The size backup generator you need depends on calculating your home's total electrical load during an outage, which typically ranges from 10kW to 30kW for residential installations, with most homes requiring a 20kW unit to power essential systems like HVAC, refrigeration, lighting, and critical appliances simultaneously.
Properly sizing a backup generator requires understanding the difference between running watts and starting watts. Running watts represent the continuous power your appliances consume, while starting watts account for the initial surge when motors like air conditioning compressors or well pumps activate. This distinction is critical because undersizing your generator means it cannot handle simultaneous startup demands, potentially causing the unit to shut down or fail to energize key systems when you need them most.
During an outage scenario, most homeowners want to maintain comfort and preserve food while keeping essential systems operational. A typical home with central air conditioning, electric water heater, refrigerator, and standard lighting loads requires approximately 15kW to 20kW of continuous capacity. However, homes with multiple HVAC zones, larger square footage, or electric heating systems often need 24kW or higher capacity to manage peak demand periods without overload conditions.
The assessment process begins with identifying your essential loads—the systems and appliances you absolutely need during an extended power outage. HVAC units typically draw 3.5kW to 5kW during operation, refrigerators consume 600 to 800 watts, electric water heaters demand 4kW to 5.5kW, and whole-home lighting might require 1kW to 2kW depending on your fixture configuration. When these loads run simultaneously, the total demand quickly escalates, which is why accurate calculation prevents costly equipment failures or inadequate backup power.
Our team at Blackmon Plumbing has spent 19 years helping homeowners across the region select appropriate backup power solutions. As a licensed contractor (MPL-38162) and authorized Generac dealer, we use industry-standard load calculation tools and sizing charts to determine your exact generator capacity requirements. We don't estimate—we calculate based on your specific home configuration, electrical panel capacity, and backup priorities.
The on-site assessment includes reviewing your electrical panel, identifying circuit loads, and discussing your comfort and safety priorities during outages. We measure your HVAC system specifications, check water heater ratings, and account for any specialty equipment like pool pumps or medical devices requiring backup power. This thorough evaluation ensures we recommend a generator that handles your actual demand profile rather than oversizing unnecessarily or undersizing dangerously.
Once we've determined your required capacity, we provide flat-rate, upfront pricing with no hidden fees. Installation includes proper fuel line sizing, transfer switch configuration, and compliance with local electrical codes. Most residential installations are completed within one to two weeks, depending on permit processing and equipment availability.
Blackmon Plumbing provides comprehensive backup generator sizing, installation, and maintenance services for homeowners throughout the service area, backed by our Generac dealer authorization and nearly two decades of residential power solution experience.