US3156233A

US3156233A - Sealing and sound absorbing means for air handling apparatus

Info

Publication number: US3156233A
Application number: US309219A
Authority: US
Inventors: Alva D O'connell
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1963-09-16
Filing date: 1963-09-16
Publication date: 1964-11-10
Anticipated expiration: 1981-11-10

Description

Nov. 10, 1964 A. D. OCONNELL 3,156,233

SEALING AND souun ABSORBING MEANS FOR AIR HANDLING APPARATUS Filed Sept. 16, 1963 INVENTOR. ALVA D. O'CONNELL H\5 ATTORNEY United States Patent 3,156,233 SEALING AND SUUND ABSORBENG ll IEANS FOR AIR HANDLING APPARATUS Alva D. 0onnell, Tyler, Tex., assignor to General Electric Company, a corporation of New York Filed Sept. 16, 1963, Ser. No. 309,219 6 Claims. (Cl. 126-410) The present invention relates to a sound absorbing medium and bottom seating means for an air handling apparatus, and particularly to an upfiow furnace or air handler that is convertible to either a bottom inlet, a left side inlet or a right side inlet of the return air from a duct system in a residence or building Where the furnace or air handler is installed.

It is well known in the heating field that warm air upflow furnaces have to be adapted at the time of installation to meet any one of three types of return inlet possibilities. Some furnace designs are provided with at least one side opening built into the furnace housing, but

if the installing dealer is faced with the need for a bottom return opening, it requires time and expense to cut a bottom inlet opening. If the furnace is used with a left or right side inlet opening, the bottom should be closed or sealed so that dust and dirt from the floor of the operating area will not be drawn into the inlet plenum chamber of the furnace due to a negative pressure developed by a motor-blower unit therein which is available for circulating the air past the combustion chamber and heat exchanger or the like.

In addition to the need for a convertible furnace design having the facility for obtaining a return air opening in either the bottom Wall or one of the two side walls of the furnace, there is also a need for lowering the operating noise level in the inlet plenum chamber. This need has become more pronounced in recent times because the rapid rise in the popularity of perimeter distribution has had the effect of shortening the return air duct and therefore revealing inlet plenum chamber noises more readily. Heretofore these noises were not noticed during the era of inside supply ducts and return ducts which were longer because return air grilles were located on an outside wall. Return air noises are made even more noticeable where the central return duct has an extremely short attenuating length between the return air grille and the furnace proper.

The principal object of the present invention is to pro vide an air handling apparatus with a facility for obtaining one of several air inlet openings in which a filter medium is installed, while at the same time benefiting from a sound absorbing medium that may be used as a bottom sealing means and/or a noise attenuator in an unused filter rack under certain conditions.

A further object of the present invention is to provide a warm air upflow furnace with a bottom air inlet opening that is sealed during shipment by a sound absorbing medium that is used as a supporting pad in the shipping carton, and Where the absorbing medium is removable so that it may be installed within the furnace housing so as to attenuate the operating noises; or alternately may be left in place in the as-shipped position to provide bottorn sealing, cushioning and attenuation.

The present invention, in accordance with one form thereof, relates to an air handling apparatus for either warming or cooling air where the apparatus has a housing forming a plenum chamber with a bottom air return opening and a top air outlet opening. This air inlet or return opening is adapted to be sealed during shipment by a sheet of soft fiberboard that is mounted beneath the apparatus within the shipping carton. A filter medium is adapted to be positioned within the bottom opening when the apparatus is installed for a bottom inlet return, while the center of the sheet of fiberboard may be cut to the size of an inlet filter and positioned along one inner side wall of the plenum chamber to attenuate the noises therein while leaving a square frame of fiberboard material on which the apparatus rests. Moreover, means are provided for forming an air inlet opening in one of the side walls of the housing so that the filter medium may be transposed to fit within the side inlet opening while the sheet of fiberboard may be left in the as-shipped position to provide sealing, vibration absorption and sound attenuation.

My invention will be better understood from the following description taken in conjunction with the accompanying drawing and its scope will be pointed out in the appending claims.

