Full Breakdown
Adjusting Air-Conditioner Settings to Trim Summer Electric Bills
7/3/2026, 8:44:49 PM
Core Adjustments That Lower Bills
Raising the thermostat a few degrees, using a setback schedule, setting the fan to “auto,” and controlling humidity cut the runtime and power draw of AC units, saving energy.
Context: Energy Prices and Heat
Nationwide electricity rates have risen as prolonged heatwaves increase cooling demand, making air-conditioning one of the largest contributors to summer utility bills.
Expert Guidance
Elizabeth Hewitt, Stony Brook University, advises a 7-10 °F setback for eight hours daily, cutting costs by about 10 % per year. Patrick Phelan, Arizona State University, says each 1 °F rise saves roughly 3 % on cooling and that smart thermostats like Nest can deliver about 10 % savings. Gregor Henze, University of Colorado Boulder, notes that insulated homes retain cool air longer, so setbacks work even for short absences.
Savings Data
Each degree increase saves ~3 % of cooling costs; a 7-10 °F setback for eight hours daily can cut energy use by up to 10 %, per the U.S. Department of Energy. Smart thermostats that learn occupancy reduce usage by 8 %, and manual upgrades can approach 10 %. Setting the thermostat far below the target offers no benefit, as AC units cool at a fixed rate.
Official Guidance
The U.S. Department of Energy advises a 7-10 °F setback for eight hours daily. New York City, amid a heat emergency, urges residents to raise indoor temperatures while away to balance comfort and efficiency.
Risks and Counterpoints
Turning AC off for long periods in humid areas can promote mold and increase compressor wear, needing 15-30 minutes to run efficiently after restart. “On” fan mode adds electricity use and hinders moisture drainage. Drafty homes heat quickly, so setbacks help even for brief outings.
Conflicting Reports & Gaps
CBS News cites a 3 % cooling-cost reduction per degree, while NBC Chicago reports a 3 % saving for a 1 °F increase—both consistent. Neither source quantifies dehumidify-mode savings, and optimal settings remain under-studied.
Verbatim Quotes
- “If you’re gone for like 15 minutes to go to the grocery store, you don’t get any gain” — Elizabeth Hewitt, Stony Brook University.
- “if you’re going for your work day, say for eight hours or so, you’ll almost always save more energy and money by turning things off,” — Elizabeth Hewitt, Stony Brook University.
- “If you’re going from just an ordinary manual thermostat to installing a smart one like a Nest, then you can expect something like 10% savings,” — Patrick Phelan, Arizona State University.
- “cheap foam spray insulation in open windows or areas that are drafty is a really low-hanging fruit that doesn’t cost a lot of money and really helps retain the indoor temperature in your home.” — Elizabeth Hewitt, Stony Brook University.
What’s Next
Meteorologists forecast a week of extreme temperatures across the tri-state area. Energy agencies plan advisories on optimal AC usage, and manufacturers are expected to promote smart-thermostat incentives to reduce residential electricity demand.
