System and apparatus for humidifier on high-efficiency forced air Furnace and kit therefore

Abstract

The present invention provides a system configured for simplified humidification in a forced-air high-efficiency furnace system, the instant system including an evaporative humidifier wick sitting in an elongated trough, both adjacent to an opening in the return air duct of a forced-air furnace. Also included is a diversion valve and tubing branch off an existing condensate drain line configured to deliver combustion condensate to a distributor tube spreading the condensate flow over the upper outer surface of the humidifier pad. A slipstream of warm air from the heated side of the furnace is conveyed through a duct to the face of the wicking evaporator pad.

Description

FIELD OF THE INVENTION

[0001] The present invention relates, in general, to humidification of indoor air and, more particularly, this invention relates to a simple non-fouling humidifier for forced-air high-efficiency furnaces.CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to US Provisional Patent Application No. 63 / 445,432 filed Feb. 14, 2023.BACKGROUND OF THE INVENTION

[0003] Prior to the conception and development of the present invention, high-efficiency fuel burning forced air furnaces for home heating have been commercially available for many decades. When a fuel such as natural gas burns it forms carbon dioxide and water vapor. The water vapor is at a higher energy level than liquid water. The high-efficiency furnaces derive the extra heat recovery by condensing the water of combustion and thus transferring that latent heat such as to warm the circulating air. Others have considered using this condensed water for humidifying the circulating air associated with a high-efficiency furnace. For example, Kopp in U.S. Pat. No. 9,459,016 discloses one embodiment (FIG. 1 herein, his FIG. 2) that uses the condensate as one source of water for humidification. It is supplemented by a city water connection, which can leave behind fouling deposits. Among the shortcomings of Kopp is that, as FIG. 1 illustrates, the excess or overflow water is routed to an adjacent floor drain, which is often not available next to a furnace. In those instances, a small sump-type pump must be used to pump the condensate to a tub or drain some distance away. Furthermore, in all embodiments, Kopp requires a pump even if there is an adjacent floor drain, which also entails needing an electrical connection. Payne is U.S. Pat. No. 5,570,068 teaches using condensate water to avoid the mineral deposit problem with humidifiers using a household water supply. Some of the conventional humidifiers on the market recommend replacing the interior pad twice per season because of the fouling that occurs with tap water. The Payne system still requires an electrical power source, a pump, and a control means tied into furnace controls. Payne claims a system that can be retrofitted to existing high-efficiency furnaces, but this still entails a pump, electrical supply, and control means. What Payne overlooks is that, unlike a steady flow from a tap water source, nearly all the condensate drains out in a very short time period after the burners shut off. There needs to be a system to deal with this surge of condensate near the end of the time when the warm air will be flowing over the evaporator pad, and thus there may not be enough water on the evaporator when most of the warm air is passing over it. Nunes in U.S. Pat. No. 10,907,842 discloses a humidification system using combustion condensate, but he acknowledges that most of that condensate does not get evaporated passing over the filter and therefore he uses an electrical steam generator to vaporize that excess condensate. This adds ann expensive addition requiring an electrical supply and also creates a potential trouble spot due to corrosion etc.SUMMARY OF THE INVENTION

[0004] The present invention provides an enhanced system configured for simplified humidification while overcoming prior-art limitations in using only condensate in a forced-air high-efficiency furnace system, the present system utilizing an apparatus including an evaporative humidifier wick with a rigid frame sitting in an elongated trough, both adjacent an opening in the return air duct of a forced-air furnace, and a diversion valve and tubing branch off a condensate drain line configured to deliver combustion condensate to a distributor tube spreading the condensate flow over the upper outer surface of the evaporative humidifier element. When the furnace is running, a slip stream of heated air is fed via a new duct portion to the outer surface of the wicking humidifier element.OBJECTS OF THE INVENTION

[0005] It is, therefore, one of the primary objects of the present invention to provide a self-regulating flow of non-fouling condensate from a high-efficiency forced-air furnace to a humidifier pad.

[0006] Another object of the present invention is to provide a system to utilize approximately 50 to 80% of the combustion condensate to humidify air circulating in a house, even without the use of a pump, and still be retrofitted to existing furnaces.

[0007] Still another object of the present invention is to provide a forced-air humidifier system not requiring any electrical connections, humidistat, or tap-water-supply lines.

[0008] Yet another object of the present invention is to provide condensate distributor which does not require perfect levelness to properly wet an evaporator pad.

[0009] An additional object of the present invention is to provide a system that can readily bypass the condensate to a drain when the humidifier operation is not desired.