FIGURE 1 is an elevational view of a warm air upflow furnace embodying the present invention with parts broken away to show the bottom used as a return air opening and a sheet of fiberboard cut into two pieces where one piece is a square frame on which the furnace rests, while the center of the sheet is mounted along one side Wall of the plenum chamber for attenuating the noise level.

FIGURE 2 is an elevational view similar to that of FIGURE 1 showing the right side wall of the furnace housing provided with a side air return opening, while the bottom opening has been sealed by a sheet of fiberboard in the as-shipped condition.

FIGURE 3 is an elevational view on a reduced scale showing the furnace of FIGURES 1 and 2 assembled in a shipping carton with parts of the carton broken away to show an over-sized sheet of fiberboard mounted beneath the bottom wall of the furnace to serve as a cushioning pad and space during shipment.

Turning to a consideration of the drawing and in particular to FIGURE 1 there is shown for illustrative purposes a warm air upflow gas-fired furnace 10 having a housing 11 formed of sheet steel into a box-like configuration having an open bottom wall 12,

opposite side walls

13 and 14, top wall 15, a front wall 16 as is best seen in FIGURE 2, and a plain back wall (not shown) that is comparable to the front wall 16. While this furnace has been shown and described as a gas-fired furnace it will be understood by those skilled in this art that fuel oil or electric resistance heaters could be substituted for the gas fuel without departing from the scope of this invention. Moreover, instead of warming the air the apparatus could be an air handler having a blower with a heat transfer surface or cooling coils for cooling the air Such a furnace housing has supported therein three main components; namely, a motor-blower unit 20 which may be either direct or belt driven, a combustion chamber 21, and a heat exchanger 22. It is considered un necessary to go into the operating principle of a warm air upflow furnace in order to explain the present invention, but it is well to have a little background information before the invention is considered in detail. This furnace is adapted to be connected in a ducted heating systern within a residence or small commercial building, thus it would have an air inlet duct such as duct 23 as well as a heated air outlet opening 24 in the top wall 15 of the furnace housing. This return duct 23 is connected into a plenum chamber 25 in which the motor-blower unit 26 is mounted. The motor is element 26 and it is positioned within the center of a blower wheel 2'7. This blower unit will draw air from the return duct 23 and supply the necessary volume of air across the heat exchanger 22, and the resultant warm air will exit from the outlet air opening 24 in the top wall 15 of the furnace housing. The front wall 16 of the furnace housing is closed by a pair of vertically spaced removable panels 29 and 39 as is best seen in FIGURE 2 to facilitate the inspection and servicing of the furnace structure and con trols at periodic intervals.

Looking again at FIGURE 1, the bottom wall 12 of the furnace housing 11 is provided with a return or cool air inlet opening 32. In the event the furnace is provided with a bottom return duct 23, a filter medium 33 in assembled within the housing to overlie the bottom opening 32 and it is held in place by a suitable filter-holding channel means or racks 34. Similar filter-supporting

racks

35 and 36 are located within the plenum chamber on the inner surfaces of the

opposite side walls

13 and 14. In at least one of these

racks

35 and 36 is supported a sheet of soft fiberboard 37 having been cut to dimensions comparable to those of the filter medium 33 so that they are interchangeable.

FIGURE 2 of the drawing shows a different mode of installation where the return air duct 23 is brought in through the right side wall 14 of the furnace housing. This is accomplished by cutting out a suitable size opening in the imperforate side wall 14 and making the necessary duct connection to the resulting opening. Then the filter medium 33 is transposed into the filter rack 36 and the sheet of fiberboard 37 is used to seal the bottom opening 32 of the furnace. An over-sized sheet of soft fiberboard 37 is shown in FIGURE 2 fastened to the underside of the furnace housing in the as-shipped position. When this sheet is left in this position upon using a side return inlet the soft fiberboard serves as a resilient pad, a bottom sealing means and a sound attenuator during the operation of the blower 20. In FIGURE 1 the fiberboard 37 has been cut into two pieces, a square frame to remain under the furnace and a cut-out sheet taken from the center of the original sheet to form the sheet that slips into one of the filter racks 35 or 36.

