Panel AC Heat Load Calculator
Estimate your enclosure cooling load and see the complete calculation, with your numbers substituted at every step.
Your cooling requirement
Required cooling at the entered conditions, including margin
Step-by-step calculation
Every substitution below uses your inputs. Calculations keep full floating-point precision; displayed working uses up to 12 significant digits. Small last-digit differences can result from display rounding.
Calculation method & assumptions
This is a steady-state, single-zone enclosure heat balance. It assumes one overall U-value and one surrounding air temperature for the counted surfaces.
Positive surface transfer adds heat. Negative surface transfer removes heat and is retained in the balance. A negative balance indicates no active cooling demand in this model; it is not a heating-system calculation.
| Mounting assumption | Counted area, in m² |
|---|---|
| Floor-standing, rear clear; bottom excluded | 2WH + 2HD + WD |
| Wall-mounted, bottom clear; rear excluded | WH + 2HD + 2WD |
| Floor-standing against wall; rear and bottom excluded | WH + 2HD + WD |
| All six faces exposed | 2WH + 2HD + 2WD |
| Custom area | The entered area is used directly |
- These are geometric exposed-face approximations, not a certified effective-area standard. Excluded faces are treated as having zero heat exchange; use a suitable custom area or a separate engineering calculation if wall/floor transfer or mounting clearances matter.
- U includes the combined surface and wall thermal resistance. For an insulated wall, a simple resistance model is U = 1 / (1/hi + Σ(thickness/conductivity) + 1/ho), with surface coefficients appropriate to the model. Material conductivity alone is not U.
- Use actual heat dissipation inside the enclosure. Electrical power exported to external equipment is not an internal heat loss.
- Solar gain, radiant sources and infiltration are not estimated automatically. Enter established additional gains separately. A margin is not a substitute for these loads.
- No universal altitude uplift is applied. Select equipment with sufficient manufacturer-rated cooling at the actual ambient, internal temperature and altitude. The optional factor translates that requirement to catalogue reference capacity.
- A zero result does not assess component hot spots, air circulation, startup transients, humidity or condensation. The U estimate may need refinement, especially when passive cooling nearly cancels the internal load.
- Input limits keep this tool within an enclosure-scale estimation range: dimensions 0.001–20 m; temperatures −50 to 150°C; U 0.01–100 W/m²·K; each heat input 0–1,000,000 W; margin 0–100%; optional capacity factor 0.01–2.
Conversions: 1 inch = 0.0254 m; °C = (°F − 32) × 5/9; 1 BTUIT = 1055.05585262 J; 1 refrigeration ton = 12,000 BTUIT/h. All displayed capacities are thermal cooling output, not electrical input power.
