A cold storage unit includes a side access storage rack for holding storage boxes. The storage rack includes a housing with a top wall, a bottom wall, and a rear side wall extending between the top and bottom walls to define a storage space. The storage rack also includes a plurality of vertical dividers extending from the rear side wall and a horizontal shelf configured to be engaged with the plurality of vertical dividers to split the storage space into a grid of box receptacles for the storage boxes. The horizontal shelf includes an angled front portion that is bent and is configured to frictionally engage divider slots in the vertical dividers to thereby hold the horizontal shelf in position with respect to the housing. This frictional engagement simplifies manufacturing and improves the functionality of the storage rack.