Exhaust demand control system and methods
AssigneeMeasured Air Performance, LLC
InventorEric Desrochers
Life of this patent
Estimating the term…
Abstract
Methods and apparatus for an exhaust demand control system for measuring one or more contaminants at one or more exhaust locations within one or a plurality of exhaust ducts or plenums served by an exhaust fan system. Example systems and methods can include sensing the one or more contaminants within the one or more exhaust duct locations using a multipoint air sampling system having one or more sensors and comparing contaminant concentration measurements from the one or more of said exhaust duct or plenum locations against an action level to create a fan setback signal.
Claims20
An exhaust demand control system for measuring one or more contaminants at one or more locations within one or a plurality of exhaust ducts or plenums served by an exhaust fan system having one or more exhaust fans, comprising systems configured to:
- sense the one or more contaminants within the one or more locations using a multipoint air sampling system having one or more sensors to determine concentration measurements;
- compare the contaminant concentration measurements from the one or more locations against an action level to create a fan setback signal which controls a setback state of the exhaust fan system;
- prevent the exhaust fan system from instability by controlling an operation of the one or more exhaust fans according to a sequence delay provided by control logic of the control system where the sequence delay is enabled when the contaminant concentration measurements from the one or more locations exceeds the action level, wherein the sequence delay in part determines a minimum time that the fan setback signal is disabled;
- ensure sensor accuracy and reliability by enabling a flow device to provide a sensor flushing function to the one or more sensors, the sensor flushing function being activated for a period of time designated by the sequence delay when contaminant levels above the action level are detected by the one or more sensors, wherein the sensing of the one or more contaminants within the one or more locations is discontinued while the sensor flushing function is activated;
- and
- incorporate one or more setback override functions to limit when the exhaust fan system is set back.
A method of performing exhaust demand control using a system for measuring one or more contaminants at one or more locations within one or a plurality of exhaust ducts or plenums served by an exhaust fan system having one or more exhaust fans, the method comprising:
- sensing the one or more contaminants within the one or more locations using a multipoint air sampling system having one or more sensors to determine concentration measurements;
- comparing contaminant concentration measurements from the one or more locations against an action level to create a fan setback signal which controls a setback state of the exhaust fan system;
- preventing the exhaust fan system from instability by controlling an operation of the one or more exhaust fans according to a sequence delay provided by control logic of the control system where the sequence delay is enabled when the contaminant concentration measurements from the one or more locations exceeds the action level, wherein the sequence delay in part determines a minimum time that the fan setback signal is disabled;
- ensuring sensor accuracy and reliability by enabling a flow device to provide a sensor flushing function to the one or more sensors, the sensor flushing function being activated for a period of time designated by the sequence delay when contaminant levels above the action level are detected by the one or more sensors, wherein the sensing of the one or more contaminants within the one or more locations is discontinued while the sensor flushing function is activated;
- and
- incorporating one or more setback override functions to limit when the exhaust fan system is set back.
Dependencies are inferred from the claim text.