Get matched with top generator install pros in Stratham, NH

Whole-house generators can run continuously for extended periods, even for weeks at a time (around 400 to 500 hours), as long as they have a sufficient fuel supply. However, this type of extensive use will increase wear and tear and can shorten the generator's overall lifespan. During long periods of operation, it's important to check and refill the engine oil as needed, potentially as frequently as daily depending on the model. If your generator uses a fuel tank, ensure it is kept full to prevent unexpected shutdowns.

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.

Generators are usually sized by running watts and starting watts. Ideally, you’ll want a generator that can offer both the necessary running watts and starting watts for everything you need to power without going beyond 90% of its capacity. Calculate your home’s electrical load based on the breakers in your home or adding up the appliance and lighting needs of connected rooms.

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.