SOLAR POWERED ROOF VENTILATION SYSTEM
A solar-powered ventilation system may be mounted to a building. Through the use of internal dampers and destratification intake doors, the system is able to cool the inside of buildings by way of hot-air venting or cold-air induction methods. Further, the system may also be configured in a combinatory manner, allowing the building to be cooled by the simultaneous use of hot air venting and cold-air induction methods.
This application is a continuation of and claims benefit from U.S. non-provisional patent application Ser. No. 13/573,359, filed Sep. 10, 2012, entitled “SOLAR POWERED ROOF VENTILATION SYSTEM,” which is a non-provisional of and claims benefit from U.S. Provisional application 61/532,291, filed Sep. 8, 2011, entitled SOLAR POWERED ROOFTOP VENTILATOR FOR COMMERCIAL, INDUSTRIAL, AGRICULTURAL APPLICATIONS, the entire contents of both of which are incorporated by reference herein.
FIELD OF THE INVENTIONThis disclosure is directed to rooftop ventilators, and, more particularly, to a rooftop ventilator that is solar powered and can be used in non-conditioned or conditioned space.
BACKGROUNDBuildings trap heat inside of them. This is especially true for a business, factory, storehouse or warehouse that operates heat generating equipment inside the building. Although many or most office buildings are air-conditioned spaces, it is generally too expensive to run air-conditioning units in factories, warehouses, storehouses, prisons, and other large buildings due to the high cost of conditioning the space.
Air-moving fans are a lower-cost option to cool buildings, even though they do not cool as much as typical air conditioning. Typically fans ventilate hot air from the building, which causes cool air to be drawn in, such as through open windows. In other modes fans may bring cool air directly in the building. Many businesses do not install ventilation fans, however, because electrical power to power the operation of the fans must also be installed, in addition to the ventilation fans themselves. In addition to the expense, running electrical power generally requires acquiring installation permits, which in turn requires inspections, which further adds to the cost of installation. Therefore, due to either the high cost of conditioning the air of large buildings, or the high cost of installing fans and their accompanying power, many large buildings have no or insufficient cooling ability, and no or insufficient destratification remedies.
Embodiments of the invention address these and other limitations of the prior art.
SUMMARY OF THE INVENTIONEmbodiment of the invention are directed to a solar-powered roof-mounted ventilation system. A solar panel creates electricity from sunlight to drive a motor-driven, variable-speed, reversible fan for air ventilation of a building. In a standard mode, the ventilator can exhaust hot air from a building or introduce cool outside air into a building, depending on the direction of the air movement due to the fan. In a destratification or thermal balancing mode, a set of dampers is closed to prevent any outside air exchange, while internal baffles are opened in an extension that protrudes through the roof and inside the building. Air is propelled in either direction through the open destratification doors by the reversible fan to promote air movement within the closed building. In a combination ventilation/destratification mode, an upper damper may be partially opened to allow a regulated amount of outside air to be introduced into a building that is being currently destratified. Sensors allow for control to be based on temperature, humidity and/or other data. The device may also include a rechargeable battery for time-delayed operation, such as operation during night hours when the cooling effect may be more pronounced. Multiple units may operate in concert and/or in tandem. In addition, the units may be used in conjunction with existing HVAC units in a building.
A power control unit 212 receives output from the solar panel 210 and converts it to usable energy, depending on the requirements of the ventilation system 200. The power control unit 212 may include a voltage regular to limit the maximum voltage. In one embodiment the power control unit 212 limits the voltage to 36 volts. Although in a preferred embodiment the ventilation system 200 uses direct current, if alternating current were used then the power control unit 212 could include a power inverter for producing the alternating current from the solar panel 210. Line conditioners may also be used to ensure clean power is available to the ventilation system 200.
