The first decision is coverage: whole-home or essential circuits. Whole-home coverage powers everything — HVAC, well pump, all outlets, lighting. Essential-circuit coverage protects a defined list: furnace, refrigerator, sump pump, select outlets. Essential coverage costs less and requires a smaller generator.
Generator size is measured in kilowatts (kW). A typical essential-circuit setup needs 10–14 kW. Whole-home coverage for a 2,000–3,000 sq ft house typically requires 18–22 kW. Homes with electric HVAC, well pumps, or large appliances may need more.
Air-cooled generators (Generac, Kohler, Briggs & Stratton) are the standard residential choice up to about 22 kW. Liquid-cooled units handle larger loads and run quieter but cost significantly more.
DMES LLC performs a load calculation for every generator installation to ensure the unit is properly sized. An undersized generator damages itself and the loads it's trying to power; an oversized one wastes money upfront and runs inefficiently.
Information provided is general guidance for homeowners. Every home is different — contact DMES LLC for advice specific to your situation.