Get matched with top generator install pros in Saint David, AZ

To determine the right size generator for your house, you should calculate the total wattage of the appliances and devices you want to power during an outage. List all essential items, note their start-up wattages, and add them together.

Here are some typical wattage requirements for common appliances:

• Refrigerator: 600 watts

• Large dehumidifier: 700 watts

• Large window air conditioner: 1,400 watts

• Water heater: 3,000 to 4,500 watts

• Electric furnace: 5,000 to 25,000 watts

A 7,500-watt generator might be sufficient for essentials like a refrigerator, freezer, well pump, and lighting circuits. However, for high-demand items like a water heater or furnace, a whole-home generator is a better choice. A portable generator may be enough if you only need to power a few critical items.

While home square footage can offer a rough estimate, it is not always a reliable indicator. For reference, here are some typical generator sizes based on square footage:

• 1,000 sq ft: 6–9 kW

• 1,500 sq ft: 7–10 kW

• 2,000 sq ft: 10–14 kW

• 2,500 sq ft: 12–16 kW

• 3,000 sq ft: 16–20 kW+

For the most accurate sizing, consult a professional who can calculate your home's peak and average power consumption and recommend the optimal generator.

The amount of time a standby generator can run continuously is around 3,000 hours on average. However, standby generators can generally run indefinitely as long as they have a continuous fuel supply. Generators hooked up to a home’s natural gas supply are the best option for extended usage, as these won’t rely on a finite fuel supply based on how much you have in storage. Generators running on liquid propane or diesel won’t last as long, as these require fuel storage and regular refueling to stay running.

Generators are safe to use as long as they are installed and operated correctly according to the manufacturer's recommendations. The most critical safety tips are to never use a portable or fuel-powered generator inside an enclosed space due to the risk of lethal carbon monoxide poisoning; always operate it outdoors where fumes can dissipate away from your home. Additionally, never attempt to connect a generator to your home’s electrical panel yourself—hire a professional to ensure the setup meets safety standards. Finally, avoid overloading the generator by not connecting more appliances than it is rated for, as this can damage your equipment or cause a fire.

It might seem counterintuitive, but installing a generator transfer switch will save you money in the long run. While you’ll have to pay between $400 and $2,500 to have the transfer switch installed, you’ll recoup that amount later on when you don’t have to pay for expensive repairs to your appliances, devices, and electrical system that may have burned out, overloaded, or stopped working due to a sudden loss of power or an incorrect hook up of a generator to your home.