Industrial and Commercial Air Coolers — How to Size and Specify Them

The method is the same as for a room but the air-change rate is higher, because large spaces have more heat sources and more door traffic. Required airflow in m³/hr = floor area (sq ft) × height (ft) × air changes per hour ÷ 35.315.

Use 40 air changes for a shop, showroom, restaurant or hall, and 60 for a factory bay or workshop where machinery is adding heat. A 2,000 sq ft factory bay with a 20 ft roof at 60 air changes needs roughly 68,000 m³/hr — which is several large units, not one. Splitting the load across multiple coolers placed along one wall also gives far more even coverage than a single unit ever will.

In a house, an open window is enough. In a shed or a hall it is not. An evaporative system pushes a large volume of humid air in, and an equal volume has to get out — through louvers, ridge vents, roof extractors or simply open shutters on the far side.

Get this wrong and the symptoms are characteristic: the space feels muggy rather than cool, condensation appears on cold surfaces, and staff report that the coolers 'stopped working' an hour after start-up. The fix is an exhaust path, not a bigger cooler. As a rule of thumb, provide a free exhaust area of roughly 1 sq ft for every 1,700 m³/hr of supply, positioned as far from the coolers as the building allows so the air sweeps across the occupied space.

• Factory and workshop — 60 air changes, units along one wall, exhaust opposite. Evaporative cooling is well suited here because the sensible heat load from machinery is exactly what it removes, and the doors are usually open anyway.
• Textile and garment units — good fit. The added humidity is often helpful for yarn and thread handling, though check any process humidity limits your own line works to before committing.
• Printing presses and packaging — check paper-handling tolerances first. Paper is dimensionally sensitive to humidity, and some presses specify a narrow band. Duct-fed systems with controlled delivery suit these better than free-standing units.
• Food production — surfaces and drains must stay cleanable, and standing water needs a maintenance regime. Specify stainless or coated cabinets and plan pad cleaning into the schedule.
• Pharmaceutical and electronics — usually NOT a fit. Both routinely run controlled-humidity environments, and evaporative cooling works by raising humidity. Verify against your own facility specification before considering it.
• Warehouses and godowns — a strong fit. Large volume, high roof, tolerant of humidity, and the cost of air-conditioning the same space would be prohibitive. Check any moisture limits on what is stored.
• Shops, showrooms and restaurants — 40 air changes, and look at the tower and commercial formats where appearance matters. Door traffic is the main variable; a shop with a permanently open front needs a higher rate.
• Gyms — a good fit in dry climates. High sensible heat load, high ventilation already required, and occupants generating their own humidity means you should err towards more exhaust rather than more cooling.

This is a genuinely good application for evaporative cooling in dry-season India, and it is nearly always a hire rather than a purchase. Tents and shamianas are permeable and partly open, so make-up air is rarely the constraint it is in a building, and the alternative — temporary air-conditioning — is dramatically more expensive.

Size on volume and on people, not on floor area alone. A crowd adds substantial heat and moisture: budget roughly 100-120 W of sensible heat per standing guest and increase the air-change rate accordingly. For a 3,000 sq ft hall at 18 ft with 300 guests, plan on 60,000-70,000 m³/hr, which is typically six to ten large units placed around the perimeter blowing inward.

Practical points that decide whether the day goes well: position units upwind of the seating rather than behind it; keep them off the aisle where guests will walk; plan a water refill route, because at full output a bank of large coolers will consume several hundred litres over an evening; and run them for half an hour before guests arrive so the pads are fully wetted. If the forecast humidity is above 65%, tell the client honestly that the effect will be limited.

The industrial and commercial models verified on this site come almost entirely from Ram Coolers, which publishes prices openly — unusual in industrial cooling, where most suppliers quote on request. 51 models run from ₹10,500 to ₹1,10,000, with tanks from 100 to 750 litres, and include duct-mounted units for installations where the cooler itself has to stay out of sight.

None of them ship with a remote, and that is not an oversight: these are commissioned installations wired to a local starter, not plug-and-play appliances. Installation, ducting and make-up air are the buyer's responsibility and are not included in the listed price.