Patent Publication Number: US-2011047924-A1

Title: Hollow brick providing thermal insulation

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to construction materials, and particularly relates to a hollow brick providing thermal insulation, the brick having relatively high R-values. 
     2. Description of the Related Art 
     In nations where hot weather prevails throughout most of year, such as the Kingdom of Saudi Arabia, a substantial amount of the total power consumption in the nation is expended cooling buildings by air conditioning. Electrical energy is primarily generated through the burning of fossil fuels, which release harmful gases, typically referred to as “greenhouse gases”, into the atmosphere. These greenhouse gas emissions contribute to global warming and major changes in climate conditions. At least one-half of the volume of emissions from the power production process is in the form of harmful greenhouse gases. 
     Thus, sustainability and energy savings are important issues aimed at the reduction of energy consumption and production of greenhouse gas emissions. Therefore, it is necessary to improve the thermal loss standards of building construction elements. 
     Heat leak calculations are of particular importance, since thermal energy transfer through constructions materials (such as wall-forming bricks) directly relates to energy conservation in buildings, and ultimately determines the suitable R-value or U-factor for building elements. In calculating air conditioning cooling load, the heat transmission through walls, in particular, is considered as a major element contributing to loss of efficiency by heating the cooler, air-conditioned air inside the building. 
     A substantial amount of energy is consumed to compensate for heat transfer through building walls and ceilings. During the mid-1970&#39;s, designers first became aware of the life-cycle cost of buildings, thus initiating the design of energy efficient walls. Walls using hollow bricks were built for their structural and moisture diverting qualities. Hollow bricks are manufactured in a wide variety of styles and sizes.  FIG. 2  illustrates a typical hollow brick  100  of the type commonly referred to as a three-core hollow block or concrete masonry unit. 
     Hollow brick  100  typically is substantially rectangular, having opposed upper and lower surfaces  110 ,  112 , a pair of longitudinally opposed sidewalls  104  (each having a recess  106  formed therein), a pair of laterally opposed sidewalls  102 , and often three open passages  108  defining cores formed transversely therethrough. Alternatively, brick  100  may be described as a rectangular prism having one or two medial partition walls defining one or two cores through the brick  100 . Today, hollow and dense cement or concrete bricks, also sometimes referred to as hollow blocks, are suitable and common alternatives to conventional bricks, and are widely used in construction. 
     Such hollow blocks are typically formed from cement, stone chips, stone dust or sand, and are not only cheaper to manufacture than conventional bricks, but have useful thermal properties.  FIG. 3  illustrates another typical hollow brick  200 , having longitudinally opposed sidewalls  210 , laterally opposed sidewalls  206 ,  208 , an upper surface  202  and three rectangular passages  204  transversely formed therethrough. Typically, passages  204  are open and the dimensions thereof are carefully selected. 
     In  FIG. 3 , each passages  204  has a cross-sectional longitudinal width of W 2  and a lateral length of L 2 , with the longitudinal spacing between the outer-most passage  204  and the sidewall  210  being W 1  (preferably, the spacing between adjacent passages  204  is equivalent), and a lateral spacing between passages  204  and sidewalls  206 ,  208  being L 1 . L 1 , L 2 , W 1  and W 2  are selected such that the cross-sectional surface are of each passage  204  is greater than 25 percent of the overall cross-sectional surface area of the block  200 , but is less than 60 percent of the overall surface area. 
     The modes by which heat transfer occurs include heat conduction in the solid sections of block  200 , along with natural convection and radiation transfer within the passages  204 . The outer surface  206  is exposed to solar radiation having a temperature of T o , and the inner surface  208  is cooled by interior air conditioning, having a temperature of T i , thus providing a thermal gradient for heat transfer to take place. The rate of heat transfer depends upon the material properties, shape and thermal parameters of the block. Typically, in the prior art hollow blocks shown in  FIGS. 2 and 3 , insulation is inserted within the passages. In order to conserve energy through reduction of powered air conditioning within a building, constructing a block having optimal insulating properties, or a high R-value, is needed. Thus, a hollow brick providing thermal insulation solving the aforementioned problems is desired. 
