Ventilation Systems and Methods

Abstract

This application describes methods and systems for ventilating a building. A method for ventilating a building includes drawing in air, using a central fan, for heating or cooling at least a portion of the building and exhausting air from the building using at least one exhaust fan. The exhaust fan can be automatically operated during time periods when the central fan is not switched on. The method further includes automatically opening a damper, during at least a portion of the time periods, such that fresh air enters the building through the damper

1 . A method for ventilating a building, the method comprising:
 drawing in air, using a central fan, for heating or cooling at least a portion of the building;   exhausting air from the building using at least one exhaust fan, wherein the exhaust fan is automatically operated during time periods when the central fan is not switched on; and   during at least a portion of the time periods, automatically opening a damper, such that fresh air enters the building through the damper.   
     
     
         2 . The method of  claim 1 , further comprising:
 receiving control signals from a controller at the central fan, the at least one exhaust fan and the damper; and   operating the central fan, the at least one exhaust fan, and the damper in accordance with the control signals.   
     
     
         3 . The method of  claim 2 , further comprising switching on the central fan in accordance with one of the control signals when a heating or cooling system is operating to heat or cool the portion of the building. 
     
     
         4 . The method of  claim 2 , further comprising switching on the exhaust fan in accordance with one of the control signals responsive to a manual input. 
     
     
         5 . The method of  claim 4 , further comprising switching off the exhaust fan after a predetermined time period. 
     
     
         6 . The method of  claim 1 , further comprising automatically opening the damper during a time period when the central fan is switched on. 
     
     
         7 . The method of  claim 1 , wherein the exhaust fan is a bathroom exhaust fan. 
     
     
         8 . The method of  claim 1 , wherein the exhaust fan is a kitchen exhaust fan. 
     
     
         9 . A controller for controlling the ventilation of a building in which there is a central fan configured to draw in air for heating or cooling at least a portion of the building, at least one exhaust fan adapted to exhaust air from the building, and a damper that, when opened, permits fresh air to enter the building, the controller comprising:
 a control logic adapted to generate signals to automatically operate the exhaust fan to exhaust air from the building during time periods when the central fan is not switched on and to open the damper during at least a portion of the time periods, such that fresh air enters the building through the damper.   
     
     
         10 . The controller of  claim 9 , wherein the controller is further adapted to generate signals to switch on the central fan in accordance with an operation of a heating or cooling system. 
     
     
         11 . The controller of  claim 9 , wherein the controller is adapted to generate signals to switch on the exhaust fan responsive to a manual input. 
     
     
         12 . The controller of  claim 11 , wherein the controller is adapted to generate signals to switch off the exhaust fan after a pre-determined time period. 
     
     
         13 . The controller of  claim 9 , wherein the controller is adapted to generate signals to open the damper during a time period when the central fan is switched on. 
     
     
         14 . The controller of  claim 9 , wherein the exhaust fan is a bathroom exhaust fan. 
     
     
         15 . The controller of  claim 9 , wherein the exhaust fan is a kitchen exhaust fan. 
     
     
         16 . A method for ventilating a building, the method comprising:
 drawing in air, using a central fan, for heating or cooling at least a portion of the building, wherein the central fan is automatically switched on during periods when a heating or cooling system is supplying hot or cold air to the building; and   expelling air from the building using at least one exhaust fan, wherein the exhaust fan is configured to be operated during periods in which the central fan is not operational, such that the total amount of ventilation of the building resulting from the operation of the central fan and the exhaust fan is controlled to approximate a predetermined amount.   
     
     
         17 . The method of  claim 16 , wherein the at least one exhaust fan is configured to be operated for a first time period responsive to a manual input and automatically for a second additional time period on determining that the exhaust fan is to be operated for the second additional time period to achieve the approximate predetermined amount of ventilation. 
     
     
         18 . The method of  claim 17 , wherein automatically operating the exhaust fan comprises operating the exhaust fan during periods when the central fan is not switched on. 
     
     
         19 . The method of  claim 17 , further comprising automatically opening a damper that permits the inflow of fresh air into the building during the first time period or the second additional time period. 
     
     
         20 . The method of  claim 16 , wherein the exhaust fan is part of a heat recovery ventilator (HRV) or an energy recovery ventilator (ERV). 
     
     
         21 . A controller for controlling the ventilation of a building having a central fan for distributing air in
 a heating or cooling system and at least one exhaust fan, the controller comprising:   a control logic adapted to generate signals to operate the at least one exhaust fan during periods when the central fan is not operational, so that the total amount of ventilation of the building resulting from the operation of the central fan and the exhaust fan is controlled to approximate a predetermined amount.   
     
     
         22 . The controller of  claim 21 , wherein the controller is further adapted to automatically open a damper during at least a portion of time periods when the exhaust fan is switched on, such that fresh air enters the building through the damper.