Patent Publication Number: US-2019186781-A1

Title: Algae reduction device for air handler systems

Description:
FIELD OF THE INVENTION 
     This invention relates generally to air handling systems, and particularly to improvements to air handling systems capable of reducing algae growth. 
     BACKGROUND OF THE INVENTION 
     Air handling systems are often termed air handlers or air handling units. Such air handling systems to regulate and circulate air as part of a heating, ventilating and air-conditioning (HVAC) system. Air handlers usually include metal housing containing a blower, heating or cooling elements. Residential air handlers typically include both heating and cooling elements. Commercial air handlers may be specifically designed to circulate heat in a large structure or vehicle. In some cases air handlers are mounted on a rooftop. In other cases air handlers are mounted in a basement in conjunction with the boiler or other heating device. 
     Air handlers usually connect to a duct work ventilation system that circulates and distributes air from the air handler to within a structure. 
     Air handlers include an air filter, at least one heat exchanger and a blower. Such residential air handlers are intended for smaller spaces, having less than 5000 ft. 2  and sometimes include multiple blower units and multiple heat exchangers. These can circulate outside air but may also re-circulate inside air. Some air handlers are automated to selectively handle both and adjusts the ratios according to temperature differences between the inside air and the outside air. Condensation is possible on or around any heat exchanger, its associated plumbing, and in the housing. 
     Common residential and commercial air handlers are constructed with a metal housing including metal infill panels. The metal is typically galvanized or otherwise coated to reduce corrosion. Corrosion is likely anywhere air changes temperature and condensation occurs. This is particularly true when warmer air having a relatively high humidity (e.g. 60%) is cooled to a lower temperature. 
     Most air handlers include mixing chamber or air-mixing plenum to combine outside air with the inside air to maintain air quality. The mixing chamber is typically equipped with dampers to control the ratio of inside and outside air. A blower is attached in fluid communication with the mixing chamber to effectuate airflow through the air handling system and through the ductwork to maintain desired temperature and humidity within a structure or vehicle. 
     Heat recovery devices are used on many air handlers to optimize efficiencies. Such heat recovery devices include a thermal wheel, a runaround coil, a heat pipe, or other heat exchanger. 
     Controls regulate every aspect of the air handler. Such controls can include arrays of sensors to detect airflow and humidity as well as temperature, pressure, vibration and functionality of component parts. Typically a control system includes a processor in electronic communication with an array of sensors and control circuitry. 
     One problem shared by manufacturers of air handlers as well as residential and commercial users of air handling systems is that condensation can lead to growth of algae and other undesirable biological life. Undesirable biological life can include fungal pathogens, mold, plants, and bacteria. Algae can grow rapidly under ideal conditions and is known to clog pan drains in air handlers. 
     Typically air handlers include at least one pan for capturing condensation and leaks. Puddles in a pan enable growth of algae in temperate locations. Algae growth, if left unchecked, can build up quite rapidly. 
     The pan is typically connected to a drain. The drain connects in fluid communication with the pan to drain fluid from the pan through a conventional drain system. This drain can become plugged with algae when algae grow in the pan causing pan to overflow. Pan overflow may corrode, or otherwise damage the air handler. Nearby flooring, walls, and other surrounding structures and equipment may also be damaged. Over time the damage can be considerable. Furthermore puddles of fluid can become a breeding ground for microbes, mosquitoes, and other forms of undesirable life. Puddles may be undesirably aromatic. 
     What is desired is a way of minimizing algae and microbial growth in the air handler system. What is also desired is a way of retrofitting existing air handling systems in a way that minimizes algae growth. What is further desired is a way of preventing drain systems of air handlers from becoming clogged with algae. 
     SUMMARY OF THE INVENTION 
     The invention includes a method, system, and kit of parts capable of retrofit and use with an air handling system. 
