Bio-Guard Furnace Filter

Abstract

An air filtering device for placement within an air duct for a residential furnace or air conditioning unit to provide at least MERV 13, preferably MERV 15, and most preferably MERV 17 efficiency. The air filtering device includes a frame which houses a filtering area having several stacked layers for removing particles from air before it is heated or cooled and then directed into air ducts for delivery throughout a building.

Description

TECHNICAL FIELD OF THE INVENTION

The present invention relates to HVAC air filtering systems. More specifically, the invention relates to air filtering devices having an efficiency rating of MERV 15 or greater for HVAC systems.

BACKGROUND OF THE INVENTION

Most every household is equipped with at least one of either a furnace for heating or an air conditioner for cooling the home. Many are equipped with both. And, in many instances, the furnace and/or air conditioner is equipped with a filter for removing particles and the like from the heated and/or conditioned air. The filter is then periodically replaced with a new filter.

Unfortunately, these disposable filters operate in the MERV 10-13 range. That is, these filters are excellent for removing particles in the 3-10 micron range (85% or better removal), good at removing particles in the 1-3 micron range (50%-90% removal), but poor at removing particles in the 0.3-1 micron range (<20% for MERV 10-12 and up 75% removal for MERV 13). This efficiency is insufficient for removing many viruses (approx. 0.1 micron), bacteria (about 1 micron), and smoke particles (approx. 2.5 micron).

To supplement these disposable filters, a good number of homeowners have invested in home air filtering systems. For example, see the '768 Publication, which has been incorporated by reference and shows a portable air filtering system which is capable of removing air contaminants down to the sub 0.3 micron range. These portable filtering systems, though effective, that effectiveness is limited to filtering air in an area or room in which the portable device is positioned—unlike a home furnace and air conditioner which pulls in and emits air via multiple ducts positioned throughout a house. Further, the portable systems are obtrusive in a home setting, and can be noisy and very expensive. These drawbacks make them unsuitable for whole home use.

Accordingly, a replaceable filter is needed which can be used with existing furnace and air conditioning systems and effectively remove particles from the air with an efficiency greater than MERV 14, and more preferably, with an efficiency greater than MERV 15.

Until the invention of the present application, these and other problems in the prior art went either unnoticed or unsolved by those skilled in the art. The present invention provides an improved reusable furnace filter which is capable of MERV 17 efficiency without sacrificing air flow or affordability.

SUMMARY OF THE INVENTION

There is disclosed herein an improved reusable air filtering device which avoids the disadvantages of prior devices while affording additional operating advantages in existing residential HVAC systems.

Generally speaking, the air filtering device is positioned within an air duct in cooperation with a furnace, air conditioning unit, or fan. The air filtering device comprises a frame defining outer boundaries of an air filter having a plurality of filtering areas or layers situated within the frame. Preferably, the filtering areas have an efficiency of at least MERV 15, and wherein the filtering areas may be rinsed clean and reused.

In specific embodiments, the plurality of filtering areas comprises at least a pre-filter layer, a catalyst filter layer, an activated carbon filter layer, and an electrostatic filter layer. Further, the height and width dimensions of the frame are approximately one of either 16 inches by 25 inches (16×25) or approximately 20 inches by 25 inches (20×25).

In specific embodiments, the thickness dimension of the filtering area is one of at least one inch (1″), at least four inches (4″), at least five inches (5″), or at least seven inches (7″).

These and other aspects of the invention may be understood more readily from the following description and the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of facilitating an understanding of the subject matter sought to be protected, there are illustrated in the accompanying drawings, embodiments thereof, from an inspection of which, when considered in connection with the following description, the subject matter sought to be protected, its construction and operation, and many of its advantages should be readily understood and appreciated.

FIG. 1 is an illustration of an HVAC system showing ductwork and a typical air filter position;

FIG. 2 is a close-up view of an air filtering device within residential HVAC ductwork;

FIG. 3 is a front perspective view of an embodiment of the disclosed air filtering device;

FIG. 4 is a rear perspective view of the embodiment of FIG. 1;

FIG. 5 is another front perspective view of the embodiment of FIG. 1;

FIG. 6 is a schematic of an embodiment of a frame for the disclosed air filtering device;

FIG. 7 is an illustration of an embodiment of the filtering area showing various filtering layers for the disclosed air filtering device; and

FIG. 8 is an illustration of another embodiment of the filtering area showing various filtering layers.

