Workshop AC Sizing Calculator

Need to size the air conditioning for a workshop? Workshops and light-industrial spaces gain heat from machinery, tools, and large doors, giving a cooling factor near 25 BTU/sq ft. Keeping a workshop cool improves both worker comfort and the accuracy of temperature-sensitive work. The calculator below is pre-set to a workshop at 500 sq ft — a workshop that size typically needs about a 1.5 Ton AC (15,125 BTU/hr, 4.4 kW) in a moderate climate. Enter your own area for an instant answer.

🧊 Find the Right AC Size for Your Room — in Tons & BTU

Convert room size (sq ft or m²) to the exact AC tonnage you need — 0.5, 1, 1.5, 2 Ton and up. ACCA Manual-J inspired, in tons, BTU/hr and kW, for the US, UK, Europe, India, UAE, Saudi Arabia & Australia.

🌍 Prefer metric? Switch units here

🏠1. Space Type

📐2. Floor Area & Ceiling

sq ft

Range: 50 – 10,000 sq ft

ft

Range: 7 – 20 ft

people

Range: 0 – 50 people

🌍3. Country / Climate

The base factor assumes a 30 °C / 86 °F design day. Change the chip above to match your region.

🧱4. Insulation

☀️5. Sun Exposure

🪟6. Windows / Glazing

Advanced loads (kitchen, appliances, exhaust) — optional

Wattage × 3.4 = BTU/hr. e.g. 500 W ≈ 1,700 BTU/hr

For office IT, gym gear, lab equipment

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Workshop AC Size by Floor Area

Typical AC tonnage for a workshop with an 8-foot ceiling and average conditions. Heavy equipment, high occupancy, or a hot climate will push these up — adjust those in the calculator:

Workshop SizeRecommended ACApprox. BTU/hr
300 sq ft1 Ton9,075 BTU/hr
500 sq ft1.5 Ton15,125 BTU/hr
800 sq ft2.5 Ton24,200 BTU/hr
1,200 sq ft4 Ton36,300 BTU/hr
2,000 sq ft5 Ton60,500 BTU/hr
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Sizing AC for a Workshop — What to Consider

Add machine and equipment heat with the equipment field, and account for large roller-doors that let heat in. Spot-cooling the work areas is often more efficient than trying to cool an entire high-bay workshop to a uniform temperature. The calculator applies the workshop heat-gain factor automatically; use the advanced fields (occupants, equipment, appliances, ventilation) to match your exact space, and remember an oversized unit short-cycles and dehumidifies poorly — right-sizing gives better comfort and lower running cost.

Frequently Asked Questions

What size AC do I need for a workshop? A 500 sq ft workshop typically needs about a 1.5 Ton AC (15,125 BTU/hr) in a moderate climate; scale up or down with your floor area per the chart above.

What size AC for a workshop? Around 25 BTU/sq ft plus machinery heat. Large open workshops are often spot-cooled at the work areas rather than cooled uniformly throughout.

How many BTU per square foot for a workshop? Roughly 25 BTU/sq ft as a starting factor, before adjusting for climate, ceiling height, occupancy, and equipment heat.

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Background reading: how the refrigeration cycle works.

Before you decide — three quick things
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Reviewed for accuracy
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.
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