Abstract:
An improved baseboard radiator comprising a substantially tubular conduit formed of cross-linked polyethylene (PEX) tubing for containing and conveying hot water; a plurality of fins disposed onto and along the conduit for radiating heat energy transferred from hot water contained within the conduit; and a housing to contain the conduit/fin assembly. Alternate embodiments include the use of an integrated return water line formed of PEX tubing.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates generally to environmental climate control devices, namely, baseboard radiant heating units. Specifically, the invention relates to an improvement on a hot water baseboard radiator for residential and commercial use, where cross-linked polyethylene tubing is substituted for copper tubing as the hot water conduit in the baseboard radiator. 
       BACKGROUND 
       [0002]    The present invention utilizes cross-linked polyethylene tubing as a substitute for copper tubing in hot water baseboard radiant heating units. 
         [0003]    Traditional baseboard radiators are typically constructed of a conduit fitted with heat dissipating fins, all contained within a housing. The conduit carries heated water from a heat source, such as a boiler, and the heat is transferred by the fins to the space in which the baseboard radiator is located. The conduit is typically made of metal, most commonly copper tubing. Copper tubing provides for efficient heat conductivity as well as providing rigidity to the baseboard radiator. However, copper tubing is relatively expensive and difficult to work with. Moreover, if copper tubing is exposed to freezing temperatures any water contained therein may expand and burst the pipe, causing significant damage to the baseboard radiator as well as to the space in which it is located. There thus is a need for an improved baseboard radiator that utilizes a cost-efficient, easy to work with substitute for copper tubing that is also freeze damage resistant. 
         [0004]    PEX is the common trade name for cross-linked polyethylene. Through one of several processes, links between polyethylene molecules are formed to create bridges (thus the term “cross-linked”). This resulting material is more durable under temperature extremes, chemical attack, and better resists creep deformation, making PEX an excellent material for hot water applications. Developed in the 1960s, PEX tubing has been in use in many European countries for plumbing and radiant heating applications. PEX was introduced in the United States in the 1980s, and has seen significant growth in market demand and production. 
         [0005]    PEX&#39;s flexibility and strength at temperatures ranging from below freezing up to 200 degrees Fahrenheit makes it an ideal piping material for hot and cold water plumbing systems, service lines, and hydronic radiant heating systems. It is flexible, making it easy to install and service. PEX is able to withstand the high and low temperatures found in plumbing and heating applications, and is highly resistant to chemicals found in the plumbing environment. 
         [0006]    Flexible systems are quieter than rigid piping. The smooth interior will not corrode which can affect other materials long term pipe flow characteristics. PEX systems have fewer joints and are easier to install providing a lower cost installation over traditional plumbing materials. Moreover, PEX is an approved material in all the current model-plumbing codes. PEX piping is also freeze damage resistant as it can expand and contract as water freezes and thaws within the tubing. This presents a significant advantage over copper piping, especially for use in seasonal homes which may be left unheated during the winter season. 
         [0007]    PEX is cost-effective as a substitute for copper due to its relatively low price and copper&#39;s relatively high price. In addition, the installation of PEX in heating systems is fast because of the easy handling of the tubing and connection methods. Crimp fittings, insert compression fittings, and outside diameter compression fittings can be used to join PEX tubing to other components, as compared to the need for soldering to connect copper piping. Many heating systems already use PEX tubing to connect baseboard radiators to the heating source; however, the connection between the PEX tubing and the copper tubing of the baseboard radiator presents difficulties. A system utilizing PEX to PEX connections eliminates these difficulties. 
         [0008]    Notwithstanding the superior characteristics of PEX for plumbing and heating applications, however, PEX tubing has not previously been used within baseboard radiators, primarily because of its characteristic flexibility. A conduit in a baseboard radiator comprised of PEX tubing will tend to sag, especially when coupled with heat dissipating fins. For this reason PEX tubing has been limited to radiant floor heating systems or radiant wall heating systems, in which the PEX tubing is embedded in a fixed matrix, such as a concrete floor. The matrix provides the rigidity to the PEX tubing that would be otherwise lacking in a baseboard radiator. 
         [0009]    The present invention addresses and solves the above-stated problems. 
         [0010]    It is therefore an objective of the present invention to provide an improved baseboard radiator which is cost-efficient to manufacture. 
         [0011]    It is a further objective of the present invention to provide an improved baseboard radiator which is easy to install. 
