Rewire Supplementary Cooling Fans

[JFXG]

Puzzled: Previous owner mounted a bank of three 3- inch muffin fans at the top of the cooling unit on my Dometic 1292. Refrigerator unit has been running ok, but the fans have been making increasing noise, and the wiring is a rats nest (pic). So I decided to R/R the fans and clean up the wiring. [sorry, I pulled the fans before I thought to get a picture.]



PO wired the fans such that 1 fan is wired direct through a simple switch. He left it constant on and I have done the same, but this fan died a while back. The other two are wired through a thermal switch strapped to the tube near the top of the riser, so they cycle. (Pic- rough, hand drawn)



Question: does this wiring arrangement make sense? I can readily see what he set up, but my question is 1) why?; and 2) should I duplicate it, or set all 3 new fans to cycle? Additional point: the old fans were 3 inch. The new fans are 4.5 inch. If I install the three new I will double the fan area. Could that be too much cooling? If I install two new fans it will be a 50% increase.

Thanks for the assistance!


John & Diane, fulltiming since '12
'02 DS, FL, Cat, '04 Element
NHSO RVM103

[Skip426]

JMHO: two 4.5" fans will be good, , wired through the thermal switch for both.
The extra air flow is required as outside temps get over 90 as the RV fridge will struggle to keep cold as temps near 100. At those temps , you'll have air conditioners running so the fan noise won't be heard.

[Lt Dan]

If you have room for the three fans, I would go for it. The more air flow over the condenser coils on the absorption fridges the better the unit will cool. As said, hooking all to the temp switch should also be fine. Just my $0.02 and others will vary.

[spyderRV]

http://www.irv2.com/forums/f54/what-...ml#post3071240

My thought process is "Overkill is the sure cure of paranoia!" so when I replaced my rotten reefer roof cap, I also added fans to help cool the coils. They are 12 volt wired in series so they turn slow and quiet when the reefer is on.