Fast, honest answers for cooling design: every calculator shows its equations, states its assumptions, and tells you when the estimate deserves a real simulation. No login, no vendor catalog, no black box.
Sealed cabinet heat balance: dimensions, internal load, and temperature limits to required cooling capacity.
Thermoelectric sizing: module capacity, input power, and the hot-side heat-sink budget for a below-ambient device.
Coolant flow in L/min and GPM for water, glycol mixes, and oils - sized at the real winter mixture.
Block ramp power and TEC stack sizing from thermal mass, ramp rate, and cycle temperatures.
Classic radial heat loss: W per meter, surface touch temperature, bare-pipe savings, and the critical-radius check.
Add insulation to your wall or attic and see the new total R, heat loss before and after, and percent reduction.
Room-level BTU/h and tons: envelope, window solar, people, equipment, and infiltration - itemized.
Parked-car cabin temperature: reflective blanket vs cracked windows vs both, charted across sunny-day temps.
These tools implement the standard closed-form heat-transfer balances every thermal engineer learns - and they show their work. Each page prints the governing equations, lists the assumptions that make the closed form valid, and is explicit about where the estimate ends: duty cycles, transients, gradients, and control behavior belong to full network simulation, not a one-line formula. Use the numbers here to scope hardware, sanity-check vendor claims, and frame the real analysis.