US3407867A - Frame construction for air treating assembly - Google Patents

Description

Oct. 29, 1968 J, NO Rls ETAL 3,407,867

FRAME CONSTRUCTION FOR AIR TREATING ASSEMBLY Original Filed Dec. 28, 1964 5 Sheets-Sheet 1 J. w.' NORRIS ET L 3,407,867

FRAME CONSTRUCTION FOR AIR TREATING ASSEMBLY Oct. 29, 1968 5 Sheets-Sheet 2 Original Filed Dec. 28, 1964 KSKKK 5 Sheets-Sheet 3 v I J. W. NORRIS ET AL FRAME CONSTRUCTION FOR AIR TREATING ASSEMBLY Oct. 29, 1968 Original Filed Dec. 28, 1964 Oct. 29, 1968 .1. w. NORRIS ET AL 3, 0

FRAME cons'raucwxon FOR AIR TREATING ASSEMBLY Original Filed Dec. 28, 1964 5 Sheets-Sheet 4 Oct. 29, 1968 J. w. NORRIS ET 3,407,357

FRAME CONSTRUCTION FOR AIR TREATING ASSEMBLY Original Filed Dec. 28, 1964 5 Sheets-Sheet 5 ITu/niara:

John ZlAMo'rrq's j Wayne]? szeflrd'zrng United States Patent- 3,407,867 FRAME CONSTRUCTION FOR AIR TREATING ASSEMBLY John W. Norris, Marshalltown, and Wayne Sieverding,

Union Grove Lake, Iowa, assignors t0 Lennox Industries Inc., a corporation of Iowa Original application Dec. 28, 1964, Ser. No. 421,427, now Patent No. 3,324,782, dated June 13, 1967. Divided and this application Apr. 10, 1967, Ser. No. 649,380

1 Claim. (Cl. 16567) ABSTRACT OF THE DISCLOSURE A unitary base frame assembly for mounting an air treating assembly on a roof. The frame assembly includes peripheralframe members and spaced brace members. A pair of air openings are defined between the frame and brace members. A first seal is provided to seal between the frame assembly and air treating assembly and a second seal is provided to seal between the frame assembly and the roof.

This is a division of application Ser. No. 421,427 filed Dec. 28, 1964 and now Patent No. 3,324,782.

This invention relates generally to air treating apparatus for heating, cooling and ventilating and, more particularly, to a novel central air treating unit capable of producing accurate and instantaneous temperature control in many zones.

, The conditioning of the atmosphere within schoolrooms and similar enclosures which present complex and highly variable requirements for heating, cooling and ventilating represents a diflicult problem for which presently known air treating units fail to provide an adequate solution. The particular difficulties encountered in schoolroom heating, cooling and ventilating will be discussed in detail so as to provide full background for understanding the typical requirements which are efficiently fulfilled by the present invention. It will be understood, however, that the present invention is not limited in any way solely to schoolroom or school construction, but is fully adapted for use in other buildings where it is desired to produce accurate and instantaneous temperature control in many different zones from one central system as, for example, medical centers, motels and hotels, restaurants with private dining rooms.

Architects, contractors and air treatment engineers recognize that classrooms frequently require cooling even when the outdoor weather is extremely cold. The cooling of such rooms frequently presents a far more challenging problem than does their heating. Body heat from the persons present in the classroom, heat from the lighting fixtures andradiant heat from the sun as it strikes the walls, windows and roof, frequently produce heat gains within the room which exceed the normal transmission or heat losses from the room to the cold outdoor weather. The number of occupants in each classroom, their physical size, their bodily activities and their lighting requirements vary greatly from room to room within a schoolhouse and within each room during the course of the day. For example, .small children in the lower-class grades transmit relatively lower totalrquantities of heat to the room atmosphere than do the older and larger children of the upperclass grades. There are also variations from class to class in the amount of lighting required dependent upon the reading activities of the various grade levels. Such factors as recess and lengths of class periods also result in a variety of different and changing conditions of heat load within various classrooms. Substantial heat is often needed in order to effect initial warming of a classroom during the early morning hours prior to the arrival of the students at the begining of the school day. After the 3,407,867 Patented Oct. 29, 1968 'ice arrival of the students, the body heat load within the room is often supplemented by direct sunlight striking against the building as the daylight hours progress. In some instances, one or several of the large number of classrooms may be subjected to use during the evening hours for adult community activities and the like requiring the maintenance of proper temperature conditions within only one or a few of a large number of classrooms within a given schoolhouse. It is apparent, therefore, that conditions within any given classroom may change in a matter of minutes from no heat being required to heat being required, or to cooling being required, and such varying conditions within one room may be entirely different from the varying conditions and requirements of an immediately adjacent room. The maintenance of comfortable temperatures within every room is a matter of great importance and it is necessary to effect the control distribution of conditioned air regardless of the outdoor weather conditions.

