Method and system for replacing an air filter

1. A raisable and lowerable filter housing for an air heating/cooling system having an air intake located in a ceiling, the air intake comprising an air return having an air inlet, comprising:

an air filter housing, said housing comprising an air intake grate having an outer side and an inner side, a plurality of filter mounts located at said inner side and spaced from said inner side of said grate and from one another for supporting at least two air filters in a spaced, vertically stacked relationship above said inner side of said grate and arranged for movement with said air filter housing;

at least a first and a second extendable connector, each of said extendable connectors having at least a first portion connected to said air filter housing and a second portion for connection to said ceiling;

wherein said air filter housing is movable between a raised position in which said grate is positioned at said air inlet of said air intake return and said at least two air filters associated with said air filter housing are configured to filter air passing through said air intake grate into said air intake return of said air heating/cooling system, and a lowered position in which said entire air filter housing and said two or more air filters associated therewith are positioned a distance vertically below said air intake, permitting a user to remove one or more of said at least two air filters from said air filter housing for replacement; and

a biasing mechanism associated with each extendable connector, each biasing mechanism configured to bias its associated extendable connector to a retracted position corresponding to said raised position of said air filter housing, each biasing mechanism including a bias adjustment mechanism, whereby a user may independently adjust a biasing force generated by each biasing mechanism.

2. The raisable and lowerable filter housing in accordance with claim 1 wherein each extendable connector comprises a cable.

3. The raisable and lowerable filter housing in accordance with claim 2 wherein said biasing mechanism comprises a coil spring.

4. The raisable and lowerable filter housing in accordance with claim 3 wherein a second portion of each biasing connector is mounted to a pulley which is supported by said ceiling and wherein a coil spring is associated with each pulley.

5. The raisable and lowerable filter housing in accordance with claim 1 wherein each filter mount defines a generally horizontal filter accepting slot.

6. The raisable and lowerable filter housing in accordance with claim 1 further comprising at least one air filter condition indicator.

7. The raisable and lowerable filter housing in accordance with claim 6 wherein said air filter housing has an exterior side and an interior side when said air filter housing is in said raised position and said indicator comprises an air passage extending from said exterior side to said interior side, at least one air pressure sensor associated with said air passage and at least one indicator which provides an output based upon said output of said air pressure sensor.

8. The raisable and lowerable filter housing in accordance with claim 7 wherein said air passage comprises a pitot tube and said at least one indicator comprises at least one light.

9. The raisable and lowerable filter housing in accordance with claim 8 wherein a color of said at least one light changes depending upon said output of said air pressure.

10. The raisable and lowerable filter housing in accordance with claim 1 further comprising at least one latch configured to be moved between a locked position in which said latch engages said air filter housing and said support structure when said air filter housing is in said raised position, thus preventing movement of said air filter housing, and an unlocked position which permits said air filter housing to be moved between its raised and its lowered position.

11. The raisable and lowerable filter housing in accordance with claim 10 wherein said latch comprises a pivot which is mounted to said air filter housing and at least one arm which is connected to said pivot, wherein movement of said pivot causes said at least one arm to move between a retracted position in which said at least one arm does not engage said support structure when said latch in said unlocked position and an extended position in which said at least one arm does engage said support structure when said latch is in said locked position.

12. The raisable and lowerable filter housing in accordance with claim 11 wherein said pivot is aligned with said threaded opening for a control tool.

13. The raisable and lowerable filter housing in accordance with claim 12 said control tool is configured to actuate both said pivot and engage said threaded opening.

14. The raisable and lowerable filter housing in accordance with claim 1 wherein said air inlet of said air intake is generally horizontally extending.

15. The raisable and lowerable filter housing in accordance with claim 1 wherein said air filter housing is configured to be moved between said raised and lowered positions in a generally horizontal orientation.

16. The raisable and lowerable filter housing in accordance with claim 1 wherein one of said at least two air filters is positioned between another of said at least two air filters and said grate.

17. The raisable and lowerable filter housing in accordance with claim 1 wherein said at least two air filters are positioned stacked in a direction of air flow through said air intake.