So I've built a aeroponic tower that uses an ultrasonic atomizer instead of spray nozzles. This approach is called "fogponics" across the hydroponic community.
My Problem is that I have to run a fan within the atomizing environment which requires the fan to be in contact with 100% humidity at all times. The fans purpose is to recirculate the generated vapor continuously. This of course brings into question the need for a waterproof fan.
I bought 2 from ebay recently and was advised to run them at 12V instead of 24V to keep the current from going too high due to the added drag of the water that would kill the driver if it was running at 24V.
Here's what I bought: http://www.ebay.ca/itm/40mm-20mm-New-Case-Cooling-Fan-24V-Waterproof-to-IP55-2-Wire-Ball-Brgs-376-/382060138074?hash=item58f48f0e5a:g:IE4AAOSwBOtZAQxW
The 2D image below shows my implemented design (Right) and an older version that better illustrates how the air circulates(Left)
Here are a few shots of my prototype:
The waterproof fan lasted around 55 hours cycling on for 2 mins and off for 1. I noticed that the sound changed towards the 40 hour mark; It started to lower in pitch and would fluctuate irregularly between it's original pitch the lower pitch every 2-10 seconds.
The fan would not start again after it's untimely demise.
What do you folks think is happening? I could really use a solution or suggestion to help me through this because I'm at my wits end and thinking about a redesign is disheartening when I'm so close!
Best Answer
I think the old adage of you get what you pay for applies here. Select a professional quality fan with IP67 or IP68 ratings made for the application. A Sanyo Denki (link) waterproof fan would seem to fit the requirements, for example.