Patent Application
20230028466
The present invention relates to a roof mounted ventilation assembly and, more particularly, to a roof mounted ventilation assembly that integrates supply and relief fans.
Most industrial ventilation consists of only relief fans which makes the ventilated space negatively pressurized; negatively pressured spaces bring in dirty air and can draw in air from any location (including flue vents).
Ventilation systems with separate supply and relief fans have their own disadvantages: from being oversized, less efficient and having a ratio of supply to relief air ratio that can be difficult to maintain. Separate supply and relief fans can also be much less effective depending on where they are required to be located relative to each other. Separate supply and relief fans are also more expensive to install. Separate supply and relief fans are typically over designed when operated in conjunction, and so separate supply and relief fan ventilation systems are typically not balanced properly and are never checked for air balance when started up. Separate supply and relief fans are not typically installed near each other. Thus, the advantageous effectiveness of moving air in low and out high (at the same location) is then typically lost on these ‘Frankenstein’ ventilation systems. Furthermore, separate supply and relief fans are more expensive to install with separate roof curbs, roof openings, structural supports, power feeds, motors, controllers, etc.
As can be seen, there is a need for a roof mounted ventilation assembly that integrates supply and relief airflow in one assembly. The assembly of the present invention assembly solves the following problems: sourcing and installing separate larger, inefficient supply and relief fans with separate control and air distribution components for industrial ventilation applications; replacing relief-only assemblies which depressurizes the space, draws dirty ambient air in from all openings (including such things as flue vents) and also leaves stagnant areas with no air movement; and recirculating contaminants from other roof equipment discharges and/or the swirl effect (eddies) of roof plumes from prevailing winds.
In one aspect of the present invention, a roof mounted ventilation system for a structure includes the following: an integrated supply and relief fan assembly mounted to an upper portion of the structure; an air inlet disposed above and relative to the integrated supply and relief fan assembly; a supply discharge plenum fluidly coupled to the air inlet by way of a supply conduit, wherein the supply discharge plenum is disposed in an interior space of the structure; and the integrated supply and relief fan assembly comprising a supply axial fan portion and a relief centrifugal fan portion, wherein the supply axial fan portion is fluidly coupled to the supply conduit, wherein the supply fan comprising a plurality of axial fan blades, and wherein the relief centrifugal fan portion fluidly couples the interior space with an external environment, whereby the supply axial fan portion draws in a supply air flow from the air inlet.
In another aspect of the present invention, the roof mounted ventilation system further includes wherein a direction of a relief air flow urged by the relief centrifugal fan portion to the external environment is transverse relative to a direction of the supply air flow, wherein the relief centrifugal fan portion comprises backward inclined centrifugal blades, wherein the relief centrifugal fan portion comprises backward incline or forward curved centrifugal blades, further including a drive shaft operatively associated with the integrated supply fan and the relief fan assembly to drive both the supply axial fan portion and the relief centrifugal fan portion, wherein the drive shaft selectively pressurizes the interior space through a ratio of the supply air flow to a relief air flow.
In yet another aspect of the present invention, an integrated supply and relief fan assembly for a roof mounted ventilation system for a structure includes the following: a central portion circumferentially defined by a plurality of centrifugal blades that extend between top and bottom plates; each said plate having a central opening; an axial supply fan disposed within the central opening of the top plate; a supply duct extending through the central portion, fluidly coupling the central openings; and the plurality of centrifugal blades fluidly communicates with a remainder portion of the central portion outside the supply duct.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description, and claims.
The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
Broadly, an embodiment of the present invention provides a roof mounted ventilation assembly having an integrated supply and relief fan assembly. The assembly is drum shaped with a central portion circumferentially defined by centrifugal blades that extend between top and bottom plates. Both top and bottom plates have a central opening, respectively, and axial supply fan blades are disposed within the central opening of the top plate. A supply duct extends through the central portion, fluidly coupling the central openings. The supply duct fluidly communicates, by way of the axial supply fan blades a roof-mounted air intake to a supply discharge plenum operatively associated with an interior space. An inlet collar is fluidly coupled to the remainder of the central portion not closed off by the supply duct. The inlet collar receives relief air from the interior space that the centrifugal blades then urge out exhaust ducts to the external environment in a direction transverse relative to air axially urged by the supply fan blades.
Referring to
The present invention pressurizes an interior space of the structure with a positive supply to relief air volume ratio. The filtered inlet option allows for the clean fresh air to the interior space of the structure for worker health and comfort. Pressurizing the interior space with multiple units eliminates stagnant zones.
The RMIV system 10 includes an inlet hood 20 with optional filters substantially above the roof level defined by the roof deck 30. In certain embodiments, the inlet hood 20 may be ten or more feet above the roof level and may be stabilized with guide wires. A round inlet duct 60 fluidly couples the inlet hood 20 with a top opening of the integrated supply and relief fan assembly 40/230 at or just above roof level. The inlet duct 60 is vertically movable relative to the roof deck 30 so that the filtered air inlet hood 20 can intake air at whatever level is needed to avoid re-circulation of other roof discharge contaminants. The bottom of the inlet duct 60 may connect to a flange 239 disposed along the top opening of the integrated supply and relief fan assembly 230.
