A home backup generator is the one you buy for the ice storm, and it is a different noise problem from the one you take camping. It is bigger, 5,000 to 12,000 watts and 240 volts, so it can feed a transfer switch or an inlet and run the furnace, the well pump and the refrigerator at once. It runs for days, not an evening. And it sits where CPSC says it must, outside and 20 feet from the house, which on most lots means near a window, or near the neighbor's. Our parent guide to the quietest generators for camping and RVs covers the small inverters; this one covers the machines that back up a house.
We read the product pages, spec sheets and manuals for every 240 V portable we could find a figure for, from Honda, Yamaha, Champion, Westinghouse, DuroMax, Firman, Briggs & Stratton, Cummins, Pulsar and Generac. We put sixteen of them in the catalog, quoted each figure in the maker's words with whatever load and distance it states, and ranked each kind of figure only against its own kind.
Our picks are listed above, with full specifications for each.
A noise figure needs a load and a distance to mean anything. Here is who gives what, in this size class.
- Load and distance, both ends of the range. Honda, for every model: 52 and 58 dB(A) for the EU7000iS at quarter load and rated load, 63 and 65 for the EB5000 at 50% load and rated load. The product pages give the load; Honda's sound level comparison chart gives the distance, 23 feet (7 meters), the side, the control panel side, and the test, ISO 9614-2. Our Honda generator decibels page lists all 13 models on that basis.
- Load and distance, quiet end only. Briggs & Stratton, on a support page rather than the product page: 66 dB(A) for the Q6500, running at 1/4 load at 7 meters from the control panel side.
- Load, no distance. Yamaha: 58 to 64 dBA from quarter load to rated load for the EF6300iSDE, and 74.5 dB on the same basis for its conventional EF7200DE. Firman: 67 dB at 1/4 load for the WT06375. DuroMax: 66 dB at 25% load for the XP13500iH inverter.
- Distance, no load. Champion: 61 dB(A) from 23 feet for the 8500W inverter 201177, 64 for its older 201175 and for the 11,000W 201417.
- Neither. Westinghouse says "as low as 64 dBA" for the iGen12000DFc and "as low as 74 dBA" for the WGen9500DFc. Our Westinghouse decibels page gathers every current Westinghouse figure and says which few name a load. Pulsar's table says "Volume (dB) 62". Cummins' spec sheet says "As low as 74dBA". DuroMax's conventional XP13000EH says "Volume (db) 74 dB".
- Nothing. Generac publishes no figure for the iQ5200 on its page or its spec sheet, only "Fully enclosed case reduces noise levels", and the iQ5200 is 120 V only. Generac's GP series pages would not load for us at all. Our Generac generator decibels page explains why Generac gives no decibel figure for its portables, and lists the figures it does publish, for its home standby units.
We never rank one group against another. A Champion figure at 23 feet with no load may have been taken at idle; a Yamaha figure at rated load with no distance may have been taken at 7 meters or at 3. Our explainer on why you cannot compare dB ratings across brands goes through the ways the same machine can get three different numbers.
Quarter load is where a backup generator lives
The quiet end of every range is the light-load end, and for home backup that matters more than it does for camping. An inverter generator slows its engine when little power is drawn. Honda's manual for the EU7000iS recommends the Eco Throttle position to further reduce noise levels when a reduced load or no load is applied. Champion says that as the electrical load is reduced, the inverter reduces engine speed, providing quieter operation. Yamaha says its Smart Throttle adjusts engine speed to match power demand and reduces noise. DuroMax lists Demand-Based Variable Idle for the XP13500iH inverter and No Load Low Idle for the conventional XP13000EH, which is the difference in one spec line: the inverter idles down whenever the load is light, the conventional unit only when there is no load at all.
Honda's two-load figures show how much this is worth. The EU7000iS climbs 6 dB(A) from quarter load to rated load. The EB5000, a conventional unit at a fixed 3,600 rpm, climbs only 2 dB(A) from 50% load to rated load, but starts 11 dB(A) higher. Over a three-day outage, the generator is at its quiet end whenever the furnace blower cycles off and the water heater is not calling, which is most of the time. A unit sized well above your running load spends more hours there.