FIGURE 3 of the drawing shows the furnace enclosed within a heavy duty cardboard shipping carton 49, where the carton is closed by top and bottom caps 41 and 42 respectively which are held in place on the carton by metal tension bands or straps 43. Suitable cardboard fillers and corner posts (not shown) would be assembled in the carton around the furnace in order to absorb the punishment of shocks that would otherwise be taken by the furnace during rough handling, storage and shipment. The over-sized sheet of fiberboard 37 is fastened to the underside of the furnace It at the factory so as to serve as a cushion means on which the furnace is supported. Suitable fastening screws (not shown) would extend through the fiberboard and into the edge of the bottom opening 32. If the furnace 10 were to be used with a side return air duct, the fiberboard 37 could remain in place beneath the furnace as shown in FIGURE 2. As an alternative for a side return installation, the sheet 37 could be removed from beneath the furnace and cut to form a smaller sheet of the size of the filter 33 so as to fit into the filter rack 34.

Having described above my invention of a convertible air handling apparatus or furnace design having either bottom or side wall return openings along with a sound absorbing medium located within or below the plenum chamber, it will readily be apparent to those skilled in this art that the sound absorbing medium would also be used to advantage during shipment as a cushion means for the furnace within the shipping carton in order to take full advantage of this material. Moreover, the furnace could be provided with factory-installed side openings and these openings could be sealed with sheets of fiberboard and this would, of course, eliminate the need for the installing dealer to cut the side wall to form the necessary openings. It has been found expedient when it is necessary to remove the fiberboard 37 from the underside of the furnace to slip off the lower front panel and tilt the furnace on its back edge of the bottom wall 12 so that the servicemans foot may be used to press out the fiberboard since it is a relatively soft composition such as is sold under the trademark Hornasote by the Homasote Company of Trenton, New Jersey and is used rather widely for interior Wallboards for home building. Other suitable materials would be foam rubber and Styrafoam as long as they had some resilience. A type of unsatisfactory fiberbord material would be Masonite because of its rigidity or hardness which would render it unsatisfactory for sound attenuation.

Modifications of this invention will occur to those skilled in this art, therefore, it is to be understood that this invention is not limited to the particular embodiments disclosed but that it is intended to cover all modifications which are within the true spirit and scope of this invention as claimed.

What i claim as new and desire to secure by Letters Patent of the United States is:

l. A convertible warm air upfiow furnace for heating air circulated therethrough from a building structure comprising a furnace housing, a combustion and heat transfer unit as well as a motor-blower unit disposed in the housing, said housing having a bottom return air opening and a top air outlet opening, a sheet of fiberboard fastened to the underside of the housing to serve as a cushion during shipment, the housing having two opposite side walls which are adapted to be formed with either a left or a right side return opening, and filter racks formed on the inner wall surfaces of the housing over the bottom return opening as well as for the two possible side return openings, and a filter member adapted to be mounted in one of the three filter racks, the fiberboard sheet formed of soft material so as to be easily cut to the same size as the filter member and thereby be interchangeable therewith in any one of the filter racks, whereby, for a bottom return, the fiberboard sheet is adapted to be cut into a square frame to underline the furnace housing and serve as a cushion seal, the central square cut from the sheet being adapted to be placed in one of the two side filter racks for noise attenuation, while the filter would be positioned within the filter racks of the bottom opening, the fiberboard sheet being adapted to seal the bottom opening when one of the side walls of the furnace is formed with a side return opening, while the filter member is adapted to be positioned in the filter rack for said side opening.

2. A convertible warm air upfiow furnace for residential use in a ducted heating system for heating air circulating through the system, said furnace comprising a sheet metal housing containing a plenum chamber supplied with a motor-blower unit, a source of heat energy and a heat exchanger cooperating therewith, said housing having an open bottom wall forming a bottom cool air return opening and a top heated air outlet opening, a sheet of fiberboard fastened to the underside of the housing over the bottom opening to serve as a cushion means during shipment, a filter member adapted to be positioned within the housing over the bottom opening when the furnace is provided with a bottom return, the central portion of the fiberboard sheet being removable to uncover the bottom opening and being adapted to be positioned along one side Wall of the plenum chamber to reduce the noise levels during operation of the blower, and means to form a side return opening in one side wall of the plenum chamber while the filter member is adapted to be mounted in the housing over said side opening, and the original fiberboard sheet is adapted to seal over the bottom opening of the housing.

