Heng's VORTEX?

Our Vortex I with an added cheap China made PWM controller is nearly silent. I believe the speed control was around $4. We chose not to have reverse, only exhaust.

Concerning the failure of the Vortex II fan with the three reversible speeds, I posted this several years ago, but I can no longer find it here.



I recently replaced my Vortex single-speed vent fan with the Vortex II multi-speed reversible fan. While installing the fan, I accidentally dropped the fan on to a soft bed. I was surprised to find that the fan had broken where one of the resistors was mounted to the printed circuit board.

The problem is that the big, heavy ceramic resistors are just soldered to the circuit board with no support.

Luckily, I am in the aviation electronics business, so it was no problem to repair the broken solder joint on the resistor, but I also realized that preventing future failures was a simple matter of under-filling the resistors. Components in aviation electronics are usually under filled with epoxy to provide structural support to improve reliability. Wherever you can eliminate movement between components, you eliminate the possibility of stress fracturing.

To help prevent future failures, I under-filled the resistors with silicone caulk. This should prevent movement that will lead to cracking. Epoxy might have been a better choice, but would have been much more difficult to install into such a large gap. Plus it might have been too brittle and cracked itself.

In my opinion, this failure mode is inexcusable. It would cost nothing to re-design the printed circuit boards such that the resistors could be mounted against the board to prevent movement. It is obvious that having the mass of two big ceramic resistors supported by nothing but printed-circuit board foil won't work for long in the bouncing, swaying environment of an RV.

If you have a Vortex II vent fan, I recommend that you remove the printed circuit board and apply some type of support to the resistors to prevent future failures. You will have to remove the fan speed switch by loosening the set-screw on the knob, removing the knob, then the nut behind it. Then the circuit board with the resistors and selector switch should come out.

I temporarily installed a PWM speed controller on my Vortex fan and hated it for two reasons: 1. The fan motor made a loud high-pitch whine for any speed other than "full", and 2. the PWM controller drew several milliamps of current even in the "off" mode.

We put the Vortex 2 in our bathroom and it is much quieter than the original noise making fan it came with(also didn't move much air either). Does a excellent job in our coach and we both love it.

It looks like I actually have a Vortex IV, my blade is 12", not 9" like the 1 and 2, and has the speed/direction control.

I'll continue to search.

Fourth: bummer to hear you don't like the Vortex. Your reason is the exact same as mine, the Fantastic require messing with the roof seal, something I'm not willing to do. My Vortex is quite loud, but it moves A LOT of air... it will suck the bathroom door shut when running on high. I also have a Fantastic Endless (same as their roof vent but in a table top housing), it is also VERY LOUD and has a whine to it, despite no electronic speed control. Just the nature of the beast I'm afraid. I like white noise from fans, so the volume doesn't bother me after a few minutes.

I am not one of the happy ones. I installed one of the Heng reversable, multi speed units because I did not want to open the roof seal. It is loud and doesen't move that much air. I regret it and wish I had installed a fantastic fan with reverse and remote control.

I have the Vortex I and added my own speed control. My understanding is that the extra weight of the II comes from resistors and maybe heat sinks for the speed control.

A search on the forum will reveal many discussions of using these fans. Most everyone is happy with them.

Reverse and speed aren't an issue but having a count down timer is nice...

Don't know about the vortex fan, but do use a PWM speed controllr of 21Khz or higher or the windings in the motor will likely Whine audibly, annoyingly, at anything but max speed.