Testing statement: Firebusters has not personally tested or operated these compressors. This comparison is based on current UNIMAC/Edisons product specifications, manufacturer manuals and Australian workplace-safety guidance.
UNIMAC Air Compressors Compared
This guide compares three different UNIMAC compressor formats: the ACM-200s 20L twin-tank oil-free model, the ACM-250s 24L Quiet Air compressor and the larger ACM-1000c 100L belt-drive workshop compressor.
The important differences are not simply 20L versus 24L versus 100L. Buyers should compare free air delivery, working pressure, electrical supply, noise, maintenance, portability and the air demand of the tools they intend to operate.
| Specification | ACM-200s 20L | ACM-250s 24L Quiet Air | ACM-1000c 100L |
|---|---|---|---|
| Receiver capacity | 20L twin tank | 24L | 100L vertical tank |
| Motor | 0.8kW / 1.1HP | 1.1kW / 1.5HP twin cylinder | 2.6kW / 3.5HP |
| Pump system | Oil-free direct drive | Oil-free direct drive | Oil-lubricated belt drive |
| Air displacement | 116L/min | 210L/min | 370L/min |
| Free air delivery | 75L/min at 100 PSI | 100L/min at 3.5 bar / 3.5 CFM | 260L/min at 7 bar / 9.2 CFM |
| Maximum working pressure | 116 PSI / 8 bar | 116 PSI / 8 bar | 116 PSI / 8 bar |
| Restart pressure | 86 PSI / 6 bar | 86 PSI / 6 bar | 86 PSI / 6 bar |
| Noise | No numerical figure located | 61 dBA LpA published | 69 dBA LpA published |
| Outlets | One ¼-inch Nitto-style outlet | One ¼-inch Nitto-style outlet | Two Nitto-style outlets |
| Electrical supply | 230–240V, 10A plug | 230–240V, 10A Australian plug | 230–240V, 15A plug |
| Weight | 21kg | 20kg | 69kg |
UNIMAC ACM-200s 20L Twin-Tank Compressor
The ACM-200s is the smallest model in this comparison by published free air delivery.
Its main specifications are:
- 20L combined receiver capacity
- 0.8kW / 1.1HP motor
- 116L/min pump displacement
- 75L/min FAD at 100 PSI
- 116 PSI maximum working pressure
- 10A Australian plug
- 21kg product weight
Possible fit
- tyre inflation
- blow-gun work
- small fastening tools where air demand is within the compressor output
- intermittent workshop jobs
- users wanting a conventional 10A power connection
A 20L tank gives some stored-air reserve, but it does not transform 75L/min FAD into the capability of a much larger compressor.
UNIMAC ACM-250s 24L Quiet Air Compressor
The 24L model being merged into this comparison is the ACM-250s Quiet Air Series, SKU TOLACMUM2C5FA.
This is not simply a 24L version of the ACM-200s. It has a higher-output 1.1kW twin-cylinder motor and substantially greater published pump displacement.
Verified ACM-250s Specifications
| Model | ACM-250s Quiet Air Series |
| SKU | TOLACMUM2C5FA |
| Motor | Twin-cylinder 1.1kW / 1.5HP |
| Motor speed | 2850 RPM |
| Air displacement | 210L/min |
| Free air delivery | 100L/min at 3.5 bar / 3.5 CFM |
| Receiver | 24L |
| Maximum working pressure | 116 PSI / 8 bar |
| Restart pressure | 86 PSI / 6 bar |
| Published noise | 61 dBA LpA |
| Outlet | One ¼-inch Nitto fitting |
| Power | 230–240V, 50Hz |
| Plug | 10A Australian Standard |
| Ingress rating | IP20 |
| Dimensions | Approximately 26 × 56 × 59cm |
| Product weight | Approximately 20kg |
Is the ACM-250s Really “Silent”?
Unlike the earlier draft, we now have an actual published noise figure.
UNIMAC/Edisons lists 61 dBA LpA for the ACM-250s.
That is useful evidence that the “Quiet Air” wording is more than an unsupported marketing label.
However, sound-pressure figures depend on the test method, distance and environment. Unless two compressors have been measured under equivalent conditions, a simple dBA comparison should not be treated as a laboratory-grade ranking.
In practical terms, the 61 dBA figure is a much stronger basis for describing the ACM-250s as a quieter-format compressor than the original draft’s unverified “silent” wording.
100L/min FAD Is the More Useful Tool-Matching Number
The ACM-250s is advertised with 210L/min air displacement, but its published free air delivery is 100L/min at 3.5 bar.
These figures describe different things.
- Air displacement: theoretical volume moved by the pump.
- Free air delivery: air actually available for useful work under specified conditions.
When matching a compressor to an air tool, use FAD wherever the manufacturer provides it.
What Might 100L/min FAD Suit?
The actual answer depends on each tool’s published requirement, but the ACM-250s is more naturally matched to intermittent lower-air-demand work than continuous high-demand pneumatic tools.
Possible applications may include:
- tyre inflation
- airbrushing
- blow guns used intermittently
- brad nailers and staplers where demand is within specification
- other intermittent tools whose manufacturer specifies suitable pressure and airflow requirements
Do not assume compatibility with impact wrenches, grinders, sanders or spray equipment simply because those types of tools can physically connect to a Nitto fitting.
Check the actual tool’s consumption at the intended working pressure.
Trade Marketing vs Domestic-Use Manual
The current Edisons listing describes the ACM-250s as a “trade quality” compressor.
However, the current UNIMAC ACM-250s manual states that the equipment is designed for domestic use only.
Electrical Setup
The ACM-250s uses:
- 230–240V AC
- 50Hz supply
- standard Australian 10A plug
- 1.1kW motor
The manufacturer manual also instructs users to operate electrical equipment through an appropriate RCD/safety switch and to use a correctly grounded outlet.
