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Author Topic: R & R - building new Stevenson Shield - Questions  (Read 1868 times)

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Offline AZ Kiwi

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R & R - building new Stevenson Shield - Questions
« on: July 15, 2018, 03:21:26 PM »
Not quite sure which sub-group to post this in - so please move as necessary.

I'm refurb'ing / rebuilding my 7-8 year old Stevenson shield (desert heat and dust storms are killers) and I'm thinking of adding a solar powered fan to it.  I have some small solar panels 2.2v, 45ma, which I can wire in series / parallel to get close to a 5v, 80ma level, which, according to a spec sheet I reviewed will comfortably drive a 3 inch / 80mm computer case fan.

Question is, what's best?  Fan at the bottom of the 'box', blowing air in, or at the top - blowing it out.  Either one will be moving air around, but which one is the most efficient for air flow?

Prototype testing  with a 2 in gap all around the bottom, and a 1.5 in gap all around the top, the test tracks .8F to 1.3F higher than the mean of 3 stations (old ones, good for something) currently in the old shield.  When I put a 2nd top - raised 2in - and overhanging by 2in each side, I drop it to .4F to .9F in direct sun exposure.  Playing now with ventilation etc. If I can drop it to a constant .4 / .5 F, I'll be satisfied.

Beauty of all this is it's not an "oh hell, gotta build a new box quick-like" and I can play around a bit.

Anyway, I'd  grateful for any feedback or advice.


Ken

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Station: http://weather.azkiwis.net
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No weather guru by a long shot, but smart enough to stay out of the desert sun...

Offline niko

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Re: R & R - building new Stevenson Shield - Questions
« Reply #1 on: July 15, 2018, 04:11:55 PM »
Theoretically the fan should be exhausting air, not blowing it in, so that the air temp isn't affected by passing by the "hot" fan motor.

Offline AZ Kiwi

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Re: R & R - building new Stevenson Shield - Questions
« Reply #2 on: July 15, 2018, 05:26:07 PM »
Thanks Niko.

I'll plan to vent it thru the 1st 'top', under the 2nd one.


Ken
Station: http://weather.azkiwis.net
CWOP: http://findu.aprsfl.net/cgi-bin/wxpage.cgi?call=CW9664
No weather guru by a long shot, but smart enough to stay out of the desert sun...

 

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