Add up your equipment demand
Use your manufacturer flow figures to compare simultaneous demand with the all-tools-together peak. Our free planner keeps any spare-capacity allowance separate.
Open the air demand plannerStart with the work, not a machine size
A useful hire enquiry begins with a list of the tools or machinery you need to run. Keep the model numbers and specification sheets together. If you are replacing an existing supply, explain whether the job and operating hours will stay the same.
Separate what you know from what needs checking. A supplier can assess a clear description more usefully than a guessed compressor size. The following steps help you prepare that description; they do not select a machine for every application.
Read the figures together
Airflow is a rate, commonly given in CFM (cubic feet per minute) or m³/min (cubic metres per minute). Pressure is usually stated in bar or PSI. Both matter: quote the equipment’s required flow and working pressure together.
Free air delivery (FAD) expresses delivered air as an equivalent volume at stated inlet or free-air reference conditions. Compare rated delivered flow at the required working pressure. Displacement describes theoretical swept volume, not the same output rating.
Receiver litres measure storage volume, not delivered flow. A larger receiver does not make an undersized compressor sustain continuous demand.
Duty cycle concerns running time and rest periods. Explain how long each tool operates and which tools run simultaneously. Continuous use needs a different assessment from occasional bursts. Do not choose by motor horsepower (HP) alone.
Your hire-sizing checklist
Work through these questions with the person who uses the equipment. Send the information you have in the hire enquiry form; unknown specifications can stay blank.
| Question | Useful detail to bring |
|---|---|
| What is using the air? | Tool or machine names, quantities and manufacturer specification sheets. Include any equipment being added for this job. |
| When will each item run? | Which items overlap, typical run lengths, breaks and shift hours. Describe the busiest part of the work as well as an ordinary day. |
| Which figures are confirmed? | Air consumption and required pressure for each item, with the units shown. Flag figures taken from an old quote or an uncertain label. |
| What supply is available? | The known voltage and phase at the intended location, or that no electrical supply is available. Ask the site contact to confirm anything uncertain. |
| What does the process need? | Any written air-quality requirement and details of existing dryers or filters. Note whether the proposed hire serves the same process or a different one. |
| Where and for how long? | Site postcode, planned position, access restrictions, start date and expected hire period. Mention any change in operating hours during the hire. |
Include the supply and treatment questions
Power availability constrains equipment choice. Air-quality needs may also require dryers or filtration; treatment must suit the process and its flow and pressure requirements.
Ask which parts of the proposed arrangement are covered by the quote and what information is still needed from the site. If an existing dryer or filter will remain in use, say so rather than assuming it forms part of the hire. Record any unanswered questions alongside the equipment list.
Not sure of the specifications?
Describe the task in everyday terms: what you are running, how many people or machines will use air at once, and when you need it. If a label is hard to read, say that rather than copying a guessed number. Have photographs or manuals ready for the follow-up conversation; the enquiry form accepts text details.
For maintenance cover or production work, use the industrial compressor hire planning page to prepare the wider site brief.
For noise-sensitive work, discuss the air requirement alongside the surroundings. Our silent compressor hire guide explains how to compare noise declarations.
Technical references:
- Atlas Copco: compressor sizing guide — flow, pressure, duty and power.
- Atlas Copco: understanding air compressor measurements — FAD and reference conditions.
- Atlas Copco: industrial air compressor hire — power and air treatment considerations.
Apply this checklist to your job: gather nozzle and duty details for sandblasting compressor hire, or identify essential machines and the changeover deadline for replacement factory air.