Solar Powered Fans

[habanerocat]

It should be ok to do that unless the fan manufacturer specifically says it's not ok.

What is the voltage and power output from your solar panel?
What is the voltage rating and wattage of the fans?

[el48tel]

Yes ... do-able .... but the threshold voltage for the fans will determine which will or won't trip in. If there's any difference in the fans whatsoever then they won't all trip in together. The total current drain on the panel by the fans needs to be considered and checked to see if the panel is capable of supporting the total requirement of the fans.

[EdMcKenna]

I have quite a large panel, 2 foot by 2 foot. I am running 5 x 12 volt pc fans from it connected in parallel. I don't use controlled or batteries just straight to fans.
They don't have much of a cooling effect but with doors and windows open they provide the vital air movement to prevent / reduce scorch.

[Chris L]

Stickers on the fans and the solar panels.

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[el48tel]

Looks favourable

[Chris L]

Looks favourable

My plan is to order some wire and connector blocks and use the two fans I've already got to test the idea. If it works I can then order some more fans.

It would be nice to have three on each side blowing a bit of a draft to create some air movement.

[habanerocat]

I can't find any information on that fan so I'm afraid I can't help.
But you seem to have a good plan there.

[esp]

It's hard to be specific, but in general, I'd expect a reduction in system efficiency as you add fans without adding more batteries and panels.
In addition, the battery may be suited to lower load applications so may be less effective and/or have a reduced life if driving multiple fans.

However, as your fans are fairly low power rated at 12v / 0.14A (so nominally 1.68W) I'd expect you to have plenty of headroom to run 3 or 4 from your panel in good light.

[ralphrmartin]

The panel produces up to 18V under load; the fans are rated at 12v. By running them at a higher voltage, they may rotate faster than designed (and consume more power, assuming the panel can supply ir), reducing the life of the bearings and otherwise be a bad idea as they may not be able to readily get rid of the heat generated as a result (I'm talking about the fan motors heating up, not the heating effect within the greenhouse)! Running motors above their rated voltage is generally not a good idea.

That's why having a battery and a controller is a good idea - to provide power at a more or less constant voltage of 12v whatever the load / sunshine (unless the battery runs flat). It also helps with the fact that motors draw extra current when they start up.

[habanerocat]

Sounds like the best plan alright to get a regulator.
Surprisingly cheap on the usual sites.