Storage and retrieval system

A storage and retrieval system comprising:

• an enclosure comprising a temperature control system configured to regulate the air temperature inside the enclosure, wherein the enclosure houses:
• a storage structure comprising:
• a supporting framework structure comprising a plurality of storage columns, each of the plurality of storage columns being arranged to accommodate a stack of storage containers;
• a track structure comprising a plurality of tracks arranged to form a grid pattern defining a plurality of grid cells, said track structure is mounted on the supporting framework structure such that each stack of storage containers is arranged below a grid cell;
• and
• a plurality of port columns comprising a drop-off column for dropping off a storage container from the track structure and a pick-up column for picking up a storage container from the track structure;
• wherein a portion of the enclosure houses an access station located below the track structure, wherein the access station is between the drop-off column and the pick-up column to define a passage between the drop-off column and the pick-up column, the access station comprising a conveying device configured to convey a storage container along the passage;
• and
• wherein the portion of the enclosure comprises an external opening for allowing access to a storage container at the access station from outside the enclosure.