     SUMMARY OF THE INVENTION 
     The hollow brick providing thermal insulation is a construction block having a relatively high R-value. The R-value is a commonly used thermodynamic measure of thermal resistance, or the measure of thermal insulation, used in the building and construction industry. A relatively high R-value is a measure of effective thermal insulation in a building material. The hollow brick providing thermal insulation includes a main brick body that is substantially rectangular, with the main brick body having opposed upper and lower surfaces, a pair of laterally opposed sidewalls and a pair of longitudinally opposed sidewalls. 
     A plurality of open passages are transversely formed through the main brick body, extending between the upper and lower surfaces thereof, with each open passage defining upper and lower open ends respectively formed through the upper and lower surfaces. The plurality of open passages are arrayed to form a plurality of laterally extending rows and a plurality of longitudinally extending columns. A longitudinal thickness between adjacent ones of the open passages in each longitudinally extending column is greater than a lateral thickness between adjacent ones of the open passages in each laterally extending row. The plurality of open passages each has a longitudinal length and a lateral width associated therewith, with the lateral width of each open passage being equal. 
     Preferably, five longitudinally extending columns and three laterally extending rows are formed by the plurality of open passages. Each open passage may be substantially rectangular, with all passages having substantially equal dimensions. The centers of each passage may be laterally aligned with adjacent ones of the open passages in each laterally extending row, and also longitudinally aligned with adjacent one of the open passages in each longitudinally extending row. Alternatively, the centers of the plurality of open passages may be laterally staggered within each laterally extending row. In this arrangement, centers of an outer pair of the plurality of open passages and a central one of the plurality of open passages are laterally aligned within each laterally extending row. 
     Alternatively, five longitudinally extending columns of open passages may be formed, with the plurality of open passages in an outer pair of the plurality of longitudinally extending columns and the plurality of open passages in a central longitudinally extending column being arrayed in three laterally extending rows. Centers of each of the plurality of open passages in the outer pair of the plurality of longitudinally extending columns and in the central longitudinally extending column are laterally aligned, however a pair of longitudinally extending columns, each being respectively positioned between one of the outer pair of longitudinally extending columns and the central longitudinally extending column, each have a pair of larger open passages and a pair of smaller open passages. 
     The longitudinal length of each open passage in the outer pair of the plurality of longitudinally extending columns and in the central longitudinally extending column is equal, with the longitudinal length of each larger open passage being equal to the longitudinal length of each open passage in the outer pair of the plurality of longitudinally extending columns and in the central longitudinally extending column. However, the longitudinal length of each smaller open passage is equal to approximately one-half the longitudinal length of each larger open passage. Preferably, the pair of smaller open passages in each respective longitudinally extending column are positioned adjacent the longitudinally opposed sidewalls of the main brick body. 
     These and other features of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a top view of a hollow brick providing thermal insulation according to the present invention. 
         FIG. 1B  is a top view of an alternative embodiment of the hollow brick providing thermal insulation according to the present invention. 
         FIG. 1C  is a top view of another alternative embodiment of the hollow brick providing thermal insulation according to the present invention. 
         FIG. 1D  is a top view of another alternative embodiment of the hollow brick providing thermal insulation according to the present invention. 
         FIG. 2  is a perspective view of a prior art construction block. 
         FIG. 3  is a top view of a prior art hollow brick. 
     
    
    
     Similar reference characters denote corresponding features consistently throughout the attached drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 1A , a first embodiment of the hollow brick providing thermal insulation  10  is shown. The hollow brick  10  is a construction block having a relatively high R-value. The R-value is a commonly used thermodynamic measure of thermal resistance, or the measure of thermal insulation, used in the building and construction industry. A relatively high R-value is a measure of effective thermal insulation in a building material. 
     It will be noted that in some contexts the term “brick” is used to refer to a block of ceramic material that is small enough to be picked up with one hand while the other hand is used to manipulate a trowel to spread mortar joining the bricks. Such bricks may be made from clay or shale, calcium silicate (typically sand and lime), or other material that is formed into rectangular prisms by the action of heat and subsequent cooling. A typical size for such bricks is about 8″×4″×2.25″. They are commonly used for buildings (particularly for external veneer), pavement, chimneys, furnaces, and the like. These bricks may be solid, or they may have hollow passages for light weight and for insulation purposes. 
