This is what a buyer checks before they shortlist a machinery and equipment supplier.
What does a buyer check before specifying an air compressor?
They check free air delivery at the working pressure they actually need, the specific power the machine draws to produce it, and the air quality class after treatment. Electricity is most of the lifetime cost of a compressor, so specific power decides the purchase more often than the capital price.
A plant engineer is comparing two machines with similar prices and very different electricity bills.
Reviewed 4 August 2026 · Written for compressor manufacturers selling to business buyers
What does a buyer check before specifying an air compressor?
What a buyer needs to identify the product
These are the fields a buyer scans before deciding whether you are worth contacting. Missing one of them usually ends the visit without an email.
- 1
Free air delivery at stated pressure
Capacity claimed without its pressure is not comparable.
- 2
Working and maximum pressure
Determines suitability for the application.
- 3
Specific power
Energy per unit of air, which dominates lifetime cost.
- 4
Compressor type
Reciprocating, screw, scroll and centrifugal suit different duty cycles and pressures.
- 5
Lubricated or oil-free
A hard requirement in food, pharmaceutical and electronics work.
- 6
Air quality class after treatment
The specification the process actually needs.
- 7
Noise level and cooling requirement
Decide where the machine can be installed.
The documents buyers ask for
Not all of them belong on a public page. Naming the ones you can issue is what separates a supplier who can be audited from one who cannot.
| Document | What it proves | Where it belongs |
|---|---|---|
| Performance datasheetAsked at: shortlisting | Free air delivery, pressure, specific power and noise under a stated test standard | Publish it |
| Test certificate for the specific machineAsked at: acceptance | Measured performance for the unit shipped, not the model | Per shipment |
| Air quality class certificationAsked at: oil-free and regulated applications | Purity class achieved for oil, water and particulates | Publish it |
| Declaration of ConformityAsked at: before shipment to regulated markets | Conformity with pressure equipment and machinery requirements | Publish it |
| Energy cost comparison basisAsked at: capital case | How lifetime running cost is calculated and on what assumptions | Publish it |
| Service schedule and parts listAsked at: total cost evaluation | What is serviced, how often and at what cost | Publish it |
| Warranty and service coverageAsked at: purchase decision | Period, exclusions and engineer coverage | Publish it |
Where compressors sites lose the enquiry
Each of these is common, cheap to fix, and costs an enquiry that never arrives — so nobody ever reports it.
Capacity published without the pressure it was measured at
Free air delivery falls as pressure rises. A capacity figure without its pressure is the standard way incomparable machines are made to look comparable.
No specific power figure
It is the number that determines lifetime cost. Its absence is read as a machine that does badly on it.
Air quality class not stated for oil-free claims
Oil-free is a class, not an adjective. Regulated buyers need the class and will not accept the word.
What the enquiry form should ask
A form that collects these can be answered properly the first time. A form that collects a name and a message cannot.
Enquiry form — compressors
Enough to reply usefully, short enough that a buyer finishes it.
- Air demand and working pressure
- The basis of every selection.
- Duty cycle and shift pattern
- Determines the machine type and size.
- Air quality requirement
- Decides treatment and whether oil-free is needed.
- Existing installation
- What is being replaced and why.
- Site constraints
- Space, ventilation, noise limits and power supply.
- Electricity tariff
- Lets you make the lifetime cost case honestly.
Questions suppliers ask
Should we publish an energy cost comparison?
Yes, with the assumptions shown: hours of operation, electricity price, pressure and load profile. Buyers know energy dominates the cost of compressed air and are looking for someone to lay it out honestly. A comparison with its assumptions visible is persuasive; one without them is dismissed.
How should air quality classes be presented?
By naming the class for oil, water and particulates for each machine and treatment combination. Food, pharmaceutical and electronics buyers specify to a class, and a supplier who writes "clean, dry air" instead cannot be specified into those plants.
What matters most in a replacement purchase?
Why the last machine disappointed. Usually it is energy cost, unplanned downtime or air quality problems. Structuring your pages around those three failures, with real figures, reaches a buyer at the moment they are actually deciding.
Documents and standards named here are the ones buyers in this industry commonly ask for; requirements vary by market, customer and contract, so treat this as a starting checklist rather than a compliance list. Clearer pages can help discovery and evaluation. They do not guarantee rankings, AI citations, enquiries or revenue.
Illustrative
An enquiry from this search looks like: Site constraints · Air demand and working pressure · Duty cycle and shift pattern · Air quality requirement
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