Rack Planner & Architecture Explorer.

· Method · How the rack planner counts

User-defined devices, and arithmetic you can check.

The planner draws 12U, 18U, 24U and 42U frames — the wall-box sizes, the 24U compact head-end frame the reference elevations above use, and the full-height floor rack. You name each device by equipment class, state its rack units and, optionally, its wattage; the tool does the addition and shows its working. It is a budgeting instrument for the design conversation, not a substitute for the rack elevation an engineer issues for construction.

Rack-unit budget

Used U is the sum of the rack-unit heights you enter, one per device. Spare U is the frame height minus that sum; when the sum exceeds the frame, the tool says by how much rather than quietly rescaling the drawing. Frame utilisation is used ÷ frame as a whole percentage. Nothing else enters the arithmetic — there is no allowance, no rounding-up factor and no hidden rail, mounting or depth deduction.

Where the rack-unit heights come from

From you. Every rack-unit height and wattage here is yours: typed in, or started from one of the illustrative reference layouts — or from a row another tool handed over, which arrives at this editor's own minimum height, says so where it sits, and can be edited or removed — and then set by you. This planner holds no per-model rack heights, power draw or heat figures of its own and offers none. Two registers in this practice do publish physical figures for their own device class — the amplifier register and the network-switch register — and neither is wired in here: between them they cover two of the many classes a rack holds, their consumption figures are published under each manufacturer's own test condition rather than as a rack load, and no record anywhere publishes a heat figure. A device's rack-unit height is printed on its own data sheet and on the carton; the honest place for that number is the visitor's hand, not a lookup table this practice would have to invent.

Connected load

Connected load is the sum of the wattages you enter against individual devices. If you also state a PoE figure — what your own switches deliver downstream — you say whether it is already inside those device wattages or additional to them, and it is counted once or not at all accordingly. The PoE budget of a switch is what it delivers to endpoints, not what the rack draws from the wall, and the two are confused often enough that the tool asks rather than assumes.

Preliminary heat

Preliminary HVAC screening, not a cooling design: connected load × 3.412142 BTU/h per watt, on the screening assumption that rack electronics dissipate their electrical input as heat. Room cooling is a room-load problem — envelope, ambient, adjacency and redundancy — and none of those inputs are asked for here. It is a screening figure that tells you whether the equipment room is in the comfortable-ventilation conversation or the dedicated-cooling conversation. It is not a tonnage, a CFM figure or a containment verdict, and it should not be used as one.

What the planner will not tell you

No cooling tonnage. No UPS runtime or battery sizing — that model is under engineering review and a rack figure may not be chained through it. No pricing, no bill of quantities and no port map. And no per-model claim of any kind: the tool never says what a named product weighs, draws or occupies, because it does not know and will not guess.

The equipment classes the planner offers are Patch panel / cable manager, Network switch, Router / firewall, Controller / processor, AV matrix / distribution, Amplifier, Server / recorder appliance, I/O or power panel, Monitor / HMI, Equipment shelf, Blanking panel, PDU / power distribution, UPS — labels only. A class carries no rack-unit height, no wattage and no manufacturer, which is why picking one can never put a figure in front of you that nobody measured.