[0010] One more additional objective of the present invention is to provide a system that can be adapted to existing furnaces having an existing condensate pump.

[0011] In addition to the various objects and advantages of the present invention described with some degree of specificity above, it should be obvious that additional objects and advantages of the present invention will become more readily apparent to those persons who are skilled in the relevant art from the following more detailed description of the invention, particularly, when such description is taken in conjunction with the attached drawing figures.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 provides a perspective view of one prior art system.

[0013] FIG. 2 is a side elevation overview of the system of the present invention on a typical high-efficiency forced air furnace.

[0014] FIG. 3 provides a perspective view of altered condensate piping of the present invention system.

[0015] FIG. 4 provides a partial sectional view of the apparatus of a first embodiment of the present invention installed at an opening in a typical furnace return air ductwork.

[0016] FIG. 5 is a side elevation view of an alternative embodiment of the present invention.

[0017] FIG. 6 provides a perspective view of a main portion of the present invention.

[0018] FIG. 7 is a cross sectional end view of a key element of both embodiments of the present invention.

[0019] FIG. 8 is a perspective view of an alternative configuration for the main portion of the present invention.

[0020] FIG. 9 is a plan overview of a kit for installing the apparatus of the first embodiment of the present invention on a typical high-efficiency forced air furnace.DETAILED DESCRIPTION OF A PRESENTLY PREFERRED AND VARIOUS ALTERNATIVE EMBODIMENTS OF THE INVENTION

[0021] Prior to proceeding to the more detailed description of the present invention it should be noted that, for the sake of clarity and understanding, very similar components which have identical functions have been identified with identical reference numerals throughout the several views illustrated in the drawing figures.

[0022] FIG. 1 provides a perspective view of one prior art system, specifically FIG. 2 from Kopp in U.S. Pat. No. 9,459,016. Some of the Kopp deficiencies were mentioned above. While there are some similarities to the second embodiment of the present invention, there are significant differences also. Kopp allows for gravity flow of condensate into the pump 47, but there is also city water coming via filter 92. Kopp teaches the overflow water going to a drain through line 43. There is little or no detail about what is inside compartment 8 of Kopp. The present invention is very specific about the distributor design and the size and nature of the evaporator pad.

[0023] Referring next to FIG. 2, this presents a side elevation overview of the system of the present invention. Cooler air 50, returning from rooms through air ducts in the house, flows under a slight negative pressure created by a blower 57 downstream (to right) of air filter 32. The burner section 55 of the furnace produces warm air stream 52; some of that heat coming from condensing the water formed from fuel combustion. That condensate flow, which conventionally goes down a drain, is herein routed via line 21 to the evaporative humidifier wick 24 which sits in a shallow trough 30. A slipstream of warm air off the main warm air stream 52 is conveyed down a duct 40, aided by the pressure differential, and flows to the face of the humidifier wick 24 with directional assistance from duct-end shroud 42.

[0024] FIG. 3 provides a perspective view of altered condensate piping of the present invention system. The condensate from the combustion zone flows out at line 21, and it typically would flow via tube 20 to a nearby household drain. With the system of the present invention, a valve 26 at a lower elevation than line 21, can be opened enabling nearly all of the condensate to flow to the present humidifier system shown in subsequent drawings. Because the furnace does not run in the warmer months, the valve is optional, but having it enables the humidifier to be readily bypassed when desired.