A round supply duct 62 depends on a bottom opening of the integrated supply and relief fan assembly 230 to fluidly couple to a supply discharge plenum 50 disposed within the interior space of the structure. The supply duct 62 is vertically movable as well as rotatably movable so as to establish a desired elevation of the supply discharge plenum 50. The supply discharge plenum 50 may have a louvered register that discharges at whatever level is needed and in whatever direction is needed allowing for maximized worker comfort.
The filtered intake assembly provides for a pressurized, clean, healthy and comfortable workspace. Combining supply air and relief air through one assembly 230 and so in one location and at the proper elevations allows for better efficiency, less total air flow and always positive ratio of supply to relief air. The combined assembly 230 is less expensive to install than separate built up supply and relief fans.
The present invention includes the following elements:
Air Inlet Hood 20: This is an air inlet adapted to draw in air with an inverted trapezoid prism shaped hood with a bird screen and optional filter 22 with low drag design reducing fan brake horsepower. The basic model includes a wire mesh screen with options for multiple MERV level filters as the customer desires. The air inlet hood 20 may be fluidly connected to the inlet duct 60 by way of a radius inlet cone 220.
Drive Unit 33: The drive unit 33 may include a single motor and drive assembly powering the drive shaft(s) with belts and pulleys or direct drive for the integrated supply and relief fan assembly 230. This may include an optional variable frequency drive motor and a control module. The control module may be a HONEYWELL SPYDER™ series (or equal) with control options to energize the assembly based on external inputs such as room temperature, humidity, or room pressure.
The integrated supply and relief fan assembly 230: The integrated supply and relief fan assembly 230 directly connects to the drive unit 33 and can come with an optional clutch to disengage the blower wheel portion 231 of the integrated supply and relief fan assembly 230 from the drive shaft while the supply fan remains energized. The assembly 230 is drum shaped with a central portion 232 circumferentially defined by centrifugal blades 233 that extend between top and bottom plates 234 and 235, respectively. Both top and bottom plates have a central opening 236, respectively, and axial supply fan blades are disposed within/around the central opening of the top plate. A supply duct 62 extends through the central portion 232, fluidly coupling the central openings 236. The supply duct 60/62 fluidly communicates a roof-mounted air intake 20 to a supply discharge plenum 50 operatively associated with an interior space. An inlet collar 145 may be part of the assembly that fluidly couples the remainder of the central portion not closed off by the supply duct to the interior space, wherein relief air in this remainder of the central portion is urged by the centrifugal blades through the exhaust ducts to the external environment in a direction transverse relative to axial supply air.
A relief assembly 40 for the integrated supply and relief fan assembly 230 may include and be fluidly coupled to a conical inlet collar/interior housing 145 and lateral relief louvers. Hot room air at the roof level may be mechanically drawn up into the blower wheel portion 231 and pushed out through relief louvers. With optional motorized actuators, shut off dampers 160 of the relief blower assembly 40 could be separately manipulated to change the ratio of supply to exhaust air as desired. Thus, the interior space could be positive, neutral, or slightly negative. Code shut off dampers 160 for both supply and the relief may be provided, including RUSKIN CD™ series (or equal) sealed shut off dampers.
The supply discharge plenum 50 includes a round conical inlet with a round conical bottom pan. Air diffusion may be provided through the supply discharge plenum 50 via a supply diffuser 150 in a circular pattern (via circumference blades) or rectangular pattern with four quadrants (with registers on given sides). Horizontal diffusion may be from adjustable vertical blades 152 around the circumference. Vertical diffusion may be from adjustable horizontal pitched rings 154. The low drag design reduces fan break horsepower.
The inlet hood and the supply discharge plenum may be connected by the installing contractor in the field with round spiral type duct MCGILL™ (or equal).
The drive unit 33 may include a motor-powered fan blade drive assembly that draws air in through the conical air inlet hood 20. The fan blade drive assembly may include a drive assembly belt. The drive unit 33 may be a belt drive unit, a direct drive unit, and may include optional variable frequency drive motor. The drive unit 33 connects to conical air inlet hood 20 with field installed round duct 60, and the drive unit 33 may directly connect to the relief assembly 40 by way of a shaft. The drive unit 33 drives the integrated supply and relief fan assembly 230. The relief assembly 40 connects to the inlet hood 20 with a field installed round duct 60. Field installed code shut off dampers 160 may be in place to shut when the unit is de-energized per International Mechanical Code Requirements.
