Cost to run

How much does an air purifier cost to run 24/7?

Air purifiers are designed for continuous operation, and most draw modest fan-level power. Auto mode keeps the average well below the maximum-speed rating that appears on the box.

Reviewed 2026-07-15 · methodology appliance-energy-1.0.0 · data vintage 2026-04-ytd

Example costs using the Texas state-average rate

These are generated examples for a consistent location. Enter your own ZIP and usage below for a more relevant state-average estimate.

Scenario	Assumption	kWh/month	Monthly range	Most likely/year
Bedroom on auto	24 hours on auto mode, mostly low speed	12.96	$1.38–$3.08	$25.35
Living room, medium	24 hours holding a steady medium speed	28.80	$3.07–$6.85	$56.34
Wildfire smoke event	24 hours at maximum speed for two weeks	30.24	$3.22–$7.19	$126.77

Source: U.S. Energy Information Administration, Electric Power Monthly Table 5.6.B. Data vintage 2026-04-ytd. State-average pricing is not your exact utility tariff.

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ApplianceHow manyHours used per day (optional)

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Rated watts (from the appliance label)Duty cycle (0–1; share of time drawing full power)Days per month

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Continuous duty is the intended pattern

Filtration only works while air is moving through the filter, so leaving the unit on is normal rather than wasteful. The meaningful question is average fan speed: sensors in auto mode drop to low speed once particle counts fall, cutting consumption sharply.

Rated watts describe maximum speed

Specification sheets usually quote draw at the highest setting, which most households rarely sustain. Real averages across a day of auto operation commonly land near a third of maximum, which the duty-cycle input represents in these scenarios.

Filters, sizing, and what is excluded

Replacement HEPA and carbon filters usually cost more per year than the electricity modeled here. The estimate also ignores clean-air delivery rate matching to room size, and it cannot judge whether a unit meaningfully improves your indoor air.

Frequently asked questions

Should I turn the purifier off when leaving home?

Short absences barely matter at these wattages, and continuous filtration keeps particle levels from rebounding. Many owners leave auto mode on around the clock.

Does auto mode really save money?

Yes. The fan spends most hours at its lowest speed once air is clean, so the average draw falls well below the rated maximum used in marketing.

Is a bigger purifier more expensive to run?

Larger units move more air at similar efficiency, and running one large unit at low speed is often quieter and no more costly than a small unit straining at maximum.

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