How we measure & compare

What we mean by “100% electric”

DirectRoaster uses electric heating (no gas burners) and an Energy Recovery System (ERS) that transfers heat (not air) from exhaust to intake. “100% electric” means there is no on-site fuel combustion for heating the roaster.

Important: coffee roasting still produces smoke and volatile organic compounds in the exhaust. You must vent exhaust appropriately, and some locations require filtration or after-treatment. Claims about “emissions” on our site refer to on-site fuel combustion, not the absence of roasting byproducts.

DirectRoaster includes an integrated chaff collection system, but chaff collection is separate from exhaust compliance: smoke and VOCs still need proper ventilation (and filtration where required).

Energy use (kWh/kg)

When we quote energy use in kWh/kg, we’re describing the electrical energy drawn at the roaster input divided by the green-bean batch weight. Results vary with roast profile, batch size, ambient conditions, warm-up strategy, and throughput.

• 0.30 kWh/kg is a typical steady-state production figure we use for planning and comparison.
• For transparency, we recommend validating with a calibrated power meter at your site if you want a site-specific ROI model.

About the “~71% less energy vs gas” figure

The ~71% figure is a comparison against a reference gas-roaster baseline used in our internal ROI model (not a claim that every gas roaster will be exactly that inefficient). The baseline assumes approximately 1.03 kWh/kg total site energy for a conventional gas drum setup in production roasting, where exhaust treatment may be required depending on local regulations and site setup.

If you have metered energy data from your current setup, that will always be more accurate than any reference baseline. We’re happy to help you compare using your numbers.

ERS A/B results (~24% and ~10%)

The ~24% lower energy use and up to ~10% shorter roast cycles claims are from internal A/B testing of the same DirectRoaster platform with the ERS active versus bypassed, holding the roast target and operating conditions as consistent as possible.

In that A/B setup, ERS bypassed is approximately ~0.39 kWh/kg versus 0.30 kWh/kg with ERS active (steady-state production conditions).

These deltas are intended to explain what the ERS contributes on top of the base electric convection system. Your results will vary with profiles and how the machine is run (especially during warm-up and low-throughput operation).

Batch sizes & “samples”

DirectRoaster supports 1–10 kg batches for development and production. In most roasteries, true sample roasting is typically 50–100g on a dedicated sample roaster. We avoid calling 1 kg a “sample roast” to keep terminology consistent with how professionals use it.