Enclosure heat rise calculator

Preliminary estimate

Inputs

Calculation note

This is a steady-state heat-rise screen using entered thermal resistance. Enclosure selection, ventilation, derating, and manufacturer data govern final review.

Method

Temperature rise C = watts loss x thermal resistance C/W

Estimated internal temperature = ambient temperature + temperature rise

Temperature margin = maximum internal temperature - estimated internal temperature

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Formula variables

  • Watts loss is the heat load inside the enclosure.
  • Ambient temperature is the surrounding air temperature.
  • Thermal resistance is the entered enclosure heat-rise factor.
  • Maximum internal temperature is the user-entered review limit.

Assumptions

  • Watts loss is entered from equipment, conductor, or manufacturer data.
  • Thermal resistance is entered by the user from enclosure or project assumptions.
  • The estimate is steady-state and does not model sun loading, ventilation cycles, or internal hot spots.
  • This calculator does not select an enclosure, verify equipment derating, approve ventilation, or replace manufacturer thermal data.

Examples

Control enclosure screen. 120 W at 0.2 C/W in 25 C ambient estimates 49 C internal temperature and 11 C margin to a 60 C limit.

Thermal workflow. Use manufacturer enclosure data, device derating, ventilation, sun exposure, and site conditions before final selection.