         [0012]    It is yet a further objective of the present invention to provide an improved baseboard radiator which resists freeze damage. 
         [0013]    It is yet a further objective of the present invention to provide an improved baseboard radiator which uses PEX tubing as the hot water conduit. 
         [0014]    It is yet a further objective of the present invention to provide an improved baseboard radiator which incorporates a support structure to provide rigidity to the PEX conduit. 
         [0015]    Other objects of this invention will be apparent to those skilled in the art from the description and claims which follow. 
       SUMMARY OF THE INVENTION 
       [0016]    The present invention discloses an improved baseboard radiant heat unit, using PEX tubing as the hot water conduit as a substitute for copper tubing. The baseboard radiator of the present invention comprises the PEX conduit, fins for radiating heat energy, and a housing. The fins are disposed onto and along the conduit, forming a fin/conduit assembly, with the fin conduit assembly contained within the housing. The fin/conduit assembly is made rigid by the use of a rigid fin unit or by the use of one or more support brackets. A return water line may be integrated with the baseboard radiator, also being comprised of PEX tubing. So configured, the improved baseboard radiator may be integrated with traditional heating systems, though it is preferably used in heating systems which utilize PEX tubing to convey hot water between the various components. 
         [0017]    Other features and advantages of the invention are described below. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a plan front view of one embodiment of the present invention, with a portion of the housing cut away to reveal the interior components. 
           [0019]      FIG. 2  is a perspective view of the embodiment of the present invention depicted in  FIG. 1 , with a portion of the housing cut away to reveal the interior components. 
           [0020]      FIG. 3  is a perspective view of one embodiment of the fins and the conduit. 
           [0021]      FIG. 4  is a perspective view of the fin unit embodiment of the present invention. 
           [0022]      FIG. 5A  is a perspective view of an embodiment of the present invention utilizing a support bracket. 
           [0023]      FIG. 5B  is an exploded perspective view of the embodiment of the present invention depicted in  FIG. 5A , with dotted lines representing how components fit together. 
           [0024]      FIG. 6  is a perspective exploded view of yet another embodiment of the present invention utilizing fin flanges. 
           [0025]      FIG. 7A  is a perspective view of an embodiment of the present invention utilizing both a support bracket and a top bracket. 
           [0026]      FIG. 7B  is an exploded perspective view of the embodiment of the present invention depicted in  FIG. 7A , with dotted lines representing how components fit together. 
           [0027]      FIG. 8A  is a perspective view of an embodiment of the present invention utilizing a return conduit. 
           [0028]      FIG. 8B  is an exploded perspective view of the embodiment of the present invention depicted in  FIG. 8A , with dotted lines representing how components fit together. 
           [0029]      FIG. 9A  is a perspective view of an embodiment of the return conduit utilizing carrier frames and carrier frame clips. 
           [0030]      FIG. 9B  is an exploded perspective view of the embodiment of the present invention depicted in  FIG. 9A . 
           [0031]      FIG. 10  is a perspective view of yet another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0032]    The present invention provides for an improved hot water baseboard radiator  1  for use with a conventional residential or commercial heating system. The improved baseboard radiator  1  comprises a primary conduit  100  formed of cross-linked polyethylene tubing (PEX), a plurality of fins  200 , and a housing  300 . See  FIG. 1 . 
         [0033]    The primary conduit  100  has a uniform outside diameter  110  and is suitably adapted to contain and convey hot water. See  FIG. 3 . The PEX tubing from which the primary conduit  100  is formed may be coiled tubing or straight tubing. Straight PEX tubing requires less external structural rigidity than coiled PEX tubing in order for the primary conduit  100  to have its desired shape, which is substantially linear with minimal bending or curving, and is thus preferred, but either may be used. Any size PEX tubing may be used, though in the preferred embodiment the primary conduit  100  is ¾ inch diameter PEX tubing, as heating systems that use PEX tubing to connect their components typically use ¾ inch PEX tubing. The length of the primary conduit  100  should be approximately the same as the width of the housing  300 , though the length of the primary conduit  100  may be slightly longer than the width of the housing  300  which results in the ends of the primary conduit  100  extending somewhat beyond the sides of the housing  300 . Such a configuration allows for easier connection of the baseboard radiator  1  to the heating system. While shorter lengths of PEX tubing may be connected together to form the primary conduit  100 , in the preferred embodiment the primary conduit  100  is formed of a single seamless length of PEX tubing. 
