How Much Electricity is Being Used With a Central AC System in North Bay?

With warm, dry summers and more frequent heat waves, North Bay homes rely heavily on central air conditioning to stay comfortable. But as temperatures rise, so can your electric bill—and many homeowners are left wondering just how much power their AC system is actually using.

Here’s what you need to know about electricity usage with central AC in North Bay including what impacts your monthly cost and what you can do to improve efficiency.

Central air conditioning systems use a significant amount of electricity—especially during a North Bay heatwave. On average, a central AC unit can draw between 2,000 and 5,000 watts per hour, depending on the system’s size and efficiency. That means running your system for 8 hours a day could cost anywhere from $3 to $12 per day, depending on local electricity rates, system age, and insulation.

In the North Bay, where PG&E rates continue to rise and time-of-use pricing is in effect, running your AC during peak hours (typically 4 p.m. to 9 p.m.) can cause your monthly energy bill to spike—especially during extended hot spells.

Not all central air systems are created equal. Several factors affect how much electricity your system uses:

System Age & SEER Rating: Older units tend to be less efficient. A central AC system with a SEER (Seasonal Energy Efficiency Ratio) of 10 or below can use significantly more electricity than newer models with a SEER of 16 or higher.

Home Size & Ducting: Larger homes (common in areas like Santa Rosa or Napa’s wine country) require more cooling power. Leaky or aging ductwork can also force your system to run longer.

Thermostat Settings: Every degree below 78°F can increase electricity usage by 3–5%.

Insulation & Windows: Poor insulation or sun-facing single-pane windows (often found in older Petaluma homes) can cause your AC to run harder and longer.

Humidity & Microclimates: While much of North Bay is dry in summer, coastal fog and humidity in towns like Bodega Bay or Sebastopol can make your system work overtime—cooling and dehumidifying at once.

If you’re looking to cut energy use, it’s worth comparing your central AC to alternative systems:

Mini-Splits: These ductless systems can be more efficient, especially for homes with zoned cooling needs or remodels with no ductwork.

Portable Units: These consume less electricity but aren’t as effective in larger rooms and can be noisy.

Window Units: A better option for single-room cooling, but still fall short for whole-home comfort.

For total household cooling, central AC remains the most reliable, but it requires mindful use and routine upkeep to prevent energy overuse.

Reducing your energy bill doesn’t mean sweating through a North Bay summer. These small changes can help:

Electricity usage in the North Bay is more than just about comfort—it’s tied directly to your monthly expenses. With PG&E’s time-of-use and tiered pricing, even small increases in usage during peak hours can create a surprisingly large jump in your bill.

In inland areas like Santa Rosa, Novato, or Napa, where summer temps regularly hit the 90s or higher, many residents find themselves running AC systems nearly around the clock during heatwaves.

If you’ve noticed your AC running longer or your electricity bill creeping up, it may be time to assess your system’s efficiency—or look into more targeted cooling solutions that fit your home layout.

If you’re unsure whether your central AC system is running efficiently—or if you’re ready to explore lower-energy cooling options—Same Day North Bay Heating, Cooling, Plumbing can help. From seasonal tune-ups to system upgrades and smart zoning, we make it easy to stay comfortable without overpaying for electricity.