and/or air conditioning requirements. The result is a building having high utility costs.
Heat and electricity costs have been rising over the past several years and are expected to continue this upward trend for years to come. There are several reasons for this trend including greater energy demand from emerging countries such as India and China, expanded population growth, limited natural resources, environmental pressures, and a host of others.
A significant portion of the American energy diet is directed towards the heating and air conditioning of buildings. Furthermore many of today's buildings including the modern ones may not be very energy efficient.
Many buildings lack good insulation. Some buildings have little to no insulation at all. Some buildings having substantial insulation thickness may still have relatively poor insulating properties due to moisture contamination and air leaks with the outside environment.
Many buildings are designed primarily for aesthetic purposes rather than energy efficiency. A simple example will now be given to illustrate this point. The highest volume to surface area ratio for any shape of any given size is a sphere. Therefore to minimize construction materials and maximize living space, buildings ideally should be made in the shape of a sphere or at least a portion of a sphere. The geodesic dome is a modified sphere or spherical portion that can be made from linear shaped commercially available construction components. Buckminster Fuller promoted this construction geometry based at least in part to practical engineering.
The sphere or modified spherical shape of the geodesic dome provides the maximum internal volume to surface area ratio attainable for any given size. This provides the least amount of surface area for heat transfer with the outside environment. In addition, the substantially curved outside surface of the geodesic dome may provide added benefits as well. For example, certain natural disasters such as hurricanes may inflict substantial wind damage to standard rectangular buildings. On the other hand, geodesic domes have no large flat surfaces facing in any one direction thereby at least theoretically reducing damage resulting from exposure to high winds.
From an engineering standpoint there is no logical reason why more buildings are not constructed as geodesic domes. From an aesthetic point of view however, the story may be somewhat different. Individuals may find the geodesic dome to be somewhat ugly and therefore prefer the less efficient but better looking rectangular shaped architecture.
It should be noted that for any given volumetric shape, such as a rectangular prism, as size increases so does the volume to surface area ratio. Of special interest are apartment buildings. Apartments are relatively large multi-dwelling buildings that house several families. This construction allows individual families to occupy a relatively small space and obtain the added energy saving benefits of a much larger building. This of course, is not the focal point of most people when they buy a condominium or rent an apartment. It is however a substantial added benefit when the heating and/or air conditioning bill arrives. A specific example will now be used to illustrate this point.
A single family occupies an apartment in the center of a large building. This apartment is completely surrounded on all sides including the floor and ceiling by other apartments. Let us assume that the family occupying this apartment has similar comfort levels with respect to heat and cold as the individuals or families occupying the adjacent apartments. In this scenario, this family could permanently turn their heating and air conditioning off and live in relative comfort. They now have the advantage of living independently from heating and air conditioning costs. Of course, most apartments have at least one surface exposed to the outside environment. This situation is however preferable to having all surfaces exposed to the outside environment.
Air conditioning represents substantial electricity use in the United States. This is particularly true for people living in the south. The southeast is relatively hot and humid during the summer months and the southwest is hot and dry. It should be noted that more and more people are moving into the southern portions of the United States.
During many summer days in the relatively dry southwestern United States, significant cooling can be achieved at relatively low cost by using swamp coolers. A swamp cooler is a cooling device that uses the evaporation of water to provide cooling. Swamp coolers add substantial humidity to the air so they are only effective in dry arid regions. It should be noted that the heat of vaporization of water is a substantial 540 calories per gram. The evaporation of a few gallons of water can provide substantial cooling to a small building such as a home or mobile home trailer.
