What is the difference between AC and EC fans?
EC fans and AC fans are very different. There’s a reason why EC fans cost more to buy.
EC fan advantages are:
- They’re cheaper to run
- Don’t buzz or hum as you change speeds
- You get a better yield
- You get precise environmental control
Ian Collins explains the difference between EC fans and AC fans in this video:
An AC fan is very old technology but it’s bulletproof. It never fails, it’s just very expensive to control without making fans hum or buzz.
That’s because an AC fan is running at 240V and 50Hz. A resistor controller basically breaks up the frequency to stop and start the fan. That’s why you get a lot of humming and buzzing at lower speeds. Step controllers don’t create the humming or buzzing, but they cost a lot more to buy.
The difference between an EC fan and AC fan is that the EC fan is a digital fan. EC stands for ‘electronically commutated, which basically means there is a PCB inside the fan to help you control it. You can control it with a 0 – 10V signal into the fan. So it’s still running at 240V, 50Hz, with no buzzing and humming from the fan.
All you do is connect a controller to the 3-pin connection on the fan. This 3-pin connection has a couple of uses:
- It takes the 0 – 10V signal out of the fan.
That helps to power the controllers
- It also sends a 10volt signal in, to control the fan.
So, if you put 0 volts into the fan, the fan runs at 0. If you put 10 volts into the fan, the fan will run at full speed.
An AC fan run with a step controller has 5 speeds you can run it at without it buzzing and humming. If you use a resistor controller, you get more speeds than this, but you also get the humming and buzzing. And you still don’t get the range of speeds you would with an EC controller.
An EC fan has 1200+ steps. So, if your temperature increases, your fan can increase at such a small percentage you don’t hear it buzzing, humming or even changing speed.
To summarise, the difference between an AC fan and EC fan is:
An AC fan has an alternating current and is very expensive to control without making it hum or buzz.
An EC fan is basically a digital fan. It’s a lot easier to control. Running an EC fan at half speed uses half the electricity. If you control the temperature in your grow room properly, you’ll increase your yield. So, use an EC fan and you’ll get better yields.
Which is cheaper to run – EC fans or AC fans?
EC fans are much cheaper to run.
When slowed down with a fan speed controller, running costs drop proportionate to your fan speed.
So, at half the speed, EC fans use half the electricity they'd use at full power.
At a quarter speed, EC fans use a quarter of the electricity.
This isn’t the case with AC fans. They use almost full power whatever speed you run them at.
We did the maths, and you’ll save £300 in year 1 if you choose an EC extractor fan. To see our maths, read ‘EC vs. AC Fans: Which One Really Costs Less?’.
Are EC Fans quieter than AC fans?
EC extractor fans are much quieter.
AC fans run at240V and 50Hz. Resistor controllers distort the 50Hz frequency when changing speeds. This creates a humming and buzzing noise at lower speeds.
Some AC fan controllers, like step controllers and the Control Freak Dynamic Frequency Fan Controller prevent humming. However, these kinds of controllers don’t come cheap. If you’re spending that kind of money, you may as well invest in EC technology.
Are EC Fans or AC Fans More Precise?
EC fans are digital fans. You can change your speed in increments as small as 1oC using an EC fan controller.
This isn’t the case with AC fans.
An AC fan used with a step controller (aka. voltage controller) can only run fans at 5 speeds. The controller sends 1 of 5 set voltages to the fan to change speeds.
An AC fan run with a resistor controller will offer you more than 5 speed settings, but you still don’t get the kind of range you’d get with an EC fan controller. You also get a lot of humming and buzzing with a resistor controller.
Are EC or AC fans more powerful?
EC fans are more powerful. They’re built to move more air on less power.
AC Fan: A 150mm RVK L1 moves a maximum of 720m3 on a max of 109W
EC Fan: A 150mm Revolution Vector moves 781m3 on a max of 77W
Because EC fans are quieter, you can also move more air without making as much noise.
Which extractor fan will give you a better yield?
You know what they say - environment is everything. The fan that gives you more control over your environment will ultimately be the one that gives you a better yield.
EC fans give you much more control over your climate. It’s easier to achieve the ideal temperature in your grow room. This means you get a better yield.