The RMIV system 10 may be mostly welded steel and aluminum construction. There are screws, filter clips, nuts and bolts for some components. The main components may be factory built. The RMIV system 10 may then be constructed in the field as noted below: Field installation is very similar to most existing packaged rooftop fan assemblies. In that regard, the RMIV system 10 may be installed in the field (at the industrial facility) mostly by a qualified mechanical contractor. Installation may also include crane, electrical, controls, steel and roofing contractors. A curb 120 may be installed over the appropriate size roof opening. The relief shut off dampers 160 may be set on a tray inside the roof curb 120. (Depending on the type of existing roof deck 30, the roof opening and roof structure 30 may have to be re-enforced to accept the new unit.) The relief assembly 40 may then be placed on the roof deck 30 The drive unit 33 may be then connected to the relief assembly 40. The air inlet hood 20 may then be set at the desired elevation with field supplied round spiral duct. (Depending on local code and/or the desired height, guide wires may need to be connected to stabilize the unit.) Finally, inside the space 80, the supply discharge plenum 50 may be set at the desired elevation (and/or rotation) with field supplied spiral duct.
The combination supply and relief fan assembly(s) are placed as needed in industrial facilities (and/or warehouses) to improve comfort and air quality for the cooling season. The one or more RMIV systems 10 replaces existing exhaust fans meant for cooling season comfort ventilation. The one or more RMIV systems 10 provide clean filtered air to the structure's interior space 80. The positive supply to relief air volume ratio remains constant at all speeds keeping the space pressurized and thereby keeping contaminants out. Constant positive space pressure keeps such items as flue vents pushing out and not recirculating back into the space.
The field supplied round spiral duct may be custom fit to place the inlet hood and supply discharge plenum as needed at any given location in an industrial facility. Also, the inlet hood 20 and the supply discharge plenum 50 can be moved up and down (relatively easily) while the base unit remains connected if field conditions change. The variable speed drive unit 33 allows the supply to relief air volume to adjust up and down in the same proportion keeping the space positive.
The present invention may further include an assembly controller that has options to energize the assembly based on external inputs such as room temperature, humidity or room pressure. With optional motorized actuators, the shut off dampers 160 could be separately manipulated to change the ratio of supply to exhaust air as desired. The space could be positive, neutral, or slightly negative.
The present invention may come with a built-in inlet bird screen. However, inlet filters and/or the filter type (i.e., the filter MERV rating) are optional. The motor type (i.e., open drip proof, totally enclosed, starter or VFD drive) is optional. The controls may be either simple on/off or variable speed with a user interface on the interior of the building or there may be an option for BacNET control via a building automation system. With optional motorized actuators, the shut off dampers 160 could be separately manipulated to change the ratio of supply to exhaust air as desired. The space could be positive, neutral, or slightly negative. The code shut off damper type at the roof level may be optional based on local code. The discharge registers type may also be optional.
The concept could be used for other process or modular room applications where the total air volume may be required to change but the supply to relief air volume needs to remain positive keeping the space positive. A direct fired heating option can be added in the supply duct 62 to convert this into a direct fired heating unit. The heating unit may be bolted on and is like a CAPTIVE AIRE™ or POWER FLAME™ equivalent direct fired burner heating unit.
As used in this application, the term “about” or “approximately” refers to a range of values within plus or minus 10% of the specified number. And the term “substantially” refers to up to 80% or more of an entirety. Recitation of ranges of values herein are not intended to be limiting, referring instead individually to any and all values falling within the range, unless otherwise indicated, and each separate value within such a range is incorporated into the specification as if it were individually recited herein.
For purposes of this disclosure, the term “aligned” means parallel, substantially parallel, or forming an angle of less than 35.0 degrees. For purposes of this disclosure, the term “transverse” means perpendicular, substantially perpendicular, or forming an angle between 55.0 and 125.0 degrees. Also, for purposes of this disclosure, the term “length” means the longest dimension of an object. Also, for purposes of this disclosure, the term “width” means the dimension of an object from side to side. For the purposes of this disclosure, the term “above” generally means superjacent, substantially superjacent, or higher than another object although not directly overlying the object. Further, for purposes of this disclosure, the term “mechanical communication” generally refers to components being in direct physical contact with each other or being in indirect physical contact with each other where movement of one component affect the position of the other.
The use of any and all examples, or exemplary language (“e.g.,” “such as,” or “the like”) provided herein, is intended merely to better illuminate the embodiments and does not pose a limitation on the scope of the embodiments or the claims. No language in the specification should be construed as indicating any unclaimed element as essential to the practice of the disclosed embodiments.
In the following description, it is understood that terms such as “first,” “second,” “top,” “bottom,” “up,” “down,” and the like, are words of convenience and are not to be construed as limiting terms unless specifically stated to the contrary.
It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.
This application claims the benefit of priority of U.S. non-provisional application Ser. No. 15/929,392, filed 30 Apr. 2020, as a continuation in part thereof, and U.S. provisional application No. 62/840,531, filed 30 Apr. 2019, the contents of which are herein incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62840531 | Apr 2019 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15929392 | Apr 2020 | US |
| Child | 17937890 | US |
