What Size Inverter for a Fan?

By:Michael Johns

what size inverter to run a fan

Looking for a portable inverter for your fan?

Or perhaps you want to run a fan and TV on an inverter…

Whatever your quest, summer off-grid adventures and power outages can be made a whole lot better with the cooling breeze of a fan. 

Thankfully, fans don’t need too much power to run meaning you can easily run them with a small or mini inverter.

Personally, I like to have a little extra oomph in my electrical setup so I can run a few other appliances and charge my phone.

If you’re looking for a power inverter to run a fan then keep reading.

Together we’ll go through the requirements including inverter size, portability, runtime, and the best inverter for fans you can buy.

By the end of this piece, making your choice will be a breeze (pun intended).

What Size Inverter for a Fan?

You can run most fans with a 150 watt inverter.

Fans are energy efficient ways of cooling a room. Whether it’s a pedestal fan, box fan, ceiling fan, or portable fan, you won’t need too much power.

In fact, the average domestic fan uses far less than 100 watts, sometimes as little as 30 watts.

How many watts is a fan

This is great as it means you don’t need a big inverter to get up and running.

In my experience, a 150 watt inverter can easily power a fan and even allow you to charge a phone at the same time.

If you want to run some other things like a fan and TV from an inverter you will need a bigger capacity such as 300W or 400W.

How Many Watts Does My Fan Use?

To pick the most suitable inverter, it is a good idea to find out how many watts your fan uses.

Usually, you can find power consumption in the technical specification or user manual. You could also contact the manufacturer if you don’t have these.

I often use a wattmeter for this task. You can hook it up to any AC appliance to get a live accurate power reading. Then you’ll have no surprises.

You should expect your fan to use between 30 – 100 watts on average.

Does a fan need pure sine wave?

Lots of people ask if a fan needs pure sine wave as it is motorized. To be honest, it will work more efficiently with pure sine wave inverters but it is not strictly necessary.

If you use a modified sine wave inverter with a fan you might get excess heat in the motor and you will notice a buzzing sound from your inverter. Pure sine wave is better as the current replicates that of the mains electricity at home. You get a smooth flow of current, more efficiency, and no annoying buzzing sound.

Inverter Efficiency

Inverters are not 100% efficient as they lose energy during the conversion of AC to DC, plus they use power for internal cooling systems and screens. Most inverters are between 85% and 95% efficiency. 

What does this mean? Well, you should have an inverter with 20% more wattage than you want to use. For example, if you want to draw 100W you should use at least a 120W inverter.

Best Inverter for Fans

Now you know the requirements for powering your fan, you will be able to pick the best inverter for your needs. Below I have shortlisted the best power inverters for fans. They all offer at least 150 watts output plus features like portability, cigarette lighter plugs, and USB ports.

How Long Will an Inverter Run a Fan?

The runtime of an inverter is determined by the appliance energy usage and the battery capacity. An inverter does not always draw full power, it’s the fan that decides how many watts are being drawn. For example, a 150 watt inverter might only run at 50 watts with your fan.

It can be a little confusing to try and work out runtime, there are tons of confusing articles out there. So I’ve created this easy formula to work out runtime for a standard 12V inverter and battery. This includes taking into account inverter efficiency.

(10 x battery capacity in Ah) ÷ fan wattage = runtime

So let’s say you have a 12 Volt 100Ah battery capacity and a 50W fan.

(10 x 100Ah) ÷ 50W = 20 hours.

A 100Ah battery could run a 50W fan for up to 20 hours.

Why a Fan is Better than AC

The reason so many people prefer fans over air-con is the price and energy usage. AC units are far more expensive to buy, install, and run.

Contrastingly, fans are much cheaper and can quickly be plugged in to use. Plus when it comes to inverters, you can use a much smaller inverter and far less battery energy with a fan.

In fact, AC can use 10 or 20 times more power and energy than a fan. This is a humongous difference for an off-grid power supply.

Final Words on Inverter to Run a Fan 

I hope this article has you one step closer to getting the fan blades spinning.

You should understand the power requirements and what size inverter you need for a fan.

They are low-powered devices that you could easily run with a portable inverter of around 150 watts.

If you want to use an inverter for a fan and TV then I would go a little bigger, you might like to read my guides to the Best 200 Watt and 300 Watt Power Inverters too.

Thanks for reading, keep it breezy.