Best generator install pros near Evansville, MN

Sizing a generator is a careful process that requires calculating the electrical load of your entire house. You have to take into account every device you want to use and their wattage requirements, plus the wattage needed to start them, and look for a generator that can safely run all that at around 80% capacity.

In more practical terms, a small home can run on a 10,000-watt generator (and if you only want to power a few key appliances, much less than that). A mid-sized home may need something between 15,000 and 22,000 watts. Larger homes require 25,000 watts or more. 

You can determine what size generator you need for a transfer switch by matching the switch to the largest outlet on your generator. Larger generators can power up to 10 circuits, while most 5,000-watt generators can provide power to six circuits. So, if your generator’s largest outlet is 30 amps, you’ll need a 30-amp transfer switch.

To power a central air system during a power outage, the whole-house generator will need to be at least 5,000 watts, and this number will significantly increase for larger units. Check the specific wattage requirements of your AC unit to choose the right generator size. Consider consulting a generator installer to ensure your whole-house generator meets your electrical load needs.

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.