Outdoor air provides an economical source of relatively cool air for effecting room cooling during all weather conditions in which the outside air temperature is lower than a comfortable air temperature desired inside the room. The proper heating, cooling and ventilating system for a schoolhouse classroom is one which makes maximum use of outside air for freshening and for cooling and which can very quickly bring in enough outdoor air when needed to offset the internal heat gains within the room and keep the room temperatures from overrunning a thermostat or other control setting. Such proper distribution system, therefore, must be one that is capable of handling either heated air or cool air in a manner that will provide even and uniform distribution of air velocity through each room or area to be treated.

The complex and highly variable requirements for heat ing, cooling and ventilating of classrooms is met by the air treating system of the present invention which is capable of shifting capacity to the areas of greatest in stantaneous demand so as to reduce the total installed capacity requirements.

A primary object of the present invention is to provide an integrated central station air treating unit for a school capable of providing for air heating, cooling and ventilating in accordance with the requirements of one or more of a plurality of zones within such school.

A further object of this invention is to provide a novel base assembly for facilitating the mounting of a factory assembled integrated air conditioning unit on the roof of a building.

Further objects and advantages of this invention will become apparent as the following description proceeds, and the features of novelty which characterize this invention will be pointed out with particularity in the claim annexed to and forming part of this specification.

A preferred embodiment to the invention is shown in the accompanying drawing, in which:

FIGURE 1 is a perspective view of the central station air treating assembly of the present invention;

FIGURE 2 is a vertical cross-sectional view of the air treating assembly constructed in accordance with the principles and features of the present invention;

FIGURE 3 is a horizontal cross-sectional view of the air treating assembly;

FIGURE 4 is an enlarged plan view of the intake and exhaust air unit incorporated in the air treating assembly of the present invention;

FIGURE 5 is an enlarged perspective view of the mixing damper unit incorporated in the air treating assembly of the present invention;

FIGURE 6 is a perspective view of the baffle employed in the mixing damper assembly of the present invention;

l 3 FIGURE 7 is aperspective view of the base frame for supporting the air treating assembly of the present invention on a roof top in one application of the present invention; I

FIGURE 8 is a detail cross-sectional view of a side of the base; and

FIGURE 9 is a detail view on an enlarged scale of the installation of the air treating assembly of the present invention on a roof top.

Referring now to FIGURES 1, 2 and 3, there is illustrated the air treating assembly of the present invention. The air treating assembly 10 is comprised of the following major components: a condensing unit 12 which may be close coupled, as shown, or which may be located remote from the air treating assembly 10; an exhaust and air intake assembly 14; a filter and blower assembly 16; a heating and cooling unit assembly comprising a heater 18, which may be a direct fire heater for any gas or resistance coils for electric heat, and a direct expansion cooling coil 19; and a mixing damper assembly 20.

The condensing unit 12 may comprise a condensing coil 22, one or more refrigerant Compressors 23 and the conventional accessory controls for connecting the condensing coil and compressor in refrigerant circuit. It is preferred that the condensing coil be air cooled and appropriate fans 24 are provided for passing air over the coil to condense the hot vaporous refrigerant moving through the tubes withinthe condensing coil 22.