Evaporation is the mechanism used to provide cooling in modern air conditioning systems as well. Unlike swamp coolers that evaporate liquid water into the air, modern air conditioning systems evaporate Freon or other refrigerants in a closed system that recycles the vapors and compresses them back into a liquid state. Evaporation of the refrigerant is an endothermic process (a thermal process that takes heat) thereby removing it. The evaporation occurs in a set of coils called the evaporator and sometimes referred to as the cooling coils. Evaporation of the refrigerant cools the evaporation coils. A fan is used to blow air over these coils to transfer heat from the room being air conditioned to the cold evaporation coils. More often than not, the temperature of the evaporation coils is below the dew point of the air in the room. Under these conditions water condenses out of the air onto the cold evaporation coils. This water gives up its heat of vaporization in the process and adds to the heat given up to the evaporation coils. The removal of water from the air also dries it out resulting in a greater level of comfort in the room being air conditioned. The evaporated gaseous refrigerant is then compressed to a high pressure that may exceed 150 pounds per square inch. Compressing the gaseous refrigerant causes it to heat up. The heat is then exchanged with the outside atmosphere to get rid of it. This heat exchange occurs in the compression or heating coils. The compressed refrigerant may then be expanded in a special valve that liquefies and/or dissolves the refrigerant into a special liquid. The liquefied refrigerant then passes into the evaporation coils to complete the cycle.
This air conditioning process requires a substantial amount of energy in the form of electricity. The majority of this energy is used to compress evaporated refrigerant to high pressure. A smaller amount of electricity is used by the fans to expel hot air from the compression coils and to circulate room air over the cold evaporation coils. Because of the electrical requirements of air conditioning systems it is desirable to prevent heat from entering buildings during hot weather.
There are two primary sources of heat that enter buildings during hot weather. The first one is radiant heat from the sun. The second one is heat transferring from the outside to the interior of the building. It should be noted that these two sources are not exclusively independent of one another but may be somewhat intertwined together. For example, sunlight may fall onto a dark roof surface and heat the attic space underneath.
The hot air in the attic may then transfer its heat by convection, conduction, and radiation into the living spaces of the building. In this way, sunlight indirectly heats the interior of the building. Alternatively, sunlight may be transmitted through windows to heat the building interior directly. It should be noted that a significant portion of sunlight consists of infrared radiation that falls outside of the visible spectrum. This infrared light does not add to the lighting of rooms but rather poses an extra burden of heat to the interior of the building that must be removed by air conditioning systems during periods of hot weather.
Special coatings can be placed onto glass surfaces that reflect and/or absorb infrared light from sunlight and let in visible light. In this way sunlight may be used to illuminate the inside living spaces of buildings while minimizing the addition of excess heat.
Buildings in warmer climates may also avoid excessive heat from sunlight by using outside materials having a high reflectance and low absorbance. A high reflectance surface is one that reflects light away rather than absorbing light and turning it into heat. Light colors such as silver and white reflect most of the light that falls on its surface. Darker colors such as black absorb most of the light that falls on exposed surfaces. The deliverable heat energy from the sun on a clear day at a direct angle is substantial and amounts to about 1,000 watts per square meter. Reflective outside building surfaces help to keep sunlight from turning into unwanted heat that burdens air conditioning systems.
The use of heavy clay tiles may provide some heat insulating properties to the outermost layer of roofing surfaces. Unfortunately, these heavy clay tiles place added weight burden on the structure, may create a hazardous condition during earthquakes, have limited insulating properties, and are only partially effective at keeping heat out of structures such as houses. One significant advantage offered by these heavy clay tiles is fire resistance. This may be particularly true in areas often ravaged by brush fires. Such fire prone areas include numerous hillside communities surrounding cities in southwestern states such as California. In addition to fire resistance, clay roofing tiles may provide some suppression of outside noise.
Cement and related materials are sometimes employed in the fastening of clay tiles to roof surfaces and/or each other. While being somewhat effective in holding them together on to roofing surfaces there is a tendency for them to come loose during high wind conditions. It should be noted that hurricanes often damage these roofing tiles and that other attachment means have been developed for the purposes of more tightly anchoring roofing tiles to the roofs of buildings. These new anchoring techniques may employ screws and/or nails to hold roofing tiles firmly into place.
The process used for mounting traditional tiles involves the application tile cement or other bonding material to the back side of tiles and/or exposed bonding substrate surfaces. Once a suitable amount of the bonding agent has been applied, the tiles are pushed into place and the bonding agent allowed hardening.
Cement and related materials are sometimes employed in the fastening of clay tiles to roof surfaces and/or each other. While being somewhat effective in holding them together on to roofing surfaces there is a tendency for them to come loose during high wind conditions. It should be noted that hurricanes often damage these roofing tiles and that other attachment means have been developed for the purposes of more tightly anchoring roofing tiles to the roofs of buildings. These new anchoring techniques may employ screws and/or nails to hold roofing tiles firmly into place.
