Home Standby Generators: Every Model Compared

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Standby generators are the set-and-forget answer to outages: permanently installed beside the house, wired in through an automatic transfer switch, and fueled by your natural gas line or a propane tank. When the grid drops they start themselves in seconds — whether you're home or not — and they carry heavy loads like central air that portables can't touch. Budget for installation (typically as much as the unit itself) and annual engine maintenance.

Outage Geek tracks 17 home standby generators from 5 brands, priced $3,899 to $7,249. The least expensive is the Cummins QuietConnect RS13A at $3,899, and the list below runs cheapest first.

~$3,899

Home Standby Generator · NG/LP · 65 dB

Cummins QuietConnect RS13A

The sleeper value in home standby: a genuine Cummins — the company that powers hospitals and data centers — at a price under the equivalent Generac or Kohler. The RS13A's QSJ999G 999cc V-twin was designed in-house for gaseous fuel, and the QuietConnect sound-insulated enclosure holds it to 65 dB at 23 feet. It holds 13kW on either natural gas or propane with no derate and meets the 18-inch NFPA 37 clearance for tight lots. The catch: the Cummins residential dealer network is sparse compared to Generac's. If there's no certified servicer within reasonable distance, warranty work becomes your problem. The Cummins app covers status and alerts but is basic.

13,000 W · up to well pump or a small central AC

running: 13,000 W
Transfer switch: transfer-switch ready

Best for Value-focused buyers near a Cummins dealer who want commercial-grade pedigree and low noise.

Full spec sheet

~$4,460

Home Standby Generator · NG/LP · 69 dB

Briggs & Stratton PowerProtect 13kW

Briggs & Stratton's small-footprint standby unit fits where a Guardian or Kohler will not: it is about 28 by 25 inches, so owners with tight lot lines or a narrow side yard shortlist it first. The 627cc Vanguard engine makes 13kW on propane and 11.5kW on natural gas, which covers a furnace, fridge, well pump and a small-to-mid central AC but not a whole large house. Shoppers weighing it against the Generac 14kW point to the 7-year warranty, which includes labor and technician travel. Two things come up again and again: it is loud, since 69 dB is louder than the 61 dB Guardian 10kW, and the listed price excludes the transfer switch, which is a separate purchase. Dealer coverage is thinner than Generac's, so check who services it locally before you buy.

13,000 W · up to well pump or a small central AC

running: 13,000 W
Transfer switch: transfer-switch ready

Best for Owners of mid-size homes with a narrow side yard who want a 7-year warranty that covers labor, and can live with 69 dB.

Full spec sheet

~$4,619

Home Standby Generator · NG/LP · 61 dB

Generac Guardian 10kW

The entry point to the Guardian line, and the one bought for smaller homes with a short essentials list because it bundles a 100-amp, 16-circuit transfer switch in the box. The 460cc G-Force 400 engine covers essentials — furnace, fridge, well pump, some lights — not whole-house AC. At 61 dB it's the quietest Guardian. The battery, oil, and some setup parts aren't included, and warranty service depends entirely on how good your local Generac dealer is. Budget for install — most people pay more for wiring and gas work than for the unit.

10,000 W · up to well pump or a small central AC

running: 10,000 W
Transfer switch: transfer-switch ready

Best for Smaller homes that want automatic backup for essential circuits without paying whole-house prices.

Full spec sheet Check price on Amazon

~$4,889

Home Standby Generator · NG/LP · 65 dB

Generac Guardian 14kW

The 14kW is the sweet spot Guardian for mid-size homes: it steps up to the 816cc twin-cylinder G-Force 800 engine, holds 14kW on both propane and natural gas, and will start a modest central AC with load management. This 7223 SKU is the bare generator; pair it with a 100A or 200A switch, and get quotes, because installed cost typically lands at double the hardware price.

14,000 W · up to well pump or a small central AC

running: 14,000 W
Transfer switch: transfer-switch ready

Best for Mid-size homes that want essential circuits plus one air conditioner covered automatically.

