Essential information to know before purchasing an air compressor.

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    ACE Compressors always welcome enquiries and general questions about the air compressors, air power tools and other components we supply. With years of experience and expertise behind us, we’re happy to help you choose the best air compressor.

    However, we know some customers want to learn more about how to make that decision, which is why this buyer’s guide looks at some of the essential information and frequently asked questions involved in the air compressor buying process.

    Essential information to know before purchase

    First, let’s look at some of the most important air compressor specifications and how to interpret them in terms of the air tools and other equipment you plan to use.

    Working Pressure

    Your air compressor’s working pressure is a measure of the force behind the air it delivers. Imagine how much more forcefully the air comes out of a fully blown balloon, and the principle is the same. More pressure gives more power.

    Working pressure is given in pounds per square inch (PSI) and/or bar, both of which are commonly used units of pressure and easy to convert between.

    Most air compressors run at around 8 bar, which should be enough for air tools that demand up to 90 PSI (just over 6 bar) with a little spare power just in case.

    You also need to consider the volume of compressed air the compressor can produce, which is typically quoted in cubic feet per minute or CFM.

    Total Air Supply Demand

    The more tools you run from the same compressor, the more the total combined air demand will be, so again make sure your compressor can service them all with a little surplus to avoid excess strain on the motor.

    We’ve included a more detailed description of air supply output at the bottom of the page, along with a table of common air tool consumption values in CFM.

    In general, running power tools from an air compressor is more cost-effective, they can cost less upfront and when used properly, they usually also require less repair.

    So if you’re considering a move from electric power tools to compressed air power tools, make sure you factor in the long-term savings you’ll make, as buying both the tools and a compressor to power them can pay for itself in the long run.

    Air Tank Size

     A larger air tank means the air compressor can discharge continually for longer before it needs to run the motor to refill the tank.

    If you only use your tools occasionally and in short bursts, you might find a small air tank is more than enough for what you need – for example if you paint individual car body panels but don’t need to repaint the whole car at once.

    For more continuous operation or to run multiple tools that add up to continual demand, choose a compressor with a larger air tank or consider adding a larger external receiver to your system, as long as the compressor has the output needed to keep it filled.

    Petrol/Diesel or Electric?

    Electric air compressors are not uncommon but remember they need an electricity supply, whether that’s a mains supply or a generator.

    Petrol/diesel air compressors are more portable as they can be used where electricity is not available, so they are more popular in disciplines like construction and automotive repair where it’s beneficial to be able to manoeuvre the compressor more freely.


    Which jobs is an air compressor suitable for?

    Air compressors have a vast range of different applications but are common in disciplines including:

    • Automotive repair and body work
    • Construction and building work
    • Dentistry and healthcare
    • Garages (domestic and commercial)
    • Home refurbishments and DIY
    • Nailing and other fixings
    • Portable power for air tools

    The list goes on and on but in general, some of the advantages of using air compressors and pneumatic air tools are:

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      Petrol/diesel air compressors eliminate electric shock risks and a leaking system will usually pose no significant risk, just air, unlike leaking hazardous fluids from hydraulic systems.


      Higher torque and higher RPM mean pneumatic power tools can get the job done faster than even professional electric power tools do.


      A single airline is compatible with many different power tools, which can be interchanged easily (as long as the inlet diameter is the correct size etc.) and can all run from a single compressor of sufficient capacity.


      Quiet-running air compressors keep the specified decibels low for safe and comfortable use in enclosed areas.

      Energy Efficient

      A single air compressor can run multiple tools with very little wasted energy, especially when combined with a regulator and a receiver to smooth out the air supply.


      Air systems can run at high efficiency for a long time with very little maintenance – just keep the compressor lubricated and the airline free from condensates.


      Air tools cost less upfront and less to maintain. Compressed air systems can run highly efficiently, especially under continuous demand. Modern compressors with few moving parts further reduce service costs and downtime, while increasing reliability.


      Compressed air power tools can be used in the home, in the workplace and on the move, with ultra-portable compact compressors and high-capacity stationary compressors and receiver tanks.

      Which air compressors are best for which jobs?

      We’re often asked to recommend a specific air compressor for a certain job, and while there’s a huge number of different models on the market, there’s almost always something to suit.

      Here are some of the most common applications of air compressors we get asked about.

      What air compressor do I need for spray painting?

      It depends where you do your painting. For indoor work, a compact and quiet air compressor like a Bambi compressor could be a good choice.

      What air compressor do I need to power an impact wrench?

      Again, it depends on location. If you need to move around, a portable air compressor can give you power where you need it. You can also get cordless air impact wrenches powered by a small cylinder of compressed air built into the tool itself.

      What air compressor do I need for automotive work?

      General automotive work can include a wide range of different jobs, from repainting body panels, to running power tools like wrenches, to inflating car tyres.

