Size radiators using load, temperatures, and airflow inputs. Review area, effectiveness, and safety margin instantly. Download outputs and example data for documented engineering decisions.
| Case | Heat Load (kW) | Coolant In (°C) | Coolant Out (°C) | Air In (°C) | Airflow (CFM) | Coolant Flow (L/min) | U (W/m²K) | Fin Efficiency (%) | Available Area (m²) |
|---|---|---|---|---|---|---|---|---|---|
| Compact skid | 20 | 85 | 70 | 28 | 2200 | 70 | 130 | 78 | 2.80 |
| Process loop | 35 | 90 | 75 | 30 | 3200 | 95 | 140 | 82 | 4.20 |
| Heavy duty set | 55 | 95 | 78 | 32 | 4800 | 130 | 155 | 85 | 6.40 |
Use these sample rows to test heat rejection, radiator sizing, and thermal margin under different engineering operating conditions.
1. Required heat duty: Q = Heat Load × 1000
2. Temperature differences: ΔT1 = Coolant Inlet − Air Inlet, ΔT2 = Coolant Outlet − Air Inlet
3. LMTD: LMTD = (ΔT1 − ΔT2) / ln(ΔT1 / ΔT2)
4. Effective U: Ueffective = U × Fin Efficiency
5. Required area: A = (Q × Safety Factor) / (Ueffective × LMTD)
6. Coolant side capacity: Qcoolant = m × Cp × (Tin − Tout)
7. Air side capacity: Qair = V × ρ × Cp × (Mean Coolant Temp − Air Inlet)
8. Estimated rejection: Minimum of coolant capacity, air capacity, and UA capacity
This model assumes water-like coolant properties for quick engineering estimates. Detailed product design should also review pressure drop, fan curve, fouling, and fin geometry.
A cooling radiator calculator helps engineers estimate how much heat a radiator can remove from a system. Proper sizing protects engines, hydraulic packs, power electronics, process skids, and thermal loops. An undersized radiator raises fluid temperature and reduces equipment life. An oversized radiator adds cost, weight, and packaging difficulty.
The most important inputs are heat load, coolant inlet temperature, coolant outlet temperature, air inlet temperature, airflow, and coolant flow rate. These values define the thermal duty and the temperature driving force. The calculator also uses the overall heat transfer coefficient and fin efficiency. Those values represent exchanger quality and surface performance.
This cooling radiator calculator uses the log mean temperature difference method. LMTD gives a better thermal estimate than a simple average difference. It reflects the changing temperature gap across the core. That makes it useful for radiator sizing, heat rejection checks, and performance comparisons during early engineering studies.
The required core area shows the minimum heat transfer surface needed for the target duty. Estimated heat rejection shows what the selected core can likely remove under the entered conditions. Coverage percentage compares estimated rejection against the required duty. Thermal margin shows whether the chosen area is above or below the required area.
Airflow and coolant flow strongly affect radiator performance. Low airflow limits air side capacity. Low coolant flow reduces fluid side heat transport. This page also estimates required airflow and required coolant flow. Those values help engineers identify whether the fan system, pump selection, or core size is the real bottleneck.
Use this calculator for concept design, maintenance reviews, retrofit studies, and thermal troubleshooting. It is helpful when comparing multiple radiator sizes or operating points. The export options also make documentation easier for proposals, design notes, and review meetings. For final design, validate results with vendor data and full thermal testing.
It estimates required radiator core area, expected heat rejection, coverage percentage, thermal margin, required airflow, and required coolant flow using standard thermal engineering relationships.
LMTD captures the changing temperature difference across the radiator. That makes the heat transfer estimate more realistic than using one average temperature gap.
The calculator flags that condition because a positive temperature driving force is needed for the LMTD method in this simplified radiator sizing model.
No. It can also support process cooling loops, hydraulic packs, compressor packages, generator sets, battery systems, and other engineering heat rejection applications.
No. It focuses on thermal sizing. Pressure drop, fan static pressure, fin density, tube geometry, and fouling should be checked separately during final design.
A safety factor helps cover fouling, ambient variation, future load growth, measurement uncertainty, and performance losses that often appear in real operating conditions.
Yes, but results will shift because glycol mixtures have different density and specific heat. For detailed work, replace the simplified coolant property assumptions.
Use vendor curves and test data for procurement and final approval. This calculator is best for early sizing, comparison studies, and engineering screening.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.