1. What is a Generac Whole Home Generator Size Calculator?

Definition: This calculator estimates the appropriate size (in kW) of a Generac whole home generator based on your total electrical load and a safety factor.

Purpose: It helps homeowners and electricians determine the correct generator capacity needed to power a home during outages.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{kW} \) — Generator size (kilowatts)
• \( \Sigma P_{load} \) — 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) then multiplied by a safety factor to ensure adequate capacity.

3. Importance of Proper Generator Sizing

Details: Correct sizing ensures your generator can handle startup surges, provides room for future expansion, and operates efficiently without overloading.

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: What is the safety factor for?
A: It accounts for startup surges (especially for motors) and provides a buffer for future electrical needs.

Q2: How do I find my total load?
A: Add up the wattage of all appliances/lights you want to run simultaneously, or consult an electrician for a professional load calculation.

Q3: When would I change the safety factor?
A: Use 1.5 if you have many motor-driven appliances (AC, fridge, etc.), or 1.1-1.2 for mostly resistive loads (lights, heaters).

Q4: What's the typical range for whole home generators?
A: Most homes need 10-22kW, with larger homes requiring up to 48kW or more.

Q5: Should I round up the calculated size?
A: Yes, Generac generators come in specific sizes - choose the next available size above your calculation.