3. A convertible warm air furnace for residential use comprising a housing forming a plenum chamber, a combustion chamber and a heat transfer unit, a motor-blower unit provided in the plenum chamber, the housing having a top air outlet opening and an open bottom wall adapted to form a bottom return air opening, a filter member adapted to be positioned within the housing over the bottom opening when the furnace is provided with a bottom return, a sheet of soft fiberboard positioned along one side wall of the plenum chamber to reduce the noise levels during the operation of the furnace, and means to establish a side return opening in one side wall of the housing to communicate with the plenum chamber, the filter member being adapted to be mounted in said side return opening, and the fiberboard sheet being adapted to seal the bottom opening in the housing as well as to attenuate the noises and vibrations during the blower operation.

4. A convertible air handling apparatus having a housing forming a plenum charnber with a motor-blower unit located therein, the housing including an open bottom wall forming a bottom air inlet opening, an opening in the top wall forming an air outlet opening, a filter medium adapted to be positioned within the bottom opening when the apparatus is provided with a bottom inlet, at least one sheet of soft fiberboard positioned along a side wall of the plenum chamber to reduce the noise level therein, the said sheet of fiberboard also being adapted to be fastened to the underside of theapparatus when the apparatus is sealed in a shipping carton to cushion the apparatus during shipment, the fiberboard sheet being adapted to remain in the as-shipped position When the air handler is installed and running with a side return air connection so as to provide a sealing cushioning and noise attenutating means.

5. A convertible air handling apparatus having a metal housing enclosing a plenum chamber that includes a motor-blower unit, the housing having an open bottom wall that forms a bottom air inlet opening, an opening in the top wall of the housing forming an air outlet opening, a filter medium adapted to be positioned Within the bottom opening when the apparatus is provided with a bottom inlet, at least one sheet of fiberboard positioned along a side wall of the plenum chamber to attentuate the noises therein, means for forming an air inlet opening in one of the side walls of the housing, the said filter medium being adapted to be transposed to fit within the side inlet opening, while the said sheet of fiberboard is adapted to be located in the bottom opening to seal the bottom opening of the housing and continue to attenuate the noise level.

6. A convertible air handling apparatus for use with a duct system for treating air circulating through the system, said apparatus comprising a sheet metal housing containing a plenum chamber supplied with a motorblower unit, said housing having an open bottom wall forming a bottom air return opening and a top air outlet opening, a sheet of resilient material fastened to the underside of the housing over the bottom opening to serve as a cushion means during shipment, a filter member adapted to be positioned within the housing over the bottom opening when the furnace is provided with a bottom return, the central portion of the resilient sheet being removable to uncover the bottom opening and being adapted to be positioned along one side wall of the plenum chamber to reduce the noise levels during operation of the blower, and means to form a side return opening in at least one side wall of the plenum chamber, a filter medium adapted to be positioned over the air return opening, while the original resilient sheet is adapted to be used as a cushion pad under the housing as well as an air seal and a means to attenuate the noise level.

References Cited in the file of this patent UNITED STATES PATENTS 2,118,328 Roland May 24, 1938 FOREIGN PATENTS 961,758 Germany Apr. 11, 1957

Claims

5. A CONVERTIBLE AIR HANDLING APPARATUS HAVING A METAL HOUSING ENCLOSING A PLENUM CHAMBER THAT INCLUDES A MOTOR-BLOWER UNIT, THE HOUSING HAVING AN OPEN BOTTOM WALL THAT FORMS A BOTTOM AIR INLET OPENING, AN OPENING IN THE TOP WALL OF THE HOUSING FORMING AN AIR OUTLET OPENING, A FILTER MEDIUM ADAPTED TO BE POSITIONED WITHIN THE BOTTOM OPENING WHEN THE APPARATUS IS PROVIDED WITH A BOTTOM INLET, AT LEAST ONE SHEET OF FIBERBOARD POSITIONED ALONG A SIDE WALL OF THE PLENUM CHAMBER TO ATTENTUATE