Whole House Fan

This invention relates to a whole house fan, and, in particular, to a direct drive whole house fan wherein the fan motor is mounted on top of a single joist.

The use of whole house fans to help keep houses cool during summer months has long been known. The advantages to using whole house fans is set out in detail in U.S. Pat. No. 4,501,194 to Brown assigned to Emerson Electric Co.

Installation of whole house fans, such that a home owner or a "do-it-yourselfer" could install them, has only recently become popular. In many prior whole house fans it was necessary to cut ceiling joists and to form a plenum box by nailing header plates between the uncut joists and the ends of the cut joists. This involves major carpentry work which, depending upon the structure of the roof, could weaken the roof.

To eliminate this problem, whole-house fans were introduced which included a frame mountable on the tops of adjacent ceiling joists over an opening in the ceiling. A venturi was carried by the frame and a skirt depended downwardly from the venturi and fit around the uncut joists to form a plenum box. The frame was mounted on the joists and the motor was mounted on crossbars of the frame beneath the venturi. The motor was thus mounted between and supported by two joists and a large frame. Importantly, these "easy-to-install" whole house fans did not require cutting of ceiling joists when the opening was made in the ceiling. The above-mentioned patent to Brown and U.S. Pat. No. 4,385,550 to Steiner et al, also co-assigned to Emerson Electric Co., are examples of such "easy-to-install" whole house fans.

In order to make the installation of whole house ceiling fans even easier and to reduce the cost of such fans, it was desirable to make the motor and fan directly mountable to a middle joist centered on the ceiling opening and to make the venturi separately mountable directly to the middle joist. However, it was feared that if the direct drive motor and fan were mounted to a single joist, the fan would be unstable and would wobble on the joist. This in turn would cause the joist to also wobble or twist and could result in damage to the joist or ceiling of the house and would result in objectionable noise.

One object of the present invention is to provide a whole house fan wherein the motor and fan can be mounted on a single joist without the motor generating objectionable noise.

Another object is to provide such a fan which may be easily installed by a homeowner.

Another object is to provide such a fan which incorporates smaller pieces than prior fans thus enabling compact shipping and insuring that the installer can readily pass the fan parts through the ceiling opening from below for ease of installation.

Another object is to provide such a fan which is sturdy, yet is inexpensive to produce, and which has a long service life.

In accordance with these objectives, generally stated, a direct drive whole house fan assembly of the present invention is provided for installation over joists in an opening in a ceiling. This whole house fan assembly includes a venturi defining an air path, a fan for forcing air through the air path, a motor for driving the fan, and a skirt depending downwardly from the venturi and accommodating the joists to form a plenum box and to define, at least in part, the above-noted air path. The opening in the ceiling exposes at least one joist spanning the opening. The motor and fan are mounted to this last-said motor joist by a motor bracket. The venturi is mounted to the joist on which the motor is mounted by means of venturi brackets separate from the motor bracket.

The motor bracket comprises a pair of identical L-shaped members which are secured to the joist and stiffening members which are attached to the tops of the L-shaped members. The fan motor is secured to the L-shaped members and elastomeric grommets are placed between the motor and the bracket to dampen vibrations.

The venturi bracket includes a U-shaped member which fits over and is secured to one side of the joist, allowing for any width joist and an upwardly extending plate to which the venturi is secured.

A method of mounting the fan is also disclosed.

FIG. 1 is a perspective view of a whole house fan of the present invention assembled and mounted on the ceiling joists in an attic;

FIG. 2 is an enlarged perspective view of the fan motor as it is mounted on a single joist spanning an opening in the ceiling:

FIG. 3 is an enlarged perspective view illustrating a portion of the fan and a venturi bracket mounted on the motor joist for locating and securing the venturi;

FIG. 4 is cross sectional view taken along line 4--4 of FIG. 2 showing the fan motor mounted on a motor mounting bracket secured to a joist (i.e., the motor joist) with the stiffening brackets, on the motor bracket omitted for clarity;

FIG. 5 is a cross sectional view taken along line 5--5 of FIG. 3 on an enlarged scale showing a venturi bracket secured to a joist;

FIG. 6 is a right side elevational view of the venturi bracket rotated 90.degree. counterclockwise from its position shown in FIG. 5; and

FIGS. 7-9 show the motor mounting bracket L-shaped member shown in FIG. 4.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

Referring to the drawings, reference numeral 1 generally indicates one illustrative embodiment of a whole house fan assembly of the present invention. Whole house fan 1 is mounted on a joist MJ over an opening O in a ceiling C. More specifically, whole house fan 1 includes a direct drive motor 3 having an upwardly extending motor shaft 5 on which a fan blade assembly 7 is mounted. Motor 3 is mounted on joist MJ by a motor mount bracket, as generally indicated at 9.

A venturi assembly 11 surrounds motor 3 and fan blade assembly 7. Venturi assembly 11 includes a venturi 13 and a downwardly extending skirt 15 which accommodates joists J and MJ to define an air path through ceiling opening O to venturi throat 13. Venturi assembly 11 is mounted to joist MJ by venturi brackets 17.