[0025] FIG. 4 provides a partial sectional view of a first embodiment of the present invention installed adjacent and outside an opening in a typical furnace return air duct 50. The apparatus of the present invention in combination with the portions of the existing furnace together create a simple novel humidifier system. With the optional valve 26 open, the condensate flows via gravity to the flow distributor 22 of the evaporative humidifier wick 24 instead of through the drain line 20 to the household drain 56. As will be described in more detail later, the elongated distributor 22 is a tube with a felt-like absorbent pad 27 wedged in an elongated slot in the distributor tube. Such a configuration does not require absolute levelness for nearly equal flow along its length. Equally important is how the high water capacity of this particular felt deals with the surge in condensate flow which comes just after the burners shut down. The distributor 22 gradually spreads condensate flow over the face of the evaporative wick 24 with the aid of optional felt appendages 27. Felt and felt-like herein apply to a variety of highly absorbent aqua-phillic cloth materials. To facilitate a gravity-flow system and provide substantial evaporation area, it is advantageous for the width 94 to be at least 1.3 times that of the height 92. An ideal size is an evaporator about 40 cm wide by 28 cm high, but no taller than 33 cm so that gravity-flow of condensate from the furnace outlet tube can be achieved. If it is taller, then it may not be possible to achieve condensate flow only by gravity. An example of a desirable evaporative humidifier wick is the 1041 Super Wick® marketed by AirCare®, but other similar ones will suffice. It has air passages between the vertical wick elements. Since it is a wicking type evaporator pad, with a rigid frame, it should be supported in a shallow trough 30 such that condensate not evaporated on the first pass over the evaporative humidifier wick can be drawn up into the evaporator to provide more opportunity for condensate to be evaporated. The height of trough 30 should not be more than 10 percent of that of the evaporative humidifier wick 24. To further aid the evaporation process, it is preferred that the “run-on” time for the furnace circulating blower after the burners shut off be about 5 minutes if possible. Not shown in this view is the warm-air ductwork that delivers heated air to the face of the evaporator. Complete evaporation is not expected; therefore, an overflow tube 28 exists to allow excess to drain to a household drain in the floor 58. An important feature of the instant invention is that even with complete evaporation, the condensate will not leave mineral deposits like tap water does, thus obviating the need to replace evaporator pads as recommended in conventional systems.

[0026] FIG. 5 is a side elevation partial cut away view of an alternative embodiment of the present invention; this one utilizing a pump 70 for delivering the condensate that drains via gravity into it. Often, a floor drain is not available near a high-efficiency furnace and a pump is needed to get the water via tubing to a sink or floor drain. These pumps operate intermittently with an internal float that triggers the pump when the sump is nearly full, and then it stops when the level is low.

[0027] Even when not necessary to route the condensate, one of these rather inexpensive pumps can be used as part of a humidifiers system using the condensate, which is preferable over tap water because it does not contain the minerals and salts that frequently foul evaporators in conventional systems. In the system depicted, condensate from combustion flows through tube 20 to the sump of the pump 70, which intermittently lifts the condensate via tube 38 to a combined reservoir / distributor 22 above the evaporator 24, which as before is an evaporative humidifier wick type resting in a shallow trough 30, which has an overflow tube tube 34 at an elevation high enough to drain to a remote location via gravity. Because of the volume of water the pump delivers quickly when it comes on, the distributor tube 22 should have a volume of at least 500 ml. An opening 44 in the warm air duct 52 allows a slipstream to flow through duct 40 to the face of the evaporative humidifier wick 24, which is covered by a duct-end shroud 42, which does not need to be air-tight given that the negative pressure on the opposite side pulls air in the desired direction. The cool return air duct 50 is under a slight negative pressure; hence, the warm air and some surrounding air are pulled through the evaporator pad. Pumped-up condensate gradually drips off the distributor appendages 27 onto the evaporator 24. That which does not evaporate collects in the trough 30 and much of it gets drawn back up into the evaporator by the wicking action. If the humidifier system is not needed or should be temporarily bypassed for maintenance, the bypass valve 26 is opened to allow condensate to get pumped to a drain elsewhere.

[0028] FIG. 6 provides a perspective view of two main portions of the present invention. The condensate distributor tube 22 is installed on or near the top of the evaporative humidifier wick 24, which sits in an elongated trough 30. The felt-like material 27 wedged in a slot in the distributor tube 22 facilitates slow draining of condensate substantially evenly across the face of evaporative wick 24. An overflow tube 28 on the trough 30 allows any excess water not evaporated to be routed elsewhere.

[0029] FIG. 7 is a cross sectional end view of a key element of both embodiments of the present invention. The water distributor tube 22 has a longitudinal slot 29 which pinches a felt-like absorbent material 27 partially inside the distributor tube 22 with most of it protruding downward so as to slow and direct the draining of the water onto the evaporator element as previously shown. This configuration enables generally equal flow downward along the length of distributor tube even if is not perfectly horizontal. Conventional humidifiers require perfect levelness for proper operation. It is preferred that the distributor tube be sloped slightly toward the side with the absorbent material.

[0030] FIG. 8 is a perspective view of an alternative configuration for the main portion of the present invention: the evaporator-distributor unit. As previously presented, the evaporative humidifier wick 24, wider than its height, sits in a shallow trough 30. The trough 30 holds water that is not evaporated on the initial path downward such that the wicking action of the evaporator can pull it upward for another opportunity to be evaporated by the warm air passing through. Not all of the condensate is expected to be evaporated, so a drain tube 28 is provided for gravity flow to a sink or floor drain. As illustrated in this Figure, the distributor tube 22 can be of various shapes and sizes, not just standard plumbing tubing. What is shown here is substantially larger in volume, which is better for accommodating the intermittent flow from a small sump-type pump. The felt-like cloth 27 wedged into a slot in the distributor tube can be of various size and shapes.

