Tall cabinets on wheels are a familiar sight on café and restaurant terraces: a front grille, controls at the top and a water tank below. Larger related units are offered for warehouses, workshops and hangars. They are often advertised as mobile air conditioners, but equipment with a water tank and evaporative pads uses a different process.
What the equipment does
An evaporative cooler draws air through wetted material. Evaporating water takes up heat, producing a cooler, more humid supply airstream. Typical components include a fan, water pump, pads, tank and water distribution system. This differs from both a plain fan and a compressor-based air conditioner.
A fan moves air. An evaporative model also uses water. A compressor air conditioner transfers heat through a refrigerant circuit; for a portable unit, the destination of the rejected hot air matters. A cabinet shape and a sales label do not establish which technology is inside.
For a café or restaurant terrace
On an open or well-ventilated terrace, the task is often local comfort: several tables, a queue near a counter or a staff position. Air direction, sound at the chosen speed and placement matter more than a headline claim of coverage up to a certain floor area.
An excessive airstream can disturb guests and blow lightweight items off tables. Mark seating and circulation routes before selecting equipment, check speed and louvre adjustment, and leave access for filling and cleaning. A canopy alone does not make equipment suitable for rain exposure: outdoor-use requirements must be checked in its documentation.
For warehouses, hangars and workshops
A larger unit may deliver more airflow, but size alone does not establish suitability for a hangar. Selection requires floor area, ceiling height, heat sources, open doors, ventilation and occupied positions. Cooling working zones can be more realistic than trying to maintain a uniform temperature throughout a high building.
Evaporative cooling adds moisture. This matters where electronics, paper or other humidity-sensitive stock is stored. An enclosed space needs a planned exhaust path. Placing a water-based cooler inside does not replace ventilation or dehumidification.
Why humidity matters
Results depend on entering air temperature and humidity. Hot, dry air offers greater evaporative cooling potential; higher humidity reduces that potential. A fixed temperature reduction cannot be promised for every location and day.
For a coastal site, including one near the Caspian Sea, request performance appropriate to local summer conditions. Compare several temperature and relative-humidity combinations rather than a single dry-climate demonstration. Increasing fan size does not remove this physical limitation.
Specifications worth comparing
- Airflow in m³/h and its adjustable range.
- Sound in dB(A), measurement distance and the operating speed used.
- Electrical input, which is not the same as an air conditioner's cooling output.
- Tank capacity, water consumption under stated conditions and permanent connection options.
- Pad dimensions and availability of filters and replacement pumps.
- Dimensions, weight, stability, castors and placement requirements.
A 60-litre tank does not guarantee a particular number of hours between refills. Runtime depends on evaporation, settings and other water use. Advertised coverage also needs to be read alongside its test assumptions.
Maintenance and purchasing
Water, tanks and pads require maintenance according to the manufacturer's instructions. Confirm drainage, cleaning access, off-season storage and replacement-part availability. Agree the configuration, electrical supply, packing and inspection of the chosen model before payment.
Send site photos, dimensions, city, operating schedule and information about power and water. These details let suppliers compare a compact terrace unit with a larger working-zone model without treating them as interchangeable.
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Technical references
Portacool: operation, water and ventilation · Energy.gov.au: evaporative cooling and humidity · Dantherm Group: commercial evaporative coolers
Minimum goods order: USD 2,000. Services and shipping are calculated separately.