Rack having scalability and compatibility

A method to configure a rack having a fixed outer volume boundary to support computerized equipment having different sizes, the method comprising:

• providing a main frame, the main frame including a plurality of fixed structural elements defining a first enclosure within an outer volume boundary of the main frame that is the outer volume boundary of the rack, the first enclosure having a particular first set of dimensions, the particular first set of dimensions including a first width and a first length, the main frame configured to directly couple with a first shelf within the first enclosure to structurally support computerized equipment having a particular dimension that is a first size within the first enclosure;
• and
• detachably coupling at least one additional frame with the main frame inside the first enclosure defined by the plurality of fixed structural elements the first enclosure to at least partially define a second enclosure within the first enclosure, the second enclosure having a particular second set of dimensions that is different from the particular first set of dimensions, the particular second set of dimensions including a second width and a second length, the second width different from the first width, the second length different from the first length, such that the plurality of fixed structural elements continue to define the first enclosure having the particular first set of dimensions simultaneously with the at least one additional frame defining the second enclosure having the particular second set of dimensions within the first enclosure, the at least one additional frame configured to couple with a second shelf within the second enclosure to structurally support computerized equipment having the particular dimension that that is a second size within the second enclosure, the second size different from the first size,
• wherein the at least one additional frame has a rectangular parallelepiped shape defining an empty interior at least partially bounded by structural material, in a structure of which one side is open,
• wherein the at least one additional frame is configured to couple with the second shelf within the second enclosure such that the main frame that defines the first enclosure is indirectly coupled with the second shelf within the second enclosure via the at least one additional frame,
• wherein the rack further includes a rear frame configured to at least partially define a rear enclosure configured to support a direct current (DC) rectifier module.