Tiles may be bonded to each other in place of bonding to sub flooring surfaces. In such instances, good adhesion between tiles becomes increasingly important. The bonding between adjacent tiles in flooring applications may be enhanced to improve durability and strength. U.S. Pat. No. 4,095,388 awarded to Horner Brealt titled “Strengthening Inter-Tile Adhesion” employs two rectangular tile sizes laid in an offset configuration that minimizes the length of individual straight lines. The result is a greater resistance to the effects of both temperature changes and humidity over time.
Tiles having interlocking properties with each other may be used to improve the weather resistance of roofing surfaces along with improving overall strength. An example of this can be found in U.S. Pat. No. 4,949,522 awarded to Shigeru Harada titled “Roofing Tile”. Roofing tiles are disclosed that engage with one another and interlock to improve strength and weather resistance.
Numerous bonding compositions may be employed to bond tiles to each other and to substrates. In many instances cement and related materials are employed to adhere tiles to their intended substrates. These materials are often employed in fastening ceramic tiles to flooring or other surfaces. Many of these materials require significant time for them to harden. In many instances this is perfectly acceptable. Under certain circumstances it may be desirable to have a relatively fast and strong cure. For example, industrial or commercial applications where long shut down times may be costly or disruptive. Other examples include vertical or up side down surfaces where tiles must be held in place during the cure cycle. U.S. Pat. No. 4,833,178 awarded to Robert E. Schaefer, Scott C Broney, and Joseph J Chesney Jr titled “Composition and Method for Setting and Grouting Tile” provides a fast setting tile bonding composition comprised of filled polymeric resin. The above described filled resin compositions have cure times ranging from about one to six hours.
Considerable attention is often paid toward providing uniform spacing between tiles. Unfortunately, controlling the spacing between tiles and their attached substrates is less commonplace. Difficulties may arise from the use of high viscosity cement or other related materials used for tile bonding. Many of these materials flow out with difficulty and therefore may form a layer of uneven thickness that may go unnoticed until after the cement has set.
The use of cement and other related materials to bond tiles to their substrates may result in poor anchorage. Subsequent exposure to harsh conditions such as temperature changes and moisture may result in the delamination of tiles from their attached substrates. In order to reduce this tendency, interlocking means may be provided between tiles and their substrate surfaces.
One example of interlocking means is disclosed in U.S. Pat. No. 6,692,813 awarded to Allen H Elder. In this patent, Elder employs at least one bonding surface having particulates attached in continuous phase with the surface substrate. The continuous phase aspect of the surface particulates with the substrate allows for a substantial amount of surface protrusion coupled with good strength. Employing this bonding technology to the attachment of tiles to substrate surfaces may prove useful when using relatively low viscosity homogeneous bonding agents like epoxy resin. High viscosity cementing and grouting materials may require further enhancements in order to optimize tile bonding.
Difficulties associated with providing uniform tile surfaces and forming strong bonds between tiles and their substrates has lead to many of the above described innovations. One particularly interesting approach for tile bonding is outlined in U.S. Pat. No. 4,932,182 awarded to John R. Thomasson titled “Floor Tile Forming and Structural Underlayment Device”. A one piece plastic molded sheet having special entrapping designs is used to cast tiles in situ. This approach is especially appealing due to its versatility. The mold entrapping designs prevent the release of the cast tiles thereby eliminating the need to cement individual tiles to the floor. Tile spacing is provided by the mold with raised portions giving the appearance of tile grout.
The use of insulating materials as bonding agents may provide the added benefit of thermal insulation.
Generally speaking, roofing tiles are heavy, and do not provide a substantial amount of insulating properties to the outer roofing surfaces of buildings. Furthermore, the bonding methods used for the attachment of roofing tiles do not possess good insulating qualities either.
