Capacity
A 40ft container roughly doubles the usable internal footprint of a 20ft unit, supporting more IT racks, larger power and cooling plant, and in many designs, a walk-in maintenance aisle.
Site Constraints
20ft containers suit sites with limited space, weight/logistics restrictions, or smaller IT load targets — common at edge or temporary sites. 40ft units suit larger, longer-term deployments.
Logistics
Both sizes move via standard ISO container logistics; 40ft units may face more restrictive access at sites with tight roads or limited crane capacity, which should be assessed during site survey.