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
(posted in both forums)