Symptom guide

Why the AC can drive up the electric bill: the federal numbers

By the HeatAndAirCost editors · Last updated October 5, 2026 · How we research prices

What people commonly report

The summer bill jumps and the AC seems to run all day. Sometimes the house is also less comfortable than last year, sometimes not. Weather alone moves cooling bills a lot, so the useful question is whether the system is using more electricity for the same job. Federal sources give a few concrete numbers to measure against.

~19%

Share of U.S. home electricity used for AC, 2020 (EIA)

5-15%

AC energy cut from clean filters (DOE)

~30%

Cooling energy lost through ducts (DOE)

up to 15%

Efficiency lost to airflow problems (ENERGY STAR)

How big a part of the bill AC is

EIA’s Residential Energy Consumption Survey found air conditioning accounted for about 19 percent of electricity used in U.S. homes in 2020, 254 billion kWh in total^[1]. About 89 percent of homes used air conditioning that year, and 67 percent had central AC, up from 27 percent in 1980. EIA notes that homes in the South are more likely to have electric heat and to use more air conditioning^[2].

What DOE and ENERGY STAR say can push AC electricity up

Dirty filters. Replacing or cleaning filters can lower an AC’s energy use by 5 to 15 percent, per DOE^[3].
Leaky ducts. DOE: air loss through ducts accounts for about 30 percent of a cooling system’s energy consumption^[3]. Ducts leaking into an attic or crawl space “can add hundreds of dollars a year” to heating and cooling bills^[6].
Dirty coils. ENERGY STAR says dirty evaporator and condenser coils make the system run longer, increasing energy costs^[4].
Wrong refrigerant charge. “Too much or too little refrigerant will make your system less efficient,” per ENERGY STAR. Checking it is a technician’s job^[4].
Airflow problems. These can reduce efficiency by up to 15 percent, according to ENERGY STAR^[4].
Thermostat habits. DOE says a programmable thermostat could save up to 10 percent a year on heating and cooling, and a ceiling fan lets you raise the setting about 4 degrees without losing comfort^[3].

How to find out if your system is the problem

Compare kWh, not dollars, for the same month last year. Rate changes and a hotter month both inflate the dollar figure.
Check the filter. DOE calls it the quickest way to save energy on home cooling^[3].
Look at the outdoor unit for leaves and debris on the fan and condenser, which DOE says to keep clear^[3], and at accessible ducts for disconnected or crushed runs^[5].
Notice comfort. High bills plus rooms that never feel right is ENERGY STAR’s duct warning pattern^[5].
Note the age. DOE suggests considering replacement when a heat pump or AC is more than 10 years old and needs frequent repairs while bills climb^[6].

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Try this while you wait

The three items tied to the DOE and ENERGY STAR figures above. None of them replaces the coil cleaning and refrigerant check in a technician's tune-up.

Replacement HVAC air filters →Programmable thermostat →Duct mastic sealant →

As an Amazon Associate we earn from qualifying purchases. It does not change your price. These are screening or upkeep items. None of them is a repair, and none replaces a licensed technician.

When to call a pro

Usage (kWh) is up year over year with similar weather and a clean filter.
The system runs constantly but the house is not cooling well. See AC not cooling.
No tune-up in the last year. ENERGY STAR suggests a pre-season check every spring for cooling ^[4].

Weighing repair against replacement? Our $5,000 rule and HVAC lifespan guides put numbers on that decision.

Related guides

What the repair can cost

City repair guides

Sources

This page is general information collected from the official and manufacturer sources listed above. It is not an inspection or a diagnosis of your system, and only a qualified technician who sees the equipment can tell you what is wrong. HeatAndAirCost is not affiliated with the U.S. Energy Information Administration, the U.S. Department of Energy, ENERGY STAR. Found an error? hello@heatandaircost.com.

Getting local help

Finding a qualified technician

We do not inspect systems, rate contractors, or recommend any particular company. Whoever you call, ask for the license number and look it up on your state or county licensing board’s public site before work starts. Refrigerant work also requires an EPA Section 608 certified technician. Our contractor hiring checklist covers licenses, insurance, written quotes and red flags.

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AC and the electric bill: FAQs

How much of my electric bill is air conditioning?

Nationally, EIA's Residential Energy Consumption Survey found air conditioning accounted for about 19 percent of household electricity use in 2020, or 254 billion kWh. Your share depends heavily on climate: EIA notes homes in the South use more air conditioning and single-family homes there use the most electricity.

Can a dirty AC filter raise the electric bill?

DOE says routinely replacing or cleaning air filters can lower an air conditioner's energy consumption by 5 to 15 percent. ENERGY STAR adds that a dirty filter can increase energy costs and damage equipment.

Do leaky ducts raise cooling bills?

DOE puts air loss through ducts at about 30 percent of a cooling system's energy consumption, and ENERGY STAR estimates 20 to 30 percent of the air moving through a typical home's ducts is lost. DOE says ducts leaking into an attic or crawl space can add hundreds of dollars a year to heating and cooling bills.

When does replacing the AC make sense for the bill?

DOE's Energy Saver guide suggests considering replacement when a heat pump or air conditioner is more than 10 years old, needs frequent repairs, and energy bills are going up. It says new efficient equipment alone can cut energy use 20 percent or more, and about 30 percent combined with insulation, air sealing and thermostat settings.