Abstract:
A radon vent fan system includes an enclosure having an air inlet and an air outlet disposed in aligned relation to one another, and an assembly having a motor and an impeller associated therewith, the assembly retained in the enclosure. The enclosure provides a first condensate path between the air inlet and the air outlet to direct condensate substantially away from the assembly and to the air inlet, with the first condensate path being formed of a channel proximate an inner wall of the enclosure.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The benefits of U.S. Provisional Application No. 60/970,909 filed Sep. 7, 2007 and entitled “Radon Vent Fan System” are claimed under 35 U.S.C. § 119(e), and the entire contents of this application are expressly incorporated herein by reference thereto. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to ventilation. The invention further relates to a radon vent fan system. 
       BACKGROUND OF THE INVENTION 
       [0003]    Radon is a naturally-occurring radioactive gas. According to the United States Environmental Protection Agency (EPA), radon is the second leading cause of lung cancer in America. Accumulation of radon in enclosed spaces such as residential settings is particularly dangerous because this gas is colorless, odorless, and tasteless and thus may remain unnoticed while posing a health risk. The EPA recommends intervention to provide radon reduction when a radon level is found to be 4 picoCuries per liter (pCi/L) or higher. 
         [0004]    Ventilation equipment is known for use in radon applications. In order to address the potential for buildup of elevated or dangerous levels of radon, mitigation equipment such as a radon fan may be installed to create a low pressure area under the slab so that the radon gas is extracted and expelled outside before it can migrate into the structure. Radon fans can be installed inside or outside a structure, and operate 24 hours per day and 7 days per week. 
         [0005]    In prior art radon mitigation systems, as shown for example in  FIG. 1 , inlet and outlet portions  10   a ,  10   b , respectively, of a fan unit  10  typically are connected to vent pipe portions  12   a ,  12   b  using a variety of external fittings  14 ,  15 ,  16 ,  17 ,  18  while a separate condensate bypass pipe  19  also extends intermediate vent pipe portions  12   a ,  12   b , as shown for example in  FIG. 1 . Such use of external fittings and a separate condensate bypass pipe increases installation complexity, time, and expense. 
       SUMMARY OF THE INVENTION 
       [0006]    A radon vent fan system includes an enclosure having an air inlet and an air outlet disposed in aligned relation to one another, and an assembly having a motor and an impeller associated therewith, the assembly retained in the enclosure. The enclosure provides a first condensate path between the air inlet and the air outlet to direct condensate substantially away from the assembly and to the air inlet, the first condensate path formed of a channel proximate an inner wall of the enclosure. 
         [0007]    In some embodiments, the enclosure may have a front portion and a rear portion demountably coupled to each other, and the front portion and rear portion may be coupled to each other in a clamshell fashion. The air inlet may be entirely formed in the rear portion, and the air outlet may be formed by combining the front portion and rear portion. The front portion may have a cover demountably coupled thereto. The channel may be integrally formed with the front portion, and the motor may be coupled to the front portion. 
         [0008]    A compartment may be provided adjacent the air inlet and in communication therewith. The compartment may include an opening in communication with a region proximate the impeller. The channel may be in communication with the compartment. 
         [0009]    The channel may be formed when the front portion and the rear portion are demountably coupled to each other. 
         [0010]    The air inlet and air outlet may be in aligned relation with respect to a first axis, and the channel may substantially extend parallel to the first axis. The enclosure may further include a wall disposed transverse to the first axis for permitting build-up of static pressure capability of the impeller. 
         [0011]    The air inlet may be disposed transverse to the air outlet, and in some embodiments the air inlet may be disposed substantially perpendicular to the air outlet. 
         [0012]    The channel may be integrally formed with the enclosure. 
         [0013]    In addition, a radon vent fan system may include an enclosure having an inlet and an outlet disposed in aligned relation to one another with respect to a first axis, the enclosure being formed of a first portion and a second portion demountably coupled to each other. The system further may include an assembly having a motor and an impeller associated therewith, the assembly being retained in the enclosure. A first condensate path may be provided between the inlet and the outlet to direct condensate substantially away from the assembly and toward the inlet, the first condensate path including a channel proximate an inner wall of the enclosure and substantially extending parallel to the first axis, the channel being in communication with a compartment adjacent to the inlet and the compartment being in communication with the inlet. A second condensate path may be provided between a region proximate the impeller and the compartment. 