A significant amount of heat may build up in the attic spaces of buildings due to absorption of solar energy by roofing surfaces. Because of this, one of the first ways to improve the usefulness of air conditioning systems is to ventilate the attic using a fan. Attic fans reduce the heat burden on air conditioning systems by removing heat in a way that bypasses the air conditioner. Hot attic air is exhausted and therefore does not transfer as much heat into interior building living spaces. Many individuals notice a significant reduction in the heat burden of air conditioning systems when they install an attic fan.
Many attics and other top floor building interior spaces are provided with natural ventilation. Some of these spaces are provided with slotted openings in the sides. Other approaches involve cutting a hole in the roof and placing a small turbine that rotates by outside wind and/or natural convection of heated air.
Of particular interest is U.S. Pat. No. 6,491,579 awarded to Harry T O'Hagin. This patent outlines a system that allows hot air to escape from an attic without negatively affecting the appearance of the roof. Vents are installed in the roof deck beneath roofing tiles. One aspect of the invention involves placing numerous small holes in specific roofing tiles as part of the ventilation system. Other aspects of the invention involve the removal of attic air along spaces between tiles. This invention is particularly interesting owing to the fact that the majority of roofing components are standard available parts, the overall system does not require any moving parts such as attic fans, and the finished roof is aesthetically pleasing.
Insulation is often placed along the bottom portions of attics in an attempt to keep hot attic air from heating living spaces below. It is interesting to note that insulation is generally placed along the bottom surfaces of attics but not along the undersides of roofing surfaces. It appears that more emphasis is placed on keeping hot attic air and its associated heat out of living spaces than keeping the heat out of attic spaces in the first place. This philosophy seems a bit unusual owing to the fact that building insulation is commonly employed in interior walls connected with the outside. More will be said on this later.
One of the oldest and most common methods employed to prevent excessive sunlight from falling on and heating roofing surfaces involves the use of one or more trees to provide shade. This method works because trees often produce good shade. Trees and other plants tend to grow leaves in a direction that maximizes their absorption of sunlight. This often results in shade that is somewhat dense. In addition, trees can provide further cooling by two mechanisms.
Radiant energy falling on growing surfaces of plants such as leaves is actually converted into chemical potential energy by the well established process of photosynthesis.
Many trees extract water from the ground and pump this water up to the leaves where evaporation occurs. This evaporation may provide additional cooling.
Many trees grow shade producing leaves in the hot months of the year and then lose these leaves during the cooler months of the year. In this way, the roofs of buildings may be shaded in hot summer months and heated by exposure of solar radiation during the colder winter months.
It should be noted that there are certain downsides to locating trees close to buildings.
A few problematic issues are summarized below:
Trees can grow to excessive size over time.
Growing trees send out roots that can tear up driveways and building foundations and may find their way into sewer lines clogging them up.
Certain trees such as pine trees are flammable and represent a fire hazard when located close to certain buildings.
Trees often lose leaves that can clog rain catching roofing gutters and can be a nuisance to clean.
The shading of roofing surfaces by trees and other plants may be done for the purposes of reducing the burden on air conditioning systems from excess radiant heat or alternatively may not be done for intentional purposes whatsoever.
Unintentional shading of roofing surfaces is a common occurrence. In some instances one building may cast its shadow on the roof of another. This may happen when buildings having different heights and architecture designs are located next to one another. Unintentional shading may also occur when solar collectors and/or electricity generating photovoltaic panels are placed directly above roofing surfaces. U.S. Pat. No. 6,061,978 awarded to Thomas L. Dinwoodie titled “Vented Cavity Radiant Barrier Assembly and Method” discloses roof mounted assemblies containing photovoltaic modules. The assemblies themselves employ a low emissivity element and may take numerous forms. This results in a vented cavity between the building surface and the barrier inner surface. Mounting methods for use in vented cavity radiant barrier systems are disclosed in U.S. Pat. No. 6,883,290 awarded to Thomas L. Dinwoodie titled “Shingle System and Method”. It should be noted that photovoltaic solar panels could be modified by adding liquid circulating coils to their underside. This option is particularly interesting owing to the fact that many photovoltaic panels run more efficiently when they are kept cool. The circulating liquid could be used to extract heat from the panel thereby improving the electric output of the device while at the same time producing useable hot water. The simultaneous production of hot water and electricity at the same time increases the utility of electricity producing photovoltaic panels Such panels would produce electricity, hot water, and provide roofing shade all at the same time. It should be noted that standard photovoltaic panels and standard solar heating panels often provide roofing shade by their very nature. This roofing shade may provide the unintentional added benefit of reducing the heat burden of air conditioning systems. Other forms of unintentional roofing shade may be provided by such things as satellite dishes located on roof tops as well as signs and billboards.
