Charlotte homeowners ask one question more than any other: how big should a standby generator be? The answer depends on the home’s loads, the way the family lives, and Charlotte’s weather patterns. This guide breaks down real numbers, common scenarios, and what Ewing Electric sees daily across Mecklenburg County.
Why sizing matters in Charlotte
Charlotte’s grid sees stress from summer humidity, storm-related outages, and occasional winter ice. A right-sized system keeps HVAC, refrigerators, sump pumps, and medical devices running through Duke Energy failures without wasting fuel or budget. An undersized unit trips, stalls, or leaves key circuits dark. An oversized unit costs more upfront and burns more fuel than necessary.
Start with a clear load picture
Every sizing decision starts at the electrical panel. A licensed electrician reviews the breaker labels, measures actual amperage where possible, and maps essential circuits. Ewing Electric uses a formal load calculation and, when helpful, data-logging to see real usage. The goal is simple: cover what matters without overbuying.
HVAC dominates in Charlotte. A single 3- to 4-ton heat pump or AC can draw 4 to 6 kW while running, with higher brief startup surge. Electric heat strips jump that number fast. Gas furnaces need far less generator power because the blower and controls draw only a few hundred watts. Refrigerators, freezers, well pumps, and sump pumps each add meaningful load. Home offices with dual monitors and a desktop might add 300 to 600 watts, but network gear and modems draw little.
Quick reference: common Charlotte scenarios
Many homes in Myers Park, Dilworth, South Park, Ballantyne, and Steele Creek fit one of these patterns. These are ballpark ranges. A site visit confirms the final size.
- Essential circuits, gas heat: 10 to 14 kW. Keeps the refrigerator, lights, outlets, gas furnace blower, Wi‑Fi, and a sump pump going. Works well for bungalows in Dilworth or Elizabeth with gas heat and a single HVAC system. Essential circuits with one central AC: 14 to 18 kW. Adds a 3- to 4-ton AC or heat pump for summer comfort. Common in Plaza Midwood and NoDa. Whole-home for mid-size homes: 18 to 24 kW. Runs most or all circuits for 2,200 to 3,000 sq ft homes, including one or two HVAC units and a range of small appliances. Frequent choice in 28210 and 28277. Large homes or estates with multiple HVAC systems: 24 to 38 kW (often liquid‑cooled). Covers larger South Park properties and Myers Park estates, especially with electric heat strips or pool equipment.
Air-cooled standby units typically cover 10 to 26 kW and serve most standard homes. Liquid-cooled generators handle 24 kW and up with steadier performance for larger loads and long runtimes.
The role of load management
Smart load management can shrink generator size without giving up comfort. A smart module staggers startup surges or sheds nonessential loads if the generator nears its limit. That may allow a 18 kW unit to run two AC systems, one at a time, instead of buying a 26 kW machine. Ewing Electric uses smart load management where budgets, gas supply limits, or municipal noise rules favor smaller units.
Natural gas vs. propane in Mecklenburg County
Most Charlotte neighborhoods have natural gas, which means steady fuel supply and no refills during a storm. Propane is common on the edges of the county and in parts of Mint Hill and Huntersville. Propane requires a tank sized for the expected runtime. A 20 kW generator whole home generator installation guide can burn roughly 2 to 3 gallons of propane per hour at half to three‑quarter load. Sizing the tank for 24 to 72 hours of runtime helps ride out multi-day outages.
Ewing Electric coordinates with licensed gas plumbers for new natural gas line sizing or propane tank set, and verifies pressure under full load.
What must run during a Charlotte outage
Charlotte outages often follow afternoon thunderstorms or overnight ice glazing. The priority list looks similar across zip codes like 28277, 28210, 28226, 28269, 28205, and 28202.
- HVAC: controlling humidity is as critical as cooling. One central system usually suffices. Homes with seniors or infants may want both systems available, managed by smart load control. Cold storage: refrigerators and freezers protect food and medication. Water control: sump pumps and well pumps prevent flooding and water loss. Medical and work: CPAPs, oxygen concentrators, home office equipment, and network gear keep life stable and work on schedule.
A focused essential-circuits plan is often smarter than brute-force whole-home coverage. Ewing Electric builds subpanel or transfer switch priorities around that plan.
The Charlotte-specific risks a generator solves
Heavy summer rain can flood basements if a sump pump stalls. Ice storms can knock lines down for days. Rolling blackouts stress freezers and home offices. Voltage spikes after restoration can damage electronics. A properly installed standby unit with an Automatic Transfer Switch (ATS) protects against these issues by switching power cleanly and stabilizing voltage.
Components that matter
A reliable system is more than a generator. The installation quality sets long-term performance.
- Automatic Transfer Switch: sized for your service and tied cleanly to the electrical panel. It isolates the home from the grid and engages standby power within seconds of grid failure. Concrete pad and enclosure: level pad, correct clearances, and a weatherproof housing reduce vibration, noise, and corrosion. Gas supply: right pipe size and regulator for full-load performance. Electrical panel work: clean labeling, balanced phases, and a tidy subpanel if using an essential-circuits approach. Battery charger and controller: keep the unit ready to start in any weather, with remote monitoring when desired.
Ewing Electric handles the full integration of the ATS with your existing breaker panel, from wiring to testing.
