Calculation sequence
Step-by-step method
- Determine average airflow and the absolute dry-bulb temperature difference.
- Use air density and specific heat appropriate to the measurement conditions.
- Multiply the terms using consistent units.
MechanicalIntermediateHeat Transfer
Airside Sensible Heat Calculator
Estimate sensible airside capacity from airflow, dry-bulb temperature difference, air density, and specific heat.
Why it matters: Measured airflow and temperature change provide a direct field check of sensible heating or cooling performance.
Calculated result
Engineering evaluation
Sensible heat transfer (Q̇s)216,000 Btu/h
- Effective sensible coefficient (Cs)
- 1.08 Btu/(h·cfm·°F)
- Temperature difference (ΔT)
- 20 °F
Engineering interpretation
Estimated sensible capacity is 216000 Btu/h. This excludes latent heat and depends directly on airflow accuracy, sensor placement, air density, and steady operating conditions.
Engineering knowledge center
Understand the calculation—not just the answer
Governing relationships
Cs = 60ρcₚ
Q̇s = CsV̇ΔT
Current substitution
Q̇s = 60ρcₚV̇ΔT = 60 × 0.075 × 0.24 × 10000 × 20 = 216000 Btu/h.
Equation legend
Inputs and calculated quantities
- V̇
- Airflow — cfm or m³/s
- ΔT
- Dry-bulb temperature difference — °F or K
- ρ
- Air density — lb/ft³ or kg/m³
- cₚ
- Air specific heat — Btu/(lb·°F) or kJ/(kg·K)
- Q̇s
- Sensible heat transfer — Btu/h
- Cs
- Effective sensible coefficient — Btu/(h·cfm·°F)
- ΔT
- Temperature difference — °F
Applications
How this calculation is used
Building design
Perform preliminary airflow and sensible-capacity checks.
Construction
Evaluate whether equipment startup data are consistent with scheduled sensible duty.
Commissioning
Compare measured airside sensible capacity with scheduled performance while documenting uncertainty.
Quality controls
Assumptions and limitations
Assumptions
- Steady airflow and representative dry-bulb temperatures.
- No latent heat included.
- Density and specific heat correspond to the selected units.
Limitations
- Sensor and airflow uncertainty can dominate the result.
- Stratification, leakage, and heat gain/loss between stations are not modeled.
Field use
Verification procedure
- Stabilize equipment and document mode.
- Measure airflow with an appropriate method.
- Average representative entering and leaving temperatures.
- Estimate uncertainty and compare with scheduled conditions.
Common engineering mistakes
- Using the rounded 1.08 coefficient at nonstandard density without correction.
- Mixing total and sensible capacity.
- Using poorly located temperature sensors.
Technical basis
References and source standards
- 2025 ASHRAE Handbook—FundamentalsChapters 1, 3, 4, and 38.
Engineering calculation disclaimer
These engineering tools are provided for educational, preliminary evaluation, field verification, and commissioning support. Results depend on the accuracy of user-entered information and the assumptions stated for each calculation. Every colored status and comparison is a screening indicator only; project criteria, contract requirements, applicable codes, manufacturer instructions, measurement uncertainty, and authorized engineering judgment govern. The tools do not replace project-specific engineering analysis or the judgment of a licensed professional engineer.
Read the full use and limitation statement