Top 5 Best Open Frame Inverter Generators

Do you need a reliable, clean power source?


In this article, we will talk about inverter generators, which are pretty standard amongst people in the market for a generator.


Then, we’ll discuss what open frame inverter generators are, how they work, and the review the best open frame inverter generator and their pros and cons.

What is an Inverter Generator?

An inverter generator is similar to any generator you may see on the market. They are all fundamental devices that utilize mechanical energy for electrical power distribution during a power outage.


Still, with a bit of twist, it has an electronically controlled throttle that controls the engine’s rpm to make sure the generator produces electrical power needed. This technology is commonly used in the power generation industry and helps improve fuel efficiency. The technology will lower its power output depending on the situation.


The electronic control over the engine rpm makes the inverter generator a fantastic option for people in the market for a product that is fuel-efficient, energy-efficient, and lasts a long time.


What is an Open Frame Inverter Generator?

The difference between an open frame inverter generator and a standard inverter generator is all in the frame. Open frame inverter generators will typically have an exposed frame. Therefore, you will be able to see the engine and other body designs of the generator.


For the most part, this will not make the generator perform better than a generator that doesn’t have an open frame. The main difference will be in the looks; some people like the aesthetics of an open frame generator, whereas the others do not mind the covered frame. But the open frame generator will be louder in comparison to the regular inverter generator.


How Does an Open Frame Inverter Generator Work?

An open frame inverter generator works very similarly to any conventional generator but with an open frame. So you will get the same technology as a regular inverter generator but with an open frame.


That does mean easy access to the engine, which will make it more convenient to do oil changes and things of that nature. But overall, it will do the same thing as any other conventional portable generator, which usually has an electronic throttle control, that will regulate the power.

Best Open Frame Inverter Generators

Now that you have a basic understanding of what an inverter generator does, let’s discuss some of the best inverter portable generators available in more detail.

Champion Open Frame Inverter Generator

The Champion 4250W Open Frame Inverter generators are known for their durability, as it’s made using high-quality material. So you can expect a quiet open frame inverter generator that works amazing.


Power Output: 4,250 starting watts, 3,250 running watts

Technology: Quiet technology

Runtime: Up to 22 hours

Fuel: Gasoline

Uses: Run tools, or power RVs

Safety: Factory Tested



  • High performance: Run time up to 22 hours at 25% load
  • Dual fuel: Runs on gasoline or propane
  • 3 year limited warranty/Free lifetime technical support


  • Heavy


Westinghouse iGen4200 Inverter Generator

The Westinghouse iGen4200  is one of the most technologically advanced generator and would be a solid option if you are in the market for a great open frame inverter generator. Of course, the generator has all the bells and whistles of most top-notch inverter generators. Still, you can expect a durable generator that will last you a long time.


Power Output: 4,200 starting watts with 3,500 running watts

Technology: RV ready outlet

Runtime: 18 hours run time

Fuel: Gasoline

Uses: RV or to power appliances

Safety: Factory tested



  • High performance: Run time up to 18 hours at 25% load
  • EPA/Certified/CARB Compliant
  • Durable steel frame
  • Quiet


  • Expensive

PowerSmart 4400W Open Frame Inverter Generator

The PowerSmart 4400W Open Frame inverter generator is excellent for outdoor enthusiasts or people who need a reliable generator. It is made using high-quality material. This generator will withstand extreme weather and still get the job done. If you are in the market for portable generators to power your RV’s or tents, you must consider this product.


Power Output: 4,400 starting watts and 3,500 running watts

Technology: Quiet technology

Runtime: Up to 16 hours

Fuel: Gasoline

Uses: Great for outdoor activities or to power RV’s

Safety: Factory tested



  • High performance: Run time up to 16 hours at 25% load
  • Affordable
  • 4400 peaks Watts of power
  • 2 year limited warranty


  • Noisy

WEN GN400i 4000 Watt Open Frame Inverter Generator

If you are looking for an inexpensive generator that will get the job done, you must consider purchasing the WEN GN400i generator. You can expect the same performance as a more expensive inverter portable generator. In addition to a great deal, you also get unique features such as eco mode, which will help you save money on fuel and keep the environment clean.