     The system includes housing and a pan with a raised edge. The pan captures leaks and condensate. The kit includes a fluid reservoir attachable to the housing for holding fluid, a pump mounted on the fluid reservoir, and a tube to transfer the fluid from the fluid reservoir to the drain pan. The drain pan includes a drain to a plumbing system to eliminate the liquid. 
     A tube clasp made from a single piece of flat material that is generally rectangular in shape and made from spring material such as steel. The tube clasp folds upon itself into a closed configuration. The tube clasp is spring-biased in the closed configuration. The tube clasp defines an opening for receiving the tube. The opening extends through two sections of the folded tube clasp and comprises two distinct openings that align to receive the tube. In one embodiment, the tube clasp has a spring loaded hinge formed by the single piece of flat material. In an alternate embodiment, the flat material is split and the hinge includes a spring loaded mechanism that interconnects the split flat material. 
     The open portion includes a flared section to enable the open portion to removeably slide and lock over the raised edge of the drain pan. It can be appreciated that the open portion of the tube clasp is configured to enable mounting of the tube clasp within the housing adjacent the drain pan to hold the tube firmly in an operative orientation with respect to the pan. 
     The pump delivers fluid into the pan from the reservoir via the tube. In one embodiment, the pump operates selectively. In another embodiment, the pump is controlled by a timer included in the kit of parts. The timer being electrically and operatively connected to the pump. The timer may be mechanical or electrical. The timer may be programmable. In one embodiment, the timer includes a wireless communication device to enable remote control of the timer. 
     In another embodiment, the pump is controlled to pulse the fluid during operation. The fluid drains from the pan via the drain. Pulsed delivery of the fluid increases latency of the fluid in the pan and drain to enable the fluid to inhibit algae growth during a longer period of time for the same, or less, volume of fluid. 
     The present invention is specifically designed for reliability and longevity. Preferably the reservoir is positioned in a manner that utilizes the force of gravity to draw fluid from the reservoir into the drain pan and reduces strain on the pump. In the embodiment where the fluid pump pulses the fluid into the drain pan, the pump has time to cool and thus maintains a desirable temperature. Utilizing fluid pulses in combination with a gravity assist orientation of the operative components reduces the need for a powerful and expensive pump. Additionally, heat generated by the pump motor is minimized due to the pulsed delivery of fluid. Pulsed delivery of fluid increases the time latency of the fluid within the pan in a tightly regulated fashion with a minimum of fluid volume being wasted. The pulsed delivery may be periodic, e.g. daily or weekly. 
     The combination of a gravity fed apparatus and the pulsing of the pump motor greatly increases the pump life and greatly minimizes the volume of fluid delivered from the reservoir to the drain pan. This is important because the reservoir contains only a finite amount of fluid and systems that waste fluid require more frequent refilling of the reservoir. Furthermore the pulsing of the pump motor in combination with the force of gravity can enable use of increase pressure in the tube to assure that the tube remains unobstructed. The pressure need not be maintained by the pump and the pulsing of the pump reduces wear on the pump motor and energy consumed by the pump motor. Reducing energy consumed by the pump motor is particularly useful in embodiments where the system is battery-powered. 
     The air handler can be used to deliver heat. Mounting the reservoir outside of the air handler housing reduces heat stress to the pump, and to the reservoir and its contents. Thus the reservoir can be made from heat resistant plastic, and the volume of fluid within the reservoir can reduce heat transfer from the housing to the pump when the pump operates. Heat reduction improves pump life and reduces wear. 
     The combination of pulsed delivery of fluid, gravity feeding the pan from the reservoir, and pulsed operation of the pump reduces heat related stress on the pump and thus improves pump longevity. Further the use of the fluid reservoir as a heat sink, or insulator, for the pump further improves pump longevity. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an air handler system in accordance with the present invention. 
         FIG. 2  is a side perspective view of a housing including a reservoir and pump assembly in accordance with the present invention. 
         FIG. 3  is a portion of the housing with a button switch assembly for operating the pump assembly. 
