Patent ID: 7655077

Claim:
A system for treating air which is to be breathed within an enclosed space, which comprises: a. a primary inlet through which air can be admitted to the system from atmosphere, b. a primary inlet valve by which the flow of air into the system through the primary inlet can be regulated, c. an outlet through which air within the enclosed space can be vented to atmosphere, d. a recirculation line through which air from the enclosed space can be recirculated, to be readmitted to the enclosed space, e. a contaminant adsorption assembly by which contaminants in atmospheric air can be adsorbed, the assembly being provided in an auxiliary supply conduit through which air from atmosphere can flow for (i) treatment by the adsorption assembly to adsorb contaminants, and (ii) mixture with air that is in or is for supply to the enclosed space, f. an auxiliary inlet valve by which the flow of air through the contaminant adsorption assembly and the auxiliary supply conduit can be regulated, g. a sensor for detecting atmospheric contaminants, h. an actuator which can generate signals to control the inlet and auxiliary inlet valves, i. components for controlling the temperature and the humidity of the air that is supplied to the enclosed space, the temperature and humidity control components being located so that air passing into the enclosed space from each of the primary inlet and the recirculation line and the auxiliary supply conduit passes through the said components before being admitted to the space, in which, when the sensor detects atmospheric contaminants, the actuator is programmed to generate signals which cause (a) the primary inlet valve to move to its fully closed position, and (b) the auxiliary inlet valve to move towards its fully open position.