How do commercial operations defrost large amounts
As Allison C commented. You move meat to walk in fridge and wait. You always have a few days reserve waiting for you. It's also safer as meat that have been in cooler for 4 days can be used on fifth day. While if you thawn it completly in room temperature (or under water but it was in room temperature while you taken it ou tof the sink) you would need to use it immediatelly.