An industrial air compressor should be purchased as part of a specified air supply. For an Australian workshop or plant, the useful comparison is whether the proposed installation can deliver the required flow, pressure and air quality at the points of use, with an understood maintenance and operating cost.
Start by documenting the demand. Atlas Copco’s sizing guidance considers applications, air consumption, working pressure, air quality and future capacity when planning an installation. CAPS likewise identifies flow, pressure, application and duty requirements as selection inputs. [1][2] Neither a motor-power figure nor a catalogue tank size is a complete design brief.
Give suppliers the same demand record
List each significant air user, its operating requirements and when it runs. Identify simultaneous peaks, continuous demand and intermittent tasks. Use measured consumption where available and ask a competent supplier to assess gaps rather than adding unverified tool ratings together.
- Flow — What to record or confirm: Required delivery and the rating basis, units and operating pressure used in the proposal.
- Pressure — What to record or confirm: Required pressure at the point of use and the supplier’s allowance for the proposed distribution system.
- Air quality — What to record or confirm: The process requirement, how it will be achieved and how acceptance will be demonstrated.
- Duty pattern — What to record or confirm: Operating hours, peaks, idle periods and realistic future demand.
- Site conditions — What to record or confirm: Available power, space, ventilation, access, noise constraints and maintenance arrangements.
Confirm whether flow figures are comparable before ranking quotes. Ask the supplier to resolve ambiguous units and rating conditions in writing. Do not silently reinterpret an implausible specification or assume that displacement, delivered air and motor power describe the same thing.
Ask for a complete system proposal
Have the supplier explain the selected compressor type and control arrangement against the documented duty pattern. If an existing installation is being replaced, include the condition of the distribution system and the reason for replacement in the assessment.
CAPS describes related equipment such as receivers and air dryers as part of its offering. [2] Ask which receiver, dryer, filtration, drains and controls are included in your proposal, and which are excluded. The required configuration depends on the process and site; a compressor advertised as oil-free does not by itself answer every air-quality question.
Require a drawing or clear scope for connections, electrical work, foundations or mounting, ventilation and access. Ask who is responsible for condensate handling and any site approvals or inspections. These items should be assigned to named parties before the delivered equipment price is compared.
Check operating cost assumptions
Request an estimate based on your operating hours and load pattern, with the assumptions shown. Include power use, planned servicing, consumables and expected downtime arrangements. Treat the estimate as conditional rather than a guaranteed saving.
Ask what evidence supports the proposed controls for periods of low demand. If a supplier recommends variable-speed operation or another control strategy, have them explain why it matches the measured pattern. A feature name alone is not a site-specific efficiency calculation.
Record what happens during a breakdown: local response arrangements, parts availability, temporary supply options and any charges outside the service contract. Confirm current lead times in the written quotation rather than relying on a website’s stock badge.
Agree commissioning and acceptance before ordering
Write the acceptance plan with the supplier and the plant’s responsible technical personnel. It should identify the representative workload, measurements, required point-of-use conditions and the person authorised to accept the result. Record any conditions that cannot be tested at commissioning and how they will be resolved.
Include equipment documentation, operating instruction, maintenance responsibilities and the installed protective arrangements in handover. SafeWork NSW describes plant guidance extending from installation and commissioning through use and decommissioning. [3] For the actual site, have a competent person identify the applicable state or territory requirements and establish which ones apply to the specific installation.
Select the quote that meets the documented air-supply requirement and allocates installation, commissioning and support responsibilities clearly. If the demand record is too uncertain to distinguish proposals, obtain a site assessment or measurement exercise before committing to a larger machine.
References
- Atlas Copco Australia — Dimensioning compressor installations (atlascopco.com)
- CAPS Australia — Air compressors and selection considerations (caps.com.au)
- SafeWork NSW — Managing the risks of plant (nsw.gov.au)
