Solar Fan

Does anyone use solar exhaust fans for there greenhouse?  If so, any advice.

Thanks

Hi Douglas,

I am in a similar position with my high tunnel.  At this point I am installing 2 no name five inch 12v DC fans I bought on sale for $5.  But, I don't expect them to do the job. I do expect them to help a little and give me an idea of what I will need. When I priced solar exhaust fans at Lowes, they cost a fortune.  I am running 110 ac to the high tunnel as an option.

I'm considering these Heat sensitive vent openers

this is a timely question...I'll be following the thread!

We just this week got out a solar attic fan that our son gave us a few years back to put in a greenhouse that never happened.  
Now, we are measuring and trying to figure out how to incorporate into our (future) second small hoop house.
It is supposed to vent up to 1200 sq feet.

If you can get air to come in down low and exit at a high spot, you can get natural convective ventilation without a fan.  But the longer the hoop, the less well that may work.  

Thanks all for your replies.   Any real life info helps!  Dean let me know if the 2 fans help move air and how much if you would.  Burl I have looked in to these, in fact I bought on and trying to make it work.  Judith I am in the same boat,  solar exhaust fan cost a lot and I am always trying to find a cheaper work around.  please let me know how the attic fan works.   Mike that is my plan to use as much passive vent as possible just wondering if a lower cost solar fan would help the process.  Again thanks all for the info

Douglas Cole wrote:Thanks all for your replies.   Any real life info helps!  Dean let me know if the 2 fans help move air and how much if you would.  Burl I have looked in to these, in fact I bought on and trying to make it work.  

I've seen those fans of Dean's piggybacked one on top of the other to increase the flow. I would attempt to get those fans to switch on when the vent opens. Maybe the vent opener might work better if the vent is restricted to the size of the fans e.g. 6"x6" I don't know.

I do the same thing as John with brushless 12v dc fans I scavenged out of large tec units. I use snap discs N.O., 90 deg close, to turn them on. You can buy them for a buck or to on computer stores.  We also use this to turn on solar air heaters to pump worm air into the barn when the sun is shinning.

Christopher Shepherd wrote: I use snap discs N.O., 90 deg close, to turn them on. You can buy them for a buck or to on computer stores.  We also use this to turn on solar air heaters to pump worm air into the barn when the sun is shinning.

A "Snap Disc" fan control that turns on at 90 degrees Fahrenheit, I get it.

As for advice, have you considered sizing your solar exhaust fan correctly?