Indoor air quality system and method

Abstract

An indoor air quality system and method for a building. In an embodiment, the system includes a plurality of exhaust fans and a plurality of controllers. The exhaust fans each have a predetermined exhaust rate. The controllers are configured to monitor an actual volume of air exhausted by the indoor air quality system, and to automatically operate the exhaust fans to exhaust a desired volume of air during a time period. In an embodiment, the method includes setting parameters in a plurality of controllers, communicating to the controllers an operating state of the fans, determining a time at which to energize the fans such that the volume of air to exchange during the time period is exchanged during the time period, and energizing the fans at the determined time.

1 . An indoor air quality system for a building, the system comprising:
 a plurality of exhaust fans, each fan having a predetermined exhaust rate; and   a plurality of controllers configured to monitor an actual volume of air exhausted by the indoor air quality system, and to automatically operate the plurality of exhaust fans to exhaust a desired volume of air during a time period.   
     
     
         2 . The system of  claim 1  wherein the plurality of controllers includes a master controller and multiple slave controllers, the master controller directing the slave controllers when to automatically operate the exhaust fans. 
     
     
         3 . The system of  claim 2  wherein a slave controller assumes the role of the master controller when the master controller fails. 
     
     
         4 . The system of  claim 1  wherein the exhaust fans communicate their exhaust rate to the controllers. 
     
     
         5 . The system of  claim 1  wherein the exhaust fans are configured to be energized manually. 
     
     
         6 . The system of  claim 5  wherein at least one of the controllers energizes at least one of the exhaust fans for a second time period after the at least one fan is turned off manually. 
     
     
         7 . The system of  claim 1  wherein the desired volume of air to exhaust during the time period is related to the number of occupants in the building. 
     
     
         8 . The system of  claim 1  wherein the plurality of exhaust fans includes a bathroom fan. 
     
     
         9 . The system of  claim 1  wherein the plurality of exhaust fans includes a range hood. 
     
     
         10 . The system of  claim 1  wherein air exhausted is replaced through infiltration. 
     
     
         11 . The system of  claim 1  wherein the time period is programmable. 
     
     
         12 . The system of  claim 1  wherein the exhaust fans energize automatically if a level of an environmental characteristic exceeds a threshold. 
     
     
         13 . The system of  claim 1  wherein a controller energizes a furnace blower when the controller energizes an exhaust fan. 
     
     
         14 . The system of  claim 13  wherein the furnace blower is energized only when at least one of the exhaust fans is energized automatically. 
     
     
         15 . The system of  claim 1  wherein the exhaust fans are energized sequentially. 
     
     
         16 . The system of  claim 1  wherein the exhaust fans are energized concurrently. 
     
     
         17 . The system of  claim 1  wherein the actual volume of air exhausted includes air exhausted during manual operation of the exhaust fans. 
     
     
         18 . The system of  claim 1  and further comprising a detector configured to determine a quantity of people in the building. 
     
     
         19 . The system of  claim 1  wherein the controllers are operable in a set back mode. 
     
     
         20 . The system of  claim 1  wherein the exhaust fans are operable in zones. 
     
     
         21 . The system of  claim 1  wherein the controllers are contained in smart switches. 
     
     
         22 . The system of  claim 1  wherein the exhaust fans include the controllers.