How to Lower Your Summer Cooling Bill in Mesa, AZ

How to lower your summer cooling bill in Mesa

Set the thermostat as high as you're comfortable and raise it when you're out, use ceiling fans, keep the filter clean, and fix leaky attic ducts. If you're on a time-of-use plan, run the big appliances outside the on-peak hours on your bill.

Updated October 28, 2026 · Sources listed at the end

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Thermostat

The Department of Energy's Energy Saver guide says to set the thermostat as high as is comfortable when you're home and awake, and to raise it when you're asleep or away. It says a ceiling fan lets you raise the thermostat about 4°F without losing comfort. A smart or programmable thermostat makes that automatic.

Don't let the house get so hot that the system can't catch up. With July lows at Sky Harbor now averaging 86.5°F, the night doesn't do much of the work for you. A setback of a few degrees while you're out is fine. Turning it off on a 112 degree afternoon and expecting it to recover by dinner usually isn't.

Going away for the summer

I'd raise the thermostat, not shut the system off. A closed house in July gets far hotter than the outside air, which is hard on pets and plants, and the system then has to pull it all the way back down when you get home. A smart thermostat lets you start cooling a day before you return.

Filter, coil and ducts

ENERGY STAR says to check the air filter every month and change it at least every three months. A dirty filter makes the system run longer for the same cooling and can freeze the coil. Keep the outdoor unit clear, rinse dust off the coil after a monsoon storm with the power off, and have it checked once a year. Tune-ups.

Clean doesn't mean thickest. A dense pleated filter can be more than an older system's fan can pull air through, and the house stops keeping up. EPA says to use as high a MERV rating as your system fan and filter slot can accommodate, and to ask an HVAC technician where that limit is.

Leaky ducts in a hot attic waste a lot of cooling. If some rooms never cool, ask a technician to check the ducts before you buy a bigger system. Duct repair.

Shade and sun

Close blinds on west and south windows in the afternoon.
Shade the outdoor unit if you can without blocking airflow around it. Leave a few feet clear on every side.
Skip the oven and the dryer on the hottest afternoons.

Help with the bill

Most of Mesa buys power from SRP. A 5.5 square mile area around downtown is served by the City of Mesa's own electric utility. The city's heat safety page lists:

Summer Electric Assistance, for income-qualified City of Mesa electric customers, July through September.
SRP's financial assistance and Weatherization Assistance Program, for SRP customers with limited incomes.
LIHEAP, the federal home energy assistance program.

Check your bill for your price plan and its on-peak hours before shifting chores around; plans differ. Confirm program details with SRP or the City of Mesa.

When the bill is a sign of a problem

A bill that jumps without a heat wave to explain it can mean a failing part, low refrigerant, a heat pump stuck on heat strips, or leaking ducts. On an old system, a new one at or above the 14.3 SEER2 minimum may cut the bill. Repair or replace.

Questions Mesa homeowners ask

What should I set my thermostat to in a Mesa summer?

The Department of Energy says to set it as high as is comfortable when you're home and awake, and higher when you're asleep or away. A ceiling fan lets you go about 4°F higher without losing comfort.

Who supplies electricity in Mesa?

SRP serves most of Mesa. The City of Mesa runs its own electric utility for a 5.5 square mile area around downtown, according to the city's service area map.