A storage battery 214 may be included in some embodiments of the ventilation system 200. The battery 214 stores power. Because the ventilation system 200 is a solar powered device, without stored power it would be inoperable when there is no or insufficient light available to the solar panel 210. For example, the ventilation system 200 would be inoperable at night. When present in the ventilation system 200, the battery 214 is charged when the solar panel 210 produces energy. Depending on the size of the solar panel 210 and the intensity of the sunlight, the power generating capacity of the solar panel may be larger than instant requirements of the ventilation system 200. During such periods, the excess generated power may be stored in the battery 214, and the ventilation system 200 may use the energy stored in the battery 214 when the solar panel 210 is not producing enough power. In embodiments that include the battery 214, the power control unit 212 may additional include a charge regulator. In addition, when the solar panel 210 is generating more power than is used by the ventilation system 200, it may provide the power to be used elsewhere in the building. In some embodiments an inverter may be used to put excess power on the grid from one or more tied ventilation systems, which may result in offsetting electrical costs of running the building itself or the equipment inside. In other embodiments the excess energy may be used for lighting, such as by suspending a lighting cable from the ventilation system down through the ceiling and over a workspace that may benefit from additional lighting. For instance, LED (Light Emitting Diode) lighting is a type of lighting that has low power requirements and may work well with power generated by the solar panel 210. In those embodiments an LED fixture could provide additional light for interior building illumination.
A motor 220 may be coupled to the battery 214, power controller 212, and/or the solar panel 210, depending on a configuration of ventilation system 200. The motor 220 drives a propeller or fan 222. The fan 222 moves air through the ventilation system 200 to remove heat from, to cool, or to recirculate air within a building, as described in detail below. The motor 220 may be a dc or ac motor depending on the specifications of the ventilation system 200. For example, the motor 220 may be a 36v dc variable speed motor that can run in either direction. The variable speed control may be continuous between 0 and 100% of maximum, or may step in pre-determined increments, depending on the application. Having a bi-directional motor 220 allows the ventilation system 200 to either draw air from a building or pull air into the building depending on the direction of the motor.
A thermal fuse may be installed in the ventilation system 200, such as between the fan 222 and motor 220. Such a fuse separates power from the fan and prohibits operation in case of thermal overload or, even more importantly, in case of structure fire. Having such a thermal fuse prevents additional oxygen to be added to the fire through the ventilation system. In operation, the thermal fuse melts or otherwise stops electricity from passing to the fan 222 when the thermal fuse reaches the activation point. Typically this activation point is set to a temperature so that the thermal fuse will activate during a fire, and automatically shut down the ventilating operation.
A damper 230 may be included in the ventilation system 200. As described in detail below, the damper 230 controls airflow through the main body of the ventilation system 200. The damper 230 may be set in a fully closed, fully open, or partially open position, and is preferably automatically controlled by a damper controller. In alternate embodiments the damper may be manually controlled, or operate automatically when the ventilation system 200 is in operation, for example automatically closing during times when the ventilation system is off, and automatically opening during times when it is running. The damper 230 may also be referred to herein as a set of baffles.
A destratifier 234 may be included in the ventilation system. The destratifier 234 controls a destratification operation by allowing air inside the building to be circulated while preventing air from passing between the building and the outside. In other embodiments a partial destratification operation is possible, as described in detail below.
Lighting 236, such as low-power or LED lighting may be part of the ventilation system as well, taking advantage of the solar power generated by the solar panel 210.
