How do you size commercial AC for a warehouse? Warehouses carry a low internal heat load from large volume with light occupancy, so they need less cooling than an equivalent office. A typical 15,000 sq ft Warehouse needs about 28.6 tons (2 × 15-Ton RTUs). The calculator below is pre-set to a Warehouse — enter your exact area.
Commercial HVAC Demands for a Warehouse Facility
Sizing an HVAC system for a Warehouse Facility involves complex variables that far exceed standard residential calculations. A Warehouse Facility experiences intense internal heat gains from specialized electronics, high-density lighting, and fluctuating occupancy levels throughout the day. Furthermore, commercial building codes mandate specific fresh air ventilation rates, which drastically increases the latent moisture load the AC must remove. Use our commercial calculator to properly size your rooftop units or CRAC systems to ensure your Warehouse Facility remains safe, comfortable, and code-compliant.
🏢 Commercial Cooling Tonnage, RTU Staging & CFM
Size commercial HVAC for offices, retail, restaurants, server rooms and warehouses. Get the required cooling tonnage, a recommended rooftop unit (RTU) staging combination, and the fresh-air ventilation CFM — factoring business type, occupancy, internal heat loads, ceilings and climate.
🏢1. Building Type
Each building type carries a different internal heat load — a restaurant kitchen or server room runs far hotter than an office or warehouse.
📐2. Floor Area & Ceiling
Range: 500 – 50,000 sq ft
👥3. Occupancy & Internal Loads
Auto-set from building type & area — adjust to your peak headcount.
🌍4. Climate & Unit Staging
Multiple staged RTUs give redundancy (if one fails, the building stays partly cooled) and better part-load efficiency — the commercial standard.
Warehouse AC Size by Floor Area
Typical commercial cooling load and RTU staging for a warehouse in a moderate climate (standard ceilings):
| Floor Area | Cooling Load | Recommended RTUs |
|---|---|---|
| 5,000 sq ft | 9.5 tons | 2 × 5-Ton RTUs |
| 10,000 sq ft | 19.1 tons | 2 × 10-Ton RTUs |
| 20,000 sq ft | 38.2 tons | 3 × 15-Ton RTUs |
| 40,000 sq ft | 76.3 tons | 4 × 20-Ton RTUs |
What Drives Warehouse Cooling Load
For a warehouse, the biggest factor is the low internal heat from large volume with light occupancy, on top of the building envelope and occupancy. Warehouses are usually only partly conditioned; if you cool the whole high-bay volume, tonnage rises quickly. Commercial systems stage multiple rooftop units for redundancy and part-load efficiency. Confirm the final design with a licensed mechanical engineer.
Frequently Asked Questions
How do you size AC for a warehouse? Start with the floor area and building type, then add occupancy, equipment and climate. Warehouses run a low internal load, so a 15,000 sq ft space needs about 28.6 tons (2 × 15-Ton RTUs).
How many tons of AC per square foot for a warehouse? Roughly 1 ton per 524 sq ft for a warehouse at standard conditions — lighter than an office. Use the calculator above for your exact size and climate.
Do Warehouses need multiple rooftop units? Yes, once the load passes about 7.5 tons — staged RTUs keep the building partly cooled if one fails and run more efficiently at partial load.
Related: the fundamentals of industrial refrigeration.
Estimates vary by contractor. Compare free quotes from licensed local pros before you commit. Request a quote →
High-efficiency systems may qualify for utility rebates and federal or state incentives. Find current programs at ENERGY STAR & DSIRE.
Figures are reviewed by the Refcon HVAC engineering team using U.S. DOE, ENERGY STAR & ACCA Manual J data. Estimates only — confirm with a licensed pro.