Gust: Air Compressor Calc — Support

Need help?

Email roman.kopaliani@gmail.com with your question. Please include:

• What you were trying to do
• What happened instead
• The app version (Gust → More → About)

Frequently asked

What's free and what's in Gust Pro?

Free forever: the Tool CFM Guide (including verdicts against your own compressor) and Air Safe. Gust Pro ($6.99, one-time) unlocks Compressor Match, Run Time, and the Blowout Check. No subscription.

What size air compressor do I need?

Size by deliverable CFM @ 90 psi — never by horsepower. Find the CFM @ 90 figure on your tool's plate (or use Gust's typical bands), and get a compressor that delivers at least that. Continuous tools like sanders, grinders, and spray guns need the pump itself to carry the demand; burst tools like impact wrenches can lean on the tank between bursts.

Why not size by horsepower?

Because "peak HP" was marketing. In 2004, a consumer class-action settlement ended the practice — Campbell Hausfeld, DeVilbiss, Ingersoll-Rand, and Coleman Powermate agreed to stop advertising peak horsepower and rate by continuous power. The number that survived is CFM @ 90 psi.

Why does my sander stall when the spec said it would run?

Per CAGI, CFM ratings on intermittent tools assume roughly a 25% duty cycle — a tool held on continuously draws several times its rated average. A sander is a continuous tool: it needs pump CFM at or above its full demand. A bigger tank only adds seconds.

Can my compressor blow out my sprinklers?

Per Rain Bird: regulate to 50 psi or less for polyethylene lines (80 psi for rigid PVC), never blow a zone for more than 2 minutes, and clearing a system takes air volume far more than pressure — rental tow-behind compressors in the 80–185 CFM class are the standard tool. Gust's Blowout Check gives an honest verdict for your compressor, including "rent one" when that's the truth.

Why does the tank need draining?

Per OSHA 1910.169, every air receiver needs a drain at its lowest point, opened frequently. Compressing air condenses water into the tank; water sitting inside is how receivers rust from the inside — and a rusted-out tank can rupture. Never weld or patch a tank.

Can I blow dust off myself or the bench?

Per OSHA 1910.242(b), compressed air used for cleaning must be reduced below 30 psi dead-ended, with chip guarding and PPE — above that, air against skin can break it and enter the bloodstream. Never point compressed air at anyone.

Does it work offline?

Yes — Gust never makes general network requests. The exception is Apple's StoreKit (price fetch, restore). Everything else is local.

Is Gust a guarantee?

No. Gust is an educational reference that shows published figures and gas-law arithmetic alongside your inputs. Pumps wear, hoses leak, and plates vary — plan margin, and follow your equipment's manual.

Refunds

Purchases are handled by Apple. Request a refund at reportaproblem.apple.com.