     By contrast, the term “block” or concrete masonry unit is used to refer to a larger unit that is typically used in foundation walls and the like. Blocks are typically made from cast concrete, i.e., Portland cement and aggregate materials. In high-density blocks, the aggregate material is usually sand and fine gravel. In low density blocks, also called cinder blocks or breeze blocks, the aggregate material may comprise fly ash or bottom ash. Section  2102  of the International Building Code defines a “concrete” masonry unit as a building unit or block larger than 12″×4″×4″ made of cement and suitable aggregates, and defines the masonry unit as “hollow” when the net cross-sectional area is less than 75% of the gross cross-sectional area in any plane parallel to the load-bearing surface. 
     For purposes of the present application, the term “hollow brick” may refer to either the smaller “brick” or the larger “block” described in the two preceding paragraphs. 
     The hollow brick providing thermal insulation  10  includes a main brick body forming a substantially rectangular prism, with the main brick body having opposed upper and lower surfaces (only upper surface  16  is illustrated in the top view of  FIG. 1A , although it should be understood that the lower surface is opposite from and substantially parallel to the upper surface  16 , being identical in appearance), a pair of laterally opposed sidewalls  14  and a pair of longitudinally opposed sidewalls  12 . 
     A plurality of open passages  18  are transversely formed through the main brick body and extend between the upper and lower surfaces thereof, with each open passage  18  defining upper and lower open ends formed through the upper and lower surfaces of the main brick body. The plurality of open passages  18  are arrayed to form a plurality of laterally extending rows and a plurality of longitudinally extending columns formed by longitudinal and latitudinal partition walls, respectively. The latitudinal partition walls define a longitudinal thickness x 1  between adjacent ones of the open passages in each longitudinally extending column. The longitudinal partition walls define a lateral thickness x 2  between adjacent ones of the open passages in each laterally extending row. The longitudinal thickness x 1  is greater than the lateral thickness x 2 . The plurality of open passages  18  each have a longitudinal length L and a lateral width W. Preferably, each passage  18  is substantially rectangular, and each passage  18  is equal in length L and equal in width W. As noted above, in typical prior art hollow blocks, insulation may be inserted within the open passages. In the hollow bricks shown in  FIGS. 1A ,  1 B,  1 C and  1 D, the open passages remain open, utilizing air solely as an insulating material. 
     Preferably, five longitudinally extending columns and three laterally extending rows are formed by the plurality of open passages  18  by the brick  10 . In  FIG. 1A , the centers of each passage is laterally aligned with adjacent ones of the open passages  18  in each laterally extending row, and also longitudinally aligned with adjacent ones of the open passages in each longitudinally extending row, thus forming a regular, rectangular grid of passages  18 . 
     In the alternative embodiment of  FIG. 1B , the hollow brick providing thermal insulation  300  includes a main brick body defining a substantially rectangular prism. The main brick body has opposed upper and lower surfaces (only upper surface  316  is illustrated in the top view of  FIG. 1B , although it should be understood that the lower surface is opposite from and substantially parallel to the upper surface  316 , being identical in appearance), a pair of laterally opposed sidewalls  314  and a pair of longitudinally opposed sidewalls  312 , similar to that described above with regard to  FIG. 1A . However, as shown in  FIG. 1B , the centers of the plurality of open passages  318  within each row are laterally staggered, alternating between an up and a down position. In this arrangement, centers of an outer pair  320  of the plurality of open passages  318  and a central one  322  of the plurality of open passages  318  are laterally aligned within each laterally extending row. 
     As in  FIG. 1A , a longitudinal thickness x 3  between adjacent ones of the open passages in each longitudinally extending column is greater than a lateral thickness x 4  between adjacent ones of the open passages  318  in each laterally extending row. The plurality of open passages  318  each have a longitudinal length L and a lateral width W. Preferably, each passage  18  is substantially rectangular, and each passage  18  is equal in length L and equal in width W. It will be noted that only the end walls  312  extend continuously across the width of brick  300 , breaking any thermally conductive bridge that might otherwise be formed by laterally extending partition walls. 
