Vertical lift modules are height-dependent systems. The unit stores trays in a column and uses an inserter/extractor to retrieve them. The efficiency gain comes from using ceiling height that would otherwise be wasted. But that efficiency is only realizable if the facility variables have been confirmed before the unit is specified.
The four variables that must be verified before a VLM installation is committed to:
Floor load capacity. VLMs concentrate significant weight on a small footprint. A unit loaded to capacity can exert floor loads that standard warehouse slab specifications don’t support. The slab must be evaluated before an order is placed — not after the unit arrives.
Clear height. The unit height is determined by the clear height available. That measurement must account for any HVAC ductwork, sprinkler heads, or structural members that reduce usable height below the nominal ceiling height shown on architectural drawings.
Power supply. VLMs require three-phase power at a specific amperage. If that service isn’t already available at the installation location, the electrical work needs to be scoped and scheduled as part of the project — not discovered at startup.
Access opening placement. The pick opening on a VLM faces a fixed direction. That direction must align with the workflow, not just fit in the available floor space. Once the unit is installed, repositioning it is not a realistic option. Access placement is an installation variable, not a layout preference, and it should be decided with the installation team present.
