1. What is Generator Sizing?

Generator sizing is the process of determining the appropriate power output (in kilowatts) needed for a backup generator to adequately power your home's essential appliances during an outage, with an appropriate safety margin.

2. How Does the Calculator Work?

The calculator uses the generator sizing formula:

Where:

• \( \Sigma P_{\text{loads}} \) — Sum of wattages for all appliances to be powered
• \( 1.2 \text{ to } 1.5 \) — Safety factor (20% to 50% margin)
• \( 1000 \) — Conversion factor from watts to kilowatts

Explanation: The safety factor accounts for startup surges, future expansion, and ensures the generator isn't running at full capacity continuously.

3. Importance of Proper Sizing

Details: Proper generator sizing prevents overload (which can damage both generator and appliances) while ensuring adequate power for essential needs. An undersized generator may fail when needed most, while an oversized one is unnecessarily expensive.

4. Using the Calculator

Tips:

1. Calculate the total wattage of all appliances you want to power simultaneously
2. Choose a safety factor based on your needs (1.2 for minimal margin, 1.5 for heavy appliances or future expansion)
3. The result shows the minimum generator size recommended in kilowatts

5. Frequently Asked Questions (FAQ)

Q1: What's a typical home generator size?
A: Most homes need 5-20 kW, depending on appliances. A 7-10 kW generator typically powers essentials (lights, fridge, furnace), while 15-20 kW can power most of a medium-sized home.

Q2: How do I calculate my total load?
A: Add the running wattage of all appliances you want to power simultaneously. Check appliance labels or manuals for wattage information.

Q3: Why is the safety factor important?
A: Many appliances (especially motors like AC units or refrigerators) require 3-5 times their running wattage during startup. The safety factor accounts for these surges.

Q4: Should I size for all appliances or just essentials?
A: For backup power, focus on essentials (lights, fridge, heating/cooling, medical equipment). Whole-house generators should include all regularly used appliances.

Q5: What if I'm between standard generator sizes?
A: Always round up to the next available size. It's better to have slightly more capacity than you need than not enough.