Dirty filter indicator

• US 6,412,435 B1
• Filed: 12/26/2000
• Issued: 07/02/2002
• Est. Priority Date: 09/11/2000
• Status: Expired due to Fees

• Current Assignee: Ronald G. Timmons Jr
• Original Assignee: Ronald G. Timmons Jr
• Inventors: Timmons, Ronald G. Jr.
• Primary Examiner(s): Gutierrez, Diego
• Assistant Examiner(s): REIS, TRAVIS M
• Application Number:
  US09/745,407
• Publication Number:
  US 20020029733A1
• Time in Patent Office: 553 Days
• Field of Search: 116/70, 116/137.R, 116/67.R, 116/112, 116/264, 116/142.FP, 116/DIG.7, 116/DIG.25, 964/19, 340/607, 340/384.1, 340/404.1
• US Class Current: 116/70
• CPC Class Codes: B01D 46/0086 Filter condition indicators
• CPC Class Codes: B01D 46/42 Auxiliary equipment or operation thereof
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/39 Monitoring filter performance
• CPC Class Codes: F24F 11/526 giving audible indications
• CPC Class Codes: Y10S 116/25 Air filter condition indicator

Abstract

A dirty filter indicator device adapted for use with a furnace, an air conditioning assembly and the like. As the filter collects dirt and dust, the overall airflow is restricted causing more air to flow through the whistle device. This increased air flow through the device alerts the occupants to the need to change the air filter. The device has a canopy to prevent large dust particles from clogging the device and an adjustable nozzle element which can be adjusted to begin whistling according to the degree of dirtiness of the filter by cutting portions of the distal end of the whistle.

Claims

1. An air filter monitor device for indicating a dirty air filter in an HVAC system, comprising:

an elongated tube having a first end and a second end;

a conical nozzle attached to the first end of said tube, the nozzle having a discharge orifice, the nozzle defining a conical passage;

a cylindrical hollow flange having a top wall and a bottom wall, the second end of said tube penetrating into the hollow flange through the bottom wall, the hollow flange having an aperture for the ingress of air into the hollow flange defined in the top wall opposite the second end of said tube; and

a canopy having a top wall and a skirt depending from the periphery of the top wall, the canopy being in spaced relation from and partially enclosing said hollow flange, the top wall and the skirt covering and surrounding the top wall of said hollow flange;

wherein a continuous air passage is defined extending under the skirt of said canopy and through said hollow flange, said tube and said nozzle; and

wherein the monitoring device is adapted for insertion through an air filter in an HVAC system, the monitoring device emitting a whistle by an increased airflow under pressure through the air passage when the air filter is overloaded with dirt and dust;

said canopy preventing dust from entering said air passage.

2. The air filter monitor device according to claim 1, wherein the top wall of said canopy is circular and the skirt depending from the top wall is cylindrical.

3. The air filter monitor device according to claim 1, wherein the top wall of said hollow flange has a plurality of holes defined therein and wherein said canopy further comprises a plurality of legs depending from the top wall of said canopy, said plurality of legs forming a snap fit with said plurality of holes defined in the top wall of said hollow flange.

4. The air filter monitor device according to claim 3, wherein each said leg further has a shoulder defined therein, said shoulder having a larger diameter than said holes, the distance between the top wall and said shoulder spacing the top wall of said canopy from the top wall of said hollow flange by a predetermined distance.

5. The air filter monitor device according to claim 4, wherein said predetermined distance is about ⅛

inch.

6. The air filter monitor device according to claim 1, wherein the skirt of said canopy is spaced apart from said hollow flange by about ⅛

inch.

7. The air filter monitor device according to claim 1, further comprising a plurality of transverse indicia lines along the length of said nozzle, the indicia lines marking the level of progressively widening diameter of the conical passage defined by said nozzle, whereby the nozzle may be trimmed in order to widen the discharge orifice.

8. A dirty filter indicator device in combination with an air filter, comprising:

an air filter for a furnace or an air conditioning unit;

a whistle device having an upstream end and a downstream end, the whistle device including;

a circular canopy on the upstream end, the canopy having a plurality of legs;

a hollow circular flange having a central aperture, and supporting said plurality of legs of the canopy, and having a smaller diameter than the canopy to leave a peripheral space;

a cylindrical tubular body portion extending into the hollow cylindrical flange and extending downstream outside the flange; and

a truncated cone shaped nozzle portion constituting a distal end of the device, the nozzle portion decreasing in radius and defining a longitudinal cavity having a narrowing diameter;

said whistle device being retained in the air filter under an airflow by inserting the truncated cone shaped nozzle portion through the air filter, the air filter supporting said whistle device between the hollow flange and the nozzle portion;

wherein the whistle emits a warning sound by the increased airflow through a restricted air passage defined by the nozzle and the tubular body portion when the air filter becomes overloaded with dirt and dust.

9. The dirty filter indicator device according to claim 8, wherein the canopy has three legs and a diameter configured to leave a peripheral space of one-eighth inch from the hollow circular flange to permit air to enter the whistle device.

10. The dirty filter indicator device according to claim 8, wherein the tubular body extends at least one-half the distance into the hollow flange portion.

11. The dirty filter indicator device according to claim 8, wherein the nozzle portion can be shortened to adjust the airflow tolerance of the whistle.

12. The dirty filter indicator device according to claim 8, wherein the device is molded in four pieces and snapped together.