This started out as a joking side discussion with one of our engineers on whether or not you could use a IP68 rated DC fan as a powerhead, this quickly turned into a friendly bet on the long term viability. The fan would need to survive in saltwater long term (greater than a year) while operating at both full speed and another fan operating in pulse mode to push its normal continual operation to a different extreme.
Typically these fans are not tested for continuous long term submersion in water, let alone in saltwater. I ventured that typically engineers "over" engineer in their designs and it may be possible for long term submersion.
I've worked with a few different IP68 rated fans in the past from quality companies such as ADDA and Sanyo. Sanyo had a 12VDC 40mm fan that was electrolytic corrosion proof, IP68 rated, and had a cfm rating that should move enough water to be somewhat viable. It is also a 4 wire fan that provides PWM and a signal wire for RPM and stall detection.
I setup a spare IM Nuvo 10 gallon nano for the experiment. One fan has been setup for a week and is currently being driven by a Instek Programmable Power Supply at 12VDC / 0.56A / 6.8W , which is slightly higher than its rated values of 0.52A / 6.2W but well within norms. Since one of the fans survived a week I can now feel comfortable programming a separate micro-controller for the other fan to run in pulse mode via PWM.
I 3D printed a basic enclosure and used a magnet from Koralina for mounting to the side glass. The enclosure minus the magnetic tab mount is 1 3/4" cubed.
The only exposed Aluminium was covered with a 0.2mm thick nylon plug and epoxy sealed. Single wires were twisted and run through aquarium safe silicon and pulled through Cat5 wire sheathing (to prevent any possible capillary action of liquid up the wire). Strain relief at the fan mount was also provided.
Initial impressions. Somewhat surprised at the amount of water the fan will move. It certainly won't compete with a MP10, but easily pushes as much water as a Koralina Nano, and is dead silent.
I'll be updating this with a video once I get an order of fluorescent micro-spheres in house so flow can be visualized.
Typically these fans are not tested for continuous long term submersion in water, let alone in saltwater. I ventured that typically engineers "over" engineer in their designs and it may be possible for long term submersion.
I've worked with a few different IP68 rated fans in the past from quality companies such as ADDA and Sanyo. Sanyo had a 12VDC 40mm fan that was electrolytic corrosion proof, IP68 rated, and had a cfm rating that should move enough water to be somewhat viable. It is also a 4 wire fan that provides PWM and a signal wire for RPM and stall detection.
I setup a spare IM Nuvo 10 gallon nano for the experiment. One fan has been setup for a week and is currently being driven by a Instek Programmable Power Supply at 12VDC / 0.56A / 6.8W , which is slightly higher than its rated values of 0.52A / 6.2W but well within norms. Since one of the fans survived a week I can now feel comfortable programming a separate micro-controller for the other fan to run in pulse mode via PWM.
I 3D printed a basic enclosure and used a magnet from Koralina for mounting to the side glass. The enclosure minus the magnetic tab mount is 1 3/4" cubed.
The only exposed Aluminium was covered with a 0.2mm thick nylon plug and epoxy sealed. Single wires were twisted and run through aquarium safe silicon and pulled through Cat5 wire sheathing (to prevent any possible capillary action of liquid up the wire). Strain relief at the fan mount was also provided.
Initial impressions. Somewhat surprised at the amount of water the fan will move. It certainly won't compete with a MP10, but easily pushes as much water as a Koralina Nano, and is dead silent.
I'll be updating this with a video once I get an order of fluorescent micro-spheres in house so flow can be visualized.