         [0014]    In some embodiments, the enclosure further includes a wall disposed transverse to the first axis for permitting build-up of static pressure. Also, the inlet may be disposed substantially perpendicular to the outlet. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0015]    Preferred features of the present invention are disclosed in the accompanying figures, wherein: 
           [0016]      FIG. 1  is a side view of a prior art radon mitigation system; 
           [0017]      FIG. 2  is a rear perspective view of an embodiment of an enclosure of a radon vent fan system; 
           [0018]      FIG. 3  is another rear perspective view of the enclosure of  FIG. 2 ; 
           [0019]      FIG. 4  is another rear perspective view of the enclosure of  FIG. 2 ; 
           [0020]      FIG. 5  is another rear perspective view of the enclosure of  FIG. 2 ; 
           [0021]      FIG. 6  is another rear perspective view of the enclosure of  FIG. 2 ; 
           [0022]      FIG. 7  is a font perspective view of the enclosure of  FIG. 2 ; 
           [0023]      FIG. 8  is another font perspective view of the enclosure of  FIG. 2 ; 
           [0024]      FIG. 9  is another font perspective view of the enclosure of  FIG. 2 ; 
           [0025]      FIG. 10  is a side perspective view of the enclosure of  FIG. 2 ; 
           [0026]      FIG. 11  is a top view of the front portion of the enclosure of  FIG. 2  (with the tabs of the rear portion of the enclosure also visible); 
           [0027]      FIG. 12  is a side perspective view of the rear portion of the enclosure of  FIG. 2 ; 
           [0028]      FIG. 13  is a bottom perspective view of the rear portion of the enclosure of  FIG. 2 ; 
           [0029]      FIG. 14  is a bottom perspective view of the front portion of the enclosure of  FIG. 2  with a fan disposed therein covered by a scroll; 
           [0030]      FIG. 15  is another side perspective view of the front portion of the enclosure of  FIG. 2  with a fan disposed therein without the scroll being installed; 
           [0031]      FIG. 16  is a top perspective view of the scroll of  FIG. 14 ; 
           [0032]      FIG. 17  is a bottom perspective view of the scroll of  FIG. 14 ; 
           [0033]      FIG. 18  is a side perspective view of the inlet of the rear portion of the enclosure of  FIG. 12 ; 
           [0034]      FIG. 19  shows additional views of the rear portion of the enclosure of  FIG. 2  including an inside perspective view ( 19 A), an outside perspective view ( 19 B), a side view ( 19 C), a cross-sectional side view through A-A ( 19 D), an outside top view ( 19 E), and another side view ( 19 F); 
           [0035]      FIG. 20  shows additional views of the front portion of the enclosure of  FIG. 2  including an outside perspective view ( 20 A), an inside perspective view ( 20 B), a cross-sectional side view through B-B ( 20 C), an outside top view ( 20 D), a side view ( 20 E), and another side view ( 20 F); 
           [0036]      FIG. 21  shows additional views of the scroll of the radon vent fan system including an top perspective view ( 21 A), a bottom perspective view ( 21 B), a cross-sectional side view through C-C ( 21 C), a top view ( 21 D), a side view ( 21 E), and another side view ( 21 F); 
           [0037]      FIG. 22  shows additional views of the electrical cover of the radon vent fan system including an outside perspective view ( 22 A), an inside perspective view ( 22 B), a cross-sectional side view through D-D ( 22 C), an inside top view ( 19 D), a side view ( 22 E), and another side view ( 22 F); 
           [0038]      FIG. 23  shows a cross-section of the enclosure of  FIG. 2  with a condensate drain therein; 
           [0039]      FIG. 24  shows another front perspective view of the enclosure of  FIG. 2 ; 
           [0040]      FIG. 25  shows a side perspective view of the enclosure of  FIG. 2 ; and 
           [0041]      FIG. 26  shows a side perspective view of the front portion of the enclosure of  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0042]    Terms such as “top,” “bottom,” “front” and “rear” as used herein are provided as a non-limiting examples of the orientation of features. 
