Abstract: An under-floor, perimeter-based heating ventilation and air conditioning pressurized air delivery system for use in a space includes a ventilation module, to be located in the floor, a multi-deflection linear bar grille covering the ventilation module, for diffusing the air entering the space, and a pair of apertured plates located below the grille, one plate moves relative to the other to either block more of the resultant apertures, so less air will flow, or to align the apertures, so more air will flow, all at nearly constant velocity and resultant plumage; nuances in aperture size or location allow one segment of the module to engage air flow on a lead-lag basis with respect to the other segments; air flow from the lead apertures induces air flow through a proximate under-floor heating module, to both increase its heat output and temper the ventilation air.

Abstract: An under-floor, perimeter-based heating ventilation and air conditioning pressurized air delivery system for use in a space includes a ventilation module, to be located in the floor, a multi-deflection linear bar grille covering the ventilation module, for diffusing the air entering the space, and a pair of apertured plates located below the grille, one plate moves relative to the other to either block more of the resultant apertures, so less air will flow, or to align the apertures, so more air will flow, all at nearly constant velocity and resultant plumage; nuances in aperture size or location allow one segment of the module to engage air flow on a lead-lag basis with respect to the other segments; air flow from the lead apertures induces air flow through a proximate under-floor heating module, to both increase its heat output and temper the ventilation air.