What the house hears, and what the neighbor hears
The makers measure at 7 meters, or 23 feet, or at a distance they do not say. CPSC's placement rule is 20 feet from the house, with the exhaust facing away. That is close enough to the 23-foot figures that the published numbers are a fair guide to what reaches your wall, but we do not convert between distances, and a wall, a window and a fence each change what gets through.
The room on the other side of that wall is what decides whether a figure is good enough. A bedroom at night is the quietest room in the house, and our quiet bedroom page covers how low its background sits once the house is asleep. During a winter outage you are sleeping with the windows shut and the furnace fan cycling, and a generator at the quiet end of its range is a steady hum under that. At the loud end it is not. A 10 dB(A) gap is roughly a doubling of perceived loudness, and the gap between the Honda EU7000iS at quarter load and the Briggs Q6500 at the same stated condition is 14 dB(A). Our decibel chart puts the figures in this guide beside everyday sounds.
Your neighbor hears the same machine from the other side. Twenty feet from your house may be ten feet from theirs. The parent guide's national park rule does not apply in a city, but a local noise ordinance may, and most are measured at the property line, as our home standby generator guide explains for permanently installed units. Some ordinances exempt emergency use; read yours before the storm, not during it. For the wider picture of what counts toward a neighbor's complaint, see our yard noise overview.
Every placement decision in this guide comes second to this one. The Consumer Product Safety Commission's words:
- "Never use portable generators inside homes or garages, even if doors and windows are open."
- "Use generators outside only, at least 20 feet away from homes with exhaust facing away."
- "NEVER operate a portable generator inside a home, garage, basement, crawlspace, shed or other enclosed spaces."
- "Look for portable generators that have a CO shut-off safety feature."
CPSC says more than 100 deaths a year in the United States are linked to portable generators, and that one portable generator can produce the same amount of carbon monoxide as hundreds of cars.
Every generator in this guide, except where we say otherwise, has a shutoff of this kind. Honda calls it CO-MINDER, Champion CO Shield, Firman CO Alert, Briggs & Stratton CO Guard, Pulsar CO Sentry, Westinghouse and DuroMax a CO sensor, Generac COsense, and Cummins a carbon monoxide detector with automatic shutoff. Champion goes a step further and says its 8500W inverter meets the requirements of ANSI/PGMA G300-2018, and lists its 11,000W unit as PGMA Compliant G300-2023. CPSC describes those two voluntary standards, ANSI/PGMA G300-2018 and ANSI/UL 2201-2018, as containing requirements for a generator-mounted shutoff system that will shut the generator off when carbon monoxide accumulates to certain concentrations around the generator.
Read that last clause carefully. The shutoff acts when CO has already built up around the generator. It is the backstop for the night the wind shifts. It is not a reason to put the machine under the eaves, and Honda's manual says never to enclose or cover a generator, even outside.
Inverter or conventional, as the makers label them
We use each maker's own label. Honda's EU7000iS, Yamaha's EF6300iSDE, Champion's 201177 and 201417, DuroMax's XP13500iH, Firman's WT06375, Westinghouse's iGen12000DFc, Pulsar's PGD95BiSCO and Briggs & Stratton's Q6500 are sold as inverters. Honda's EB and EM lines, Westinghouse's WGen9500DFc, DuroMax's XP13000EH, Yamaha's EF7200DE and the Cummins P9500df are not; Cummins' spec sheet says "Built-in inverter: No" in so many words.
The inverters here cost more per watt, and the conventional units publish the weaker figures. Westinghouse lists 64 for its inverter and 74 for its conventional unit, both "as low as"; DuroMax lists 66 at 25% load for its inverter and a bare 74 for its conventional one. Those are within-brand comparisons, which is the only kind we trust, and in both cases the inverter is lower.
