METHOD AND APPARATUS FOR CONTROLLING VENTILATION SYSTEMS
First Claim
1. A ventilation system comprising:
- a ventilator;
a first direct current (DC) fan drawing air from an exterior of a building for circulation into an interior of the building, the first DC fan producing a supply airflow through the ventilator;
a second DC fan drawing a return air from the interior of the building for exhausting to the exterior of the building, the second DC fan producing an exhaust airflow through the ventilator enclosure, said supply airflow and said exhaust airflow undergoing an energy exchange therebetween in the ventilator; and
a controller controlling of a first speed of the first DC fan and a second speed of the second DC fan, thereby separately adjusting the supply airflow and the exhaust airflow in response to a first input received from a first temperature sensor in the supply airflow positioned upstream of the energy exchange in the ventilator, a second input received from a second temperature sensor in the supply airflow positioned downstream of the energy exchange in the ventilator and a third temperature sensor in an exhaust airflow positioned downstream of the energy exchange in the ventilator, said first, second and third temperature sensors each independently outputting temperature signals to the controller for use in optimizing the supply and exhaust airflows.
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Accused Products
Abstract
An energy recovery ventilation system is described which allows for continuous fan speed control through pulse width modulation of direct current fans. The energy recovery ventilation described is capable of fine motor speed control without the disadvantages of high noise, low efficiency and a fixed number of speeds present in commonly-used speed-varying techniques used with alternating current (AC) fans. This may be accomplished through the use of direct current (DC) fans and pulse width modulation. A controller is used to optimize the ventilation and energy efficiency of the system through the use of several temperature sensors. The energy recovery ventilation also provides a control process for self-optimization of the energy recovery ventilation, in case the supply and exhaust airflows are unequal. An unbalance may be detected by calculating the thermal efficiencies of the exhaust and supply airflows.
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Citations
34 Claims
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1. A ventilation system comprising:
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a ventilator; a first direct current (DC) fan drawing air from an exterior of a building for circulation into an interior of the building, the first DC fan producing a supply airflow through the ventilator; a second DC fan drawing a return air from the interior of the building for exhausting to the exterior of the building, the second DC fan producing an exhaust airflow through the ventilator enclosure, said supply airflow and said exhaust airflow undergoing an energy exchange therebetween in the ventilator; and a controller controlling of a first speed of the first DC fan and a second speed of the second DC fan, thereby separately adjusting the supply airflow and the exhaust airflow in response to a first input received from a first temperature sensor in the supply airflow positioned upstream of the energy exchange in the ventilator, a second input received from a second temperature sensor in the supply airflow positioned downstream of the energy exchange in the ventilator and a third temperature sensor in an exhaust airflow positioned downstream of the energy exchange in the ventilator, said first, second and third temperature sensors each independently outputting temperature signals to the controller for use in optimizing the supply and exhaust airflows. - View Dependent Claims (2, 3, 4, 8, 9, 12, 14, 16, 17)
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5-7. -7. (canceled)
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10-11. -11. (canceled)
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13. (canceled)
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15. (canceled)
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18. A ventilator comprising:
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a ventilator enclosure comprising a supply inlet receiving a supply airflow from an exterior of a building, a supply outlet discharging the supply airflow to the interior of the building, an exhaust inlet receiving an exhaust airflow from an interior of the building, and an exhaust outlet discharging the exhaust airflow to the exterior of the building, a first direct current (DC) fan drawing supply air through the supply inlet and discharging supply air through the supply outlet, said first DC fan producing a supply airflow through the ventilator enclosure; a second DC fan drawing return air through the exhaust inlet and discharging the exhaust air from the exterior of the building thereby creating the exhaust airflow through the ventilator enclosure; a first temperature sensor, proximate to the supply inlet, determining a first temperature of supply air entering the ventilator enclosure; a second temperature sensor, proximate to the supply outlet, measuring a second temperature of supply air exiting the ventilator enclosure; a third temperature sensor, proximate to the exhaust outlet, measuring a third temperature of return air exiting the ventilator enclosure; and a controller controlling the fans and regulating the supply airflow and the exhaust airflow, said controller comprising receiver receiving a first input from the first temperature sensor, a second input from the second temperature sensor, and a third input from a third temperature sensor, and drivers for independently adjusting a first fan speed for the first DC fan and a second fan speed for the second DC fan in response to each of said first, second and third inputs, thereby optimizing the supply airflow and the exhaust airflow.