A significant amount of sunlight falls on the roofing surfaces of buildings. During periods of warm weather this radiant energy can place an unwanted burden to air conditioning systems causing them to overwork. A common approach used to deal with this issue is to employ more powerful air conditioning systems to remove this added burden of heat. Unfortunately, this approach results in the consumption of excessive amounts of electric power. Other approaches employ removing hot attic air with various ventilation systems and/or placing insulation between attic spaces and living spaces.
Keeping the heat out of attic spaces and/or other spaces directly below the roofing in buildings in the first place is not commonly employed. Deliberate shading by trees is one method in current use today as is the use of light colors that tend to reflect rather than absorb sunlight. The above mentioned methods are commonly employed in buildings to keep unwanted heat from entering attics and roofing undersurfaces.
In addition to keeping unwanted heat from entering living and working spaces of buildings, there is also a need to provide heat to the living and working spaces of buildings during periods of cold weather. In this instance, attic ventilation may have the undesirable effect of removing warm air from the building. This is particularly troublesome owing to the fact that warm air rises and cold air sinks. Any leaks between the attic space or any other space directly under the roof of a building and living and/or working spaces located underneath represents a significant loss of heat. This heat loss places an added burden to heating systems.
Interior heating of buildings is carried out in cold weather to keep living and working spaces at a comfortable temperature. For the most part this heat comes from the combustion of flammable materials. Natural gas is commonly employed in many areas of the country. Natural gas burns clean and efficiently and is relatively low in cost. Oil is burned in some areas of the country for heat. This practice is particularly prevalent in the northeastern United States. Wood may be burned to generate heat, but in order to be efficient a good system is required that transfers heat from the burning wood into living spaces. One of the more familiar systems is the wood burning stove. A wood burning stove is a cast iron stove placed in a room that is to be heated. A smoke stack at the back of the stove is vented outside to remove toxic smoke. The wood burning stove has adjustments to control air flow and thereby control the rate of burning. This control allows the user to heat efficiently without losing large quantities of heat up the smoke stack.
A large majority of homes have fireplaces. A fireplace is an area of a wall that is meant for burning wood or other combustible material. Unfortunately, burning wood in a fireplace often results in only a small amount of heat being generated for living spaces and a relatively large amount of heat going up the chimney. Burning wood in a fireplace can actually suck more heat out the chimney than the fire produces. This is because chimneys can suck interior air right out of building living spaces. A flu damper adjustment is often provided to minimize this effect, but is only somewhat effective. In general, fireplaces are used to create a warm relaxing atmosphere and are rarely used for heating purposes. Numerous systems have been developed for the purposes of increasing the heat output of ordinary fireplaces. Many of these systems employ a set of curved metal pipes. These metal pipes take air from inside the room and expel hot air out the top and back into the room. The pipes often surround the fire with the flames passing over the top portions. Some of these systems use natural convection while others used forced air from a fan.
It should be noted that in many areas of the United States such as the northeast that the coldest winter days occur under clear skies. This is because cold fronts coming down from Canada (sometimes called the Canadian express) contain cold and dry air. This results in numerous cold sunny days throughout the winter months. This is significant because a large amount of heat is available in the form of radiant solar energy during numerous cold days.
On a clear sunny day the rate of radiant heat falling on surfaces at right angles to the sun is about one kilowatt per square meter. In the winter months the sun is at an angle that is somewhat oblique. Because of this the rate of radiant heat delivered may be somewhat less. In addition, dark surfaces having a high level of absorbance still reflect some radiant energy. In addition, heat losses may occur when moving heat containing liquids and/or gasses through areas of lower temperature. A good approximation is that 500 watts of useful heat can be extracted per square meter for eight hours during each clear winter day.