Air-cooled vs. liquid-cooled in practice
Air-cooled units, common in neighborhoods like Plaza Midwood and NoDa, fit most homes. They cost less, install faster, and cover 10 to 26 kW. Liquid-cooled units suit larger homes in South Park or Ballantyne that run multiple HVAC systems, pool equipment, or extensive lighting. They offer better surge handling, quieter operation under load, and longer continuous runtimes.
Brand insights and sizing accuracy
Ewing Electric installs Generac and Kohler most often because parts, service, and support are strong in Charlotte. Generac Guardian series offers good value and strong ecosystem support. Kohler Power systems are known for voltage stability and durable engines. Honeywell-branded units add premium remote monitoring and low-noise features. Briggs & Stratton, Cummins, Champion, and Westinghouse also appear in the field, and the team services many of them.
As experts in Generac and Kohler, the team sizes units to your actual loads. For many Charlotte homes, a 22 kW air-cooled standby generator is the sweet spot if the goal is near-whole-home coverage with one or two HVAC systems.
What a professional whole home generator installation includes
A complete project covers site planning, permits, fuel, and testing. Ewing Electric manages permitting and inspections with the City of Charlotte and Mecklenburg County, including historic areas like Myers Park and Dilworth. The team pours the concrete pad, sets the enclosure with proper setbacks, wires the ATS, and syncs with the Duke Energy meter. For natural gas, they coordinate the line and pressure test. For propane, they size and set the tank.
Located within range of Freedom Park and central to the Queen City, the crew provides rapid response across Charlotte, from Ballantyne to Huntersville, and to Matthews, Pineville, Mint Hill, Concord, Belmont, and Gastonia.
Cost ranges and what drives them
For a typical home in 28277 or 28210, air-cooled standby systems with essential circuits often land in the mid–to–upper five figures installed, depending on gas work, ATS size, and site conditions. Whole-home coverage with larger liquid-cooled units, long gas runs, or complex panels increases cost. A site visit and load calculation produces a firm estimate and options for phasing or smart load management.
Maintenance and runtime expectations
Standby generators start automatically and exercise weekly. Annual service includes oil and filter changes, spark plugs as needed, valve checks on some models, battery test, and a full system inspection. With proper service and clean fuel, modern units run for many years. Remote monitoring flags issues early and allows quick service calls before the next storm.
Where whole-house truly makes sense vs. essential circuits
Whole-house coverage fits families who work from home full-time, care for medical needs, or manage smart homes with integrated systems. It also suits properties with sensitive basements, pools, or detached structures. Essential-circuits plans fit smaller homes with gas heat and a single AC. The trade-off is upfront cost versus how normal life feels during an outage. Ewing Electric lays out both paths with clear numbers.
Neighborhood examples from field experience
A two-story home in Ballantyne with gas heat and two 3-ton AC systems chose an 18 kW air-cooled unit with smart load management. It runs one AC at a time and all essential circuits. A South Park estate with three systems and a wine cellar required a 36 kW liquid-cooled generator to stabilize temperature and humidity. A Dilworth bungalow with a damp basement installed a 14 kW unit focused on the sump pump, refrigeration, and one mini-split for comfort.
Frequently asked questions
How much does a whole house generator cost in Charlotte?
Most air-cooled systems with installation fall within a wide mid–five-figure range, influenced by gas line work, ATS size, and site prep. Liquid-cooled systems for larger homes cost more. A free, on-site estimate clarifies the total.
Will a standby generator run my central air conditioning?
Yes, if sized correctly. A 14 to 18 kW unit often handles one 3- to 4-ton system. Larger homes may use load management or step up to 22 to 26 kW or liquid-cooled models.
Does Ewing Electric handle the electrical permits and inspections?
Yes. The team manages permitting, inspections, utility coordination, and the final Duke Energy meter sync.
Do I need natural gas or propane?
Either works. Most Charlotte homes choose natural gas. Propane is common where gas is unavailable and requires tank sizing for expected runtime.
Which brands do you install and service?
Generac and Kohler are primary. The team also works with Honeywell systems and services other brands, including Briggs & Stratton, Cummins, Champion, and Westinghouse.
Ready to size your system?
Ewing Electric provides whole home generator installation for Charlotte, NC, including Myers Park, Dilworth, South Park, Elizabeth, Plaza Midwood, NoDa, Steele Creek, and nearby Matthews, Pineville, Huntersville, Mint Hill, Concord, Belmont, and Gastonia. The licensed, insured, factory-trained electricians deliver turnkey installation, maintenance contracts, and remote monitoring.
Contact Ewing Electric today for a comprehensive load calculation and a free generator installation estimate. They will size the Automatic Transfer Switch, confirm gas capacity, pour the concrete pad, and commission the standby generator so your home stays comfortable through the next storm.
Ewing Electric Co provides dependable residential and commercial electrical services in Charlotte, NC. Family-owned for over 35 years, we handle electrical panel upgrades, EV charger installation, generator installation, whole-home rewiring, and 24/7 emergency repairs. Our licensed electricians deliver code-compliant, energy-efficient solutions with honest pricing and careful workmanship. From quick home fixes to full commercial installations, we’re known for reliable service done right the first time. Proudly serving Charlotte, Matthews, Mint Hill, and nearby communities.
Ewing Electric Co
7316 Wallace Rd STE D
Charlotte,
NC
28212,
USA
Phone: (704) 804-3320
Website: https://ewingelectricco.com/ | Electric Company in Charlotte
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