Quick Answer
Choose a generator size that matches your home's power requirements by calculating the total wattage of appliances and devices. Consider a 10-20% increase for startup surges and additional loads. Select a generator with a slightly higher wattage to account for future upgrades.
Calculating Power Requirements
To choose the right generator size, start by calculating the total wattage of your home’s appliances and devices. Add the wattage of major appliances like refrigerators, air conditioners, and water heaters (typically 1-5 kW each). Also, include the wattage of smaller devices like lights, computers, and televisions (typically 50-200 watts each). Consider the National Electric Code (NEC) requirement of 3-5 watts per square foot for lighting and miscellaneous loads.
Generator Size Selection
Once you have the total wattage requirement, add a 10-20% increase to account for startup surges and additional loads. For example, if your home requires 10 kW, add 1-2 kW for startup surges, resulting in a total requirement of 11-12 kW. Finally, select a generator with a slightly higher wattage to account for future upgrades and potential increases in energy demand.
Standby Generator Selection Criteria
For whole-house standby generators, look for a unit with a high surge capacity (typically 200-300% of the rated wattage) and a low frequency deviation (less than 0.5 Hz). Consider a generator with a high continuous power rating (typically 90-95% of the rated wattage) and a low no-load current (less than 0.5 amps). Also, ensure the generator is compatible with your home’s electrical system and has a suitable control panel and remote monitoring capabilities.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.