The Best Natural Gas Generator for Whole House Power

Written By: MJ Logan

House Below a Stormy Sky with Upstairs and Downstairs Lights.

Natural gas is the most common fuel for home backup generators. Commonly used for heating and cooking, this fuel is readily available in most municipalities, burns clean, and is one of the most cost-efficient fuels available. During an outage, a whole-house natural gas generator supplies the entire main circuit-breaker panel which distributes power throughout the house during an outage. Manufacturers offer both air-cooled and liquid-cooled whole house natural gas backup generator models across a broad power-capacity spectrum.

Some generator and automatic transfer switch configurations provide power management options for air-conditioners and other high-voltage appliances. Power management allows household appliances to share generator capacity without overloading. Automatically managing the power may allow a smaller, less expensive, and more fuel-efficient generator to power an entire home. However, not every application is a good fit for a managed-power solution.

The power requirements of every home and family are different. A small, one-bedroom house with two window air conditioners uses far less power than a two-story, 3000-foot four-bedroom with two or three 5-ton central air units.

If a pair of central air conditioners run continuously to keep the home cool on a hot day, sharing power between them will not work, and the house requires a higher-capacity generator. In the Southwest, an air-cooled generator may easily overheat when temperatures climb above 100 degrees. In that case, a liquid-cooled machine makes a better choice.

Shop for a Natural Gas Generator at Norwall PowerSystems

Sizing a Whole House Natural Gas Generator

Generac Standby Generator Providing Power during a Power Outage Once you've decided to power your entire home, the first consideration is generator sizing. How much power does your house require? Norwall’s Power Calculator helps you determine the capacity of a whole house generator to fit your home and family’s needs.

Keep in mind that the power calculator is a guide and not a definitive calculator for every house. Understand how it works. Each appliance uses a specific number of watts to run—running watts. Appliances with motors require more power to start—starting watts or surge watts.

Buyer Guide - What Size Standby Generator Do I Need?

Most appliances have a tag that specifies their electrical requirements in volts and amperes or volts and amps. To calculate Watts, multiply volts by amps. For example, a small window air-conditioner plugs into a standard home outlet (120 volts.) If it draws five amps, it uses 120 volts x 5 amps = 600 Watts. Because an air conditioner uses a motor, we multiply the running watts by three to determine starting watts. 600 Watts x 3 = 1800 Starting Watts.

Manufacturers rate standby generators in kilowatts. 1000 watts = 1 kilowatt.

Understanding Generator Watts - Volts - Amps

Make a list of all the appliances in your home including the lights, televisions, cable boxes, and anything else that uses power. Include the starting watts for appliances with motors larger than a window fan.

Add up the power requirements for all your appliances, then add in the highest starting watts on the list. The total number of watts equals the minimum size whole house natural gas generator required. A 15 to 25 percent margin between the power needed and the maximum capacity of the generator ensures the generator can supply the entire home.

Whole House Generator Catalog

Power Management Considerations

Two Central Air Conditioning Units Next to a HomePower management works by allowing the generator / ATS to determine when an appliance might cause an overload. High voltage (240-volt) appliances consume a higher percentage of power than 120-volt appliances. When the generator senses an outage and switches to the house onto generator power, power management waits to enable the high-voltage appliances for about five minutes. Waiting allows the generator to accept the rest of the house load including starting motors on pumps, refrigerators, and freezers.

After five minutes, the generator enables the highest priority 240-volt load. If the appliance causes an overload, the generator “sheds” it by turning it off. Five minutes later it tries to start the next priority load and follows the same logic. If it sheds the second load, then it waits until the first is finished to start the second.

Some power management systems manage up to eight loads this way. Others take a more proactive approach and monitor power use during normal operation. During an outage, power management ‘remembers’ how much power each managed appliance uses and starts them only when there is enough power available from the generator.

Include the method of power management when choosing a generator.

As stated previously, power management is not always the best choice. If you have two or more central air conditioners that run for eight hours out of eleven from nine in the morning until ten at night, sharing power between them will not keep the house cool. In that case, choose a generator that can supply all the air conditioners at the same time.

Keep in mind that operating at the very limit of a generator’s capacity is never recommended. Allow some margin for periods when your demand goes up, or you add another appliance to your home.

Buyer Guide - Backup Generator Automatic Transfer Switch

Air Cooled Generator vs Liquid Cooled and Why it Makes a Difference

Air-Cooled Whole House Generator Natural Gas

Generac 22 Kilowatt Home Backup GeneratorAn Air Cooled Generator blows air through the generator cabinet to cool the engine and the generating unit. Some have two ratings—one for Natural Gas (NG) and the other for Propane (LP). Propane carries a higher usable energy content than Natural Gas. Running on natural gas may lower the air-cooled generator’s actual capacity. For instance, a generator rated at 20 kilowatts while using propane may only supply 18 kilowatts running on natural gas. When the Natural Gas capacity from LP Gas, manufacturers list the LP capacity first.