The ventilation system 200 may also include a control system 250 used to control operation of the system. The control system 250 may be powered from the solar panel 210 and coupled to the power controller 212 or other appropriate power connection. The control system may include a processor 260 that controls operation of the ventilation system 200. A user interface 252 allows an operator to control operation of the ventilation system 200, such as by turning it on or off, controlling the direction of the ventilation, controlling speed of the motor 220, and controlling a position of the damper 230. The user interface may also include an ability to control the lighting 236. The user interface 252 may take many forms. For instance the user interface 252 may be a simple mechanical interface having an on/off switch, motor direction switch, and speed control. In other embodiments the user interface 252 may present information about the ventilation system 200 to the operator. For example the user interface may report back an instant speed of the fan. If sensors or stored data is included in the ventilation system 200, described below, the user interface 252 may report any information available to the ventilation system 200. The user interface 252 may show information in real-time, or may be used to review historical information of ventilation system 200 operation, as described below. The user interface 252 may also be used to control lighting generated by the device, as described above. For instance the user interface may have an on/off switch or an intensity control for the light. The user interface may include a remote controller 253 that may couple through a wired or wireless connection to the user interface 252 and/or to the processor 260. Any operation by the user interface may also be viewed or controlled by the remote controller 253. For example the remote controller 253 may be mounted on a wall in a convenient location. In some cases the remote controller may be connected to line voltage, or include a line voltage sensor so that it could generate a signal if the line voltage dropped below a threshold, such as when the building lost power. In such a case the remote controller 253 could generate a signal that is received by the user interface 252, and cause the lighting system 236 to activate. In such a case the ventilation device may also operate to provide emergency lighting. In another example the remote controller 253 may be a program operating on a portable computer, such as an iPAD or a smartphone running an application, and may be used to control any function described above or below.
A ventilator interface 267 is used to couple multiple ventilator systems to one another so that they may be operated together, or in conjunction with one another. For example, consider a building that has four ventilators all coupled to one another. As one portion of the building is heating, the ventilator closest to the hot portion of the building may begin ventilating at a 50% of full vent level, and the next closest ventilator may operate at 25% full vent level. As the building continues to heat, then the all of the ventilators operate at 25% while the ventilator closest to the hot area runs at 100%. One of the control systems 250 may assume a “master” role to control all of the other control systems, or there may be a separate master. In another mode of operation, a single control system may control all of the ventilators to operate in the same mode, at the same levels, at the same time. In yet other modes, a centralized control system uses all of the sensors and data from all of the systems, and controls all of the coupled ventilators individually for the most efficient operation.
Using the user interface 252, an operator may be able to select and run any number of pre-programmed operations 254. For example, two pre-programmed operations 254 may be stored, one to control operation for the day and another to control nighttime operation. The user would simply select which program to run, depending on the desired operation. For example, the fan 222 may vent during the day, but may draw during the night, so that cool air may be drawn into the building. Thus, the pre-programmed operations would control things such as motor direction, speed, baffle position, and destratification door position. The pre-programmed operations may also be automatically controlled based on time, for example. With additional information from sensors, described below, elaborate pre-programmed operations may be devised. For example, a program may be devised that causes the ventilation system 200 to operate only when the difference between inside and outside temperature exceeds 10 degrees F., except when the difference between inside and outside humidity is less than 15%, during which times the ventilation system operates when the difference between inside and outside temperature exceeds 5 degrees F.
Sensors 262, such as temperature and humidity sensors, may be coupled to the processor 260 for use by the ventilation system 200. Multiple sensors 262 may be used for temperature, for example multiple sensors in the building, and one or more temperature sensors within the ventilation system 200 itself. External temperature sensors that measure a temperature of the outside air may also be coupled to the processor 260 for use by the ventilation system 200. Similar sensors may be used for humidity. Other sensors may include atmospheric pressure, wind speed, instant power used by the building, etc. Sensors may be coupled to multiple ventilation systems 200 that may be part of a large installation for a building or complex. For example, with use of a CO2 sensor 262, the ventilation system 200 may trigger all connected ventilation systems to vent as much air from the building as possible when a threshold amount of CO2 is detected. Sensor 262 information may also be viewable or controllable from the user interface 252. A motion sensor 262 may be used to cause a lighting controller 286 to automatically turn on the lighting 236.
A data store 264 may record operation data, temperature data, humidity, or other data about the ventilation system 200 for use by the processor 260 or for a historical record. For instance the building temperature and external temperature may be stored at regular intervals for later recall. The data store 264 may additionally or instead store operational data such as motor speed, motor direction, generated power by the solar panel 210, etc., which may or may not be correlated to the stored temperatures. The data store 264 may include a real-time clock. Data analysis from data stored in the data store 264 may help a building manager develop an optimum cooling program for the building. Further, data from the data store 264 may be available to the user interface 252 to allow a user or operator to view historical data, such as in list or graphical form.
