Air quality control system

Claim 1

A system for controlling air quality in a building, said building having an interior and an exterior, a heating and cooling unit, an economizer in fluid communication with said exterior and said interior for bringing in fresh air from the exterior to the interior, a supply air duct in fluid communication with said economizer, a return air space and a bypass duct in fluid communication with said supply air duct and said return air space said system comprising: air quality sensing means disposed in said interior for sensing air quality in said interior, said sensing means generating an output signal; flow increasing means for increasing a flow of air from said exterior to said interior, wherein said flow increasing means includes a bypass damper disposed in said bypass duct, said bypass damper being closable for increasing the flow of air through said supply air duct; and outside temperature sensing means, in communication with said control means, for sensing the temperature of outside air, said flow increasing means arranged to assume a first state and a second state, said second state resulting in a greater flow of air than said first state, wherein said control means establishes said second state when said air quality falls below a predetermined level for a predetermined duration if said outside air temperature is within a lockout range of temperatures.

Claim 2

A system for controlling air quality in a building, said building having an interior and an exterior, a heating and cooling unit, an economizer in fluid communication with said exterior and said interior for bringing in fresh air from the exterior to the interior, a supply air duct in fluid communication with said economizer, a return air space and a bypass duct in fluid communication with said supply air duct and said return air space said system comprising: air quality sensing means disposed in said interior for sensing air quality in said interior, said sensing means generating an output signal; flow increasing means for increasing a flow of air from said exterior to said interior, wherein said flow increasing means includes a bypass damper disposed in said bypass duct, said bypass damper being closable for increasing the flow of air through said supply air duct; and outside temperature sensing means, in communication with said control means, for sensing the temperature of outside air, said flow increasing means arranged to assume a first state and a second state, said second state resulting in a greater flow of air than said first state, wherein said control means establishes said second state when said air quality falls below a predetermined level for a predetermined duration if said outside air temperature is within a lockout range of temperatures.

Claim 3

A system for controlling air quality in a building, said building having an interior and an exterior, a heating and cooling unit, an economizer in fluid communication with said exterior and said interior for bringing in fresh air from the exterior to the interior, a supply air duct in fluid communication with said economizer, a return air space and a bypass duct in fluid communication with said supply air duct and said return air space said system comprising: air quality sensing means disposed in said interior for sensing air quality in said interior, said sensing means generating an output signal; flow increasing means for increasing a flow of air from said exterior to said interior, wherein said flow increasing means includes a bypass damper disposed in said bypass duct, said bypass damper being closable for increasing the flow of air through said supply air duct; and outside temperature sensing means, in communication with said control means, for sensing the temperature of outside air, said flow increasing means being arranged to assume a first state and a second state, said second state resulting in a greater flow of air than said first state, wherein said control means establishes said first state when said air quality falls below a predetermined level for a predetermined duration if said outside air temperature is not within a lockout range of temperatures.

Claim 4

A system for controlling air quality in a building, said building having an interior and an exterior, a heating and cooling unit, an economizer in fluid communication with said exterior and said interior for bringing in fresh air from the exterior to the interior, a supply air duct in fluid communication with said economizer, a return air space and a bypass duct in fluid communication with said supply air duct and said return air space said system comprising: air quality sensing means disposed in said interior for sensing air quality in said interior, said sensing means generating an output signal; flow increasing means for increasing a flow of air from said exterior to said interior, wherein said flow increasing means includes a bypass damper disposed in said bypass duct, said bypass damper being closable for increasing the flow of air through said supply air duct; and outside temperature sensing means, in communication with said control means, for sensing the temperature of outside air, said flow increasing means being arranged to assume a first state and a second state, said second state resulting in a greater flow of air than said first state, wherein said control means establishes said first state when said air quality falls below a predetermined level for a predetermined duration if said outside air temperature is not within a lockout range of temperatures.

Claim 5

A method for improving air quality in a building, said building having an interior and an exterior, and a climate control system comprising an inlet air duct providing fluid communication between said exterior and said interior, a fan assembly disposed proximate an inlet end of said inlet duct, a bypass duct, a supply air duct, a return air duct, and a plurality of zone ducts for distributing air to each of several zones of said building, each zone duct having a zone damper, said method comprising: monitoring a zone air quality sensor disposed in one of said zones; monitoring a system air quality sensor disposed in said return air duct; upon detection of an air quality problem by either of said sensors evaluating whether at least one of said dampers can be open to a full open position, without, according to a predetermined criteria, adversely affecting air temperature in said at least one zone; and if at least one zone damper can be open to a full open position increasing a flow of outside air into said building.

Claim 6

A method for improving air quality in a building, said building having an interior and an exterior, and a climate control system comprising an inlet air duct providing fluid communication between said exterior and said interior, a fan assembly disposed proximate an inlet end of said inlet duct, a bypass duct, a supply air duct, a return air duct, and a plurality of zone ducts for distributing air to each of several zones of said building, each zone duct having a zone damper, said method comprising: monitoring a zone air quality sensor disposed in one of said zones; monitoring a system air quality sensor disposed in said return air duct; upon detection of an air quality problem by either of said sensors evaluating whether at least one of said dampers can be open to a full open position, without, according to a predetermined criteria, adversely affecting air temperature in said at least one zone; and if at least one zone damper can be open to a full open position increasing a flow of outside air into said building.