Full spec sheet Check price on Amazon

~$4,999

Home Standby Generator · NG/LP · 62 dB

Champion aXis 14kW

Champion's aXis system is the disruptor bid in standby: a 14kW unit with a 200-amp service-entrance transfer switch AND a 10-year warranty — double the coverage of Generac, Kohler, or Cummins — for about five grand. The clever bit is Power Line Carrier technology: the generator talks to the transfer switch over your home's existing wiring, so installs skip the extra control-wire run, and the aXis load management prioritizes up to four loads. The 754cc Milwaukee-series V-twin runs a claimed 62 dBA, quiet for the class, and it operates from -22°F to 104°F with a 24V starting system. The drawbacks: the certified installer network is young and sparse, some electricians are unfamiliar with the PLC setup, and 12.5kW on natural gas trails the LP rating.

14,000 W · up to well pump or a small central AC

running: 14,000 W
Transfer switch: transfer-switch ready

Best for Value hunters who want the longest warranty in the industry and a complete package price.

Full spec sheet Check price on Amazon

~$5,279

Home Standby Generator · NG/LP · 65 dB

Generac Guardian 18kW

The 18kW is the value pick in the Guardian range on a dollars-per-kilowatt basis — same 816cc G-Force 800 twin as the 14kW, tuned for 18kW on propane and 17kW on natural gas, at only a few hundred dollars more. One owner's first real outage went as advertised, with the central AC starting on no more than a flicker of the lights, and the G-Flex variable-speed exercise keeps the weekly test tolerable at 65 dB. The ownership caveats are pure Generac: dealers are the only sanctioned path for warranty work, and the battery and cold-weather kit are extras to budget for up front. If you're between the 14 and this, most owner advice says spend up.

18,000 W · up to whole home with central air

running: 18,000 W
Transfer switch: transfer-switch ready

Best for Average-size homes that want near-whole-house coverage at the lowest cost per kilowatt.

Full spec sheet

CumminsRS17A

~$5,327

Home Standby Generator · NG/LP · 65 dB

Cummins QuietConnect RS17A

Cummins' 17kW air-cooled unit, positioned between the RS13A and RS20A. Its V-twin QSJ999G engine is rated 17kW on both natural gas and propane (70.8 amps at 240V), so there is no natural-gas penalty to budget around. Cummins says it will start and run a 5-ton AC under full pre-load, and it can control four loads through built-in load management. The 65 dB(A) rating, measured at 23 feet, and the 18-inch clearance from the house under NFPA 37 are what owners mention first. The caveats are practical. It runs on one fuel at a time, set to natural gas at the factory and switched in the field, so it is not a dual-fuel unit. Cummins does not publish a list price; $5,327 is a retailer list, and dealer quotes run lower. The dealer network is smaller than Generac's, and the transfer switch is a separate purchase.

17,000 W · up to well pump or a small central AC

running: 17,000 W
Transfer switch: transfer-switch ready

Best for Homeowners who want a quiet, full-rated 17kW air-cooled unit on natural gas and do not want to pay for a liquid-cooled machine.

Full spec sheet

~$5,449

Home Standby Generator · NG/LP · 67 dB

Kohler 14kW RCA

Kohler's answer to the Guardian 14kW, and the one owners pick for its engine. The commercial-grade CH740 V-twin uses hydraulic valve lifters — no break-in, no valve adjustments — and the corrosion-proof aluminum enclosure holds up in coastal salt air where painted steel rusts. It punches above its class on motor starting with 33kVA of surge capacity via PowerBoost, so a 4-ton AC is realistic. Owners rate the hardware a grade above Generac, but the dealer network is thinner, and with no built-in Wi-Fi the OnCue Plus monitoring app needs an ethernet run or a wireless bridge. Note the honest ratings: 14kW on propane but 12kW on natural gas, and 67 dB at full speed is still loud beside a patio or bedroom window.

14,000 W · up to well pump or a small central AC

running: 14,000 W
Transfer switch: transfer-switch ready

Best for Buyers who prioritize engine build quality and coastal durability over app polish and dealer density.

Full spec sheet Check price on Amazon

~$5,699

Home Standby Generator · NG/LP · 69 dB

Kohler 20kW RCA

The 20RCA is Kohler's volume whole-house unit and the direct rival to Generac's 22/24kW, built around the bigger CH1000 V-twin. Its party trick is 41kVA of motor-starting capacity — enough on paper to start a 5-ton AC without dropping the rest of the house, which smaller-surge competitors need load-shedding modules to manage. Owners mostly report boring, dependable service, the best compliment a standby can get. Trade-offs are the familiar Kohler ones: 18kW on natural gas, 69 dB at full-speed operation is on the loud side, OnCue Plus monitoring trails Generac's app, and you may wait longer for both the unit and a certified installer depending on your region.