The exhaust and air intake assembly 14 comprises a housing 26 provided in one end wall with exhaust air dampers 28 and in another end wall with outdoor air intake grille 30. An opening 32 is provided in the bottom of the housing 26 for communicating with the room or area to be conditioned. Thus return air enters the air treating unit 10 through opening 32. Upright walls 34 and 35 are provided in the housing 26 at either side of the inlet opening 32. The wall member 34 is imperforate so as to separate the incoming outdoor air from the air being returned to the air treating assembly from the area or areas to be conditioned. The upright wall 35 is provided with louvers or dampers 36 so as to permit regulated passage of the return air from the area or areas being treated to the atmosphere through the exhaust air dampers 28. Dampers 37 are provided in a side wall of the housing 26 to communicate the inlet air with the blower assembly 16. Also provided in the side wall of housing 26 are dampers 38. The dampers 38, which are in communication with the outdoor air inlet dampers 30, permit the passage of outdoor air to the blower and filter unit 16.

Dampers 28 are pivoted at the top so as to be normally closed. They function as light back-draft dampers to prevent entry of outdoor air into the exhaust and air intake unit 14 when the exhaust fan 40 is inoperative.

The dampers 28 are opened only by the pressure of exhaust fan 40, which is provided to assure the use of one-hundred-percent outside air when needed. Fan 40 is operatively driven by motor 42. The motor and fan are supported on bracket 43 within housing 26.

Affixed to bracket 43 adjacent motor 40 is a modulating damper motor 44 for simultaneously actuating dampers 36, 37 and 38 to properly regulate the quantities of outside air, return air, and exhaust air passing through housing 26. The dampers 36, 37 and 38 are interconnected with moduluating damper motor 44 by means of linkage 45 (FIGURE 4).

The dampers 36, 37 and 38 are sized so that onehundred percent of the air handled by the unit can go through any one of the three damper sets. This allows one-hundred-percent recirculation, or one-hundred-percent outside air with assured exhaust to make it possible, or any mixture thereof.

The modulating motor 44 is commanded by a combination of mixed air temperature downstreams from the blowers and outside air temperature.

Regulated quantities of outside air and/or return air are, drawn from housing 26 through dampers .38 and 37, respectively, by blowers 46. T he blowers 46 are driven by motor 48 operatively connected to the blower by a belt and pulley drive arrangement 49. Preferably, all the moving parts of the blower assemblynamely, the blower wheels, shafting, bearings, drives and motor' are mounted in a rigid frame. The entire subassembly of moving parts is resiliently suspended in the housing or cabinet '16.

The blowers 46 draw air through filter 50. Filter 50, which may be made from a highly eflicient urethane foam filter material, is detachably connected in blower and filter unit 16. The filter can be vacuum cleaned in place, if desider, and a 115-volt convenience outlet is provided in the unit 16 for convenient connection of a tank-type domestic vacuum cleaner.

The discharge of air from blowers 46 is suitably directed by baffles 52, which are interconnected to oneanother by linkage 53 and are actuated by damper motor 54. Air may be directed primarily to the heater 18 or to the cooler 19 for suitable conditioning.

The heater 18 may be a gas-fired furnace or an electric resistance-type unit.

The cooling coil or evaporator 19 is operatively connected in a refrigerant circuit with the condenser 22 in the condensing unit 12. As will be apparent to those skilled in the art, the cooling components need not be incorporated into the air treating unit 10 initially, but can easily be added at a later time by virtue of the design of the assembly 10.

The warm air and the cool air discharged from the heater 18 and evaporator 19, respectively, flows into the mixing damper assembly 20 for suitable blending of the air prior to discharge into the conduits leading to the rooms to be treated. The inlet openings to the mixing damper assembly are disposed in side-by-side relationship in one side of the housing defining assembly 20.

The warm air from heater 18 is guided below stationary baffle 60 and uniformly spread across the width of the compartment defined below baflie 60 as indicated by the dotted arrow lines in FIGURE 3. The cool air from coil 19 is guided above baffle 60 and uniformly spread across the width of the compartment defined above baffle 60 as indicated by the solid arrow lines in FIGURE 3.

Provided in the entrance to each of the compartments 64-73 defined at the rear of unit 20 by upright divider plate 64a-72a are damper means for regulating the quantity of air entering each compartment. As seen in FIGURE 5, each damper means 75 comprises an upper damper 76 for regulating the cool air entering a mixing compartment and a lower damper 77 for regulating the warm air entering the mixing compartment. The dampers 76 and 77 are mounted upon a common shaft 78. Rotation of the shaft will move one damper toward open position and the other damper toward closed position. Modulating damper motor 7 5' is operatively connected to the shafts 78 for actuating the dampers in response to a predetermined condition.