         [0034]    The plurality of fins  200  used in the improved baseboard radiator  1  may be any standard heat dissipating fins known in the art. The fins  200  need only be adapted to radiate heat energy transferred from hot water contained within the primary conduit  100  to the ambient environment. The preferred embodiment uses aluminum fins  200  being substantially planar and having a substantially square or rectangular shape. See  FIGS. 2 and 3 . However, other configurations and materials are also contemplated. The only limitation on the choice of fins  200  is that each fin  200  must have a central aperture  202  that allows the primary conduit  100  to pass through the fin  200 . See  FIG. 3 . In the preferred embodiment the central aperture  202  is substantially circular in shape and has an inside diameter  204  substantially equivalent to the outside diameter  110  of the primary conduit  100 . This permits the primary conduit  100  to be inserted into and through the central apertures  202  of the fins  200 , resulting in the fins  200  being snugly disposed upon and along the length of the primary conduit  100  on its outer surface  108 . See  FIG. 2 . In other embodiments, the central apertures  202  may be of different shapes and diameters, with only a subset of the fins  200  being snugly fitted onto the primary conduit  100 . In the preferred embodiment the fins  200  are disposed along substantially the entire length of the primary conduit  100 . In other embodiments the fins  200  may be clustered at one end or the other of the primary conduit  100 , or at the center of the primary conduit  100 , or at random intervals. 
         [0035]    The conduit/fin assembly  250  is the combination of primary conduit  100  and fins  200  where the fins  200  are disposed onto and along the primary conduit  100 . See  FIG. 5A . In one embodiment the fins  200  in the conduit/fin assembly  250  are fixedly attached to each other into a fin unit  270 , such that the conduit/fin assembly  250  is a substantially rigid structure. See  FIG. 4 . In this embodiment the primary conduit  100  is maintained in the preferred straight configuration within the central apertures  202  of the fins  200 . This embodiment has the advantage of not requiring any further means for maintaining structural rigidity, but has the disadvantage of requiring non-standard fins  200  and/or requiring the use of connection means between the fins  200 . In the preferred embodiment the fins  200  are not attached to each other, with the result that the conduit/fin assembly  250  is flexible. This configuration is the most cost-efficient as standard fins  200  may be used without modification, but additional structural rigidity means must be employed. 
         [0036]    The housing  300  of the baseboard radiator  1  of the present invention may be any standard baseboard radiator housing that can accommodate the conduit/fin assembly  250  within its interior. Typically the housing  300  will be constructed of metal, to improve radiation of heat energy, but other materials may also be used. In the preferred embodiment the housing  300  will be of standard dimension so as to be available for new construction or easily retrofitted into existing facilities without special modification. 
         [0037]    The improved baseboard radiator  1  of the present invention may comprise a first coupling  410  and a second coupling  420 . See  FIG. 1 . The first coupling  410  should be adapted to connect one end of the primary conduit  100  to the heating system, and the second coupling  420  should be adapted to connect the other end of the primary conduit  100  to the heating system. Where the heating system uses PEX tubing to connect its components, the first and second couplings  410 , 420  will be PEX-to-PEX couplings, such as crimp fittings, insert compression fittings, and outside diameter compression fittings. Where the heating system uses copper tubing to connect its components, the first and second couplings  410 , 420  will be PEX-to-copper fittings, which may require soldering of the fitting to the copper pipe. 
         [0038]    In embodiments of the baseboard radiator  1  of the present invention in which the conduit/fin assembly  250  is flexible, the baseboard radiator  1  further comprises a support bracket  500 . See  FIGS. 5A and 5B . The support bracket  500  is adapted to support the conduit/fin assembly  250 . It may be constructed of any rigid material, though in the preferred embodiment it is metal and in the most preferred embodiment it is aluminum. The support bracket  500  should be substantially planar, with or without edge flanges  530 . In embodiments using edge flanges  530 , the edge flanges  530  depend upwards in a substantially vertical orientation and the distance between the edge flanges  530  should be substantially the same as the width of the fins  200  in the conduit/fin assembly  250 , such that the conduit/fin assembly  250  is fitted snugly between the edge flanges  530  and held therein when the conduit/fin assembly  250  is placed onto the support bracket  500 . See  FIG. 5B . The support bracket  500  is fixedly attached to an inside portion  302  of the housing  300  to hold the conduit/fin assembly  250  in place. 