The manual says not to use the compressor in wet or damp conditions.
The published IP20 rating reinforces that this should be treated as indoor/protected electrical equipment rather than weatherproof outdoor plant.
UNIMAC ACM-1000c 100L Belt-Drive Compressor
The ACM-1000c is a substantial step up from the two smaller models.
Its current specifications include:
- 100L vertical receiver
- 2.6kW / 3.5HP motor
- 370L/min air displacement
- 260L/min FAD at 7 bar
- 116 PSI working pressure
- two Nitto outlets
- oil-lubricated belt-drive pump
- 69 dBA LpA published noise
- 69kg product weight
- 15A Australian plug
At 260L/min FAD, it has substantially greater continuous air-delivery capability than either the 20L or 24L model.
It also requires more infrastructure: a proper 15A outlet, greater floor space, oil maintenance and safe handling of a 69kg machine.
Tank Size vs Free Air Delivery
A larger receiver stores more compressed air, which can provide useful reserve during short bursts of high demand.
But a large tank cannot permanently compensate for an undersized compressor pump.
For example:
- A 100L tank connected to a low-output pump can provide a useful initial reserve but may take a long time to recover.
- A smaller tank connected to a higher-output pump may recover pressure more quickly.
Therefore, compare both receiver volume and FAD.
Duty Cycle Still Matters
The current ACM-250s product information does not publish a conventional duty-cycle percentage.
The ACM-1000c listing states a duty-cycle value of 0.75, but the current sales text does not clearly explain the reference period or operating conditions behind that figure.
Do not interpret either compressor as being designed for continuous 100% operation unless the manufacturer specifically confirms that operating pattern.
For frequent production use, confirm allowable run/rest periods directly with the supplier.
Air Receivers Need Maintenance Too
The tank is a pressure vessel, not simply an empty storage container.
Condensation can collect inside an air receiver during normal compressor operation.
Follow the current manufacturer manual for draining condensate, inspecting fittings and maintaining the safety valve.
WorkSafe Victoria also emphasises that inspection and maintenance must include the air receiver itself—not just the compressor motor and pump.
Which One Makes the Most Sense?
| Model | Strongest reason to choose it | Main limitation |
|---|---|---|
| ACM-200s 20L | Compact 10A compressor for intermittent low-demand work | 75L/min FAD |
| ACM-250s 24L | 100L/min FAD plus published 61 dBA quiet-operation figure | Still limited for sustained high-air-demand tools |
| ACM-1000c 100L | 260L/min FAD and larger receiver for workshop applications | 69kg, 15A power and oil/belt maintenance |
Safety Essentials
- Use the compressor within its published working-pressure limits.
- Inspect hoses, fittings, cables, gauges and the receiver before use.
- Do not use damaged electrical equipment.
- Use an appropriate grounded outlet and RCD/safety switch.
- Keep electrical compressors away from rain and wet conditions.
- Do not direct compressed air towards people or animals.
- Use eye and hearing protection appropriate to the task.
- Drain receiver moisture and maintain pressure-relief equipment as directed by the manufacturer.
- Keep the compressor away from flammable or explosive atmospheres.
Frequently Asked Questions
What is the exact 24L model?
It is the UNIMAC ACM-250s Quiet Air Series, SKU TOLACMUM2C5FA.
What is its free air delivery?
UNIMAC/Edisons publishes 100L/min, or approximately 3.5 CFM, at 3.5 bar.
What is the pump displacement?
The published displacement is 210L/min.
Is the 24L compressor really quiet?
The manufacturer publishes 61 dBA LpA. That is much more useful than simply calling it “silent”, although exact comparison with other machines depends on equivalent measurement conditions.
Does it use a standard Australian outlet?
Yes. The ACM-250s is listed with a standard Australian 10A plug.
How much does it weigh?
Approximately 20kg.
How large is it?
Approximately 26cm wide × 56cm long × 59cm high.
How many air outlets does it have?
The current specification lists one ¼-inch Nitto outlet.
Can it run an impact wrench?
Only if the particular wrench’s air consumption and required pressure fall within what the compressor can supply. Do not assume compatibility based only on the fitting or tank size.
Is it suitable for commercial use?
The sales listing uses trade-oriented language, but the ACM-250s manual states that the equipment is designed for domestic use only. Confirm intended use and warranty conditions before commercial operation.
Has Firebusters tested these compressors?
No. Firebusters has not personally tested or operated these models.
Final Assessment
The newly added ACM-250s fills a useful gap between the 20L ACM-200s and the considerably larger ACM-1000c.
Its strongest figures are 100L/min FAD, 116 PSI working pressure, 61 dBA LpA, a 24L receiver and standard 10A power.
That makes it a more capable compact option than the ACM-200s on published airflow while avoiding the 15A electrical requirement, weight and maintenance of the 100L belt-drive model.
Our recommendation: choose according to tool air demand first. The 24L ACM-250s makes sense where 100L/min FAD is enough and lower published noise is valuable. Move to the 100L model where the tools genuinely require substantially greater sustained airflow.
Research Sources
-
Edisons – UNIMAC ACM-200s 20L specifications
-
Edisons – UNIMAC ACM-250s 24L Quiet Air specifications
-
UNIMAC ACM-250s instruction manual
-
Edisons – UNIMAC ACM-1000c 100L specifications
-
WorkSafe Victoria – Air receiver pressure vessels
Research checked September 2026. Specifications, warranty, availability and package contents can change.
General information only. Firebusters has not personally tested these products. Follow the current manufacturer manuals and applicable Australian electrical and workplace-safety requirements.
