⚡ Load Inputs

From BTU/hr Values
From Airflow + Conditions
Dry heat: conduction, solar, lights, people (sensible)
Moisture: people, OA humidity, infiltration

📚 Typical SHR by Space Type

Space TypeTypical SHRLatent Load SourceLevel
Office / Commercial0.85–0.95People, ventilation OALow Latent
Retail0.80–0.90People, OA, infiltrationLow Latent
Restaurant / Kitchen0.65–0.75Cooking, high OA, steamHigh Latent
Gym / Fitness0.65–0.75Heavy occupancy sweat loadHigh Latent
Natatorium / Pool0.30–0.55Evaporation from water surfaceHigh Latent
Hospital Patient Room0.70–0.80People, OA requirementsMed Latent
Warehouse0.90–0.98Minimal occupancyLow Latent
Humid Climate (summer)0.70–0.80OA humidity, infiltrationHigh Latent

📝 About This Calculator

This sensible vs latent split calculator finds the sensible heat ratio (SHR) and the breakdown of a cooling load into dry sensible heat and moisture-removal latent heat. Enter the loads directly in BTU/hr, or enter supply airflow with room and supply dry-bulb temperatures and humidity ratios and let the tool compute each component.

SHR is the single number that tells you whether a space is mostly a cooling problem or also a humidity problem. The tool plots the split, reports total tons, and flags low-SHR cases where supplemental dehumidification — reheat, a dedicated dehumidifier, or a desiccant wheel — is usually needed.

🔢 Formula & Method

QuantityEquation
Sensible heat ratioSHR = Sensible ÷ (Sensible + Latent)
Sensible loadQ‑sens = 1.08 × CFM × ΔT (°F)
Latent loadQ‑lat = 0.68 × CFM × ΔW (gr/lb)
Total coolingTons = (Sensible + Latent) ÷ 12,000

The airside constants follow ASHRAE Fundamentals: 1.08 for sensible heat (specific heat × density × 60) and 0.68 for latent heat when the humidity-ratio difference ΔW is in grains per pound of dry air. SHR is the sensible fraction of the total; equipment SHR is typically 0.70–0.80, so a lower space SHR signals a need for supplemental dehumidification.

❓ Frequently Asked Questions

What is sensible heat ratio (SHR)?
Sensible heat ratio is the sensible cooling load divided by the total cooling load, where total is sensible plus latent. An SHR of 0.80 means 80 percent of the load is dry sensible heat and 20 percent is moisture removal. It describes the balance between cooling the air down and drying it out, which drives how a cooling coil and any dehumidification are selected.
What does a low SHR mean for equipment selection?
A low SHR, below about 0.75, means a large share of the load is latent moisture. Standard cooling equipment has an SHR near 0.70 to 0.80, so when the space SHR is even lower, the coil tends to over-cool the air before it removes enough moisture. That points to supplemental dehumidification such as hot gas reheat, a dedicated dehumidifier, or a desiccant wheel.
How is the split found from airflow and conditions?
Sensible load is 1.08 times CFM times the dry-bulb temperature difference between room and supply air. Latent load is 0.68 times CFM times the humidity-ratio difference in grains per pound between room and supply air. The 1.08 and 0.68 factors are the standard sea-level airside constants from ASHRAE Fundamentals. Adding the two gives the total, and sensible over total is the SHR.
Which spaces typically have high latent loads?
Spaces with lots of moisture or high outdoor air have low SHRs and high latent fractions: restaurants and kitchens, gyms and fitness rooms, natatoriums and pools, and any space in a humid climate with significant ventilation. Offices, retail, and warehouses are mostly sensible with SHRs from about 0.85 to 0.98. The reference table on this page lists typical values by space type.

🔗 Related Tools

Supply Air Temp Cooling Coil Calculator Quick Load Estimator Infiltration Load Humidity Ratio
Free 14-Day Trial  ·  No Credit Card

Do the full calculation in AIM Works

This calculator handles one step. AIM Works runs the complete MEP design workflow — thermal load calculations, duct & pipe networks, equipment selection, code compliance, and an AI design assistant — in one tool.

  • ✓  ASHRAE 62.1 ventilation + CLTD/CLF/RTS load methods
  • ✓  Darcy-Weisbach pipe & duct network solvers
  • ✓  ASHRAE 90.1 / IMC / NFPA compliance checks
  • ✓  20 free AI design messages included in trial
Try It Free for 14 Days →
No credit card  ·  Cancel anytime
See plans & pricing →