The opening in the bottom of each compartment 64-73 is connected with a conduit for conducting the treated air to a room. If desired, the openings may be formed in the rear wall of unit 20 rather than in the bottom. There may be as many compartments as zones to be treated. It is noted that ten compartments are shown in FIGURE 3 and eight compartments are shown in FIGURE 5.

Referring to FIGURE 6, there is better seen the construction of bafile 60. The bafile includes a plate 79 having a sharply upwardly inclined portion 80 having a flange 81 at the front thereof generally in alignment with the heater 18 and a slightly upwardly inclined portion 82 having a flange 83 at the front thereof generally in alignment with the coil 19. The inner edges of wall portions 80 and 82 are connected by a vertical divider wall 84.

The flow directing baflle 60 guides the air discharged from the heater 18 and coil 19 into the mixing damper unit 20 in flow paths that are separated from one another. The segregated air is directed uniformly into the compartments 64-73 for proper mixing and blending within each compartment.

Control of the air temperature in the air treating unit is obtained through control elements, such as ductstats located downstream from the heater 18 and the cooling coil 19. The ductstats may use long capillary tubes to sense an average air temperature.

'On the heating side, the ductstat is compensated in accordance with outside air temperature in a predetermined manner, as for example, on a one-to-one basis. Assuming a one-to-one basis, as outside air temperature drops one degree, the ductstat allows one degree warmer air to be maintained on the hot side of the system. The elfect of this is to modulate the hot side temperature that is continuously available to the mixing dampers.

On the cooling side, the ductstat is normally set to maintain a predetermined temperature below normal room temperature on the cold side of the system. For example, the ductstat may be set to maintain about 55 F. whenever outdoor temperature is 55 F. or above. As the outdoor temperature drops below 55 F., the compressors 23 are shut off because outdoor air temperature now has adequate capacity to do all of the cooling required.

Inlet air to the blowers 46 is normally a mixture of outside air and return air when the air treating apparatus is in use and the schoolhouse is occupied. A hydraulic bulb which senses mixed air temperature from the downstream side of the blowers modulates damper motor 44 to move the dampers 36, 37 and 38 to positions to maintain a predetermined mixed air temperature. A temperature of about 60 R, has been found satisfactory for efficient operation of the system. This provides proper air freshening and ventilation and adequate cooling by means of the use of outside air (rather than the cooling coil) without being a burden to heating for those zones or areas requiring heating. At temperatures above the selected temperature condition, the dampers will be open to one-hundred-percent outside air until attainment of a higher predetermined temperature, about 67 F., at which point the dampers are returned to the minimum position for required ventilation.

At outside temperatures below 60 F., the dampers 36, 37 and 38 will modulate to a position of outside and return air that provides a mixed air temperature of 60 F.

Control of the temperature in a room or zone is obtained by a room thermostat which commands the threeposition damper motor 75' which actuates the mixing damper or dampers feeding to that zone. It will be understood that there may be one damper motor for each upper and lower damper or that one damper motor may control a plurality of upper and lower dampers.

Considering FIGURES 7, 8 and 9, there is shown a air treating system in place for use on the roof of a school or like building. The frame is comprised of heavy metal extruded peripheral members 86a and cross members 86b, with panel members 86c closing the spaces between adjacent frame members. Aluminum may be used to form the members 86a and 86b. Insulation 87 is bonded to the inside of the frame members making up all six sides of the base (top, bottom, and four sides). Such insulation may be a polyurethane foam, which adds structural rigidity to the frame.

The frame 84 is adapted to be positioned directly on a roof top or on an auxiliary mounting frame such that opening 88 therein communicates with a return air opening in the roof and opening 89 communicates with an opening in the roof communicating with the zones in the building to be conditioned. Frame 84 is sealingly engaged with the bottom of device 10 and has sufiicient strength and rigidity to support the air treating apparatus 10 at any four points under perimeter frame.

