Compressed Air Cost Calculator: What Your Diaphragm Pump Really Costs to Run
An air-operated diaphragm pump's biggest cost is usually the compressed air behind it. At Graco's own factor of about 20.7 kW of compressor input per 100 SCFM, a 3-inch AODD using 100 SCFM draws roughly 20 kW, every hour it runs. Enter your duty below to see the yearly cost of the air, and what an electric diaphragm pump such as the Graco QUANTM i230 could cost instead.
Get the Air vs Electric Diaphragm Pump Energy Worksheet
The method, the DOE and Graco factors, a fill-in worksheet for every air pump in your plant, and the QUANTM i230 fit checklist. We'll email it with your result, and James will review your numbers if you want a real Graco figure for the electric side.
How the compressed air cost calculation works
Step 1: air use. If you pick the FT30P option, the calculator reads FTI Air's published air-consumption lines for the 3-inch FT30P at your flow and head (head = psi × 2.31). Otherwise enter the SCFM from your own pump's curve.
Step 2: compressor power.
The default 20.7 kW per 100 SCFM is the constant inside Graco's own QUANTM Advanced ROI calculator (0.25 bhp per SCFM, 90% motor efficiency, 0.746 kW per hp). The U.S. DOE's Improving Compressed Air System Performance sourcebook lists 15 to 24 kW per 100 cfm at 100 psig, depending on compressor type, for the compressor package alone.
Step 3: electric pump power (estimate).
Graco publishes no power or energy curve for the QUANTM i230, so the efficiency is your assumption. When LibertyCES gets Graco's figure for your duty, enter it as kW instead.
Step 4: yearly energy and cost. kWh = kW × hours; cost = kWh × $/kWh. The calculator also checks your duty against the i230's published pressure-flow curve (Graco manual X063399, p.39): it is rated 100 psi and 230 gpm.
QUANTM i230 published curve (approximate)
| Flow | 25 gpm | 50 gpm | 75 gpm | 100 gpm | 125 gpm | 150 gpm | 175 gpm | 200 gpm | 225 gpm |
|---|---|---|---|---|---|---|---|---|---|
| Max pressure | 100 psi | 93 psi | 85 psi | 76 psi | 65 psi | 54 psi | 42 psi | 29 psi | 15 psi |
Read by LibertyCES from Graco's chart (no table is published). Full specs on the QUANTM i230 page.
Most of the compressor's power never reaches the pump
The U.S. DOE puts the overall efficiency of a typical compressed air system at 10 to 15 percent. Its tip sheet notes that running a 1 hp air motor at 100 psig takes about 7 to 8 hp of electricity at the compressor, and that poorly maintained systems lose 20 to 30 percent of their air to leaks.
An electric diaphragm pump skips the compressor, dryer and air lines. Graco states its QUANTM pumps cut energy costs by up to 80% compared with pneumatic pumps. The i230 is the 3-inch, 230 gpm version. See its specs, curve and limits →
Illustrative render. DOE: Compressed Air Tip Sheet #1 and Improving Compressed Air System Performance (3rd ed.).
Deeper dive: Liberty Specs Podcast Ep. 4, What Compressed Air Really Costs (11 min, full transcript).
Compressed air cost questions
What does compressed air cost to run a diaphragm pump?
Multiply the pump's air use (SCFM) by your compressor's specific power and your hours and power rate. Graco's own QUANTM ROI calculator uses about 20.7 kW of compressor input per 100 SCFM; the U.S. Department of Energy lists 15 to 24 kW per 100 cfm for packaged compressors at 100 psig. A 3-inch AODD using 100 SCFM therefore draws roughly 20 kW at the compressor, before leaks.
Why is compressed air so expensive?
Most of the electricity a compressor uses becomes heat, not useful air. The U.S. DOE puts the overall efficiency of a typical compressed air system at 10 to 15 percent, and notes that running a 1 hp air motor at 100 psig takes about 7 to 8 hp of electricity at the compressor. Leaks add more: DOE says poorly maintained systems can lose 20 to 30 percent of capacity.
How much energy does an electric diaphragm pump save?
Graco states its QUANTM electric diaphragm pumps cut energy costs by up to 80% compared with traditional pneumatic pumps. Graco publishes no power curve for the 3-inch QUANTM i230, so this calculator estimates the electric side from hydraulic power and an efficiency you set; ask LibertyCES for Graco's figure at your duty.
Is the electric pump a drop-in replacement for my air pump?
Check four things: the duty must sit under the electric pump's curve (the i230 is rated 100 psi and 230 gpm), the wetted materials must suit the fluid (the i230 fluid section is aluminum only), the site needs 380–480 V three-phase power, and the area must be non-hazardous: the i230 is not approved for hazardous or explosive locations.
Is the calculator result a quote or a guarantee?
No. It is a Draft Proposal Worksheet. The air side uses your inputs and published factors; the electric side is an estimate. LibertyCES confirms the real figures with Graco before you buy.
Draft Proposal Worksheet, not a quote. Air-side factors from Graco's ROI calculator and U.S. DOE; electric side is an estimate until Graco confirms your duty. Related: diaphragm pump sizing calculator · FT30P 3-inch AODD · Graco QUANTM electric diaphragm pumps.
Reviewed by James Riggins, 30+ years specifying water and chemical process equipment · Updated