Introduction: Solar Exhaust / Vent Fan
The idea here is to study & teach the young minds about how easy is to generate solar power, what are the affecting factors, a simple and practical utilization of the generated power.
Step 1: Collect Required Items
1.) Solar PV Panel (12 Volts ~5 Watts or better)
2.) 12 V DC Fan (Low Noise, High CFM preferred)
3.) Control switch (Optional)
4.) Misc Items such as cables, mounting screws, connectors, nuts & bolts etc., as per your site conditions.
Step 2: Putting It Together
Here, I got a scrapped solar PV (6V 1W) from a old solar powered 1 W LED light by dlight designs.
The cooling fan is from a discarded laptop stand, which was running at 5 volts USB powered, which had low noise and good CFM output.
1st identify a suitable location in your home /site where you will get most of the direct day time lighting (Sun light).
In my case I had a bath room, which has a ventilator facing south during Dec to June which will get direct sun light.
I have chosen this place because this will not be visible from out side the apparent building, so no aesthetics problem. I just kept the PV out in the floor of the ventilator and the wires are taken inside and connected directly to the cooling fan.
Caution: Make sure that you connect the right polarity, else, it may damage the fan motor.
As long as the sun is out on the Panel the fan will start rotating. Here in Hyderabad, India the fan starts rotating at about 7:30 AM & it keeps running till 2:20 PM after that the shadow will mask the sun light. Any way this time is the peak utilization period in my family.
Well, wonder how much this is effective ? On a cold day such as Dec to Feb, we use hot water for bathing. Usually, after a bath, the Mirror inside the bathroom is filled with mist. But with this solar powered fan, the mist condensation on the mirror is greatly reduced. Now we can see the condensation is only 5-10%. :)
Right now, since its a proof of concept, every thing is just kept hanging, no proper dressing done.
More over, this is just kept on top of an electric fan, which will be used when there is no Sun or at night or on a rainy day. Please note I tried to keep the parts count as minimal as possible to achieve this. No Soldering done. Its just twisted wires to make contact, as I live in a rented facility & I may have to vacate any time soon.
Step 3: Scope of Improvement
1.) Right now its running in uncontrolled fashion, since we dont have air conditioned buildings as like in our western countries. So, did not added any control switch as it was not necessary here.
2.) Might add a DC to DC Converter with as slightly larger wattage panel so that even with shadow it can run till 6 PM in summer.
3.) Can be connected to a battery and then later use it at night for an LED lighting.
Any suggestion comments are welcomed.