Hi all.

I'm such a nerd......   ;)

After reading Richard Jones findings on muffin fans (IIRC, he
speculated that 2 muffin fans may block convection air flow at
rear of Dometic thus forcing it to run more often) it occurred to me
that the Dometic prop might be a better design for this
application. Certainly better than the over sized CPU fan I currently
have mounted on my Dometic.
I figured a new, and possibly stronger motor, might improve
performance of the stock prop.
Lucky me. Found a new cassette motor for $5.00.

http://tinyurl.com/nbfqjf

(sorry for crappy pic, but you get the idea)

specs for muffin fan

http://tinyurl.com/kvtjll

A few observations.

A 5x CFM and 37 CMF CPU fan shown above, both feel like they move the
same amount of air.
My VOM showed the higher rated fan as drawing more than the rated
power. Ironically, the CPU fan in my crappy pic,
draws less than it's rated .2 amps. But....  my homemade fan, feels
like it pushes more air than either CPU fan
and with a wider pattern. It draws ~ .16 amps. About the same as the 37 CFM fan.

Has anyone else found that the Dometic blade is a better design than a
muffin fan?

Anyone else swapped the Dometic prop onto a bigger motor? If so, was
it an improvement?

And could anyone tell my why the cassette tape motor fan spins faster
when polarity reversed?

Neil.

--
Neil Nicholson '81 VanaJetta 2.0 "Jaco"

http://tubaneil.googlepages.com/

http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines