Whole House Fan

This invention relates to a whole-house fan and in particular to a whole-house fan which is easier to install than those presently known.

A whole-house fan typically includes a fan assembly framed into the floor joists of an attic area and a shutter assembly secured to the fan assembly through an opening in the ceiling of the living-area below the fan assembly. The fan assembly includes a sheet metal venturi having a peripheral depending skirt and a central opening or throat. Brackets mounted on the venturi support a fan impeller in the venturi throat. The impeller is driven by an electric motor which is typically mounted either coaxially above the impeller for directly driving the impeller, or on a corner of the venturi for a belt drive. Whole-house fans are sometimes also mounted vertically on a gable or other wall.

Whole-house fans effectively prevent the build-up of heat in the building interior and attic, with a minimum of energy consumption. Their expanded use, however, has been hindered because the fan assemblies are difficult to install. To create the required opening between the living-area and the attic, a hole is cut in the living-area ceiling. The impeller diameter is typically on the order of 2 feet to 3 feet, the opening is typically from 2 feet to 4 feet square, and ceiling joists are typically 16 inches or 24 inches on center. Therefore, one or more joists must be cut. A frame is then built by nailing headers to the ends of the cut joists. In unfinished attics, a platform is laid over the joists to support the fan. The fan assembly is then mounted to the platform, and the shutter assembly is mounted to the ceiling.

One of the objects of this invention is to provide a whole-house fan which is easier to install in a ceiling than presently existing fans.

Another object is to provide such a fan which is simple and relatively inexpensive to manufacture.

Other objects will occur to those skilled in the art in light of the following description and accompanying drawings.

In accordance with one aspect of this invention, generally stated, a whole-house fan assembly is provided which includes a venturi for defining an air path, the venturi having an opening defining a throat, an impeller for drawing air through the venturi throat, and a motor for driving the impeller, characterised in that the venturi includes a depending skirt having means in it for accommodating joists to permit the skirt to fit over at least one joist and into close propinquity with the ceiling. Preferably, the skirt is made of corrugated sheet material, and includes a plurality of pre-scored tabs for accommodating differently spaced joists and joists of different heights.

In accordance with another aspect of the invention, a frame is provided which supports the impeller, the motor and the venturi, and which includes mounting means for mounting the frame to the upper faces of joists. Preferably, the frame includes a pair of spaced-apart U-brackets, the housing is attached to up-turned arms of the U-brackets and the impeller motor is attached by a mounting plate to horizontal reaches of the U-brackets.

In accordance with another aspect of the invention, a whole-house fan assembly is provided which includes a venturi for defining an air path, the venturi having an opening defining a throat, a fan for drawing air through the venturi throat, and a motor for driving the fan, characterized in that the motor is mounted coaxially with and below the fan.

Preferably, the venturi includes a sheet metal fan housing part and a separate skirt formed of one or more panels.

Other aspects of the invention will be better understood in light of the following description of the preferred embodiment.

In the drawings, FIG. 1 is an exploded view in perspective of one illustrative embodiment of whole-house fan of the present invention mounted in an ceiling structure.

FIG. 2 is a top plan view, partially cut away, of the fan of FIG. 1.

FIG. 3 is a view in side elevation of the fan of FIGS. 1 and 2.

FIG. 4 is an exploded view in perspective of a shutter assembly for use with the fan of FIGS. 1-3.

FIG. 5 is a somewhat diagrammatic view in end elevation of the fan of FIGS. 1-3, partially installed in a ceiling.

FIG. 6 is a somewhat diagrammatic view in end elevation of the fan and shutter assembly of FIGS. 1-4, corresponding to FIG. 5, showing the fan and shutter assembly installed in a ceiling.

FIG. 7 is a detail of a skirt part of the fan of FIGS. 1 and 2.

FIG. 8 is a partial sectional view taken along the line 8--8 of FIG. 2.

Referring now to the drawings, reference numeral 1 indicates a whole-house fan assembly of the present invention. The fan assembly 1 includes a pair of parallel U-shaped brackets 3, a fan mounting bracket 5 welded to the horizontal reaches of the U-shaped brackets 3, a fan motor 7 extending through a central opening 9 in the fan mounting bracket 5, a three-bladed fan impeller 11 mounted on the upwardly extending shaft 13 of the motor 7, and a venturi 15 including a sheet metal fan housing 17 and a peripheral depending skirt 19.