      What size air compressor do I need for a framing nailer or nail gun?

      Air nailers and nail guns have a specified average air consumption. Make sure your air compressor can supply at least this much air (see our guide to air supply output at the bottom of this page).

      I am setting up a body/auto shop, what compressor do I need?

      Think about the kinds of body work you will be doing. For panel painting, a compressor with very clean oil-free output can ensure a high-quality finish. If you plan to use air power tools, allow enough capacity from your compressor for when these are in use too.

      What is the best air compressor for a home garage?

      For domestic purposes, choose a compact and quiet air compressor. Rotary screw compressors are a popular choice for garages, both domestic and commercial.

      What is the best air compressor for painting?

      If you’re worried about contaminating your paint, choose an oil-free air compressor and invest in a good quality paint spray canister to use with it.

      What is the best air compressor for car tyres?

      If you need to move around the car to reach each tyre, consider SIP super-portable compressors which output up to 8 bar, 3-4 times more than most car tyres need.

      Frequently Asked Questions

      Do I need a regulator on my air compressor?

      If you use air tools and other equipment with a much lower average air consumption than your compressor’s output, a regulator can be an important way to adjust the output for improved efficiency and prolonged tool life.

      Some compressors have a built-in regulator but we also supply them separately so you can install regulators in multiple locations along your air supply, if appropriate.

      What is the best portable air compressor to buy?

      We supply SIP ultra-portable air compressors, which are among the best on the market if portability is your top priority.

      Can you use a 6 cfm brad nailer on a 14 cfm compressor?

      A 6 cfm brad nailer needs 6 cfm of compressed air for 25% of the time (see our full explanation of this at the bottom of the page). A 14 cfm compressor should be enough to run this tool for up to 50% of the time, with a little capacity spare.

      What are the best portable air compressor brands?

      SIP Airmate are some of the most portable air compressors on the market. Some larger air compressors can be supplied on wheels for occasional repositioning too.

      What happens if an air compressor runs out of oil?

      Unless your compressor is oil-free, you should make sure to keep it well lubricated or you risk a significant fall in efficiency and/or damage to the internal moving parts.

      How tight should air compressor fittings be secured?

      A tight fit helps to reduce the risk of leakage; however, make sure the fittings can be accessed and maintained later. Generally by using the correct fittings you can get a good seal without over-tightening, while hoses can also be secured using jubilee clips.

      Should a compressor be noisy or vibrate?

      Compressors come with specifications including normal operating noise, so your compressor should not be significantly louder than that unless something is wrong or you are overloading it.

      Vibrations can be caused by the compressor being poorly mounted, unstable, or misalignment of rotary elements inside the compressor. They can also be transmitted along the airline from machinery at the other end, so try to find the true source of the problem.

      We stock anti-vibration mounts that can help to reduce noise and vibration from stationary air compressors – check our website or ask for more information about these.

      Resources about air compressors

      Do you have a question about air compressors we didn’t answer here? Are you planning on investing in an air compressor or new air tool? 

      Our blog has a wealth of information, we’re sure you’ll find the answer here. If you still can’t, get in touch with us!

      Important information about air supply output

      Compressed air power tools come with a specified average air consumption figure, which is a measure of the expected output needed from the air compressor to run the tool over a typical work cycle.

      However, an average work cycle is defined as using the tool for 25% of the time (e.g. for 15 seconds in any given minute) and if you need to use the tool more continuously than that, you should scale up the compressed air demand accordingly.

      So if the tool runs for 30 seconds in each minute, double the air consumption. For tools that run at or near continuously, your compressor must supply four times the stated average consumption – and with sufficient output for all your tools’ consumption added together.

      Finally, make sure that your compressor’s duty cycle (the ratio of running time vs. rest time) does not run more than 10-12 times per hour, as this can reduce the available air consumption. Make this an important factor to consider from the start of the design process for any new compressed air installation.

      Air Tool Air Pressure (bat) Average Air Consumption (CFM)
      Air Drill 6.2 4
      Angle Grinder 4” 6.2 6
      Angle Sander 7” 6.2 5
      Caulking Gun 6.2 1
      Cut Off Tool 3/8” 6.2 4
      Die Grinder 6.2 8
      Dual Action Sander 6.2 6
      High Speed Saw 6.2 5
      Hydraulic Riveter 6.2 4
      Impact Wrench 1” 6.2 12
      Impact Wrench 1/2” 6.2 4
      Impact Wrench 3/4” 6.2 7.2
      Impact Wrench 3/8” 6.2 4
      Long Bed Sander 6.2 8
      Mini Die Grinder 6.2 8
      Needle Scaler 6.2 4
      Orbital Sander 6.2 6
      Punch and Flange Tool 6.2 0.3
      Ratchet 1/2” 6.2 6
      Ratchet 1/4” 6.2 3
      Ratchet 3/8” 6.2 4
      Shears 6.2 5