Advice on deep cycle setup?

landyacht318 wrote:

Ventilation, and tight fitting reflectix window shades on the sunny side.

I can keep my van as cool or cooler than ambient temps until late afternoon with adjustable speed computer fans. Mostly 120MM fans but I do have one 180MM fan.

Computer fans vary widely in air moved for amps consumed and noise made so do not just think any old computer fan is a good match for your desires.

My favorite fans are the silverstone fm121, as it is powerful and comes with a speed control. 110cfm max and 0.4 amps, down to 0.08a and 32CFM.

The silverstone fm181 is ~165CFM for 0.27 amps, and on low is 65cfm and 0.9 amps and basically silent at that speed.

The Silverstone AP182 is much more powerful at 1.3 amps, but it does not like battery charging voltages at max speed. Lowest speed is 0.05 amps.

The other fans I like best are 3000 rpm Noctua industrial versions of the NF-f12. These on highest speed, move the same CFM as the Silverstonefm181 , for 25% less amperage consumed, and have twice the static pressure rating, meaning it can fight restriction better.

Noctua has more recently come out with a speed controller which is plug and play with PWM fans and can handle more than one fan.

Since the solar should have the battery in absorption by 11Am anyway, there is excess solar wattage available to run fans and keep the interior cooler.


I have 3 intake fans in a conversion van window slider, in a shroud for 100% air displcement. I rarely slide the window all the way open and use all 3 fans. My roof has 2 inline counter rotating 120M exhaust fans pushing through a 4 inch aperture through mushroom vent.

The silverstone fm121 appreciates the counter rotating arctic cool f12 fan, airflow increases dramatically and noise lessens when the f12 fan is fired up. I went to install a noctua fan in place of the silverstone and it did NOT appreciate the counter rotating feeder fan.

Bascally if all my fans are on the highest speed, the complete volume of air inside my an is exchanged in under 2 minutes, and it never has a chance to start baking inside.

A fantastik fan on the roof is also a great way to go, as long as tere is an entry for fresh air somewhere below.

Keeping your van interior cooler will keep your internal battery muh happier too. Don't forget to secure that battery properly. So many people seem to rely on the battery weight to keep it in place. Imagine what happens in a rollover. Its like a 72LB piece of shrapnel in a hand grenade.

Wow - sounds awesome. Have you posted any pictures anywhere?

Perhaps a single-fan solution could improve my situation ... I could install a vent in the roof if needed ... my sunshades are decent but could also probably be improved.

Especially with the summer coming up, this is an important issue.

Thanks for all the detail etc. - I appreciate it.

Yours,

L