20,000 W · up to whole home with central air

running: 20,000 W
Transfer switch: transfer-switch ready

Best for Whole-house buyers with big AC loads who want maximum motor-starting muscle and proven long-term reliability.

Full spec sheet

~$5,746

Home Standby Generator · NG/LP · 68 dB

Briggs & Stratton PowerProtect 18kW

The mid-range PowerProtect answers the most common standby question: what is the biggest air-cooled unit that does not lose power on natural gas. Briggs' NGMax tuning holds the full 18kW on both fuels, where several rivals in this class list a lower natural-gas rating, and the 993cc Vanguard has 45 kVA of motor starting for a 3 to 4 ton AC. Owners who run it through summer outages report it carrying AC, well pump and range together without sag. Complaints are the usual ones for the class: it is audible at 68 dB, the quoted price leaves out the transfer switch, and dealer support is patchier than for Generac. The 7-year warranty including labor and travel is the real selling point against a Guardian 18kW, and install labor, gas and electrical work usually cost more than the generator itself.

18,000 W · up to whole home with central air

running: 18,000 W
Transfer switch: transfer-switch ready

Best for Owners of 2,000-3,000 sq ft homes who run central AC and want full rated power on natural gas.

Full spec sheet

~$5,926

Home Standby Generator · NG/LP · 65 dB

Cummins QuietConnect RS20A

The RS20A's headline is noise: Cummins holds it to 65 dB at 23 feet — dishwasher territory — while still starting a 5-ton air conditioner and managing four loads with its built-in intelligent load control. The same QSJ999G V-twin as the RS13A runs harder here, delivering 20kW on propane and 18kW on natural gas, and it ships cold-weather-ready to 0°F out of the box. The trade-offs also mirror the RS13A — sparse residential dealer coverage makes pre-purchase service planning essential, stock frequently slips to pre-order, and the app is functional but bare-bones. For sound-sensitive neighborhoods it's arguably the class benchmark.

20,000 W · up to whole home with central air

running: 20,000 W
Transfer switch: transfer-switch ready

Best for Noise-sensitive neighborhoods and HOAs that still need full whole-house starting power.

Full spec sheet

~$5,999

Home Standby Generator · NG/LP · 67 dB

Generac Guardian 22kW

For years the best-selling home standby generator in America, and the sheer volume of owner reviews shows why: the 22kW carries most whole homes — two AC units with load management — and every electrician and gas fitter in the country has installed one. The G-Force 1000 engine and 67 dB noise level are unremarkable but proven; owners report units carrying whole houses through multi-day storm outages. The newer 24kW (7209/7210) has largely replaced it at similar money, but the 7042 remains widely stocked, slightly cheaper, and the known quantity — a big deal when your installer has done fifty of them.

22,000 W · up to whole home with central air

running: 22,000 W
Transfer switch: transfer-switch ready

Best for Whole-house backup buyers who want the most-installed, most-understood generator on the market.

Full spec sheet Check price on Amazon

~$6,037

Home Standby Generator · NG/LP · 68 dB

Briggs & Stratton PowerProtect 22kW

Briggs' PowerProtect 22kW has one spec nobody else in the class matches: NGMax tuning delivers the full 22,000 watts on natural gas — no derate — where Generac's 22kW drops to 19.5kW and Kohler's 20kW to 18kW. If your home runs on NG, that's effectively a size-class upgrade for free. The commercial-grade Vanguard 993cc V-twin (Briggs' premium engine line) drives it, the aluminum enclosure is rated for 186-mph hurricane winds, and the 7-year parts/labor/travel warranty beats the standard 5-year offers. So why isn't it everywhere? The dealer network is thin, parts distribution has been slower since Briggs' 2020 bankruptcy and KPS acquisition, and retail visibility is low — Lowe's is the main storefront. At 68 dBA normal / 64 dBA idle-mode it's mid-pack for noise.