DETAILED DESCRIPTION OF THE INVENTION

While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail at least one preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to any of the specific embodiments illustrated.

With reference to FIG. 1, a typical up-flow furnace configuration, including air ducts is illustrated. Air is pulled in at a return grill within a home, via a blower, and directed through a return duct where the air encounters a filtering device 10. As air passes through the filtering device 10 contaminants are removed and clean air is then pushed back into the home, via the blower, through additional ducts and air vents. During the disclosed loop, the clean air may be heated, cooled, humidified, or maintained before it is returned to the home, as is well-understood in the art.

FIG. 2 further illustrates the positioning of an air filtering device 10 within the disclosed an air flow loop for a residential HVAC system as described above. The typical air filtering device 10—which in prior art systems is usually just a standard disposable filter—is housed within an open channel situated between incoming air duct and a blower chamber. The channel is preferably sealed by a door panel 22 attached to the frame 12 of an air filtering device 10. The door panel 22 may be slightly larger than the frame height and width to provide a proper seal when positioned within the air duct. Accordingly, the air filtering device 10 is preferably inserted within the channel much like a drawer slides into a track.

FIGS. 3-5 illustrate at least one embodiment of the disclosed air filtering device, generally designated by the numeral 10. The particular illustrated air filtering device 10 is for most any residential HVAC system. That is, the air filtering device 10 is to be positioned within the air flow, preferably within the system ductwork, to allow air (see arrows) to pass through the device 10, as illustrated in the configuration of FIG. 1. The air filtering device 10 is generally comprised of the frame 12 and filtering area 14. The frame 12 includes four connected walls 20 forming a rectangle. As previously mentioned, in specific embodiments, one of the walls 20 may be configured as a door panel 22 (with or without a handle), the door panel 22 serving to seal the filtering area 14 within a duct, as is presently done with some furnaces using larger filters as illustrated in FIG. 2.

In use, with the air filtering device 10 properly positioned, as illustrated in FIGS. 1 and 2, air enters at an intake surface 30 of the filtering area 14 (see arrows of FIGS. 3 and 4), passes through the plurality of filtering layers 32 where contaminants are removed. The air is then discharged as clean air from the discharge surface 40 of the filtering area 14 (see arrows of FIGS. 3 and 5).

Referring to FIG. 6, the air filtering device 10 can be sized to accommodate various HVAC systems. In conjunction with the following TABLE below, preferred dimensions of two versions of the disclosed air filtering device are set forth. In the referenced illustration, “A” represents the height of the frame 12 of the device 10, “B” represents the height of the filtering area 14, “C” represents the width of the door 22 of the device 10, “D” represents the height of the frame 12 of the device 10, “E” represents the length of the filtering area 14, and “F” represents the length of the frame 12 of the device 10.

	TABLE
	Preferred Dimensions	Version 1	Version 2
	A	18⅜ inches	21⅞	inches
	B	15⅛ inches	18⅝	inches
	C *	11⅛ inches	11⅛	inches
	D	17½ inches	21	inches
	E	22⅛ inches	22⅛	inches
	F	25¼ inches	25¼	inches
	* Also, 1 inch, 4 inches, and 7 inches for both versions

As can be seen in FIGS. 6 and 7, the frame 12 of the air filtering device 10 encloses a filter area 14. The preferred filter area 14 is comprised of multiple zones or layers secured within the outer frame 12. While preferred zones/layers are recommended for most applications, different configurations are possible for different air environments—e.g., higher VOCs, higher pet dander, higher allergens, etc. The different zones or layers may include a pre-filter area 102, which is used to remove larger particles from incoming air. These large particles may pose a threat to the other filter layers in the filter area 14. Another preferred filter zone/layer is known as a cold catalyst filter 108. The cold catalyst filter layer 108 is used to remove pollutants and harmful volatile organic compounds (VOCs), including ozone (O₃) from the incoming air. The cold catalyst filter 108 decomposes a variety of harmful gases, such as formaldehyde, ammonia, benzene, hydrogen sulfide and more VOCs, to produce water and carbon dioxide. As water is produced by this filter zone/layer 108, a proper water tray and discharge port and/or tubing is necessary. Finally, an electrostatic filter zone/layer 110 can also be used in the disclosed filter area 14. This filter zone/layer is known in the art as a bio-guard filter. The electrostatic filter layer 110 has two contacts which couple to contacts within the filter frame. These two sets of contacts electrically couple the electrostatic filter layer to a power source to create the necessary charge on the filter layer. The electrostatic filter zone/layer 110 is able to charge incoming contaminant particles using ionizer 104, the particles which are then collected on an oppositely charged surface provided by the plurality of filter strips at 106. These strips are arranged close together within the filter frame to maximize efficiency.