Power Output: 4,000 starting watts, 3,500 running watts

Technology: Eco-mode feature

Runtime: 7 hours half load

Fuel: Gasoline

Uses: Great for powering tools, or RVs

Safety: Factory tested



  • Affordable
  • EPA Certified/CARB Compliant
  • Automatic low fuel and low oil shutdown
  • Built-in overload protection


  • Run time not as long as others
  • A bit noisy

Generac GP3500i Open Frame Inverter Generator

If you are in the market for an incredible generator that is quiet and easy to use, then you must consider the Generac GP3500 Open Frame inverter generator. Even though the power produced is lower than most of its competition, this generator is consistent. So if you want something that is not too powerful, but is reliable, then this product would be a great option.


Power Output: 3,500 starting watts, 3,000 running watts

Technology: PowerRush technology

Runtime: 7 hours half load

Fuel: Gas

Uses: Power RV’s and electronic devices

Safety: Factory tested



  • 1-3 year limited warranty
  • Low oil shutdown


  • Peak watts not as high as others
  • Run time not as long as others

What’s the Difference Between Inverter and Conventional Generator?

When you compare the conventional generator vs inverter portable generator, it works unexpectedly. To start with, Inverter generators produce power from a fixed DC source and use a microprocessor to convert DC power into AC power.


The power created by the alternator is sent straightforwardly to the rectifier. A rectifier is a gadget that changes over the power from the (AC) or the alternating current to the direct current (DC power).


At that point, the electrical energy from DC power is reversed back to the AC power utilizing the generator’s PC before being conveyed to the control board. This process is how the generator gets its name, “inverter generator.”



There are many pros associated with an inverter generator so let’s talk about them.

  • Saves gas: As you know, the inverter generator will electronically adjust its ac power to ensure it does not use more energy than it needs.
  • Eco-Friendly: The way the inverter generator produces its power and the fact that it increases fuel efficiency makes this generator very eco-friendly compared to other conventional generators available in the market.
  • Quiet: Most inverter generators are quiet when compared to conventional generators in the market. This makes it an excellent option for people in need of a generator for home use during a power outage.


Like every product available in the market, not one of them will be perfect. There will always be a negative associated with the product so let’s talk about the negatives of an inverter generator.

  • Expensive: Since these generators have great technology, they are more costly than a regular portable generator.
  • Low power output: These generators are fuel-efficient and produce clean AC electricity, which comes at a price. You see, the inverter portable generator does not have much power in comparison to conventional generators in the market, which makes it not so ideal for powering more oversized items.

Features and Specifications

Now that we have provided you with the best open frame inverter generators and their specifications, let’s discuss each spec and its importance. It is one thing to know about the data, but it’s a different story when you precisely know what that data means.


So make sure to understand the reason behind why specific specs and features are so important and what you should look for as a customer when purchasing an inverter portable generator.


Power Output

How much power a portable generator can produce is critical when picking up the right portable inverter generator. It would be best to look for an inverter generator with adequate electrical power to help you utilize your appliances or your RV truck.


Always look for an inverter portable generator with around 3,000 to 5,000 starting watts. This will give you enough power to comfortably rely on the generator when you are on a camping trip, or you would like to use your appliances outside.


If you want to generate electricity for more appliances or more oversized items, you should consider purchasing a generator with over 5,000 starting Watts. Keep in mind that the higher the starting watts, the more expensive the generator will be. Make sure to have a clear idea of your budget before opting for a high-powered generator.



Technology is essential when it comes to buying an inverter portable generator. For the most part, the inverter generator will have significant technology since it controls the power output electronically. But always look for a generator that promotes their technology. That will give you a good idea of what the generator can produce.


Technology should not be a deal-breaker for you, as most conventional generators have enough technology to keep you safe and help you power appliances. But if an inverter generator has technology that makes the product quieter or helps you produce more eco-friendly power, that is a great bonus when buying an inverter generator.



The run time is a crucial aspect of an inverter generator. It helps you understand how long the generator will run on a full tank of fuel. A good rule of thumb is to look for a generator with around 7 hours of run time at half a gas tank or any other power source.


Most portable generators will run up to 18 to 22 hours on a full tank of gas. This runtime will give you enough power source for the day, especially if you are camping outside or need to power your RV truck. In some cases, the more powerful the inverter portable generator is, the longer its run time. So always look for an inverter portable generator with a decent run time or a long enough run time for your needs.



Most portable inverter generators will run on gasoline, as it is the most available fuel source. However, some generators will have a dual fuel option that will allow you to use gas or propane or any other fuel to power the generator. So if you are looking for a more versatile generator, you can always look for a dual fuel option generator.


