Air Compressor Buying Guide
Buying a compressor is three decisions at once: what type, what size, and who's going to service it. Plus one thing nobody tells you about: the lifetime cost. Vendors will happily pick all of it for you, in their favor. This is the independent way through.
Interactive Buying Guide — coming soon
Soon you'll be able to answer a handful of questions about your application — CFM, pressure, use case, location — and get a short list of compressor types, sizes, and brands that fit. With annual electricity cost and lifetime cost shown for each model, so the "cheap" option doesn't end up being the most expensive. In the meantime, work through the decisions and use-case guides below.
The three decisions
Pick the one you want to think about first.
1. What type of compressor?
Rotary screw, reciprocating piston, scroll, centrifugal, portable diesel — or oil-free for any of the above. Each one does a different job, each one is terrible at the wrong job. The most expensive mistake I see in plants is the wrong type of compressor, not the wrong brand.
2. What size compressor?
Compressors are rated two ways — pressure (psi / bar) and capacity (CFM / m³/hr). They're different things, and mixing them up is the most common buying mistake there is. Then there's the demand profile — constant, peaky, day-only. Most plants buy way too big «just to be safe» and waste money for 20 years. Right-size, plus a bigger receiver, beats oversize every time.
3. Who will service it?
The spec nobody puts on the datasheet. The same brand can be the best machine in your plant in one city and the worst in another, with the only variable being which local distributor is supporting it. Get this one wrong and the type and size stop mattering.
And one more thing — the price tag isn't the price
The purchase price is roughly 10% of what a compressor will cost you over its life. The other 90% is electricity, leaks, maintenance, and downtime. A "cheap" compressor that wastes 20% energy every year is the most expensive choice you can make. Get the type right, get the size right, get the service relationship right, and then head over to System Optimization so the lifetime cost doesn't bite you.
The full buying guides
Once you've worked through the decisions above, this is where the actual purchasing happens. Two guides — one for rotary screw, one for piston (reciprocating). Pick the type you're after and dig in.
The workhorse of industry. Continuous duty, oil-injected or oil-free, with all the options that drive lifetime cost.
- Sizing & duty profile
- VSD vs fixed speed
- Oil-injected vs oil-free
- Service, warranty & downtime
- + 4 more topics
For industrial duty — intermittent use, lower upfront cost, simpler service. Where piston still beats screw, and where it doesn't.
Open the piston buying guideOr pick your scenario
Most people landing here are in one of a handful of common situations. Pick the one that fits — each walks through your specific decisions and routes you to the right type guide.
Your first proper compressor
Small manufacturer, workshop, or new production line. How to size from scratch, what type to start with.
Replacing an old compressor
Your existing one is at end of life. What to do differently, whether to upsize for growth.
Upgrading from a piston to a rotary screw
You've outgrown your piston compressor and need continuous-duty screw capacity. Specific traps to watch for.
Adding capacity to an existing system
You need more air. The #1 mistake: adding a compressor to fix a piping problem. Read this first.
Or pick by application
Sometimes the easiest way in is to start from what you're actually doing with the air. Pick the application that matches your tools or equipment — each page covers the specifics for that use and routes you to the right type-specific guide.
Compressor for sandblasting
One of the most CFM-hungry applications. Sizing right, type, and the placement issues nobody warns you about.
Compressor for spray painting
Clean dry air matters more than CFM. The air-treatment chain that separates good paint jobs from ruined ones.
Compressor for CNC machining
Moderate CFM, fussy about quality, dirty environment. Spindle air specs vary — check before you buy.
Compressor for injection molding
Continuous duty, planning for line expansion, and the piping mistake that bites everyone the second time around.
Compressor for a packaging line
CFM is usually moderate — but uptime is everything. Backup planning is half the buying decision.
See all applications
More application-specific guides will be added over time. Browse the full list or send your specific application via the contact form.
Browse by brand or model
The full searchable database of brands, series, and models is coming — with annual energy use, total operating cost, and lifetime cost for each individual model. Until that's ready:
Brands & Models Database (coming soon)
Enter your CFM, pressure, use case, and location — get a shortlist of models with annual electricity and lifetime cost figures. Then request a quote or go to the supplier.
Air Compressor Manufacturers Overview
The major brands in the industrial compressed air market — who makes what, where, and how they compare.
Rotary Screw Compressor Brands & Series
The series and model ranges from the major rotary screw manufacturers — capacity, pressure, options.
Got a specific buying question?
"Should I buy A or B?" "Is X HP enough for my plant?" "Is brand Y any good?" — send it to me directly. I read everything that comes in, and for sizing and brand-comparison questions you'll usually get a straight answer back the same week.