Each of the U-shaped brackets 3 includes a horizontal reach 21 having pre-drilled holes 20 spaced sixteen inches apart and twenty-four inches apart for mounting the fan assembly 1 on joists 22. In the illustrative embodiment, the joists 22 are two-by-six boards spaced on sixteen inch centers. The upper ends of vertical arms 23 of the U-shaped brackets 3 are welded to a down-turned peripheral flange 25 of the fan housing 17. The fan housing 17 further includes a conventional central throat 27 in which the fan impeller 11 is mounted.

Ears 29 are welded to the fan motor 7 for mounting the motor 7 to the bracket 5 by means of bolts 31 and rubber vibration-damping grommets 33.

The skirt 19 is formed of two identical sheets of corrugated board, preferably polypropylene. The two pieces forming the skirt 19 are held to each other by corner brackets 35 into which the free ends of the skirt 19 are pressed during installation of the fan assembly 1. All four walls of the skirt 19 include pre-scored holes 37 for securing the skirt 19 to the flange 25 of the fan housing 17. Three sets of holes, spaced two inches apart vertically, are provided on all four walls of the skirt 19, to accommodate joists 22 which are nominally four, six or eight inches tall. Two opposing walls of the skirt 19 further include pre-scored tabs 41 for accommodating joists on different spacings and of different heights. FIG. 7 shows details of the tabs 41, with pre-scored cutting lines shown as solid lines and pre-scored bending lines shown as dotted lines. It will be seen that the tabs 41 are bent out along the joists 22 and facilitate taping the openings around the joist if desired. Likewise, a flap 43 is bent out at the bottom of the skirt 19 to form a tight fit with the upper face of the ceiling 45.

Referring now to FIG. 4, the shutter assembly 47 includes a frame 49 carrying a plurality of shutters 51 which are conventionally connected to each other for simultaneous movement. A spring 53 biases the shutters closed. The frame 49 includes openings 55 for wood screws 57. The openings 55 are spaced sixteen inches and twenty-four inches apart, for surface mounting the shutter assembly 47 to the underside of ceiling 45 and securing it to the joists 22. Plugs 59 are provided for all eight openings 55, to provide a finished appearance for the frame 49.

The assembly of the fan 1 and shutter assembly 47 to a ceiling, without cutting joists, is accomplished as follows. A suitable place is chosen in accordance with established criteria. If the place selected is a hallway, the joists must run perpendicular to the hallway. Any obstructions such as pipes or wires in the attic are removed. A hole is drilled from below in the center of the desired location, and a wire is passed through the hole to mark the spot. Using the wire as a transverse center line, the point half way between joists is found and a second hole is drilled from above. Using the second hole as the center, an opening is cut in the ceiling to fit the fan assembly 1. Rubber grommets 61 are forced into the appropriate holes 20 in the U-shaped brackets 3 for the spacing of joists 22. The fan assembly 1 is lifted through the ceiling hole and placed on the joists 22, centered on the ceiling opening. Electrical connections are made to the fan motor. The skirt 19 is assembled with clips 35, the appropriate tabs 41 are bent out for the spacing and height of the joists 22, and the skirt is attached to the housing 17 by fasteners 39. The assembly is then secured to the joists by screws 63 extending through the grommets 61, as shown in FIG. 8. It will be seen that when the fan assembly 1 is installed, the motor 7 extends below and between the joists 22. If desired, the joint between the skirt and the ceiling and joists may be taped or caulked to reduce air leakage.

The spring 53 on the shutter assembly 47 is stretched between brackets on the frame 49 and on the shutters 51 to an adjustment at which the spring 53 just closes the shutters 51. The shutter assembly is then secured to the joists 22 by screws 57. The shutters 51 are mounted in the frame 49 in such a manner as to clear the bottoms of the joists 22 when the shutters are open. The shutters are balanced to be pulled open by the draft of the fan, but to close when the fan is not running, as is conventional.

Numerous variations in the whole-house fan of the present invention, within the scope of the appended claims, will occur to those skilled in the art in light of the foregoing disclosure. Merely by way of example, the preferred fan assembly may be mounted vertically to an exterior wall, without cutting the wall studs, by mounting the fan assembly with the support brackets to the inside of the attic and using four mounting brackets extending from the studs to and around the flange 25 of the fan housing 17 to hold the fan housing the proper distance from the wall. The skirt 19 is then attached to the flange 25, between the fan housing and the wall, and the tabs 41 are bent around the studs. Exterior shutters are then attached to the exterior of the wall. Likewise, the fan assembly 1 may be mounted on a ceiling or wall by cutting joists or studs and building a frame in the conventional manner, to permit the shutters to be recessed flush into the ceiling or wall. Preferably, a pair of two-by-six supports are notched and mounted in the frame, so that the fan assembly is mounted to the supports and the bottom of the skirt is sealed to the top of the frame. These variations are merely illustrative.