[0031] FIG. 9 is a plan overview of a kit 9 for installing the apparatus of the first embodiment of the present invention on a typical high-efficiency forced air furnace. The key portion is the evaporative humidifier wick 24 having a height 92 and a first width 94 at least 1.3 times that of the height 92. The height should be limited, but greater width provides more area for evaporation. Also included in the kit is an elongated flexible duct 40 having an internal diameter 96 and preferably insulation 46. The diameter 96 should be in the 10-20 cm range. When installed, one end of the duct 40 connects to a duct-end shroud 42 which will be positioned adjacent to the front face of the evaporator pad 24. Both the duct 40 and shroud 42 are configured and installed to provide a stream of warm air to the face of the evaporator pad, which will be positioned in front of an opening low in the cold air duct which is under slight negative pressure when operating. Another important portion of the apparatus that is in the kit is the distributor tube 22 with an integral absorbent pad 27 extending mostly outward. Since not all the condensate will get evaporated on the first pass over the evaporative humidifier wick 24, the wick 24 will sit inside a shallow trough 30 such that some water can be wicked upward into the evaporative wick 24. Any excess water not evaporated can eventually overflow via drain tube 28. The final portion of the kit is the condensate valve 26 connected to inlet tubing 21 and outlet tubing 29. This portion will be positioned at an elevation below the condensate port out of the furnace such that there can be gravity flow into the distributor tube 22.

[0032] While a presently preferred and various alternative embodiments of the present invention have been described in sufficient detail above to enable a person skilled in the relevant art to make and use the same, it should be obvious that various other adaptations and modifications can be envisioned by those persons skilled in such art without departing from the spirit of the invention as claimed in the claims filed herewith.

Examples

second embodiment

[0022]FIG. 1 provides a perspective view of one prior art system, specifically FIG. 2 from Kopp in U.S. Pat. No. 9,459,016. Some of the Kopp deficiencies were mentioned above. While there are some similarities to the present invention, there are significant differences also. Kopp allows for gravity flow of condensate into the pump 47, but there is also city water coming via filter 92. Kopp teaches the overflow water going to a drain through line 43. There is little or no detail about what is inside compartment 8 of Kopp. The present invention is very specific about the distributor design and the size and nature of the evaporator pad.

[0023]Referring next to FIG. 2, this presents a side elevation overview of the system of the present invention. Cooler air 50, returning from rooms through air ducts in the house, flows under a slight negative pressure created by a blower 57 downstream (to right) of air filter 32. The burner section 55 of the furnace produces warm air stream 52; some of ...

first embodiment

[0025]FIG. 4 provides a partial sectional view of the present invention installed adjacent and outside an opening in a typical furnace return air duct 50. The apparatus of the present invention in combination with the portions of the existing furnace together create a simple novel humidifier system. With the optional valve 26 open, the condensate flows via gravity to the flow distributor 22 of the evaporative humidifier wick 24 instead of through the drain line 20 to the household drain 56. As will be described in more detail later, the elongated distributor 22 is a tube with a felt-like absorbent pad 27 wedged in an elongated slot in the distributor tube. Such a configuration does not require absolute levelness for nearly equal flow along its length. Equally important is how the high water capacity of this particular felt deals with the surge in condensate flow which comes just after the burners shut down. The distributor 22 gradually spreads condensate flow over the face of the ev...

FIELD OF THE INVENTION

[0001] The present invention relates, in general, to humidification of indoor air and, more particularly, this invention relates to a simple non-fouling humidifier for forced-air high-efficiency furnaces.CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to US Provisional Patent Application No. 63 / 445,432 filed Feb. 14, 2023.BACKGROUND OF THE INVENTION

