1. What is a Whole House Generator Size Calculator?

Definition: This calculator estimates the required generator size in kilowatts based on your total electrical load and a safety factor.

Purpose: It helps homeowners and electricians determine the appropriate generator capacity for backup power during outages.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{kW} \) — Generator size (kilowatts)
• \( \Sigma(P_{load}) \) — Sum of all electrical loads (watts)
• \( SF \) — Safety factor (typically 1.25 for residential)

Explanation: The total wattage is converted to kilowatts (divided by 1000) then multiplied by a safety factor to account for startup surges and future needs.

3. Importance of Proper Generator Sizing

Details: Correct sizing ensures your generator can handle all essential loads without being overloaded, while avoiding unnecessary costs from oversizing.

4. Using the Calculator

Tips: Enter the total wattage of all appliances/lights you want to power simultaneously and the safety factor (default 1.25). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How do I find my total load?
A: Add up the wattage of all appliances you want to run simultaneously. Check appliance labels or manuals for wattage information.

Q2: Why use a safety factor?
A: The safety factor accounts for motor startup surges (which can be 3-5x running watts) and potential future electrical needs.

Q3: What's a typical safety factor?
A: 1.25 is common for residential, while commercial may use 1.5. Adjust based on your specific needs.

Q4: Should I size for all appliances or just essentials?
A: This depends on your needs. For whole-house coverage, include everything. For essential circuits only, include just those loads.

Q5: Does this include HVAC systems?
A: Only if you include them in your total load calculation. Remember HVAC systems have high startup demands.