As shown in FIG. 4, motor bracket 9 comprises an identical pair of L-shaped brackets 19a, 19b. Each L-shaped bracket has a flanges 21a, 21b and 23a, 23b. As shown in FIG. 7, each flange 21a, 21b of each bracket 19a, 19b has circular apertures 28b and 37b therein. While, as shown in FIG. 8, flanges 23a, 23b of each bracket have elongate slots 28a, 37a therein. Elongated slots 28a and 37a allow for adjustment of the motor 3 on bracket 9 and for adjustment of bracket 9 on joist MJ.

Downwardly extending flanges 21a, 21b of L-shaped brackets 19a, 19b are secured to opposite sides of joist MJ in the center of opening O by screws 22 or the like. Outwardly extending horizontal flanges 23a, 23b of brackets 19a, 19b have stiffeners 25a, 25b (see FIG. 2) on either side thereof. Stiffeners 25a, 25b extend from one flange 23a across joist MJ to the other flange 23b. Stiffeners 25a, 25b each include a horizontal flange 27 which is secured to flanges 23a, 23b by screws 26 through apertures 28a in the flanges 23a and 23b, and upwardly extending flanges 29 which stiffen motor mount bracket 9. The use of a pair of L-shaped brackets instead of a single U-shaped bracket allows for motor mount bracket 9 to accommodate joists of different widths by means of apertures 28a and 37a in flange 23a.

Motor 3 has a shell or housing 31 with end plates 33a, 33b on opposite sides thereof. Throughbolt 35 extend through housing 31 and protrude beyond bottom end plate 33b. Apertures 37a in flanges 23a and 23b receive elastomeric grommets 39 which receive throughbolt 35 to secure motor 3 to motor mount bracket 9. Elastomeric grommets 39 (see FIG. 4) surrounding throughbolt 35 are interposed between motor 3 and bracket 9 to reduce the effects of motor vibration. More specifically, grommets 39 vibrationally isolate motor 3 from bracket 9 and joist MJ and thus the vibrations, and undue noise, will not be transmitted into the motor joist. Motor 3 is secured to angle brackets 19a, 19b by suitable washers 41 and nuts 38 threaded on throughbolt 35.

As shown in FIGS. 5 and 6, venturi bracket 17 comprises a U-shaped sheet metal channel 41 having side legs 43a, 43b and a top plate 45. A venturi plate 47 extends up from top plate 45 and engages the inside face of venturi 13. Channel 41 is secured to one side of joist MJ by screws 49 driven through leg 43a or 43b into the joist. The unsecured leg is preferably bent inward against the joist MJ, as shown by dotted lines in FIG. 5. Venturi 13 is secured to venturi plate 47 by screws 51 (see FIG. 3).

Venturi skirt 15 (see FIG. 1) is formed of two sets of two identical pieces of corrugated board. The four pieces are held together at corners by means of tape as at 53. Three sets of pre-scored tabs 55 are provided on two opposing sides of skirt 15 to create openings 57 in the skirt to accommodate joists J and MJ, as shown in FIG. 1 The skirt is secured to venturi 13 by means of tape at the junction of the skirt and the fan housing, as at 59.

To install the fan assembly 1, the installer must first cut a hole O in the ceiling C. At least one joist must span the center of opening O. The joists are not cut. The installer then passes the venturi 13 up between the joists, positions it over the joists, centers it with respect to the opening O, and secures it to one side of the center joist MJ with venturi brackets 17. Joist L-shaped brackets 19a, 19b of motor bracket 9 are assembled to stiffeners 25a, 25b by screws 27. Grommets 39 are installed in L-shaped brackets 19a, 19b in flanges 23a, 21b. Washers 41 are placed on motor throughbolt 35. Motor through bolts 35 are then put through grommets 39. Another washer 41 is then placed on motor throughbolt 35 and motor 3 is secured to motor bracket 9 by means of nuts 38. The motor 3 and bracket 9 are centered with respect to venturi 13 on joist MJ and secured in place by screws 22. Fan blade 7 is installed on motor 3. The installer then secures the skirt to venturi 13, making sure it properly accommodates (i.e., surrounds) the joists J and MJ. A shutter assembly 61 (see FIG. 1) is then secured to the ceiling beneath the opening to cover the opening. Shutter assembly 61 has hinged shutters which open only when the fan is operating. Such a shutter assembly is well known in the art.

The components, especially the brackets, of this invention are smaller than the components of prior art whole house fans. A comparison of motor brackets 9 and the elongate, U-shaped brackets of certain other "easy to install" whole house fans, as shown in U.S. Pat. No. 4,385,550, shows that bracket 9 is considerably smaller. The smaller components allow for easier installation of whole house fan 1 from beneath opening O and for more compact packing and shipping of the fan.

The foregoing disclosure set forth for illustrative purposes only. Various changes could be made in the disclosed structure and method without departing from the scope of the invention.