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19-25. -25. (canceled)
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26. A method for optimizing ventilation efficiency of a ventilation system having a first direct current (DC) fan producing a supply airflow through a ventilator to an interior of a building, a second DC fan for producing an exhaust air flow of return air through a ventilator for exhausting to an exterior of the building, a first temperature sensor determining a temperature of the supply airflow upstream of the ventilator, a second temperature sensor determining a temperature of the supply airflow downstream of the ventilator, a third temperature sensor determining a temperature of the exhaust airflow downstream of the ventilator and a controller for independently adjusting the fan speed for each of the first and second DC fans in response to input received from the first, second and third temperature sensors, said method comprising the steps of:
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determining a thermal efficiency for the supply airflow and the exhaust airflow from temperature data for the supply airflow and the exhaust airflow obtained from each of the first, second and third temperature sensors, comparing the thermal efficiency for each of the supply airflow and the exhaust airflow with predetermined values, determining whether the thermal efficiencies for supply and exhaust airflows are substantially equal to predetermined values, and adjusting the fan speed of the first and/or the second fan where the thermal efficiencies of the supply airflow and/or the exhaust airflow are determined to be unequal.
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27. A method for self-balancing a supply airflow and an exhaust airflow in a ventilation system, the ventilation system comprising a direct current (DC) supply fan for producing a supply airflow through a ventilator for circulation inside a building, a DC exhaust fan for producing an exhaust air flow of return air through a ventilator for exhausting outside of the building, a first temperature sensor for determining a temperature of the supply airflow at a supply inlet of the ventilator, a second temperature sensor for determining a temperature of the supply airflow at a supply outlet of the ventilator, a third temperature sensor for determining a temperature of the exhaust airflow at an exhaust outlet of the ventilator and a controller for independently adjusting the fan speed for each of the first and second DC fans in response to input received from the first, second and third temperature sensors, the method comprising:
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at a preselected time, automatically determining a first thermal efficiency for the supply airflow using the supply inlet temperature and a second thermal efficiency for the exhaust airflow using the supply outlet temperature; and adjusting the fan speed of the supply fan and/or the exhaust fan so as to substantially equalize the first thermal efficiency and the second thermal efficiency for the exhaust airflow. - View Dependent Claims (28, 29)
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30. (canceled)
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31. A method for controlling a ventilation system comprising:
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measuring a temperature property of incoming supply air; measuring a temperature property of treated supply air; measuring a temperature property of exhaust air; determining a flow rate of supply air and a flow rate of exhaust air for maximizing the effectiveness of the ventilation system based upon said measured temperature properties; and adjusting duty cycles of PCM signals to each of a supply fan and an exhaust fan to substantially achieve said flow rates. - View Dependent Claims (32)
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33. A storage medium readable by a computer encoding a computer program for execution by the computer to carry out a method for optimizing ventilation efficiency of a ventilation system having a first direct current (DC) fan producing a supply airflow through a ventilator to an interior of a building, a second DC fan for producing an exhaust air flow of return air through a ventilator for exhausting to an exterior of the building, a first temperature sensor determining a temperature of the supply airflow upstream of the ventilator, a second temperature sensor determining a temperature of the supply airflow downstream of the ventilator, a third temperature sensor determining a temperature of the exhaust airflow downstream of the ventilator and a controller for independently adjusting the fan speed for each of the first and second DC fans in response to input received from the first, second and third temperature sensors, the computer program comprising:
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code means for determining a thermal efficiency for the supply airflow and the exhaust airflow from temperature data for the supply airflow and the exhaust airflow obtained from each of the first, second and third temperature sensors, code means for comparing the thermal efficiency for each of the supply airflow and the exhaust airflow with predetermined values, code means for determining whether the thermal efficiencies for supply and exhaust airflows are substantially equal to predetermined values, and code means for adjusting the fan speed of the first and/or the second fan where the thermal efficiencies of the supply airflow and/or the exhaust airflow are determined to be unequal.
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34. A storage medium readable by a computer encoding a computer program for execution by the computer to carry out a method for self-balancing a supply airflow and an exhaust airflow in a ventilation system, the ventilation system comprising a direct current (DC) supply fan for producing a supply airflow through a ventilator for circulation inside a building, a DC exhaust fan for producing an exhaust air flow of return air through a ventilator for exhausting outside of the building, a first temperature sensor for determining a temperature of the supply airflow at a supply inlet of the ventilator, a second temperature sensor for determining a temperature of the supply airflow at a supply outlet of the ventilator, a third temperature sensor for determining a temperature of the exhaust airflow at an exhaust outlet of the ventilator and a controller for independently adjusting the fan speed for each of the first and second DC fans in response to input received from the first, second and third temperature sensors, the computer program comprising:
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code means for determining a first thermal efficiency for the supply airflow using the supply inlet temperature and a second thermal efficiency for the exhaust airflow using the supply outlet temperature; and code means for adjusting the fan speed of the supply fan and/or the exhaust fan so as to substantially equalize the first thermal efficiency and the second thermal efficiency for the exhaust airflow.
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Specification