Racked up units presumably around storage facility (5)
I believe the answer is:
depot
'storage facility' is the definition.
'racked up units presumably around' is the wordplay.
'racked up units presumably' becomes 'toped' (tope can mean to drink alcohol).
'around' shows that the letters should be reversed in order.
'toped' backwards is 'DEPOT'.
(Other definitions for depot that I've seen before include "Storage base" , "storeroom" , "Storehouse or warehouse" , "Headquarters - storehouse" , "Military HQ" .)