1. What is a Whole House Generators Calculator?

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

Purpose: It helps homeowners and electricians determine the appropriate generator size for whole-house power backup.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{kW} \) — Generator power (kilowatts)
• \( \sum P_{load} \) — Total electrical load (watts)
• \( SF \) — Safety factor (typically 1.25 for residential)

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

3. Importance of Proper Generator Sizing

Details: Correct generator sizing ensures reliable power during outages, prevents overload conditions, and maximizes fuel efficiency.

4. Using the Calculator

Tips: Enter the total electrical load in watts and safety factor (default 1.25). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How do I determine my total electrical load?
A: Add up the wattage of all appliances you want to power simultaneously, or use our Electrical Load Calculator.

Q2: Why is a safety factor needed?
A: It accounts for motor startup surges (which can be 3-5x running wattage) 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 or higher depending on critical loads.

Q4: Should I round up the generator size?
A: Yes, generators are typically sold in standard sizes (e.g., 5kW, 7.5kW, 10kW) - round up to the nearest available size.

Q5: Does this include HVAC systems?
A: Yes, if included in your total load calculation. Remember HVAC startup wattage can be significantly higher than running wattage.