The single side of a roof for a small house has about 60 square meters of surface area. The useable amount of heat energy per day for such a small house will now be calculated. 60 square meters×500 watts/square meter×8 hours per day=240,000 watt hours or 240 kilowatt hours of deliverable daily heat energy. At a cost of 15 cents per kilowatt hour, this represents $30.00 worth of electric heat per day. For the less expensive natural gas heat this represents almost $10.00 per day of available heat energy.
The capture and subsequent use of solar heat has traditionally involved systems employing a significant amount of complication. Many of these systems employ a liquid heat transfer agent such as an antifreeze mixture of water and ethylene glycol. A solar heat collector consisting of a dark absorbent panel having liquid filled tubes and a glass cover is often used to collect the heat. The liquid in the tubes is then pumped to a storage tank. When the liquid in the storage tank reaches sufficient temperature it is then pumped to a heat exchanger. The heat exchanger then transfers this heat to where it is needed. All in all this system is relatively expensive, bulky, and cumbersome. These solar heating systems usually deliver a limited amount of heat owing to their small size.
Traditional solar heating systems may provide useable heat in the form of heated liquids that can be used to heat living spaces and can provide hot water. This tends to be the limit of utility for these traditional heating systems. It would however to be desirable to use this heat for other purposes as well. For example, during winter months in northern climates significant snowfall may occur onto roofing surfaces. This snowfall may place a significant weight burden onto buildings. This may be particularly troublesome for buildings having flat horizontal roofing surfaces. It may therefore be desirable to use solar heat for the purposes of melting unwanted snow and ice from roofing surfaces. It should be noted that this takes place naturally to some extent, however augmentation of this natural process may provide for faster removal.
It is an object of this invention to prevent unwanted heat from entering the roofing portions of building surfaces during periods of hot weather.
It is a further object of this invention to remove unwanted heat from the roofing surfaces of buildings during periods of hot weather.
It is a further object of this invention to extract useable heat from the roofing surfaces of buildings during periods of cold weather.
It is a further object of this invention to provide a tile bonding system forming interlocking bonds between individual tiles and their bonding substrates.
It is a further object of this invention to provide tiles having bonding surfaces of uniform thickness.
It is a further object of this invention to provide tiles having bonding surfaces compatible with traditional tile bonding agents.
It is a further object of this invention to provide tiles that when pushed against substrate surfaces spread bonding agents to a uniform thickness.
It is a further object of this invention to provide tile bonding substrates that form interlocking bonds with bonding agents.
It is a further object of this invention to provide thermal insulating attachment means suitable for the adhesion of tiles and/or laminate constructions to the roofing surfaces of buildings.
Finally, it is an object of this invention to provide a low cost simple system suitable for extracting and transferring solar heat from roofing surfaces into the interior spaces of buildings.
SUMMARY OF THE INVENTIONIn summary, the present invention provides ventilated roofing tiles that may be used to transfer air of various temperatures for heating and/or cooling purposes including the heat management of interior building spaces. The transfer of air may be purely in the form of natural convection or alternatively may employ forced air convection from a fan or other source of forced air motion. Air may be used to remove heat during hot weather or alternatively, hot air may be collected and transferred into interior building spaces during periods of cold outside temperatures. Attachment means may also be employed having numerous advantages that may include thermal insulation properties. The ventilated roofing tiles of this invention may have enhanced thermal insulating properties.
BRIEF DESCRIPTION OF THE DRAWINGS
The tile shown in
A beaded geometry may be used to facilitate the fastening of objects to one another. This may be carried out using bonding agents such as resins and cement related materials. Such beaded geometry may be used to provide curved bonding surfaces. Curved bonding surfaces are less likely to initiate stress fractures than bonding surfaces containing sharp edges. In addition, beaded bonding surfaces can be made to mechanically interlock with a bonding agent. Mechanical interlocking between a bonding agent and surface substrate may enhance bonding and reduce the need for chemical compatibility between the bonding agent and surface substrate.