E.g., A 20 / 18 Kilowatt Standby Generator means 20 kilowatts on LP, and 18 kilowatts on NG.

Power capacity ranges from 10 kilowatts to 19.5 kilowatts for air-cooled whole house generators—Natural Gas.

Need to Know - Portable Generator vs Home Backup Generator

Generac

The Generac Guardian Series is the #1 Best-Selling Home Standby Generator with G-Force Industrial OHV engines specifically designed and built to withstand the rigors required of a standby generator with features that include plateau-honed cylinder walls, plasma-moly rings, and fully pressurized lubrication for a long and reliable lifetime of service. TruePowerTM Technology and Frequency Compensated Voltage Regulation provide clean, stable, utility-grade power. Backed by Generac’s 5-Year, 2000-hour limited consumer warranty. Designed and Built in the USA.

22kW Generac Guardian Home Standby Generator with 200A SE Rated ATSGenerac Guardian Whole House Natural Gas Generator with a 200-Amp, SE-Rated ATS

Generac 26kW Generator | 7291

Generac 24kW Generator | 7210

Generac 22kW Generator | 70432

Generac 18kW Generator | 7228

Generac 14kW Generator | 7225

All Generac Air-Cooled Whole House Generator—Natural Gas

6+ Reasons to Buy a Generac Backup Generator

Briggs and Stratton

More than 110 years of Trust, Reliability, and Innovation from Briggs and Stratton to America’s homes and yards. Reliable commercial-grade V-twin Vanguard Engines power Briggs and Stratton air-cooled whole house natural gas backup generators. The 20kW to 26kW PowerProtect Series Generators run on either Natural Gas or LP Propane. All the PowerProtect generators are compatible with the Symphony II and Amplify Power Management systems.

New in 2022, Briggs and Stratton leads the industry with a 6-Year Limited Warranty that covers all parts, labor, and travel for the entire 6 years. 

Briggs and Stratton 20 kW Standby with 200-Amp SE-Rated ATS and Symphony II Power ManagementBriggs and Stratton Whole House Natural Gas Generator with a 200-Amp, SE-Rated ATS

Briggs and Stratton 20kW Generator | 40676

Briggs and Stratton 17kW | 40360

Briggs and Stratton 12kW Generator | 40692

Briggs and Stratton 10kW | 40450

All Briggs and Stratton Air-Cooled Whole House Generator Natural Gas

Briggs and Stratton 2017 Air-Cooled Home Standby Features & Benefits

Cummins

Cummins Power Generation is a worldwide leader of power generation systems, components, and services. The V-twin air-cooled engine has a fully pressurized fuel system with automatic low oil shutdown to prevent engine damage. The patented “crank-only” mode reduces engine wear, fuel use, and noise during the exercise cycle for longer life.  Intelligent Load Management monitors power requirements for each load. After an outage, the generator restores the loads the generator has the power to run. Extensible, 5-year, 2000-hour base warranty.

Cummins Power Generation RS20AC Home Standby Generator Package with 200-Amp SE-Rated ATSCummins Natural Gas Whole House Generator

Cummins Quiet Connect 20kW | RS20AC

Cummins Quiet Connect 17kW | RS17A

Cummins Quiet Connect 13kW | RS13A

All Cummins Quiet Connect Air-Cooled Whole House Generator Natural Gas

2017 Cummins Quiet Connect Features and Benefits

Kohler

Kohler Power Systems implements advanced voltage regulation and extraordinarily low harmonic distortion for exceptionally clean electrical power. V2 four-stroke engines with fully pressurized lubrication system and electronic speed governing give a smooth and reliable source of mechanical energy. Exclusive PowerBoost delivers excellent motor starting ability for heavy duty loads including air conditioners and well pumps. Kohler natural gas whole house generators offer excellent reliability backed by a 5-year, 2000-hour limited warranty.

Kohler Home Standby Generator with 200-Amp ATSKohler Whole House Natural Gas Generator with 200-Amp, SE-Rated ATS

Kohler 20kW | 20RECL-200SELS

Kohler 14kW | 14RESAL-200SELS

All Kohler Air-Cooled Whole House Generator Natural Gas

Kohler Power Systems Residential and Commercial Standby Generators

Champion

Champion Global Power Equipment home standby generators are designed and engineered in the USA to meet exacting standards for North American residential installation. Champion Milwaukee Series OHV Commercial V-Twin engine with fully pressurized lubrication and low-pressure shutdown.  The 24-volt starting system is rated down to -22o F without battery warmers. Quietest air-cooled generator in its class at just 63.5dB. Champion Air-cooled whole-house generators come with a 10-year limited warranty.