         [0043]    In one exemplary application, a radon fan is installed on the exterior of a house and connected to an exterior venting pipe. For example, an exemplary radon mitigation system includes a radon vent pipe such as a 3 inch Schedule 40 PVC pipe extending from sub-slab gravel up to a vent stack discharge point above the highest eave of the roof (e.g., 12 inches above the roof surface), and an electric vent fan connected to the vent pipe. The radon vent fan is installed in a vertical run of the vent pipe, for example near where the radon vent pipe protrudes from the basement level of the house to the outside. 
         [0044]    An exemplary embodiment of an inventive radon vent fan system is shown in  FIGS. 1-26 . 
         [0045]    As shown for example in  FIGS. 2-10 , a radon vent fan system includes a housing or enclosure  20  formed with a rear portion  22  and a front portion  24  coupled together in a clamshell fashion. Enclosure  20  includes an inlet  32  which is integrally formed with rear portion  22  in the exemplary embodiment. Enclosure  20  also includes an outlet  34  of which a first portion  34   a  of outlet  34  is integrally formed with rear portion  22  and a second portion  34   b  of outlet  34  is integrally formed with front portion  24 . 
         [0046]    As can be seen for example in  FIG. 13 , in the exemplary embodiment, rear portion  22  includes an outer rim  22   a  while front portion  24  includes a protruding rim  24   a . Outer rim  22   a  mates within protruding rim  24   a  of front portion  24 , as shown for example in  FIG. 3 . Portions  22 ,  24  may be coupled to one another for example using protrusions such as posts, for example a post at corner  24   b  extending through a hole at corner  22   b . Moreover, as shown for example in  FIGS. 8 and 14 , front portion  24  of housing  20  may include a removable cover  42  for an electric compartment  44   b . Cover  42  may be coupled to rear portion  22  for example with fasteners extending through holes  42   a ,  42   b  and received in rear portion  22 . A hole  45  for example may be provided in rear portion  22  so that wires from electrical compartment  44   b  may extend therethrough. 
         [0047]    Rear portion  22  of enclosure  20  includes a three point mounting system in the form of tabs  30 . Each of tabs  30  includes a hole therein to accommodate a fastener such as threaded fastener  31 . The vent fan enclosure thus may be fastened to the side of a structure such as a house. Two tabs  30  are disposed proximate the inlet  32  (low pressure end), while one tab  30  is disposed proximate the outlet  34  (high pressure end). Such a three point mounting system assists in minimizing vibration and noise transferred between the radon vent fan system and the house. 
         [0048]    In addition, rear portion  22  includes a central wall disposed transverse to line  38  which permits build-up of static pressure capability of the fan. 
         [0049]    Turning to  FIG. 2 , the positioning of the inlet  32 , outlet  34 , and motor/fan unit  36  with respect to one another is shown. Inlet  32  and outlet  34  preferably are aligned about line  38 , while being offset from motor/fan unit  36 . Inlet  32  and outlet  34  may open in directions perpendicular to one another, such that if the inventive radon fan system were installed in place of fan unit  10  in  FIG. 1 , inlet  32  would be coupled to pipe portion  12   a , while outlet  34  would be coupled to pipe portion  12   b . Preferably, the inventive radon fan system would not require external fittings or a separate condensate bypass pipe as shown in  FIG. 1 . 
         [0050]    The exemplary inventive radon vent fan system permits condensate to migrate from outlet  34  to inlet  32  without interacting with motor/fan unit  36 . By placing the motor/fan unit  36  out of the direct path of the condensate, motor failures due to moisture can be decreased. It is known that significant moisture can accumulate in the vent pipe, for example in cold weather when warm, moist air from underground is circulated through the vent pipe which is exposed to colder temperatures. The exemplary inventive radon vent fan system provides positive drainage to the ground beneath the slab or soil-gas-retarder. Thus, condensate drips into the high pressure scroll region (an open region although covered by cover  44 ) such as in direction D, where it flows to region E (as shown in  FIG. 15 ) and then through a small opening such as a notch  60  (shown in  FIG. 20B ) which may be provided so that the condensate further passes back to chamber  24   c  and then down through inlet  32 . 
         [0051]    Motorized impeller unit  36  includes a motor  36   a  and an impeller  36   b . The motor for example may be an external rotor motor, typically with the rotor external, as known in the art. The impeller for example may be a backward curved impeller as known in the art. In an exemplary embodiment, the impeller may have a diameter of 7.48 inches, while the motor may have a power of 88 watts. 