The processor 260 is also coupled to controllers, such as a motor controller 270, damper controller 280, destratifier controller 284, lighting controller 286, and solar panel controller 290. The controllers 270, 280, 284, 286, 290 are used to operate their respective devices. For example the motor controller 270 may vary a voltage supplied to the motor 220 to regulate the speed and direction of the motor, while the damper controller 280 may regulate a position of a motor or solenoid used to open and/or close the damper 230. The destratifier controller 284 controls the position of destratifier doors by controlling a small position motor or solenoid. The lighting controller 286 controls light operation. The solar panel controller 290 may control a pitch or a direction at which the solar panel 210 is facing. For example the panel controller 290 may cause the solar panel to track the sun for most effective power generation by controlling a small positional motor that causes either the panel itself or the entire ventilation system 200 to turn as the sun changes position across the sky.
The ventilation system 200 may be coupled to and used in conjunction with existing HVAC (Heating Ventilation and Cooling) equipment. The control system 250 may include an HVAC interface 266, which may be a wired or wireless interface. Through the interface, an existing HVAC system of a building may be used to control any function of the ventilation system 200. For example, the building HVAC system may first use one or all of the connected ventilation systems 200 to begin venting hot air. Later, when the building continues to heat, the HVAC system, through the HVAC interface 266, causes all of the connected ventilation systems 200 to operate at full venting capacity. If the building continues to get hotter, then the HVAC system may instruct all of the ventilation systems 200 to stop venting, close their associated dampers to prevent any air from exchanging between the building and the outside, and the HVAC system takes over conditioning the space, by air-conditioning the space. Even further, the HVAC system may then instruct the ventilation systems 200 to begin destratifying the air within the building, with no outside air exchanges, as described in detail below. Through the HVAC interface 266, the HVAC system of a building may control each of the ventilation systems 200 coupled to it to act together or in cooperation.
Components other than those illustrated in
A plenum enclosure 301 contains a control system 350, which may be the same or similar to the control system 250 described above with reference to
Solar brackets 311 sit on the sloped face 305 and support a solar panel 310, which may be the same or similar to the solar panel 210 described above. In general, the brackets 311 hold the solar panel 310 in a position aligned with the sloping face 305 of the plenum enclosure 301. In some embodiments the sloping side is approximately forty-five degrees offset from the horizontal base 303, or other reference. Other degrees of slope are possible, such as between approximately 20-70 degrees. In some embodiments the solar brackets 311 may include slotted holes so that the solar panel may be manually adjusted for best exposure to the sun, for example depending on a latitude of the installation. In other embodiments the sloped face 305 or solar brackets 311 may support a positioning motor (not illustrated) that allows the panel controller 290 of
The base housing 302 extends through a venting hole in the roof 207 by way of a base extension 308 to give air inside the building a path through the ventilation system 300 and to the outside. A motor 320 and fan 322 are mounted within the base housing 302, or within the base extension 308, either above or below the level of the roof 307 depending on the particular installation. The fan 322 may further be enclosed by a shroud (not illustrated) to increase airflow. A set of dampers 330 control airflow through the base housing 302 as described in detail below. The dampers may be actuated by, for example, a damper actuator 338, which is controlled by the damper controller 280 of
Within the base extension 308 is a set of destratification intake doors 309, the operation and purpose of which are described below with reference to
The shape and size of the plenum enclosure 301, base housing 302, and base extension 308 may be sized to fit the particular needs of the ventilation system 300 without changing the operating principles of the ventilation system.
Operation of various embodiment of the invention are now described with reference to
The ventilation system 400 is powered by a solar array 410 that receives energy from the Sun 411, as described above. In general, the ventilation system 400 is positioned so that the solar array 410 faces a direction to maximize solar exposure and resultant power generation. In Northern Hemisphere installations, the solar array 410 generally faces south, while in Southern Hemisphere installations the solar array 410 generally faces north. Also, as described above, the ventilation system 400 may include a motor that can turn the solar array 410, or the entire ventilation system itself, to follow the sun for maximum energy generation.
