Australian plant operators comparing compressed-air dryers need a common duty specification before they can compare brands or prices. Start with the required moisture condition at the point of use, then define the flow, pressure and temperatures the dryer must handle. A nominal capacity alone does not establish suitability for the plant.
The practical purchasing question is which proposed system can meet that specification under the site’s expected conditions, with an understandable energy and maintenance cost.
Specify the required pressure dew point
Pressure dew point describes the temperature at which moisture would begin to condense at the stated compressed-air pressure. Atlas Copco’s selection guidance identifies pressure dew point, flow and operating conditions as relevant to dryer choice. It describes refrigerated drying around +3°C and desiccant options for substantially lower dew points, including -40°C and -70°C. These are technology examples, not ratings for every model. [1]
Have the process owner specify the required value and where it must be achieved. Avoid selecting an unusually low dew point merely because it looks like a higher specification; ask suppliers to explain the consequences for equipment, energy and maintenance.
Compare the proposed technology and operating point
- Atlas Copco Australia — Documented starting point: Provides refrigerated, desiccant and other dryer technologies with guidance on matching requirements to a drying approach. [1]; Evidence needed in the proposal: A named model sized to the stated inlet conditions and required outlet moisture condition.
- KAESER Australia — Documented starting point: Lists refrigerated, desiccant, combination and membrane dryer ranges with different pressure-dew-point capabilities. [2]; Evidence needed in the proposal: The selected technology, condition-specific capacity and the assumptions behind the recommendation.
- Pilot Air — Documented starting point: Lists refrigerated dryers, including the TFD 6–72 range with a published 35°C ambient rating. [3]; Evidence needed in the proposal: Confirmation of capacity and performance at the plant’s actual ambient and inlet temperatures, including hotter conditions where relevant.
Published ranges help identify suppliers to approach; they do not replace a model-specific selection. The shortlist above is not an independent efficiency comparison.
Give every supplier the same duty sheet
Record measured peak and typical air demand, the pressure range, inlet temperature, ambient temperature range and expected operating hours. State the flow units and reference conditions so quotations can be compared. Include future demand only as an explicit scenario with its own assumptions.
Describe the existing compressor and air-treatment arrangement, available space, service access and the downstream process requirement. Ask suppliers to specify any required filtration and condensate-management equipment. Moisture removal is only one part of the requested air-quality specification; have the complete requirement assessed.
Ask for performance at the demanding operating conditions as well as the normal point. If a proposal relies on a capacity correction, request the correction basis and the resulting selected capacity in writing.
Compare energy using a defined system boundary
A simple purchasing worksheet is annual electrical energy multiplied by the applicable electricity rate. That calculation is useful only when the energy figure covers the same scope for each proposal.
Request a duty-based estimate that identifies dryer electricity, regeneration demand where applicable, and any additional compressor energy associated with purge air or pressure loss. Have the supplier explain which effects are included so they are not omitted or counted twice. Keep energy assumptions separate from measured results.
Add filters, consumables, planned servicing, commissioning and installation to the ownership comparison. Request AUD prices with GST shown explicitly. Avoid assuming a payback period until the alternatives use the same operating hours, electricity basis and maintenance scope.
Agree on acceptance before placing the order
Ask the supplier and responsible plant team to define how outlet pressure dew point, delivered flow, pressure loss and relevant operating conditions will be recorded during commissioning. Specify the instruments, observation period and responsibilities in the proposal.
Advance a dryer proposal when its operating-point evidence matches the duty sheet and its installed cost is complete. If a supplier cannot support a critical assumption, resolve that gap before ordering rather than compensating with a larger nominal model or an unsupported efficiency claim.
References
- Atlas Copco Australia — Compressed-air dryers (atlascopco.com)
- KAESER Australia — Compressed-air dryers (kaeser.com)
- Pilot Air — Compressed Air Dryers (pilotair.com.au)
