Get matched with top generator install pros in Durham, NH

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.

You can expect a diesel generator to last for up to 30,000 hours of use, which works out to 20 to 25 years with the proper maintenance, of course. That depends on how much you use it, so a diesel generator used for emergencies a couple of times a year will last a lot longer than a generator that takes over for a faulty electrical grid every month for a day or two. 

In some situations, yes. Never try to put biofuel into any home generator without checking the specifics first. If a generator has the ability to run on diesel, it can also run pure biofuel (the clear kind made from seed oils, for example). But if you are using biofuel made from animal fats or vegetable oils, the generator will need significant modifications before it can handle a sludgier type of biofuel.

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.