Coltri Compressors: The Range Explained Model by Model

The Coltri range, when viewed from the list of models, seems more complicated than it is. Icon, Mini Compact, Mini Silent, Predator, Smart, Ergo, Mark III, Super Silent, Eolo: names that say nothing about what distinguishes one machine from another, and which are multiplied by the engine codes.

However, the divisions that really matter are few, and none of them are the commercial name. They are the operating pressure, flow rate, maintenance interval, and power supply type. Once these four are known, the range can be understood in a few minutes.

This article covers them one by one, with prices updated as of August 2026.

High Pressure vs. Low Pressure

This distinction needs to be clarified first, because it is also where the most costly mistake is often made.

Almost all models in the range are high-pressure compressors: they compress breathable air up to 232, 300, or 330 bar, which is what is needed to fill a scuba tank.

The Eolo 330 series does not belong to this category. It is a low-pressure compressor: it delivers 300 liters per minute at 8 bar, with a 6-liter tank, and is intended for underwater work with surface supply and ventilated helmets. An Eolo does not fill a tank, and no accessory can make it do so.

The fact that it costs less than several high-pressure models — 2,154 euros — makes it a natural candidate for misunderstanding for those looking for the lowest price. It is worth checking the operating pressure before any other consideration: 8 bar and 330 bar identify two machines with uses that do not overlap at any point.

Flow Rate is in the Model Name

The number accompanying the commercial name indicates the flow rate in liters per minute of free air aspirated. The Icon LSE 100 delivers 100 l/min, the Smart 125 delivers 125, the Predator 140 delivers 140, and the Ergo 210 delivers 210. Reading is immediate once the criterion is known.

The flow rate determines the filling time, but it is not the parameter on which to base the choice. A 15-liter cylinder filled from 50 to 200 bar requires 2,250 free liters, which is about twenty-two minutes at 100 l/min and sixteen at 140. The difference has little impact on occasional use, and a lot on the number of consecutive operating hours in a working day.

The Division that Really Matters: Oil Change Interval

Comparing the specifications of individual models reveals a difference not found in commercial names, which divides the range into two distinct groups.

Icon LSE, Icon Petrol, Mini Compact, and Mini Silent declare an oil change interval of one year or 50 hours of operation. Predator, Smart, Ergo, Mark III Silent, and Super Silent declare one year or 1,000 hours.

The difference is twenty-fold, and describes two distinct machine categories. The former are portable compressors designed for short cycles and intermittent use: fifty hours correspond to a few dozen refills. The latter are work machines, sized to operate for long periods and regularly.

This is the first parameter to check when comparing two similarly priced models, as it affects the operating cost more than any other item.

The Four Families of the Range

Once pressure, flow rate, and maintenance interval are clarified, the models naturally group together.

Open Portables. Icon LSE, Icon Petrol, and Mini Compact share the 100 l/min pumping unit and open frame. They are the lightest and most economical machines in the range, between 2,533 and 2,746 euros, and this is the segment for personal use. The Mini Compact features a reinforced, more enveloping frame, designed for marine use.

Enclosed Portables. The Mini Silent series uses the same pumping units — MCH 6 at 100 l/min and MCH 8 at 125 — inside a soundproofed enclosure, with automatic condensate drain and auto-stop as standard. The surcharge compared to the open version corresponds to the enclosure and features, not to a different work capacity.

Compact Work Machines. Predator and Smart belong to the 1,000-hour class. The Predator features the MCH 7 three-stage pumping unit with Maxifilter filtration system, automatic condensate drain, and auto-stop as standard; the Smart is the reference model in its category, with two cylinder connections.

Heavy-Duty Machines. Ergo, Mark III Silent, and Super Silent add monitoring: interstage pressure gauges, oil level control, internal cabin temperature with automatic shutdown, and rotation direction detector. These are the machines for diving centers and refill stations, ranging from 9,314 euros for the Ergo 210 to 14,904 for the Super Silent 235.

Engine Codes

The letters following the flow rate indicate the power supply, and this is the parameter that most often excludes models even before choosing them.

• EM — single-phase electric motor, typically 230 V 50 Hz;
• ET — three-phase electric motor, typically 400 V 50 Hz;
• SH — Honda GP 200 petrol internal combustion engine.

The available power should be checked before selecting the model. A 3 kW single-phase compressor draws about 13 amperes during operation, a value that a standard 3 kW domestic contract cannot support. Where a three-phase line is present, the ET version results in more efficient operation and less strenuous starts.

The petrol version makes the machine independent of the grid, a necessary condition on board or on expedition, but introduces engine maintenance — with its own lubricants, filters, and intervals — and requires attention to the position of the air intake relative to the exhaust.

Maximum Operating Pressure

Not all models reach the same pressure, and this data matters for those using 300 bar cylinders.

Icon, Mini Compact, and Mini Silent declare a maximum operating pressure of 330 bar. The Predator reaches 350. Smart, Ergo, Mark III Silent, and Super Silent reach 420 bar, with the caveat that on the Mark III the limit depends on the motorization: 232 bar in the single-phase electric version, 420 in the three-phase.

This data should be read on the specific configuration sheet, not on the model family.

What's Consistent Across the Entire Range

Some features do not vary among high-pressure models and therefore do not constitute a selection criterion.

All models produce breathable air according to EN 12021 and are declared compatible with nitrox up to 40% oxygen, helium, and nitrogen. All use the same Coltri ST 755 synthetic oil. All declare an allowed temperature range between -10 and +40 degrees and a maximum inclination of 6 degrees. The suction pressure is atmospheric, with a maximum of 300 millibars.

The altitude limit varies slightly: 2,000 meters for open portables, 1,500 for enclosed and heavy-duty machines.

A Case Worthy of Attention

For the same flow rate, the Mini Silent 125 and the Smart 125 both deliver 125 liters per minute. The former costs 7,621 euros and declares an oil change interval of 50 hours; the latter costs 6,225 euros and declares 1,000 hours.

The advantage of the Mini Silent is the soundproofed enclosure, which in a residential or condominium setting can be the decisive criterion. But if quietness is not a constraint, the Smart costs less and belongs to the higher maintenance class.

This is the type of comparison that the commercial name does not suggest, and it is why it is advisable to read the specifications before the price list.

Conclusion

The Coltri range can be understood in four steps: check whether the model is high or low pressure, read the flow rate in the name, check the oil change interval to understand which class of machine it belongs to, and verify that the motorization is compatible with the available power supply.

Commercial names distinguish families, not performance. Performance lies in the specifications, and it is these that determine whether a machine is suitable for a particular use.