Commercial HVAC Load Calculator
Calculate heating and cooling loads for commercial buildings following ASHRAE standards. Professional tool for office buildings, retail stores, restaurants, warehouses, hospitals, and schools.
Building Information
Conditioned floor area
Load Factors
Outside air requirements per code
Watts per square foot
Plug loads, computers, equipment
Percentage of wall area that is windows
Building Construction & Climate
Peak outdoor temperature for cooling design
Minimum outdoor temperature for heating design
Commercial Load Calculation
This professional calculator follows ASHRAE standards for commercial building load calculations, considering all major heat gain and loss factors.
- Building envelope analysis
- Internal heat gains (lighting, equipment, occupancy)
- Ventilation requirements
- Operating schedule considerations
- Equipment sizing recommendations
ASHRAE Compliant: Calculations follow industry standard methodologies for accurate commercial HVAC system sizing and design.
Using the Commercial Load Calculator
This ASHRAE-compliant calculator determines heating and cooling loads for commercial buildings. Follow these guidelines for accurate results that meet professional engineering standards.
Calculator Input Guide
Building Information
- Building Type: Select from office, retail, restaurant, warehouse, hospital, school, or hotel
- Square Footage: Enter total conditioned floor area
- Stories: Count all conditioned levels
- Ceiling Height: Average height from floor to ceiling
Load Factors
- Ventilation CFM: ASHRAE 62.1 outdoor air requirements
- Lighting Load: Watts per sq ft (0.8-3.0 typical range)
- Equipment Load: Plug loads, computers, process equipment
- Window Area: Percentage of total wall area
Building & Climate
- Orientation: Primary building face direction
- Wall Type: Steel frame, masonry, concrete, or curtain wall
- Design Temps: Summer/winter outdoor design conditions
- Occupancy: Peak number of people in building
Building Type Guidelines
Office Buildings
Lighting: 1.0-1.5 W/sq ft | Equipment: 1.0-2.0 W/sq ft | Occupancy: 150-200 sq ft/person
Retail Stores
Lighting: 1.5-3.0 W/sq ft | Equipment: 0.5-1.0 W/sq ft | Occupancy: 100-300 sq ft/person
Restaurants
Lighting: 1.0-2.0 W/sq ft | Equipment: 2.0-5.0 W/sq ft | Occupancy: 15-50 sq ft/person
Warehouses
Lighting: 0.5-1.0 W/sq ft | Equipment: 0.5-2.0 W/sq ft | Occupancy: 500-2000 sq ft/person
Ventilation Requirements
ASHRAE 62.1 Minimum Outdoor Air:
Understanding Results
Results provide total building heating and cooling loads, equipment sizing recommendations, and ventilation load analysis. Use these values for preliminary equipment selection and system design. All calculations follow ASHRAE standards for commercial applications.
Next Steps
- • Consult mechanical engineer for detailed design
- • Consider equipment sizing options
- • Plan ductwork and distribution systems
- • Review local code requirements
Additional Resources
Professional Engineering Required
Commercial HVAC systems require design by licensed professional engineers. This calculator provides preliminary estimates for planning. Final design must include detailed analysis, local code compliance, and professional engineering review.