[0003] Prior to the conception and development of the present invention, high-efficiency fuel burning forced air furnaces for home heating have been commercially available for many decades. When a fuel such as natural gas burns it forms carbon dioxide and water vapor. The water vapor is at a higher energy level than liquid water. The high-efficiency furnaces derive the extra heat recovery by condensing the water of combustion and thus transferring that latent heat such as to warm the circulating air. Others have considered using this condensed water for humidifying the circulating air associated with a high-efficiency furnace. For example, Kopp in U.S. Pat. No. 9,459,016 discloses one embodiment (FIG. 1 herein, his FIG. 2) that uses the condensate as one source of water for humidification. It is supplemented by a city water connection, which can leave behind fouling deposits. Among the shortcomings of Kopp is that, as FIG. 1 illustrates, the excess or overflow water is routed to an adjacent floor drain, which is often not available next to a furnace. In those instances, a small sump-type pump must be used to pump the condensate to a tub or drain some distance away. Furthermore, in all embodiments, Kopp requires a pump even if there is an adjacent floor drain, which also entails needing an electrical connection. Payne is U.S. Pat. No. 5,570,068 teaches using condensate water to avoid the mineral deposit problem with humidifiers using a household water supply. Some of the conventional humidifiers on the market recommend replacing the interior pad twice per season because of the fouling that occurs with tap water. The Payne system still requires an electrical power source, a pump, and a control means tied into furnace controls. Payne claims a system that can be retrofitted to existing high-efficiency furnaces, but this still entails a pump, electrical supply, and control means. What Payne overlooks is that, unlike a steady flow from a tap water source, nearly all the condensate drains out in a very short time period after the burners shut off. There needs to be a system to deal with this surge of condensate near the end of the time when the warm air will be flowing over the evaporator pad, and thus there may not be enough water on the evaporator when most of the warm air is passing over it. Nunes in U.S. Pat. No. 10,907,842 discloses a humidification system using combustion condensate, but he acknowledges that most of that condensate does not get evaporated passing over the filter and therefore he uses an electrical steam generator to vaporize that excess condensate. This adds ann expensive addition requiring an electrical supply and also creates a potential trouble spot due to corrosion etc.SUMMARY OF THE INVENTION

[0004] The present invention provides an enhanced system configured for simplified humidification while overcoming prior-art limitations in using only condensate in a forced-air high-efficiency furnace system, the present system utilizing an apparatus including an evaporative humidifier wick with a rigid frame sitting in an elongated trough, both adjacent an opening in the return air duct of a forced-air furnace, and a diversion valve and tubing branch off a condensate drain line configured to deliver combustion condensate to a distributor tube spreading the condensate flow over the upper outer surface of the evaporative humidifier element. When the furnace is running, a slip stream of heated air is fed via a new duct portion to the outer surface of the wicking humidifier element.OBJECTS OF THE INVENTION

[0005] It is, therefore, one of the primary objects of the present invention to provide a self-regulating flow of non-fouling condensate from a high-efficiency forced-air furnace to a humidifier pad.

[0006] Another object of the present invention is to provide a system to utilize approximately 50 to 80% of the combustion condensate to humidify air circulating in a house, even without the use of a pump, and still be retrofitted to existing furnaces.

[0007] Still another object of the present invention is to provide a forced-air humidifier system not requiring any electrical connections, humidistat, or tap-water-supply lines.

[0008] Yet another object of the present invention is to provide condensate distributor which does not require perfect levelness to properly wet an evaporator pad.

[0009] An additional object of the present invention is to provide a system that can readily bypass the condensate to a drain when the humidifier operation is not desired.

[0010] One more additional objective of the present invention is to provide a system that can be adapted to existing furnaces having an existing condensate pump.

[0011] In addition to the various objects and advantages of the present invention described with some degree of specificity above, it should be obvious that additional objects and advantages of the present invention will become more readily apparent to those persons who are skilled in the relevant art from the following more detailed description of the invention, particularly, when such description is taken in conjunction with the attached drawing figures.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 provides a perspective view of one prior art system.

[0013] FIG. 2 is a side elevation overview of the system of the present invention on a typical high-efficiency forced air furnace.

[0014] FIG. 3 provides a perspective view of altered condensate piping of the present invention system.

[0015] FIG. 4 provides a partial sectional view of the apparatus of a first embodiment of the present invention installed at an opening in a typical furnace return air ductwork.

[0016] FIG. 5 is a side elevation view of an alternative embodiment of the present invention.

[0017] FIG. 6 provides a perspective view of a main portion of the present invention.

[0018] FIG. 7 is a cross sectional end view of a key element of both embodiments of the present invention.

[0019] FIG. 8 is a perspective view of an alternative configuration for the main portion of the present invention.

[0020] FIG. 9 is a plan overview of a kit for installing the apparatus of the first embodiment of the present invention on a typical high-efficiency forced air furnace.DETAILED DESCRIPTION OF A PRESENTLY PREFERRED AND VARIOUS ALTERNATIVE EMBODIMENTS OF THE INVENTION

[0021] Prior to proceeding to the more detailed description of the present invention it should be noted that, for the sake of clarity and understanding, very similar components which have identical functions have been identified with identical reference numerals throughout the several views illustrated in the drawing figures.

