Solar Exhaust / Vent Fan




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.

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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.

Thank you!

Have Fun.

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    8 Discussions


    3 years ago

    Thanks for the method. Do you think this can be run off of a cellphone charger that outputs at 4.8 to 5V?


    Reply 3 years ago

    Yes, it's possible. But make sure that you have a 5 volts fan. The one you find on USB based fans are usually 5 volts. But recently I have seen a Chinese fan which is supposed to be for 5 volts but ratted as 9 volts.


    4 years ago on Introduction

    I Have a Question How many Watts your Solar Panels???


    Reply 4 years ago on Introduction

    Its 6 watts officially as per name plate. But it generates only 4.8 to 5 with peak sun light with perpendicular light of incident to the panel. If I need to get little more (8.2 Watts), I can use a Fresnel lens to boost the power. But on the down side, it will soon kill my panel because of the intense heat.
    CAUTION: Be very careful while using lens as it can damage your surrounding / building if not taken care properly.


    Reply 4 years ago on Introduction

    No. I don't have any battery in my current setup. As long as the sun is there, it runs.
    If I need it after sun set I have the regular electric fan which I can use. That is why, this is mounted on top of the existing electric fan :). Hope it helps.

    Wow that's so smart and it looks like it works really well! Welcome to instructables, I hope we see more from you in the future!


    Reply 5 years ago

    Thanks a lot for your encouraging comments.
    Sure I will keep posting few more very soon.
    Thanks once again.