In a building venting operation, a fan 422 draws hot air from within the building and causes it to move toward the plenum area 401. Generally the plenum 401 is vented, for example at the bottom, through a series of vents 421, which allows the air be drawn from the building, moved through a base extension 408, and exhausted through the plenum vents. Additional detail of the vents is given with reference to
Generally, because hot air rises, it will be the hottest air of the building that is closest to the roof-mounted ventilation system 500. The destratification doors 509 are opened into this hottest airspace, which allows the hot air to be drawn through the destratification doors and pushed out through a vent 513 toward the main operating space of the building. For example, in the winter months, heat may accumulate at the ceiling of a building due to the hot air rising. Using the ventilation system 500 in the destratification mode works to thermally balance the air within a building by bringing the hottest air back down into the main operating space, where it may be the most useful. In the summer it may be desired to reverse the operation of the fan 522 from what is illustrated in
In some embodiments it is possible to perform the destratification operation while the dampers are partially opened, or, depending on the airflow within the ventilation system 500, even fully opened. This allows both a destratification operation as well as a venting operation to take place simultaneously. Recall that the ventilation system 500 may also operate in conjunction with a control system, such as the control system 250. Using a control system the ventilation system 500 may have an automatic operation mode that directs the ventilation system to vent or perform an air exchange during certain times of the day, or based on temperature differentials, and to perform destratification at other times. In sophisticated systems including multiple sensors, the ventilation system 500 may be programmed to operate with autonomy, bringing a maximum cooling, heating, or air movement benefit with a minimum of effort. Because the ventilation system 500 is solar powered, this benefit comes with nearly zero operating cost as there is no ongoing power cost.
In another operation, the set of destratification doors 609 may be closed and both dampers 630, 632 are opened, which allows the ventilation system 600 to vent hot air from one conditioned and/or confined space, through another confined space to the outside. Or, conversely, by reversing the fan, the ventilation system 600 may draw air from outside and bring it through a confined space into another confined, and possibly conditioned, living/working space.
The air brought into the living/working space is introduced from or pulled through a register 642. In some embodiments a light 650 may also be mounted on the register 642, and controlled as described above.
The components of the plenum are attached to the outside portions of the frame 903 as illustrated. A vertical wall 904 may be a structural component of the plenum, or may operate as an access door to allow access inside. Side panels 901 are self-explanatory, although they may also include access panels to the plenum. The angled panel 905 provides a base for attaching the solar panel 901.
In some flush-mounted systems there may not be a body extension. In such a case all of the components of the system would be contained fully within the plenum and body areas.
As described above, it is obvious that embodiments of the invention have application in buildings such as factories, storehouses or warehouses. There is also application in areas such as living and occupied spaces, bathrooms, crawlspaces, attics, fireplaces/chimneys, wall cavities, clean rooms, hospital/medical applications, military applications, mobile crafts, shipping containers, etc.
Although particular embodiments of a ventilation system have been described, it will be appreciated that the principles of the invention are not limited to those embodiments. Variations and modifications may be made without departing from the principles of the invention as set forth in the following claims.
Claims
1. A self-contained solar-powered ventilation system unit for mounting on a building, the system comprising:
- a solar panel structured to convert solar energy to electrical power for use by the ventilation system;
- a battery coupled to the solar panel and structured to store the electrical power generated by the solar panel;
- a fan motor structured to use the electrical power generated by the solar panel to operate a fan to move air through the air path;
- at least one damper structured to prevent or allow air from flowing through the air path by changing position; and
- an electric damper actuator coupled to the battery and structured to change the position of the at least one damper.
Type: Application
Filed: May 1, 2018
Publication Date: Aug 30, 2018
Inventor: Jason Eric Wright (Gaston, OR)
Application Number: 15/968,021