The frame or base 84 is supported in a typical installation (FIGURE 9) on an air seal 90 which rests on an annual support wall defined by roof curbing 91, rigid insulation 92, and counter flashing 93 provided about the periphery of the frame 84. The air seal which may be formed from vinyl sponge, lies beneath the periphery of frame 84 and prevents entry of air between the frame 84 and the adjacent portions of the roof. The seal 90 also accommodates minor variations in flatness between the frame and the roof and thus functions as a water seal. Further, the resilient seal 90 forms a vibration elimination seal for isolating any high frequency vibration that has not been dampened by the mounting for the blowers 46.

The construction shown assures an accurate fit of the air treating apparatus to the roof opening. Further, the annular support wall cooperates with the roof and frame 84 to define a retrun air collection chamber. Use of frame 84 will allow placement of the air treating apparatus 10'on the annular support wall at any period before or after the roofing or insulation is in place. This frame also permits elimination of roofing underneath the apparatus 10 and thus provides easy access to the bottom of the apparatus 10 for the application of wiring conduit for both the power and control wiring. Thus, the unit 10 will not have to be moved or removed in the event that any of the built up roofing must be repaired or replaced.

The air treating system of the present invention is ideally suited for use in meeting the variable and complex heating and cooling requirements in multizone buildings, as for example, schoolhouses, medical centers, and motels. The complete heavily-insulated outdoor package is assembled, wire-d, and piped at the factory, thus requiring minimum installation costs on the job site. Though the air treating system may be conveniently mounted on a roof top, it can easily be installed on a slab adjacent to the building or even installed in an equipment room, if required by the building design.

Integrated within the air treating assembly are air dampers that control return air, outside air, and exhaust air, all the dampers being interconnected and actuated by an electric modulating damper motor. A powered exhaust fan is provided to assure the use of one-hundredpercent outside air when needed. The dampers can be adjusted to continuously introduce the amount of outside air required for proper freshening and odor removal during all periods of occupancy. During nonoccupied periods, onehundred-percent recirculated air may be used for economy.

A mixing damper assembly is provided in the air treating unit for supplying a plurality of separate zones with desired conditioned air. The mixing damper assembly is capable of shifting capacity to areas of greatest instantaneous demand, thereby reducing the total installed capacity. For certain applications, for example, 'when the system is installed for dual duct distribution the mixing damper assembly is omitted and the discharge from the heater 18 and the direct expansion coil 19 communicates with a warm air duct and a cool air duct, respectively, for transmission to a mixing box adjacent to the area to be treated. Thus, it is seen that the air treating system of the present invention provides for great design flexibility.

While there has been shown an described a particular embodiment of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention and, therefore, it is intended in the appended claim to cover all such changes and modifications as fall within the true spirit and scope of the invention.

We claim:

11. A base frame assembly for facilitating the mounting of an integrated air treating assembly on the roof of a buildin said air treating assembly including an exhaust and air intake unit, a blower and filter unit, air heating means, air cooling means, and a unit receiving the heated air and the cooled air and conducting same to the interior of the building, said roof having a return air opening adapted to communicate with said exhaust and air intake unit and a treated air opening adapted to communicate With said conducting 'and receiving unit, said base frame assembly comprising peripheral frame members defining a generally rectangular unit and spaced transverse frame members for bracing said peripheral frame members, panel members closing the spaces between said frarne members, said frame members defining a first opening complementary to said return air opening in said roof and a second opening complementary to said treated air opening in said roof, said frame members defining said openings being supported in sealing engagement With said roof by air seal means including a resilient seal member to prevent the ingress of outside air into said exhaust and air intake unit and to prevent the bypass of air discharged from said receiving and conducting unit to anarea being treated, and means sealingly engaging said base frame assembly to said ,air treating UNITED STATES PATENTS 2,282,373 5/1942 Minkler et al. 165-48 XR 2,779,572 1/1957 Holman 16548 2,886,955 5/1959 Bauman 165-48 XR 3,252,508 5/1966 Goettl 16548 3,254,704 6/1966 Beisel et a1. 16567 FOREIGN PATENTS 718,592 11/1954 Great Britain.

ROBERT A. OLEARY, Primary Examiner.

M. A. ANTONAKAS, Assistant Examiner.

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