Choosing the right size Generac home standby generator is the most important decision in the buying process. Too small and your generator won't power everything you need. Too large and you're overspending. Here's how to size it right.
Quick Sizing Chart
| Home Size | AC System | Recommended Generator |
|---|---|---|
| Under 1,500 sq ft | 2 Ton | 10–14kW |
| 1,500–2,500 sq ft | 3 Ton | 18–22kW |
| 2,500–3,500 sq ft | 4 Ton | 22–24kW |
| 3,500+ sq ft | 5 Ton | 24–26kW |
What Uses the Most Power?
Your central AC system is by far the largest electrical load in most homes. A 3-ton AC system draws approximately 3,500–4,500 watts at startup (with a surge up to 7,000W). Everything else — refrigerator, lights, electronics, well pump — adds another 3,000–5,000 watts.
Generac Model Lineup (2026)
- 10kW Guardian (Model 7171): Essential circuits — great for smaller homes or budget-conscious buyers. Won't run a large AC system.
- 14kW Guardian (Model 7223): Powers most of the home including a 2–2.5 ton AC. Sweet spot for smaller Florida homes.
- 18kW Guardian (Model 7226): Whole-house backup with a 3-ton AC. Popular choice for average-sized homes.
- 22kW Guardian (Model 7042): Comfortably runs a 3–4 ton AC plus full house loads. Most popular size overall.
- 24kW Guardian (Model 7209): Handles 4-ton AC with room to spare. Multiple AC zones.
- 26kW Home Standby (Model 7290): Maximum residential power. 5-ton AC + everything else.
Where to Buy a Generac Generator
Furnace Direct sells the full Generac Guardian and Home Standby lineup at factory-direct pricing — typically lower than Home Depot, Lowe's, or local dealers. Every unit includes a free automatic transfer switch and WiFi monitoring module. We ship nationwide. Call (888) 762-1334 for sizing help and current pricing.
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