         FIG. 4  is a tube and tube clasp. 
         FIG. 5  is a tube and locking clasp. 
         FIG. 6  is a wiring diagram for a push button switch of  FIG. 3 . 
         FIG. 7  is a reservoir enclosure mounted on the housing. 
         FIG. 8  is a reservoir enclosure mounted on the housing with a push button switch. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows an air handling system generally designated with the reference numeral  10 . The air handling system  10  is an air handler with the housing  12 . The housing  12  includes a kit of parts attached to the housing  12  for reducing algae growth. 
     The kit of parts includes the reservoir  14  having a removable lid  16  and a pump motor  18 . The reservoir  14  is preferably a heat resistant plastic reservoir designed to hold fluids having a pH range of 2-7. 
     The tube  20  attaches to the pump motor for delivering fluid from the reservoir  14 . The housing  12  includes a pan  22  removeably mounted at the bottom  23  of the housing  12  for capturing fluid such as condensate and leaking fluid. The tube  20  attaches to the pan  22  with a tube clasp  24 . 
     Preferably the tube  20  is manufactured from a flexible and heat resistant material such as silicon. The housing includes a blower  28  and at least one heat exchanger  30 . The blower  28  draws air past the heat exchanger  30  to either heat or cool air. The air flows outwards from the housing  12  into duct work via the opening  26 . The housing  12  is further configured with a mount  32  having openings to enable power connection from the pump  18  to a power source. The housing  12  is further configured with a mount  34  for enabling the attachment of control hardware for controlling operation of the pump  18 . The control hardware can be mechanical, or electrical. For example, the control hardware may include a wireless networking device integrated therein to enable remote control from a computer or hand held wireless communication device e.g. a smart phone with an enabling software application. 
     In the embodiment shown, the air handling system  10  extends vertically from the pan  22  at the bottom to the opening  26 . In an alternate embodiment the air handling system  10  lies horizontally, and the pan  22  removeably mounts within the lateral side  25  of the air handling system housing  12  so that the pan  22  lies in a generally horizontal position under at least one heat exchanger  30 . 
       FIG. 2  shows a portion of the housing  12 . The reservoir  14  is a fixed on the lateral side of the housing  12  the pump  18  connects to a pair of tubes  20   a  and  20   b  respectively. The pump  18  includes a DC motor. Accordingly power inverter  36  is provided to convert AC power into DC power and operatively connects with the DC motor of the pump  18 . Utilizing more than one tube  20   a  and  20   b  enables a more uniform distribution of fluid from the reservoir to the pan. While two tubes  20   a  and  20   b  are shown, it can be appreciated that an array of tubes can be employed in accordance with the present invention. The pump  10  and associated control system can pulse fluid through a single tube at a time, or can deliver fluid from the reservoir through all tubes simultaneously. An advantage of pulsed delivery of fluid through each tube includes the use of an array of tubes without increasing the pump capacity, using an array of tubes and pulsed delivery increases the latency of the fluid in the pan during pump operation because fluid is being delivered intermittently to a number of possible locations in the pan. 
       FIG. 3  shows a portion of the housing  12  including manually actuated switch  40 . To switch  40  includes a button that causes the pump  18  to operate and deliver fluid from the reservoir into the pan. In one embodiment the fluid is non-toxic and capable of draining from the pan into the ambient environment. Preferably the fluid is vinegar having a pH of less than six. More preferably the vinegar has a pH of between two and six. Acidic vinegar is known to inhibit algae growth. Inhibiting algae growth in the pan reduces any possibility of algae growth in any drain system connected to the pan. 
       FIG. 4  shows the tube  20  and a tube clasp  42 . In this embodiment the tube clasp  42  is fabricated from a single piece of metal  43  having generally rectangular shape. The metal is preferably spring steel. The single piece of metal is folded upon itself creating a hinge  48  that causes two ends of the single piece of metal to press towards each other. Single piece of metal includes two openings. When the single piece of metal is folded upon itself two holes that align creating an opening  44  that enables the tube  22  extend there through. Preferably the opening is sized having an internal diameter of approximately the same diameter as an exterior surface of the tube to enable the tube to press-fit through the opening  44 . 
