Bay Area heat waves have become more frequent and intense. Preparation helps your home and HVAC system handle extreme heat.
Pre-Season Preparation
Service your AC before summer. Heat waves strain systems that are already struggling. Address problems before peak demand.
Check refrigerant levels. Low refrigerant means reduced capacity exactly when you need maximum cooling.
Clean condenser coils. Dirty coils reduce heat rejection. A clean system handles extreme heat better.
Replace filters. Maximum airflow helps your system keep up during extreme temperatures.
During Heat Events
Pre-cool your home. Run AC hard in the morning when outdoor temperatures are lower. Your system works more efficiently in moderate conditions.
Close blinds and curtains on sun-facing windows. Solar heat gain can exceed your system's capacity to remove it.
Minimize heat sources. Avoid using the oven. Turn off unnecessary lights and electronics. Even small heat sources add up.
Be patient with your system. During extreme heat, even properly functioning AC may not reach your normal setpoint. Maintaining 78-80 degrees during a 100+ day is normal.
Protecting Your Equipment
Shade the outdoor unit if possible. A shaded condenser operates more efficiently. But do not restrict airflow.
Clear area around condenser. Maximum airflow is critical during peak operation.
Consider misting systems that spray water on the condenser. This aids heat rejection in extreme conditions. (Use wisely to avoid water waste.)
What to Do If Your AC Cannot Keep Up
During extreme heat waves, even well-maintained systems may struggle: - Accept a higher temperature (78-80 instead of 72) - Use fans to improve perceived comfort - Focus cooling on occupied rooms - Stay hydrated and limit activity
If the system stops working entirely, seek cooler locations - cooling centers, malls, or friends' homes.
When to Call for Service
Before heat waves: Address any concerns in advance. Wait times during heat events can be days.
During heat waves: If your system stops entirely, frozen coil or obvious malfunction, emergency service may be needed. Simple underperformance in extreme heat may be normal.
Bay Area Specific Considerations
Inland areas bear the brunt of heat waves. Systems need adequate capacity for 100+ degree temperatures that may occur several times per summer.
Coastal areas traditionally escaped heat waves but increasingly see high temperatures. Systems sized for mild weather may struggle during heat events.
Flex alerts and grid stress may prompt voluntary or mandatory conservation. Having backup cooling strategies (fans, shading, hydration) helps if you need to reduce AC use.
Long-Term Planning
If your system cannot handle heat waves: - Consider upgrading to higher capacity equipment - Add mini-splits for supplemental cooling - Improve insulation to reduce cooling load - Install whole-house fans for evening cooling
Climate trends suggest heat waves will continue. Planning now prepares your home for the future.