How Do I Estimate the Hourly Fuel Consumption of a Diesel Air Heater?

Fuel cost is one of the main practical concerns when living or working with a diesel air heater through winter. Unlike an engine that burns at a steady rate, an air heater modulates its output, so its consumption depends on how hard it works rather than on its rated kilowatts. A rough estimate is enough for planning and can be refined with a little observation.

Typical Consumption Range by Output

As a planning baseline, a small 2 kilowatt heater burns roughly 0.1 to 0.2 liters of diesel per hour when modulating in a moderately insulated space, rising toward 0.25 liters per hour during long warm-up in very cold weather. A 5 kilowatt unit uses about 0.4 to 0.6 liters per hour at its higher output steps. These figures sit well below the fuel an idling engine would consume to provide the same warmth, which is why fleets notice lower fuel bills.

Measure It Yourself in a Few Hours

The clearest estimate comes from a simple on-site test. Use a marked auxiliary tank or a clear fuel bottle, record the level before an overnight run, and read it again in the morning. Divide the difference by the hours the heater actually ran, accounting for any time the engine was also drawing from the same supply. Repeating the test on a calm night and a windy night shows how weather affects the rate.

Plan the Tank for the Trip

Once an hourly figure is known, multiply by the expected heating hours and add a comfortable margin. A heater burning 0.2 liters per hour over a ten-hour night needs about 2 liters, so a 5 liter auxiliary tank comfortably covers two nights between refills. Carrying spare fuel in approved containers removes the worry of running dry in remote locations, and it avoids the awkward restart that follows an empty fuel line.

References

GB/T 7714: YEK P N Y, LAU C E, LAU S Y, et al. A novel microwave air heater integrated with thermal energy storage [J]. International Journal of Energy Research, 2022, 46(13): 19269-19277.

APA 7th: Yek, P. N. Y., Lau, C. E., Lau, S. Y., et al. (2022). A novel microwave air heater integrated with thermal energy storage. International Journal of Energy Research, 46(13), 19269-19277.

MLA 9th: Yek, P. N. Y., et al. "A Novel Microwave Air Heater Integrated with Thermal Energy Storage." International Journal of Energy Research, vol. 46, no. 13, 2022, pp. 19269-19277.