초록 ▼

A heating, ventilation, and air conditioning (HVAC) system uses unvitiated secondary return air to control the amount of a contaminant, such as carbon dioxide, in a space to maintain an improved air quality throughout the area served by the system. Preferably a terminal box controls the CO.sub.2 lev

A heating, ventilation, and air conditioning (HVAC) system uses unvitiated secondary return air to control the amount of a contaminant, such as carbon dioxide, in a space to maintain an improved air quality throughout the area served by the system. Preferably a terminal box controls the CO.sub.2 level in the space served by the box by selectively drawing air representative of air in other rooms to lower the CO.sub.2 level in the space being served. This reduces cost because air which is provided from other rooms within the building will require less total system heating or cooling in order to maintain the occupied space at the desired air quality.

대표청구항 ▼

[ What is claimed is:] [1.] A method of controlling the concentration of a contaminant in an indoor space to be conditioned, comprising:determining a contaminant concentration in an indoor space;comparing the contaminant concentration to a predetermined concentration value of the contaminant; anddec

[ What is claimed is:] [1.] A method of controlling the concentration of a contaminant in an indoor space to be conditioned, comprising:determining a contaminant concentration in an indoor space;comparing the contaminant concentration to a predetermined concentration value of the contaminant; anddecreasing the contaminant concentration in the indoor space when the contaminant concentration exceeds the predetermined concentration value by increasing the flow of secondary return air drawn, at least in part, from an indoor space that has a lower contaminant concentration, into the indoor space.