Appliance Cost Lab

Seasonal room cooling

How much electricity does a portable air conditioner use?

A seasonal estimate uses electrical input, active hours and days, compressor duty cycle, quantity, and separately entered standby days.

Rated power × elapsed time can overstate energy when the compressor cycles. Representative multi-hour or daily measured kWh is preferable where it can be obtained safely with correctly rated equipment.

Three reproducible seasonal scenarios

Three published portable-air-conditioner seasonal electricity-cost scenarios
ScenarioPublished inputsAnnual energyAnnual cost
900 W for six hours on 90 active days at 70% duty900 W; 6 h/active day; 90 active days/year; 70% duty; quantity 1; 2 W standby for 18 h on 365 standby days; $0.18/kWh353.340 kWh$63.60
1,200 W for eight hours on 120 active days at 65% duty1,200 W; 8 h/active day; 120 active days/year; 65% duty; quantity 1; 2 W standby for 16 h on 365 standby days; $0.18/kWh760.480 kWh$136.89
1,500 W for ten hours on 150 active days at 60% duty1,500 W; 10 h/active day; 150 active days/year; 60% duty; quantity 1; 3 W standby for 14 h on 365 standby days; $0.18/kWh1,365.330 kWh$245.76

$0.18/kWh is an illustrative comparison rate, not a national or current market price. The duty cycles and schedules are arithmetic fixtures, not claims about products or homes.

Inputs that materially affect cooling energy

Temperature, humidity, thermostat setting, room size, insulation, sunlight, cooling capacity, efficiency, installation, exhaust configuration and compressor cycling affect consumption. BTU/h describes cooling capacity, not electrical watts. Do not substitute one for the other.

SEER, SEER2, EER, CEER and label values have defined scopes and test conditions. This site does not convert them with an unverified shortcut. Use electrical input, measured kWh, or the applicable model-specific label method.

Measurement and limitations

Measure representative multi-hour or daily kWh that includes compressor and fan cycling. Record weather, thermostat setting and measurement duration. One observation does not predict a different season, room or installation.

Smart-plug economics are blocked. Scheduled disconnection requires conservative handling and cannot bypass manufacturer instructions, electrical ratings, restart behavior, condensate management, exhaust requirements or required cooling functions.
Source: ENERGY STAR room air conditioners supports sizing, installation and efficiency-label context. It does not validate these illustrative inputs, duty cycles, schedules or results.

Calculate your portable AC’s seasonal electricity use

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Last reviewed: August 14, 2026