Heat Dissipation Calculator

Every watt of power your equipment consumes has to go somewhere, and that somewhere is heat — no exceptions, it's just physics. This converts equipment wattage into BTU/hr so you can figure out the actual cooling capacity a server room or rack needs before you deploy into it, not after the temperature alarms start.

The equation people forget

Your cooling system has to remove at least as much heat as your IT equipment generates — plus the heat the cooling system itself generates doing the work, which is where PUE comes in.

PUE, and what "good" actually looks like

PUE = Total Facility Power ÷ IT Equipment Power. A PUE of 1.0 would mean every watt goes to compute, which doesn't happen in the real world:

• 1.1–1.2 — hyperscale-tier (Google, Facebook-scale facilities)
• 1.2–1.4 — a well-run, purpose-built modern data centre
• 1.4–1.6 — typical colocation facility, unremarkable but acceptable
• 1.6–2.0+ — an underplanned facility, or a server closet doing its best in a room that was never designed for it

Sizing the actual cooling

AC capacity is measured in tons of refrigeration — 1 ton = 12,000 BTU/hr ≈ 3.517kW. A 10kW room needs roughly 3 tons (34,000 BTU/hr) as a starting point, before you add margin for the cooling system's own overhead. Don't size to exactly match the calculated load — add 20–30% for redundancy and future growth, and if the room is anything you'd call mission-critical, plan for N+1 cooling so a single unit failure doesn't turn into an emergency. The failure mode nobody plans for well enough is a cooling unit going down on a Friday evening with nobody watching the temperature graph until Monday.