[0022] FIG. 1 provides a perspective view of one prior art system, specifically FIG. 2 from Kopp in U.S. Pat. No. 9,459,016. Some of the Kopp deficiencies were mentioned above. While there are some similarities to the second embodiment of the present invention, there are significant differences also. Kopp allows for gravity flow of condensate into the pump 47, but there is also city water coming via filter 92. Kopp teaches the overflow water going to a drain through line 43. There is little or no detail about what is inside compartment 8 of Kopp. The present invention is very specific about the distributor design and the size and nature of the evaporator pad.

[0023] Referring next to FIG. 2, this presents a side elevation overview of the system of the present invention. Cooler air 50, returning from rooms through air ducts in the house, flows under a slight negative pressure created by a blower 57 downstream (to right) of air filter 32. The burner section 55 of the furnace produces warm air stream 52; some of that heat coming from condensing the water formed from fuel combustion. That condensate flow, which conventionally goes down a drain, is herein routed via line 21 to the evaporative humidifier wick 24 which sits in a shallow trough 30. A slipstream of warm air off the main warm air stream 52 is conveyed down a duct 40, aided by the pressure differential, and flows to the face of the humidifier wick 24 with directional assistance from duct-end shroud 42.

[0024] FIG. 3 provides a perspective view of altered condensate piping of the present invention system. The condensate from the combustion zone flows out at line 21, and it typically would flow via tube 20 to a nearby household drain. With the system of the present invention, a valve 26 at a lower elevation than line 21, can be opened enabling nearly all of the condensate to flow to the present humidifier system shown in subsequent drawings. Because the furnace does not run in the warmer months, the valve is optional, but having it enables the humidifier to be readily bypassed when desired.

[0025] FIG. 4 provides a partial sectional view of a first embodiment of the present invention installed adjacent and outside an opening in a typical furnace return air duct 50. The apparatus of the present invention in combination with the portions of the existing furnace together create a simple novel humidifier system. With the optional valve 26 open, the condensate flows via gravity to the flow distributor 22 of the evaporative humidifier wick 24 instead of through the drain line 20 to the household drain 56. As will be described in more detail later, the elongated distributor 22 is a tube with a felt-like absorbent pad 27 wedged in an elongated slot in the distributor tube. Such a configuration does not require absolute levelness for nearly equal flow along its length. Equally important is how the high water capacity of this particular felt deals with the surge in condensate flow which comes just after the burners shut down. The distributor 22 gradually spreads condensate flow over the face of the evaporative wick 24 with the aid of optional felt appendages 27. Felt and felt-like herein apply to a variety of highly absorbent aqua-phillic cloth materials. To facilitate a gravity-flow system and provide substantial evaporation area, it is advantageous for the width 94 to be at least 1.3 times that of the height 92. An ideal size is an evaporator about 40 cm wide by 28 cm high, but no taller than 33 cm so that gravity-flow of condensate from the furnace outlet tube can be achieved. If it is taller, then it may not be possible to achieve condensate flow only by gravity. An example of a desirable evaporative humidifier wick is the 1041 Super Wick® marketed by AirCare®, but other similar ones will suffice. It has air passages between the vertical wick elements. Since it is a wicking type evaporator pad, with a rigid frame, it should be supported in a shallow trough 30 such that condensate not evaporated on the first pass over the evaporative humidifier wick can be drawn up into the evaporator to provide more opportunity for condensate to be evaporated. The height of trough 30 should not be more than 10 percent of that of the evaporative humidifier wick 24. To further aid the evaporation process, it is preferred that the “run-on” time for the furnace circulating blower after the burners shut off be about 5 minutes if possible. Not shown in this view is the warm-air ductwork that delivers heated air to the face of the evaporator. Complete evaporation is not expected; therefore, an overflow tube 28 exists to allow excess to drain to a household drain in the floor 58. An important feature of the instant invention is that even with complete evaporation, the condensate will not leave mineral deposits like tap water does, thus obviating the need to replace evaporator pads as recommended in conventional systems.

[0026] FIG. 5 is a side elevation partial cut away view of an alternative embodiment of the present invention; this one utilizing a pump 70 for delivering the condensate that drains via gravity into it. Often, a floor drain is not available near a high-efficiency furnace and a pump is needed to get the water via tubing to a sink or floor drain. These pumps operate intermittently with an internal float that triggers the pump when the sump is nearly full, and then it stops when the level is low.