22,000 W · up to whole home with central air

running: 22,000 W
Transfer switch: transfer-switch ready

Best for Natural-gas homes that want maximum NG output per dollar and a longer warranty than the big two.

Full spec sheet

~$6,849

Home Standby Generator · NG/LP · 67 dB

Generac Guardian 26kW

The biggest air-cooled generator Generac makes, and the one owners of large homes buy to avoid stepping up to liquid-cooled money. 26kW on propane (22.5kW on natural gas) with a redesigned alternator delivering 230 LRA of starting grunt means dual 5-ton AC setups are realistic with load management. It's 'smart grid ready' and runs the same Evolution 2 controller and Mobile Link stack as the rest of the line. Generac claims 68% less space than comparable output, and the service ecosystem is familiar; the trade-offs are the usual dealer-dependent warranty service, the meaningful NG derate, and 67 dB of noise that a big home's yard absorbs better than a small lot does.

26,000 W · up to whole home with central air

running: 26,000 W
Transfer switch: transfer-switch ready

Best for Large homes with heavy AC loads that want maximum air-cooled power before liquid-cooled prices kick in.

Full spec sheet Check price on Amazon

~$6,970

Home Standby Generator · NG/LP · 65 dB

Briggs & Stratton PowerProtect 26kW

Briggs' answer to the Generac Guardian 26kW and Kohler 26RCA, and the only one of the three that ships with a 10-year comprehensive warranty. It uses the same 993cc Vanguard as the 18kW, tuned to 26kW on propane and 24kW on natural gas, with 65.5 kVA of motor starting at a 35 percent voltage dip. That is enough to run a 5-ton AC or two units on a whole-house transfer switch with load management. At 65 dBA it is the quietest PowerProtect on the spec sheet, though still a loud neighbor. The price is $6,970 before a transfer switch, and a 200-amp switch with install is where the real money goes. It is rated for off-grid and demand-response use and can sit 18 inches from a building where local code allows. The catch is the same as for the whole Briggs line: a smaller dealer network than Generac.

26,000 W · up to whole home with central air

running: 26,000 W
Transfer switch: transfer-switch ready

Best for Large homes that want whole-house air-cooled backup with the longest warranty in the class, and have a Briggs installer nearby.

Full spec sheet

~$7,099

Home Standby Generator · NG/LP · 67 dB

Kohler 26kW RCA

Kohler's air-cooled flagship goes head-to-head with Generac's 26kW and quietly wins the spec that matters for most buyers: 24kW on natural gas versus Generac's 22.5kW. Built on the CH1006 V-twin with PowerBoost starting, it carries large homes — dual AC compressors, well pumps, the works. The critical silencer and sound enclosure keep the tone lower and less mechanical than the raw 67 dB figure suggests, though it's still not quiet. Ownership realities: it's a 625-lb unit that needs a serious pad, Kohler/Rehlko dealer coverage is uneven so line up your servicer before you buy, and lead times can stretch after major storm seasons. The 26RCAL variant bundles a 200A transfer switch if you want one quote for everything.

26,000 W · up to whole home with central air

running: 26,000 W
Transfer switch: transfer-switch ready

Best for Large homes on natural gas that want the smallest NG derate and top-tier build in an air-cooled unit.

Full spec sheet Check price on Amazon

~$7,249

Home Standby Generator · NG/LP · 67 dB

Generac Guardian 24kW

Generac's current volume flagship: 24kW on propane and 21kW on natural gas from the G-Force 1000 platform, bundled here with a 200-amp service-entrance transfer switch with PWRview energy monitoring. It's pitched as the 22kW's replacement, squeezing 2.6x the power of the baseline air-cooled units from the same-size enclosure. Real-world reports are mostly strong, with noise at 67 dB under load and a much quieter 57 dB Quiet-Test. The complaints are familiar: dealer-network variability makes your installer choice as important as the machine, and turnkey quotes for the same box differ by thousands. Ships as a complete package, which simplifies quotes compared to the à-la-carte SKUs.

24,000 W · up to whole home with central air

running: 24,000 W
Transfer switch: transfer-switch ready

Best for Larger homes that want a complete whole-house package with the transfer switch in the box.

Full spec sheet Check price on Amazon