Vulcraft’s joists can be custom designed with rectangular Vierendeel openings to allow large heating, ventilation, and air conditioning (HVAC) ducts to pass through the open web system. Doing so reduces the required floor-to-floor height, as the MEP can run through the Vierendeel opening rather than beneath the joist bottom chord.
The Vierendeel opening should be located near the minimum vertical shear across the steel joist (typically near the joist mid-span for a uniformly loaded joist). Doing so reduces the combined vertical shear forces required to be carried by the joist top and bottom chords, resulting in the greatest joist weight savings. Vierendeel openings provide maximum flexibility with MEP layout – making them ideal for multi-story buildings.