     In the alternative embodiment of  FIG. 1C , the hollow brick providing thermal insulation  400  includes a main brick body forming a substantially rectangular prism. The main brick body has opposed upper and lower surfaces (only upper surface  416  is illustrated in the top view of  FIG. 1C , although it should be understood that the lower surface is opposite from and substantially parallel to the upper surface  416 , being identical in appearance), a pair of laterally opposed sidewalls  414  and a pair of longitudinally opposed sidewalls  412 , similar to that described above with regard to  FIGS. 1A and 1B . In  FIG. 1C , five longitudinally extending columns of open passages  418  are formed. The open passages in an outer pair  420  of the plurality of longitudinally extending columns  418  and the plurality of open passages in a central longitudinally extending column  422  are arrayed in three laterally extending rows. Centers of each of the plurality of open passages in the outer pair  420  of the plurality of longitudinally extending columns and in the central longitudinally extending column  422  are laterally aligned. A pair of longitudinally extending columns  424  are alternately positioned between one of the outer pair of longitudinally extending columns  420  and the central longitudinally extending column  422 . Each of the alternate columns  424  have a pair of larger open passages and a pair of smaller open passages. 
     As in  FIGS. 1A and 1B , a longitudinal thickness x 5  is defined between adjacent ones of the open passages in each longitudinally extending column, and a lateral thickness x 6  is defined between adjacent ones of the open passages in each laterally extending row. However, as shown, x 5  and x 6  are preferably substantially equal in this embodiment. The larger open passages each have a longitudinal length L and a lateral width W. 
     The longitudinal length L of each open passage in the outer pair of the plurality of longitudinally extending columns  420  and in the central longitudinally extending column  422  is equal, defined by L, with the longitudinal length of each larger open passage formed in the columns  424  being equal to the longitudinal length L of each open passage in the outer pair of the plurality of longitudinally extending columns  420  and in the central longitudinally extending column  422 . However, the longitudinal length of each smaller open passage in columns  424  is equal to approximately one-half the longitudinal length of each larger open passage (i.e., ½L). As shown, the width W of each open passage  418  is preferably equal in all columns and rows. Preferably, the pair of smaller open passages in each respective longitudinally extending column  424  are positioned adjacent the longitudinally opposed sidewalls  412  of the main brick body. Once again, only the end walls  412  extend continuously across the width of brick  400 , breaking any thermally conductive bridge that might otherwise be formed by laterally extending partition walls. 
     In  FIG. 1C , each passage  418  preferably is substantially rectangular. It should be understood that the shape of passages  418  may be varied. In  FIG. 1D , a hollow brick  500  is provided that has a configuration similar to that shown in  FIG. 1C  (i.e., longitudinally opposed sidewalls  512 , laterally opposed sidewalls  514 , an upper surface  516 , and five columns of open passages  518  arrayed in a manner similar to that shown in  FIG. 1C ). However, although the open passages  518  are arrayed identically to open passages  418 , each passage  518  is substantially oval. Once again, only the end walls  412  extend continuously across the width of brick  400 , breaking any thermally conductive bridge that might otherwise be formed by laterally extending partition walls. 
     In the hollow bricks of  FIGS. 1A ,  1 B,  1 C and  1 D, the R-value of each design is substantially greater than that of the conventional bricks and blocks shown in the prior art of  FIGS. 2 and 3 . The increase in R-value is effected by the orientation and dimensioning of the open passages, and the reduction in the thickness of the solid material used to form the main brick body. The five columns of openings decreases the volume available to form thermal bridges, thus reducing the rate of heat loss due to thermal conductivity. Additionally, the use of passages having a high aspect ratio decreases the heat transfer effects due to convection. In the configuration of  FIG. 1A , the hollow brick has an R-value approximately 43.16% greater than that of a conventional hollow block. Staggering the passages, as in  FIG. 1B , increases the R-value by an additional 17.65%. It should be understood that in the above, any desired number of columns may be utilized. Preferably, in order to maintain structural stability in addition to the increase in R-value, the number of longitudinally extending columns is greater than three and less than or equal to six. 
     It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.