[0027] Even when not necessary to route the condensate, one of these rather inexpensive pumps can be used as part of a humidifiers system using the condensate, which is preferable over tap water because it does not contain the minerals and salts that frequently foul evaporators in conventional systems. In the system depicted, condensate from combustion flows through tube 20 to the sump of the pump 70, which intermittently lifts the condensate via tube 38 to a combined reservoir / distributor 22 above the evaporator 24, which as before is an evaporative humidifier wick type resting in a shallow trough 30, which has an overflow tube tube 34 at an elevation high enough to drain to a remote location via gravity. Because of the volume of water the pump delivers quickly when it comes on, the distributor tube 22 should have a volume of at least 500 ml. An opening 44 in the warm air duct 52 allows a slipstream to flow through duct 40 to the face of the evaporative humidifier wick 24, which is covered by a duct-end shroud 42, which does not need to be air-tight given that the negative pressure on the opposite side pulls air in the desired direction. The cool return air duct 50 is under a slight negative pressure; hence, the warm air and some surrounding air are pulled through the evaporator pad. Pumped-up condensate gradually drips off the distributor appendages 27 onto the evaporator 24. That which does not evaporate collects in the trough 30 and much of it gets drawn back up into the evaporator by the wicking action. If the humidifier system is not needed or should be temporarily bypassed for maintenance, the bypass valve 26 is opened to allow condensate to get pumped to a drain elsewhere.

[0028] FIG. 6 provides a perspective view of two main portions of the present invention. The condensate distributor tube 22 is installed on or near the top of the evaporative humidifier wick 24, which sits in an elongated trough 30. The felt-like material 27 wedged in a slot in the distributor tube 22 facilitates slow draining of condensate substantially evenly across the face of evaporative wick 24. An overflow tube 28 on the trough 30 allows any excess water not evaporated to be routed elsewhere.

[0029] FIG. 7 is a cross sectional end view of a key element of both embodiments of the present invention. The water distributor tube 22 has a longitudinal slot 29 which pinches a felt-like absorbent material 27 partially inside the distributor tube 22 with most of it protruding downward so as to slow and direct the draining of the water onto the evaporator element as previously shown. This configuration enables generally equal flow downward along the length of distributor tube even if is not perfectly horizontal. Conventional humidifiers require perfect levelness for proper operation. It is preferred that the distributor tube be sloped slightly toward the side with the absorbent material.

[0030] FIG. 8 is a perspective view of an alternative configuration for the main portion of the present invention: the evaporator-distributor unit. As previously presented, the evaporative humidifier wick 24, wider than its height, sits in a shallow trough 30. The trough 30 holds water that is not evaporated on the initial path downward such that the wicking action of the evaporator can pull it upward for another opportunity to be evaporated by the warm air passing through. Not all of the condensate is expected to be evaporated, so a drain tube 28 is provided for gravity flow to a sink or floor drain. As illustrated in this Figure, the distributor tube 22 can be of various shapes and sizes, not just standard plumbing tubing. What is shown here is substantially larger in volume, which is better for accommodating the intermittent flow from a small sump-type pump. The felt-like cloth 27 wedged into a slot in the distributor tube can be of various size and shapes.

[0031] FIG. 9 is a plan overview of a kit 9 for installing the apparatus of the first embodiment of the present invention on a typical high-efficiency forced air furnace. The key portion is the evaporative humidifier wick 24 having a height 92 and a first width 94 at least 1.3 times that of the height 92. The height should be limited, but greater width provides more area for evaporation. Also included in the kit is an elongated flexible duct 40 having an internal diameter 96 and preferably insulation 46. The diameter 96 should be in the 10-20 cm range. When installed, one end of the duct 40 connects to a duct-end shroud 42 which will be positioned adjacent to the front face of the evaporator pad 24. Both the duct 40 and shroud 42 are configured and installed to provide a stream of warm air to the face of the evaporator pad, which will be positioned in front of an opening low in the cold air duct which is under slight negative pressure when operating. Another important portion of the apparatus that is in the kit is the distributor tube 22 with an integral absorbent pad 27 extending mostly outward. Since not all the condensate will get evaporated on the first pass over the evaporative humidifier wick 24, the wick 24 will sit inside a shallow trough 30 such that some water can be wicked upward into the evaporative wick 24. Any excess water not evaporated can eventually overflow via drain tube 28. The final portion of the kit is the condensate valve 26 connected to inlet tubing 21 and outlet tubing 29. This portion will be positioned at an elevation below the condensate port out of the furnace such that there can be gravity flow into the distributor tube 22.

