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Solar powered vent fan
Does anyone use something like this?  I'm thinking putting one of these in the potty closet where the composting toilet is gonna be so it runs pretty much all the time without using house battery charge.  Maybe one in the shower too, dunno yet.

[-] The following 1 user says Thank You to Motrukdriver for this post:
  • MN C Van (06-29-2018)
Solar has so many interesting possibilities
Sometimes dweller in 234k miles '07 Grand C-van w/ a solar powered fridge and not much else
First thing i did, after ripping out the door buzzer in my Van after purchase, was cut a hole at the roof Apex for a solar powered Nicro marine vent fan requiring a 4 inch hole

It was rated at 1000 cubic feet per hour. It had a little C sized nicad battery and would run all night too which was a huge selling point. I suspect th 1000 CFH figure was what the fan was rated at, in open air, no restriction such as the mushroom vent itself.

But after the install i was dissappointed in the total airfow.

It started clicking when cold after a year or 2.

After 5 years I removed the impeller, cut the wires to the motor and from panels to battery, and force fed the vent with computer fans. and was amazed just how much better it was, with just a 50CFM fan feeding that same aperture

Later on I cut out the motor and battery for less resistance to flow.

This marine Nicro vent was some 70$ when i got it in 2001, now a similar version is 150$

Right now below the opening of this Vent, i have a 4.75" to 4" step down ring, and two 120 MM fans (4.75 inch), inline exhausting. One of these fans is the silverstone FM121. It comes with a speed control knob for ~30 CFm to 110CFM and 0.09 amps to 0.4 amps.

I feed this fan with an Arctic cool F12, which is an open case fan and also spins the opposite direction. It s rated at 56CFm and 0.15 amps.

Both together move a significant amount of air, and the feeder fan reduces the noise of the silverstone fan at higher speeds. Two fans inline in close proximity that do not counterrotate, do not work well together.

The silverstone fm121 is rated at 110 CFM, the F12 at 56 at 12.0v. Together at 14volts+, who knows, through the resistance who knows, but I will estimate they move between 120 and 140 CFM together on high midday.

So the original fan moved 1000 CFH, my fans at an estimated 120CFM combined =7200CFH and do it for 0.55 amps at 12v.

That is my experience with these 1 piece solar powered fans. Not powerful enough, and short lived.

For a bathroom fan, certanily better than no fan. but will it be powerful to prevent bathroom air from escaping bathroom or portapotty closet?

Who knows. no Specs lised as to airflow, either CFM or static pressure.

If one is going to cut a hole in their roof for powered ventilation, not having to run wires is nice, but a 1.5v motor is only going to spin so fast, and move so much air, and whether that will be enough is subjective to the user.

I'd personally prefer to force feed a mushrom vent with a more powerful fan, on a speed controller, and with an on off switch, but I am a ventilation Nazi.

Check out the marine offerings:

A powerful bilge blower on a 21KHZ plus PWm motor speed controller force feeding a mushroom vent, in a bathroom, can evacuate a significant portion of the air inside the whole RV. and be slowed down or turned off when that power is not required.

As for these not using any of the house battery, well i fully understand that desire. But if one has solar on their roof feeding house battery anyway, then it becomes a Non issue, other than routing the wires. Running 22 agw Zip wire to a computer fan from fuse panel, is quite simple, and A Fan like th Noctua NF-f12 1500 rpm model uses only 0.05 amps and moves 53CFM very quietly.

The NF-F12 3K rpm industrial version uses only 0.3 AMPS at max rpm, and can be speed controlled easily via the noctua Na-f1 speed controller, and dialed down to the minimum the amp draw is so Low I cannot record it with my tools. Even this low it likely moves more air than the solar vent would in full sun.

I do not see that specific vent fan as having a battery to run after sundown. It is likely only waterproof mounted horizontally, not on a wall or any other angle.

Before i gutted my solar roof vent of its motor, sometimes when the wind was blowing good, in a certain way across my Van, the fan blade would stop spinning and i could feel air being forced through the vent. granted it was rare, but this occurring in a portapotty closet could be unpleasant.

For the weak solar fan to exhaust unpleasantness, there would have to be an air entrance in the closet nearly the same aperture as the aperture of the fan.
[-] The following 4 users say Thank You to sternwake for this post:
  • Motrukdriver (06-29-2018), S Cello (06-30-2018), TWIH (06-30-2018), Scott7022 (07-01-2018)
Let me paraphrase sternwake. "That fan ain't gonna put up with your shit."
[-] The following 1 user says Thank You to ratfink56 for this post:
  • Scott7022 (07-01-2018)
A few weeks ago I ordered a bilge blower/fan, speed control, ducting, and marine vent. The idea, perhaps harebrained, is to have the blower pull from a manifold and push out the vent. Anything that needs venting will tap into the manifold. The fan will run on the opportunity circuit, so it will be on during Absorption and Float.

First things to be tapped in: battery box, composting toilet.

Right now the manifold is just a 3" Y-adapter. The eventual idea, if needed, is to use a sealed shoebox or something to allow more connections.
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