Industrial Chiller Cooling Load Calculator

For electrical motors: multiply motor kW × 3,412 BTU/hr per kW, then multiply by the heat fraction (typically 0.80–0.95 for motors driving fluid pumps or compressors, where most energy converts to heat). For hydraulic systems, assume 80–90% of motor power becomes heat in the hydraulic oil. For resistive heaters: 100% of kW becomes heat. Use the "Area / kW Input" mode in this calculator and select kW to automate this conversion. For spindle motors and servo drives, check the OEM's stated heat rejection rate — often provided in BTU/hr or kW in the machine specifications.

They're the same unit: 1 ton of refrigeration = 12,000 BTU/hr = 3.517 kW. The term "refrigeration ton" comes from the amount of heat required to melt one ton of ice in 24 hours. This unit applies to both process cooling and HVAC applications — there is no difference between a "refrigeration ton" and an "air conditioning ton." Where confusion arises: tower tons (15,000 BTU/hr) are different from refrigeration tons (12,000 BTU/hr) — the tower must reject 25% more heat than the chiller removes.

Water-cooled chillers are 30–40% more efficient than air-cooled (0.55–0.75 vs 0.90–1.20 kW/ton) but require a cooling tower, condenser water pump, and water treatment program. For industrial plants above 50–100 tons with continuous operation, the energy savings almost always justify the water-cooled system within 2–4 years. Air-cooled makes sense for: loads under 50 tons, seasonal or part-time operation, locations with water scarcity, or when the installation cost of cooling tower infrastructure is prohibitive. Note: air-cooled efficiency degrades significantly in hot weather — at 95°F ambient, an air-cooled chiller may derate to 80–90% of its rated capacity.

Always use the warmest supply temperature that meets your process requirement — colder water requires more energy and may cause condensation problems. Standard HVAC: 44°F supply / 54°F return (10°F ΔT). CNC machine tools: 50–60°F supply (check OEM spec — most modern CNC requires only 55–65°F). Injection molding: varies by resin — HDPE runs at 60–70°F mold temp, PET at 40–50°F, ABS at 65–75°F. Hydraulic oil coolers: 65–80°F supply. Each 1°F increase in chilled water supply temperature improves chiller efficiency by approximately 1.5–2%. Running at 50°F instead of 44°F saves 9–12% of chiller energy.

You need glycol only if the chilled water temperature at any point could drop below 35°F (with 5°F safety margin above freezing). For standard 44°F supply systems, pure water is fine. Use glycol when: supply temperature is below 40°F; the chiller evaporator could freeze during off-hours; the system runs in a freezing environment. Glycol reduces the heat capacity of the fluid (lower Cp), so you'll need higher flow rates or accept higher supply temperature. Ethylene glycol 25% protects to 15°F; 50% to −35°F. Propylene glycol is preferred for food and pharmaceutical applications due to its lower toxicity. Always account for the glycol correction factor in sizing calculations — this calculator does this automatically.