For the tile shown in
This particular configuration functions on multiple levels at the same time. A significant portion of incident radiation from sunlight falling on the reflective top surface is reflected away. The small amount of absorbed radiation that is converted into heat is substantially limited to the outer top layer of the tile. The thermal insulating layer thus acts as a second impediment to heat absorption of lower roofing surfaces. Finally the channels along the bottom portion of roofing tile 84 remove more heat by convective action.
Light transmitting insulating layer 168 may be formed from any number of clear light transmitting materials. Of particular interest is corrugated polycarbonate. Corrugated polycarbonate is a clear corrugated construction that is readily available, lightweight, and is relatively low in cost.
This method of bonding may be used for numerous applications and may be used to provide a low cost way of forming a strong bond between two surfaces. Closed cell foam is lightweight and affords the added advantage of being thermally insulating in nature. Polyurethane foam is one material choice. This foam is available from building supply houses and hardware stores in the form of a spray can. Small amounts of foam may be applied to either surface or both. After the application of the freshly sprayed foam the two pieces may then be aligned to interpose their beaded surfaces. The pieces can then be held together while the foam expands. Excess foam may ooze from the edges during the expanding process. This excess foam may then be trimmed with a knife or other suitable cutting implement.
The above described method may employ other bonding agents as well. For example, numerous bonding agents may be used with hollow glass or polymeric micro-spheres.
Additionally, bonding agents lacking foam properties may be used as well. It should be noted that foam based bonding agents may be preferred where lightweight and thermal insulating properties are desired.
Roofing tile 262 is the same as roofing tile 246 with added beads 264 fixedly attached to bottom surface 266. Also shown is pressure sensitive adhesive layer 268 along with release liner 270. The use of pressure sensitive adhesives in bonding roofing tiles may facilitate the rapid construction of roofs.
Of further interest is the employment of bead protrusions on one substrate and matching holes on the other as shown in
It should be noted that the holes may be modified from straight wall geometry to a geometry that may represent a hollow cavity having more of a spherical shape than the standard cylindrical shape of traditional holes. The spherically modified holes may be produced in a variety of ways including angled machining, chemical etching and EDM (electrode discharge milling). Holes modified in this manner may provide improved anchorage for the finished part when employing bonding agents.
Those skilled in the art will understand that the preceding exemplary embodiments of the present invention provide foundation for numerous alternatives and modifications. These other modifications are also within the scope of the limiting technology of the present invention. Accordingly, the present invention is not limited to that precisely shown and described herein but only to that outlined in the appended claims.
Claims
1. A channel containing ventilated roofing tile for transferring heat along underline pitch roofing surfaces of buildings comprising:
- a rigid multilayer construction having a top surface and bottom surface;
- said top surface of said rigid multilayer construction having light reflective characteristics;
- said bottom surface of said rigid multilayer construction having channels and attachment means;
- wherein said channels are of suitable geometry for moving air by natural convection within said channels along said underlying pitch roofing surfaces, and wherein said attachment means are suitable for fixedly attaching said bottom surface of said rigid multilayer construction to said underlying pitched roofing surfaces.
2. A ventilated roofing tile comprising:
- (a) a tile;
- (b) a top surface;
- (c) a bottom surface;
- (d) said top surface is coated with a material to absorb or reflect sunlight and said bottom surface is formed with a plurality of beads thereby improving said tiles ability to attach to a surface.
3. The ventilated tile of claim 2 wherein the bottom surface has numerous channels attached to said bottom surface thereby enhancing natural as well as forced air convection.
4. The multi-layered ventilated tile comprising:
- (a) a first tile;
- (b) a second tile;
- (c) said first tile has a bottom surface and a top surface, said bottom surface has a plurality of beads formed into said bottom surface;
- (d) said second tile has a top surface and a bottom surface, said top surface a plurality of channels formed into said second tile said top surface;
- (e) said first tile is placed over said second tile whereby said channels form a convection zone facilitating a laminar flow of air between said first and said second tiles.
Type: Application
Filed: Dec 2, 2006
Publication Date: Jun 14, 2007
Applicant:
Inventor: Fred Miekka (Arcadia, CA)
Application Number: 11/607,153
International Classification: E04H 12/28 (20060101); F24F 7/02 (20060101); E04B 1/70 (20060101); E04B 7/00 (20060101);