[0032] While a presently preferred and various alternative embodiments of the present invention have been described in sufficient detail above to enable a person skilled in the relevant art to make and use the same, it should be obvious that various other adaptations and modifications can be envisioned by those persons skilled in such art without departing from the spirit of the invention as claimed in the claims filed herewith.

Examples

second embodiment

[0022]FIG. 1 provides a perspective view of one prior art system, specifically FIG. 2 from Kopp in U.S. Pat. No. 9,459,016. Some of the Kopp deficiencies were mentioned above. While there are some similarities to the present invention, there are significant differences also. Kopp allows for gravity flow of condensate into the pump 47, but there is also city water coming via filter 92. Kopp teaches the overflow water going to a drain through line 43. There is little or no detail about what is inside compartment 8 of Kopp. The present invention is very specific about the distributor design and the size and nature of the evaporator pad.

[0023]Referring next to FIG. 2, this presents a side elevation overview of the system of the present invention. Cooler air 50, returning from rooms through air ducts in the house, flows under a slight negative pressure created by a blower 57 downstream (to right) of air filter 32. The burner section 55 of the furnace produces warm air stream 52; some of ...

first embodiment

[0025]FIG. 4 provides a partial sectional view of the present invention installed adjacent and outside an opening in a typical furnace return air duct 50. The apparatus of the present invention in combination with the portions of the existing furnace together create a simple novel humidifier system. With the optional valve 26 open, the condensate flows via gravity to the flow distributor 22 of the evaporative humidifier wick 24 instead of through the drain line 20 to the household drain 56. As will be described in more detail later, the elongated distributor 22 is a tube with a felt-like absorbent pad 27 wedged in an elongated slot in the distributor tube. Such a configuration does not require absolute levelness for nearly equal flow along its length. Equally important is how the high water capacity of this particular felt deals with the surge in condensate flow which comes just after the burners shut down. The distributor 22 gradually spreads condensate flow over the face of the ev...

Claims

1. An apparatus for humidification of air circulating through a high-efficiency forced-air furnace comprising:a) an evaporative humidifier wick having a first predetermined height and a first predetermined width;b) an elongated liquid distributor with an integral felt-like absorbent element;c) a liquid-retaining trough with a second predetermined height and a second predetermined width;d) an elongated air duct configured for delivering warm air to a face of said evaporative humidifier wick; ande) a tubing portion configured to enable gravity flow of condensed water from a high-efficiency furnace.

2. The apparatus of claim 1 wherein said first predetermined width is at least 1.3 times said first predetermined height.

3. The apparatus of claim 1 wherein said first predetermined height is less than 33 centimeters.

4. The apparatus of claim 1 wherein said second predetermined height is less than 10 percent of said first predetermined height.

5. The apparatus of claim 1 wherein said second predetermined width is greater than said first predetermined width.

6. The apparatus of claim 1 wherein said tubing portion includes a shut off valve.

7. The apparatus of claim 1 wherein said elongated air duct is flexible and insulated.

8. The apparatus of claim 1 wherein said elongated air duct further includes a duct-end shroud.

9. An apparatus for humidification of air circulating through a high-efficiency forced-air furnace comprising:a) an evaporative humidifier wick having a first predetermined width;b) an elongated liquid distributor with an integral felt-like absorbent element;c) a liquid-retaining trough with a second predetermined width;d) an electric pump with an interior chamber and a float switch; e) an air duct configured for delivering warm air to a face of said evaporative humidifier wick; and, f) a tubing portion configured to enable gravity flow of condensed water vapor from a high-efficiency furnace to said electric pump.

10. The apparatus of claim 9 wherein said second predetermined width is greater than said first predetermined width.

11. The apparatus of claim 9 wherein said elongated liquid distributor is configured to also temporarily hold a liquid volume of at least 500 ml.

12. A kit for assembling an apparatus for creating a system to humidify air circulating through a high-efficiency furnace using condensate therefrom, said kit comprising:a) an evaporative humidifier wick having a first predetermined height and a first predetermined width;b) an elongated liquid distributor with an integral felt-like absorbent element;c) a liquid-retaining trough with a second predetermined height and a second predetermined width;d) an elongated air duct configured for delivering warm air to a face of said evaporative humidifier wick; ande) a tubing portion with a valve.

13. The kit of claim 11 wherein said kit further includes a duct-end shroud configured to attach to an end of said elongated air duct.

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