The outlet, the switch and the inlet
A generator backs up a house through one of two things: a manual transfer switch, which moves selected circuits from the grid to the generator, or an interlocked inlet, which lets the generator feed the main panel while the utility breaker is locked off. Both need a 240 V cord from the generator. The common outlets are the L14-30R, a 30 A twist-lock, and the 14-50R, a 50 A outlet. Honda uses its own 30 A 125/250V locking receptacle. Champion, DuroMax, Firman and Westinghouse give you both an L14-30R and a 14-50R. Cummins gives an L14-30R and says "manual transfer switch ready". Briggs and Yamaha say "120V-240V locking" and "120/240 dual voltage 4 prong twist locking" without naming the type, so check the cord before you buy.
Firman's panel prints the limit that matters: its L14-30R is rated 22.9 A at 240 V, 5,500 W, and its 14-50R 5,300 W. The outlet, not the generator's peak rating, caps what a transfer switch can draw. The switch or inlet itself is an electrician's job under your local code, and a generator that is "transfer switch ready" still needs one installed.
Natural gas changes the arithmetic. Firman's tri-fuel inverter and DuroMax's XP13500iHT can run on a house gas line, which does not run dry on day three. Firman rates the WT06375 at 4,900 running watts on natural gas against 6,300 on gasoline, so the quiet end moves closer to your actual load.
How much should you spend?
Around $1,300 to $1,400 buys a 9,500 to 10,500 running watt conventional generator with a bare figure: DuroMax's XP13000EH at $1,299 or Westinghouse's WGen9500DFc at $1,399 MSRP.
Around $2,200 to $2,700 buys a big dual-fuel or tri-fuel inverter: Westinghouse's iGen12000DFc at $2,199, Firman's WT06375 at $2,299.99, DuroMax's XP13500iH at $2,699. Only the last two tie their figure to a load.
Around $2,800 to $3,300 buys a conventional Honda with a 50% load figure at 7 meters: the EB5000 at $2,799, the EM5000SX at $2,999, the EM6500SX at $3,299.
Around $4,900 buys the Honda EU7000iS, and the lowest figure in the guide at a fully stated condition.
Champion, Yamaha and Briggs & Stratton show no price on their own sites. Cummins shows none either, and its pages refused us.
Mistakes buyers make
Treating "as low as" as the running level. It is the quietest moment the generator has, and the maker has not told you when that is.
Comparing a 23-foot figure with a quarter-load figure. Champion's 61 and Yamaha's 58 are different kinds of statement. Neither is wrong; they just cannot be ranked.
Buying on peak watts. Starting watts last seconds. Size on running watts, and on the 240 V outlet's own rating.
Moving the generator closer to muffle it. CPSC says 20 feet, exhaust away, and never in a garage with the door open. The CO shutoff is for the night that goes wrong, not for every night.
Forgetting the neighbor. Your 20 feet from your house may be their 10 feet. Put it where the exhaust and the noise both face away from both houses.
Expecting a bare figure to hold on natural gas or propane. Makers rate output lower on those fuels, and none states a separate noise figure for them.
Ignoring a battery for the small hours. A power station can carry the refrigerator and a phone charger overnight with the engine off, then recharge from the generator by day.
How we chose
We read the product page for every generator, and the spec sheet or manual wherever one is published, and recorded each noise figure in the maker's own words with the load and the distance whenever the maker gives them. We grouped the figures by their stated condition and ranked only within a group. We then compared running watts on each fuel, the 240 V outlets, weight, run time at its quoted load, the carbon monoxide shutoff, warranty, and the maker's own price where one is shown. We read CPSC's generator advice and its description of the shutoff standards, and quoted them directly. Where a maker's site would not load for our tools, as DuroMax's product pages, Cummins' pages and Generac's GP pages would not, we say so, and we used the maker's own listing data or spec sheet where we could, and nothing where we could not.
We did not measure any of these generators, and we did not convert any figure from one distance or load to another. Every number here is the maker's own, quoted as published, and the ranking inside each group follows those numbers and nothing else.