         [0039]    In another embodiment the baseboard radiator  1  may comprise a top bracket  600 . The top bracket  600  is adapted to be placed over the top of the conduit/fin assembly  250 . It may be constructed of any rigid material, though in the preferred embodiment it is metal and in the most preferred embodiment it is aluminum. The top bracket  600  should be substantially planar, with or without edge flanges  630 . In embodiments using edge flanges  630 , the edge flanges  630  depend downwards in a substantially vertical orientation and the distance between the edge flanges  630  should be substantially the same as the width of the fins  200  in the conduit/fin assembly  250 , such that the top bracket  600  is fitted snugly onto conduit/fin assembly  250  and held therein by the edge flanges  630  when placed on the conduit/fin assembly  250 . 
         [0040]    In yet other embodiments both the support bracket  500  and the top bracket  600  are used. See  FIGS. 7A and 7B . In these embodiments the top bracket  600  may be fixedly attached to the support bracket  500  by one or more brace members  700 . The brace members  700  may be constructed of any rigid material, though in the preferred embodiment they are metal and in the most preferred embodiment they are aluminum. The brace members  700  may have any shape or configuration, though in the preferred embodiment they are substantially planar and rectangular. The brace members  700  may be fixedly attached to the top and support brackets  600 , 500  by any known means, such as fasteners, welds, adhesives, and the like. In the most preferred embodiment using brace members  700  the top and support brackets  600 , 500  also comprise edge flanges  530 , 630 . See  FIG. 7B . So configured, the conduit/fin assembly  250  is maintained substantially rigid, without sags or bends. 
         [0041]    In an alternative embodiment of the present invention, each of the plurality of fins  200  comprises one or more bottom flanges  212 . See  FIG. 6 . Each of the bottom flanges  212  depends downward from the bottom edge  210  of its respective fin  200 . In conjunction with the flanged fins  200 , the support bracket  500  comprises one or more corresponding slots  512  formed into its top surface  510 . See  FIG. 6 . Each of the slots  512  runs along the length of the support bracket  500  and, where more than one slot  512  is used, each of the slots  512  is oriented substantially parallel to each other slot  512 . The bottom flanges  212  of the fins  200  are inserted into the corresponding slots  512  of the support bracket  500  to provide a snug attachment of the conduit/fin assembly  250  to the support bracket  500 . 
         [0042]    In yet another alternative embodiment, each of the plurality of fins  200  comprises one or more top flanges  222 . See  FIG. 6 . Each of the top flanges  222  depends upward from the top edge  220  of its respective fin  200 . In conjunction with the flanged fins  200 , the top bracket  600  comprises one or more corresponding slots  612  formed into its bottom surface. Each of the slots  612  runs along the length of the top bracket  600  and, where more than one slot  612  is used, each of the slots  612  is oriented substantially parallel to each other slot  612 . The top flanges  222  of the fins  200  are inserted into the corresponding slots  612  of the top bracket  600  to provide a snug attachment of the conduit/fin assembly  250  to the top bracket  600 . In yet another alternative embodiment, both top and bottom fin flanges  212 , 222  are used, along with slots  512 , 612  formed into both the support and top brackets  500 , 600 . With the fin flanges  212 , 222  inserted into the corresponding bracket slots  512 , 612 , the conduit/fin assembly  250  is maintained substantially rigid, without sags or bends. 
         [0043]    The baseboard radiator  1  of the present invention may further comprise a return conduit  150  to serve as a water return line. See  FIGS. 8A and 8B . The return conduit  150  is formed of cross-linked polyethylene tubing. The PEX tubing from which the return conduit  150  is formed may be coiled tubing or straight tubing. Straight PEX tubing is preferred. Any size PEX tubing may be used for the return conduit  150 , though in the preferred embodiment the primary conduit  100  is ¾ inch diameter PEX tubing. The length of the return conduit  150  should be approximately the same as the width of the housing  300 , though the length of the return conduit  150  may be slightly longer than the width of the housing  300  which results in the ends of the return conduit  150  extending somewhat beyond the sides of the housing  300 . While shorter lengths of PEX tubing may be connected together to form the return conduit  150 , in the preferred embodiment the return conduit  150  is formed of a single seamless length of PEX tubing. 