Remember that most dual fuel generators won’t produce the same power and run time when running on gas. But if you are okay with purchasing a generator that solely runs on gasoline, then this specification should not be an issue.



You can expect uses to be limited for these portable generators. inverter generators has a lower power output than standby generators. The usage will be to power an RV, campsite, or power appliances and power tools for most people.


Some powerful inverter generators will allow you to power larger spaces and electrical devices. Still, you will have to pay a pretty penny to get those generators. You can expect portable inverter generators to produce power for most sensitive electronics, but they won’t produce electricity for your house for days.



When it comes to safety, modern inverter generators are going to be safe. Most inverter generators already have technology such as auto shut-off which stops power supply in case of sudden power spikes and other safety features that will protect the generator and the users.


But if you want to be more sure, you can always look up more information on the specific model you are looking to purchase. However, safety should not be too concerning for you, as many inverter generators are factory tested, which means they will be safe even under heavy use.



A typical inverter generator price will be around $400 to $1,000+ depending on the model and electrical output. Most inverter generators will fall in the $600 range. Still, the more powerful inverter generators will cost you much more than that, so make sure to have a clear idea of your budget before searching for inverter generators.


The price should not be your primary objective; if you buy an inexpensive backup generator that does not perform, that is wasted money. Instead, look at the generator’s specifications and see if that’s a good fit for you.


This should give you a clear idea of what you should be looking for when buying an inverter generator. Purchasing an inverter generator should not be too hard, as long as you know what you need. Make sure to assess your needs and budget, and based on that, make an educated decision on what you should purchase.


Also Read: Best Dual Fuel Generators [2022]

Frequently Asked Questions (FAQs)

What’s the difference between a conventional portable generator and an inverter generator?

The main difference is how it manages power; the inverter generator controls the throttle electronically, adjusting the power produced based on the needs. This allows for a more eco-friendly product that will use less gas and keep the environment safe. conventional generators do not have these features.


Are open frame inverter generators quiet?

The open frame inverter generators are quiet, but they are not as quiet as conventional generators. The inverter generator with a covered frame will insulate the noise since it’s covered. The open frame inverter generator won’t be able to do that, as it’s exposed. But the open frame inverter generator will be quieter than traditional generators.


Will an inverter generator run a refrigerator?

Yes, the inverter generator has plenty of power to run a refrigerator. But if you are powering too many modern household appliances or power tools, it might get difficult to power a large item such as a refrigerator. But for most who have basic needs, it will have no issues powering a fridge.


What are an open frame and a closed frame? 

To put it simply, the open frame is when the generator has an exposed frame that makes the engine visible. A closed frame is when a generator has a covered frame, making it hard to see the machine. The open frame is easy to work on, as it has easy access to the engine, which makes oil change easy, but the generator will be louder. The closed frame is more challenging to work on, but the noise will be much lower as it will insulate the noise because of the cover.

Wattage Needed For Appliances

ApplianceStarting WattsRunning Watts
Furnace (1/4 HP)1000600
Sump Pump (1/3 HP)1300800
Washing Machine22501150
Window AC 13K BTU28001800
Well Pump21001000

So, Which is Best?

All of these generators have open frame inverter technology, but which one is best?


There are no one-size fits all answer, as they each have different pros and cons. But here are the best in each area.



The Champion 4250 is the best performing option with a maximum run time up to 22 hours at 25% load.



The WEN GN400i s the most affordable option.



At only 66 lbs, the WEN GN400i is the most lightweight and portable.



The Champion 4250 has the best safety features including low oil shutdown. Its also EPA certified and CARB compliant, making it safer for the environment. Included is a 3 year limited warranty to keep your financial investment safe.



The WEN GN400i is the most quiet option as low as 60 dB.


Open frame inverter generators are an excellent option for people who need to power their outdoor activities or power tools. In addition, since these generators are eco-friendly and have electronic throttle control to manage the power, it makes it an excellent option for people who want a low-maintenance generator that gets the job done.

If you are looking for a generator that will withstand some of the harsh weather on your next camping trip, consider the PowerSmart 4400 Watt inverter generator.


The  Champion 4250 Watt inverter generator is the best open frame inverter generator overall because of its combination of affordability, high performance, and good safety features.


However, the WEN GN400i  is the most affordable option.


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