Best Portable Generator for Home Use: Buyer Guide
Portable Home Generators
The need for backup home power grows annually with hurricane disasters, blackouts, winter storms, and derechos causing an increasing number of outages. Every year, millions of utility customers experience power outages that last from minutes to days. Following a hurricane or derecho, it can take weeks to restore power to a devastated region.
Essentials that Need Power During an Outage:
- Refrigerator
- Freezer
- Sump Pump
- Lights
- Medical Equipment
- Well Pump
- Furnace
- Air Conditioner
You may not need to supply all these appliances with power during every outage and you might have other critical circuits or appliances that you want or need to power.
How to Use a Portable Generator for Home Backup in an Power Outage
How Big of a Generator Do I Need
Common appliances and circuits that homeowners need most during a power outage.
| Appliance / Circuit | Running Watts | Starting Watts |
| Refrigerator | 900 | 1800 |
| Freezer | 900 | 1800 |
| Sump Pump | 500 | 1700 |
| Forced Air Furnace | 600 | 1600 |
| Kitchen Appliance* | 1500 | 1500 |
| Microwave | 1000 | 1000 |
| Lights- LED 100 Watt Equivalent | 13 Watts Each | 13 Watts Each |
| Internet Router | 20 | 20 |
| Television- 60 Inch LED or OLED | 90-120 | 90-120 |
| Total | 5670 Watts |
Selection criteria includes asking yourself one question. How big of a generator do I need? Make a list of all the appliances or circuits in the home that need power during an outage. Then add up the total power required.
Manufacturers rate Portable Home Generators in watts.
- Running Watts = how much power the generator can supply continuously.
- Starting Watts = the power a generator can supply over 1-3 seconds to start a motor. Starting watts is usually 2-3 times the running watts for electric motors.
Watts = Volts x Amps. Nearly all appliances have a required tag with electrical information.
Not sure? Norwall’s Power Calculator helps you estimate the power requirements for appliances generator sizing.
- Make a list of the appliances / circuits you need during an outage with running watts and starting watts.
- Total the running watts for each appliance you want to run during an outage.
- Add 25% to the total running watts.
- Add the highest running watts from your list to the total.
Choose a generator that can supply the running watts with enough surge watts for the appliance that needs the most surge watts.
Portable Generator Sizing Guide
For example, a small window air conditioner might draw 6 amps on a 120-volt circuit.
6 Amps x 120 Volts = 720 Running Watts
720 Watts x 3 = 2160 Starting Watts
If all the appliances add up to 7000 Running Watts, a 7000 watt generator with 9120 Starting Watts is the bare minimum.
In practice, it’s better to have a little margin, usually about 25 percent, especially for a house.
- It’s hard on a generator to run it at maximum capacity for extended periods.
- You might have to run something you didn’t plan to run.
- An appliance might use more power than expected.
Consider the appliances in the table above- With 10 LED lights on, the total is 5670 Watts.
5670+25%=7088 Running Watts
7088 + Highest Starting Watts = 7088 + 1800 = 8887 Watts
Select a generator with at least 7100 Running Watts and 8900 Starting Watts.
Do you want Central Air? A 2-Ton A/C Unit adds about 3800 Running Watts and 8750 Starting Watts.
The starting watts on a heavy load like air conditioners will challenge most portables. However, a soft-start device installed by your HVAC professional can lower the starting watts to a manageable level. The additions of a load like this will require consultation with a licensed HVAC technician or electrician.
Power Calculator—How Big of a Generator Do I Need?
What Kind of Generator Do I Need
Portable Generators for Home Use fall into two basic categories: Standard Portable and Inverter.
Standard portables run at a constant speed of 3600 RPM to maintain a frequency of 60 Hertz. Ratings include models up to 17,500 watts. As the power capacity goes up, the amount of noise also increases. Noise levels start around 68 dB—compare to an older central air conditioner.
Inverter portables vary their engine speed to meet the load requirement. This decreases noise and reduces fuel consumption. Noise levels start at 51 dB. At least one model runs up to 34 hours on a single LP Propane tank. Available models produce 1600 watts to 5000 running watts.
Inverter vs Portable Generator. What's the Difference?
Most of the smaller inverter generators are 120 Volt only. A few offer 120/240-Volt operation.
Features to look for:
- Gasoline provides the most power.
- Propane runs cleaner and stores longer, but produces less power
- Natural Gas equates to a virtually endless fuel supply but produces less power than propane.
- 120/240-Volt models can power hard-wired loads through a transfer switch.
- Get an electric start or remote start on larger generators.
- Fuel Gauge keeps you informed about fuel levels.
- Low Oil shutdown protects the engine if you run out of oil.
- Carbon monoxide shutdown helps protect against CO poisoning and death.
Should I Buy a Portable Generator for Home?
Portable Generator for Home Fuel Options
Gasoline only models are a little cheaper than Dual Fuel or Tri Fuel options. The biggest advantage gasoline has over LP Propane and Natural Gas is power. As a fuel, gasoline carries more energy than either NG or LP.
For example, Champion rates the Tri Fuel 8000 watt generator for 8000 Running Watts on Gasoline, 7200 Watts running Propane, and just 7000 Watts using Natural Gas.
However, the tradeoff with a dual fuel or tri fuel model is the additional flexibility. LP Propane stores longer and better than gasoline. Tank sizes are readily available in 20, 30, 40, and 60, and 100-pound sizes.
An HVAC or plumbing company can install an adapter and valve for use with larger tanks or for use with your natural gas connection. Municipal Natural Gas offers a virtually unlimited fuel supply for extended run times.
Large propane tank sizes extend the run time before refueling. Don’t forget to check the generator oil daily and top it off as required, and to change the oil and filter according to the maintenance schedule.
Gasoline Generators for Home Use | Dual Fuel Generators for Home Use | Tri-Fuel Generators for Home Use
Portable Generator for Home Transfer Switch Connections
The safest, easiest, and most reliable connection between your generator and home appliances is the manual transfer switch. Instead of running multiple extension cords through windows, a transfer switch supplies power directly to the circuits you choose at installation.
A generator cord plugs into the 30-Amp or 50-Amp receptacle on your generator. The other end plugs into the inlet box connected to your transfer switch.
When the power goes out, connect the generator to the inlet box. Start the generator and turn on the generator's main breaker. Set the transfer switch to the generator position. Your essential and convenient circuits have power.
Manual Transfer Switch for Portable Generator
Updated June 26, 2024