Champion 14 / 12.5 kW Whole House Generator and ATSChampion Whole House Natural Gas Generator with 200-Amp, SE-Rated ATS

14kW Champion Whole House Generator

12.5kW Champion Whole House Generator

The Best Natural Gas Champion Whole House Generator

How it Works - Key Components of a Home Backup Generator

Liquid-Cooled Whole House Generator Natural Gas

Liquid Cooled Whole House Natural Gas GeneratorLiquid-cooled generators pump coolant through the engine and a radiator with a fan like an automobile. These generators are better suited to hot climates than air-cooled generators or in homes with higher capacity requirements. Liquid-cooled generators have larger, automobile style engines with the capability to provide the same electrical energy on natural gas or propane.

Power Capacity ranges from 22 kilowatts to 150 kilowatts for liquid-cooled whole house generators—natural gas.

Note: Automatic Transfer Switches for Liquid Cooled Generators Sold Separately.

The Best Whole House Natural Gas Generators for Hot Climates

Generac

Generac Protector Series whole house natural gas backup generators can power luxury homes, estates, and large properties with up to 60 kilowatts of clean, reliable power for appliances, sensitive electronics, and every-day use. Powered by Generac 4-cylinder inline engines with hydraulic lifters. The Protector and Protector QS Series Whole House Natural Gas Generators have a significantly quieter exercise cycle—typically between 59dB to 60dB—than full load operation. Generac Protector generators include a 5-year limited warranty.

Generac Protector Series Standby GeneratorGenerac Protector

Generac Protector 22kW | RG022

Generac Protector 25kW | RG025A

Generac Protector 27kW | RG027

Generac Protector 30kW | RG030

Generac Protector 32kW | RG032

Generac Protector 36kW | RG036

Generac Protector 38kW | RG038

Generac Protector 45kW | RG045

Generac Protector 48kW | RG048

Generac Protector 60kW | RG060

Generac Protector Series Whole House Backup Generators

Kohler

Kohler Liquid-Cooled whole house natural gas backup generators run exceptionally quiet at just 54dB during weekly exercise and 61dB at full load for 24-kilowatt to 60-kilowatt models. Engines range from 2.2-liter, 4-cylinders to 8.8-liter, 8-cylinders. Models up to 150 kilowatts are available for the large estates or agricultural operations. 5-year, 2000-hour consumer warranty

Kohle Liquid Cooled Home Standby GeneratorKohler Liquid Cooled

Kohler 24kW | 24RCL

Kohler 30kW | 30RCL

Kohler 38kW | 38RCLB

Kohler 48kW | 48RCLA

Kohler 60kW | 60RCL

Kohler 80kW | 80ERESD RCL

Kohler 100kW | 100ERESD

Kohler 125kW | 125ERESC

Kohler 150kW | 150ERESC

All Kohler Liquid-Cooled Whole House Generator Natural Gas

Kohler Liquid-cooled Whole House Backup Generators

Cummins

Cummins, the worldwide leader in power generation products, manufactures residential whole house generators from 22 kilowatts to 60 kilowatts in the Power Connect and Quiet Connect Series. Designed and built to start and run in extreme environments down to -40 degrees Fahrenheit and in winds up to 180 MPH, they withstand harsh winters and hurricanes. Customers can choose to run the exercise mode just 2 minutes every six months to save fuel, eliminate noise, and reduce emissions. Extendible base warranty of 2 years or 400 hours.

Cummins Quiet Connect Liquid-Cooled GeneratorQuiet Connect Series

Exceptionally Quiet Operation down to 60dB

Cummins Quiet Connect 25kW | RS25

Cummins Quiet Connect 20kW | RS30

Cummins Quiet Connect 36kW | RS36

Cummins Quiet Connect 40kW | RS40

All Cummins Liquid-Cooled Whole House Generators Natural Gas

The Quiet Cummins Keeps Life Peaceful for New Orleans Family

Briggs and Stratton

Large, luxury homes enjoy the safety and security of Briggs and Stratton commercial-grade whole-house generators. Robust engines like those in automobiles are built and tested to meet stringent quality and durability standards. Utility-grade electrical power from the company that has delivered reliable engine power for more than 105 years. Briggs and Stratton whole house natural gas generators include 4-year parts, labor, and travel warranty.

Briggs and Stratton Liquid Cooled Whole House Standby GeneratorBriggs and Stratton Liquid Cooled

Briggs and Stratton 25kW | 76180

Briggs and Stratton 48kW | 76150

Briggs and Stratton 60kW | 76160

Briggs and Stratton 25kW with Dual 200-Amp Split 400-Amp ATS | 76107

All Briggs and Stratton Whole House Generators Natural Gas

Whole House Backup Power by Briggs & Stratton

Updated February 3, 2020

POWER EXPERT

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