With reference to FIG. 8, an optional embodiment of the air filtering device 10 is illustrated. The air filtering device 10 may include a first bio-guard filter zone 210 and a second bio-guard filter zone/layer 310. Other layers, such as a HEPA filter layer 120 may also be included with or without the removal of other layers/zones. Another potential filter zone is an activated carbon filter layer 130 for removal of odors from the air.

In use, the filter system can be inserted into the designated filter channel of an existing furnace/AC system proximate an air output duct. The fan of the furnace/AC unit draws air into an air intake then, after heating/cooling, the air passes through each of the filter layers as it is output to a duct system. An air sensor or timer may be used to indicate a time when the filter system needs to be cleaned or replaced.

In preferred embodiments, the dimensions of the disclosed air filtering device are one of either (H×W) 16 inch×25 inch, or 20 inch×25 inch. These dimensions provide a suitable surface area for air to pass through the filter system at a desired air flow in cubic feet per minute (CFM). The thickness or depth (D) of each filter is one of either one inch (2.54 cm), 4 inches (10.16 cm), 5 inches (12.7 cm), or 7 inches (17.78 cm). These filters provide efficiency ratings of between MERV 14 and MERV 17.

The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. While all the embodiments illustrated and described are directed to use in residential HVAC systems, it should be understood that the principles of the invention may be more broadly applied to include air filtering systems used commercially, as well. It will be apparent to those skilled in the art that changes and modifications may be made to the disclosed embodiments without departing from the broader aspects of applicants' contribution. The actual scope of the protection sought is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.

Claims

1. An air filtering device for use in residential HVAC ductwork in cooperation with at least one of a furnace, an air conditioning unit, and a fan, the air filtering device comprising: a frame having four sides defining a periphery of the air filtering device;a first face and a second face opposite the first face, each of the first and second faces having a surface area defined by the periphery; anda plurality of distinct filtering areas positioned within the frame and extending from the first face to the second face;wherein the filtering areas have an efficiency of at least MERV 13.

2. The air filtering device of claim 1, wherein the filtering areas are washable.

3. The air filtering device of claim 2, wherein the filtering areas are reusable.

4. The air filtering device of claim 1, wherein the plurality of filtering areas comprises at least a pre-filter layer, a catalyst filter layer, an activated carbon filter layer, and an electrostatic filter layer.

5. The air filtering device of claim 1, wherein height and length dimensions of the frame are approximately 16 inches by 25 inches, respectively.

6. The air filtering device of claim 1, wherein height and length dimensions of the frame are approximately 20 inches by 25 inches, respectively.

7. The air filtering device of claim 5, wherein a width dimension of the filtering area is at least four inches.

8. The air filtering device of claim 5, wherein a width dimension of the filtering area is at least five inches.

9. The air filtering device of claim 5, wherein a width dimension of the filtering area is at least seven inches.

10. The air filtering device of claim 6, wherein a width dimension of the filtering area is at least four inches.

11. The air filtering device of claim 6, wherein a width dimension of the filtering area is at least five inches.

12. The air filtering device of claim 6, wherein a width dimension of the filtering area is at least seven inches.

13. An air filtering device for use in residential HVAC air duct in cooperation with at least one of a furnace, an air conditioning unit, and a fan/blower, the air filtering device comprising: a frame having four sides defining a periphery of the air filtering device;a first face and a second face opposite the first face, each of the first and second faces having a surface area defined by the periphery; anda plurality of distinct filtering areas positioned within the frame and extending from the first face to the second face;wherein the filtering areas have an efficiency of at least MERV 15.

14. The air filtering device of claim 13, wherein the filtering areas are washable.

15. The air filtering device of claim 14, wherein the filtering areas are reusable.

16. The air filtering device of claim 13, wherein the plurality of filtering areas comprises at least a pre-filter layer, a catalyst filter layer, and two electrostatic filter layers.