         [0052]    As shown in  FIG. 14 , fan inlet  32  is located at the lowest point of the fan housing, remote from the Venturi inlet  40 , such that condensate can exit the fan housing from the low pressure section of the fan. Also shown in  FIG. 14 , the electrical compartment  44   b  is disposed in a corner region and is covered by electrical cover  42  shown in detail in  FIG. 22 . In addition, a scroll  44  is shown in installed position in  FIG. 14 , and is separately shown for example in  FIG. 21 . 
         [0053]    The water path for condensate is shown for example in  FIGS. 23-26 . With reference initially to  FIG. 14 , condensate may accumulate in chamber  24   c , which is an enclosed space formed between the wall  24   d  of front portion  24  and a wall  27  formed proximate a portion of a fan covered by scroll  44 , as well as rear portion  22 . The condensate flows on the inside wall of ducting communicating with housing  20  above the air flow outlet  34 . In the exemplary embodiment, such condensate is directed through a channel  50  generally disposed along line  50   a  (shown in  FIG. 24 ) proximate the perimeter of housing  20  which extends from proximate inlet  32  to proximate outlet  34 . Channel forms a condensate drain, and may be in the form of a tube created by the coupling of opposing portions of rear and front portions  22 ,  24 , respectively. As shown in the cross-section of  FIG. 23 , channel  50  need not be circular, but in some exemplary embodiments may be circular. In particular, as seen in  FIG. 15 , a coupling  43  (partially shown) is attached to and extends around air flow outlet  34 , being coupled thereto at the circumference of the region of greater diameter  34   c  (which includes the portions of outlet  34  on both rear and front portions  22 ,  24 , respectively). A space  35  thus is created between coupling  43  and outlet  34  proximate the region thereof of lesser diameter  34   d  (with space  35  preferably extending all the way around outlet  34 , such that condensate flowing on the inside wall of the ducting is directed into channel  50 , which in the exemplary embodiment is disposed substantially vertical except a short dogleg region  50   b.    
         [0054]    Advantageously, in the exemplary embodiment, channel  50  is disposed substantially parallel to the direction of condensate flow (e.g., vertical). By orienting channel  50  substantially parallel to the direction of condensate flow between inlet  32  and outlet  34 , rather than perpendicular to the direction of condensate flow, the likelihood of freezing and clogging of channel  50  is lowered. During very cold weather, it is important to facilitate draining of condensate and the exemplary embodiment permits condensate to flow with gravitational assistance. 
         [0055]    Advantageously, the condensate drain of the exemplary embodiment may be molded into the housing  20 . Moreover, because relatively warm air enters cavity  24   c  through inlet  32 , the space therein may be maintained at relatively warm temperature to resist freezing of condensate during cold weather. 
         [0056]    Moreover, as shown in  FIG. 18 , a gasket  52  may be disposed around inlet  32  such that inlet  32  may be press fit to a pipe portion  12   a  thereby eliminating the need to apply any sealant to the interface as necessary with prior art devices. The gasket thus reduces installation and service time as well as associated costs. 
         [0057]    In the exemplary embodiment, rear portion  22  has a length d 1  of about 44.7 cm, a width d 2  of about 33.1 cm, and a height d 3  of about 11.5 cm. In the exemplary embodiment, front portion  24  has a height d 4  of about 7.3 cm, a length d 5  of about 40.4 cm, a length d 6  of about 45.1 cm, and a width d 7  of about 34.0 cm. In the exemplary embodiment, cover  44  has a length d 8  of about 31.4 cm and a length d 9  of about 27.8 cm. In addition, in the exemplary embodiment, cover  42  has a height d 10  of about 4.18 cm, a length d 11  of about 15.0 cm, and a length d 12  of about 9.6 cm. 
         [0058]    Finally, the inventive system is provided in an aesthetically pleasing outer shape suitable for use on the side of a house. 
         [0059]    While various descriptions of the present invention are described above, it should be understood that the various features can be used singly or in any combination thereof. Therefore, this invention is not to be limited to only the specifically preferred embodiments depicted herein. 
         [0060]    Further, it should be understood that variations and modifications within the spirit and scope of the invention may occur to those skilled in the art to which the invention pertains. Accordingly, all expedient modifications readily attainable by one versed in the art from the disclosure set forth herein that are within the scope and spirit of the present invention are to be included as further embodiments of the present invention. The scope of the present invention is accordingly defined as set forth in the appended claims.