     The piece of metal  43  is formed with a flanged end  46  design to receive an edge of the pan and to hold the tube  20  relative to the pan. The tube clasp  42  thus removeably holds the tube  20  and the desired position on the pan. 
       FIG. 5  shows a variation of the tube clasp  42 . Having two holes which align defining the opening  44  for receiving the tube  20 . The hole includes extensions  50  that grip the tube  20 . The extensions  50  are angled from the tube clasp  42  to allow movement of the tube  20  in only one direction. The extensions thus prevent the tube  20  from retracting from the pan  22 . The tube clasp end  46  attaches directly to the raised edge  52  of the pan  22 . 
       FIG. 6  shows a wiring diagram for a push button switch  58 . The electrical connections between the push button switch  58  includes a power inverter  56  and an AC plug  54 . The power inverter  56  electronically connects to the motor  60  of the pump. The push button switch  58  selectively completes the circuit to enable DC power to operate the motor  60  and pump fluid through the system. 
       FIG. 7  shows a portion of the housing  12 . The kit of parts is enclosed in the enclosure  62 . The housing  60  includes the reservoir  14  the inverter  56 , the pump  18  and a portion of the tube  20 . The push button switch  58 , the inverter  56  and the pump  18  electronically connect with each other. The inverter  56  includes an AC plug  54 . 
       FIG. 8  shows the enclosure  62  with a cover  66  removeably affixed to the enclosure  62 . The enclosure  62  mounts on a wall  13 . The tube  20  extends from the enclosure  62  and is connectable with an air handling system  10 . The plug  54  is electronically connected with a wall outlet  64 . Thus the kit of parts of the present invention can be sold as a single unit in an enclosure  62 . The kit of parts can be mounted independently of any air handling system  10 , and connected with the air handling system pan via the tube  20 . 
     A method of the present invention includes mounting a kit of parts including a reservoir, a pump and a tube with a tube clasp in an air handler. Filling the reservoir with an algae inhibiting fluid. Attaching the tube to the pan and to the pump. Operating the pump to deliver the fluid to the pan. The timing of the operation of the pump can be manual, scheduled, or remotely regulated. Operation of the pump, when activated, can be continuous or intermittent. Where an array of tubes are used, intermittent operation can deliver fluid through the tubes sequentially. 
     Although the present invention is described having an AC power source and an inverter, the present invention can also utilize battery power, preferably with a 12 V system. Alternately the AC power source can be a 220 V power source with the appropriate inverter to connect directly to the power supply of the air handling system. Typically air handling systems have 220 V service. 
     Although the tube clasp is shown having been formed from a single piece of metal and can be appreciated that numerous tube clasp designs can be utilized in accordance with the present invention including any that removeably hold the tube on a pan. 
     Further while the present invention describes a push button actuation the actuator can be adapted with Wi-Fi capability so that it can be actuated via an electronic device such as a smart phone. Additionally when the reservoir is nearly empty a sensor included with the reservoir can signal the electronic device when a refill is required. 
     A timer can be utilized to automatically actuate the pump. The pump can be periodically actuated in an automated fashion to assure that no algae will grow in the pan in any drain system attached thereto. The timer can be mechanical or electronically programmable. 
     In an alternate embodiment, the tube includes a check valve to regulate fluid flow. In this embodiment, the reservoir mounts below the blower. The tube extends upwards relative to the pump and reservoir then down towards the pan. The pump pumps fluid upwards in the tube initially and then downwards towards the pan. The check valve prevents backflow of the fluid. This embodiment is preferred where the pump does not include a valve that inhibits fluid flow from the reservoir to the pan.