         [0044]    The return conduit  150  is supported by one or more hangers  800 . Each hanger  800  is attached to the support bracket  500 , if used, or to the fin unit  270 , such that the return conduit  150  is supported beneath the conduit/fin assembly  250 . See  FIG. 8A . The hangers  800  may be formed of any substantially rigid material. In the preferred embodiment the hangers  800  are formed of metal into a substantially u-shape. See  FIG. 8B . The first and second ends  802 , 804  of each hanger  800  are then attached to the bottom surface of the support bracket  500  or the fin unit  270 . Other configurations of the hangers  800  are also contemplated by the invention. 
         [0045]    Where the return conduit  150  is formed of coiled PEX tubing, added structural rigidity may be needed to maintain the return conduit  150  in the preferred straight configuration. One embodiment uses a carrier frame  900  to maintain the return conduit  150  in a substantially straight configuration. See  FIGS. 9A and 9B . The carrier frame  900  is substantially rigid and accommodates the return conduit  150 . The return conduit  150  is placed upon the carrier frame  900  and the return conduit  150  and the carrier frame  900  are supported below the conduit/fin assembly  250  by the hangers  800 . In the preferred embodiment the carrier frame  900  is formed of two intersecting planar portions  910 , 912 , thereby giving the carrier frame  900  a v-shaped cross-section. See  FIG. 9B . With the v-shape of the carrier frame  900  opened at the top, the return conduit  150  is placed within the carrier frame  900  between and onto the two planar portions  910 , 912 . The length of the carrier frame  900  should be substantially identical to the length of the return conduit  150  to best provide structural rigidity, though shorter lengths are also contemplated. 
         [0046]    In one embodiment using a carrier frame  900 , one or more frame clips  950  may also be used to retain the carrier frame  900  to the return conduit  150 . See  FIG. 9A . Each frame clip  950  is substantially C-shaped and made of a substantially rigid material having a small amount of flex, such as spring metal. See  FIG. 9B . The one or more frame clips  950  are placed onto and over the return conduit  150  and carrier frame  900 , thereby holding the carrier frame  900  firmly to the return conduit  150 . In an alternative embodiment a second carrier frame  900  is used, configured identically to the first carrier frame  900  and placed over the top of the return conduit  150 . See  FIGS. 9A and 9B . When the second carrier frame  900  is used, it is preferred to also use one or more frame clips  950  to retain the carrier frames  900  to the return conduit  150 . Other configurations of the carrier frame  900  may be used, provided they serve to maintain the return conduit  150  in a substantially straight configuration. 
         [0047]    Where a baseboard radiator until is being placed in series with other baseboard radiator units, the primary conduit  100  and the return conduit  150  within the baseboard radiator  1  are not in direct communication with each other. Hot water flowing out of the primary conduit  100  of one baseboard radiator  1  flows into the primary conduit  100  of the next baseboard radiator  1 , and water flowing out of the return conduit  150  of one baseboard radiator  1  likewise flows into the return conduit  150  of the next baseboard radiator  1 . However, where a baseboard radiator unit is the sole unit used, or is the unit placed at the end of the water line, the primary conduit  100  and the return conduit  150  may be placed in direct communication with each other. In these embodiments, the primary conduit  100  has an open end  104  and a linked end  106  and the return conduit  150  has an open end  154  and a linked end  156 , with the linked ends  106 , 156  of the primary conduit  100  and the return conduit  150  substantially aligned and in fluid connection with each other. See  FIG. 10 . Thus, hot water enters the baseboard radiator  1  through the open end  104  of the primary conduit  100  and flows through the primary conduit  100 , then exits the primary conduit  100  through the linked end  106  of the primary conduit  100  and enters the return conduit  150  through the linked end  156  of the return conduit  150 , and finally flows through the return conduit  150  and exits the baseboard radiator  1  through the open end  154  of the return conduit  150 . 
         [0048]    Where the primary conduit  100  is linked to the return conduit  150 , the improved baseboard radiator  1  of the present invention may comprise a first coupling and a second coupling. The first coupling is adapted to connect the open end  104  of the primary conduit  100  to the heating system, and the second coupling is adapted to connect the open end  154  of the return conduit  150  to the heating system. Where the heating system uses PEX tubing to connect its components, the first and second couplings will be PEX-to-PEX couplings, such as crimp fittings, insert compression fittings, and outside diameter compression fittings. Where the heating system uses copper tubing to connect its components, the first and second couplings will be PEX-to-copper fittings, which may require soldering of the fitting to the copper pipe. Those skilled in the art will perceive improvements, changes and modifications in the invention. Such improvements, changes and modifications within the skill of the art are intended to be covered by the claims set forth herein, and that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.