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gondolaguy · 07-10-2013, 17:40

(07-10-2013 15:19)davidmbrady Wrote: I wouldn't bother with solar Corey - we don't run our generators enough as it is. Just run the genny!

Let's see, my Dometic doesn't have fans, and the 12W inside light only comes on when the door's open. The 12V controller board draws milliamps tops. With our LXi battery bank capacities, these Dometics and Norcolds can probably run the LP tank dry before we need to start the genny!

Are you sure you don't have fans? My Dometic had two large capacity 12V fans on the back of the appliance.

davidbrady · 07-10-2013, 18:31

Hey Corey,

I'll check when I get to the bus this weekend - you've piqued my interest. There's no fan on the schematic on the back of my fridge and I've never heard them although they may not be working, and I've been on the roof lots snooping around that area. I assume the fans would be located way up top by the roof vent? If I do have fans then add in another half amp or so. Say 1A total for the light, fans (if any), and control board. With 620 AH's to burn, that comes out to 26 days.

davidbrady · 07-10-2013, 21:02

Check out the refrigerator in this Liberty P-Bus.

davidbrady · (This post was last modified: 07-14-2013 18:58 by davidbrady.)

(07-10-2013 17:40)gondolaguy Wrote: Are you sure you don't have fans? My Dometic had two large capacity 12V fans on the back of the appliance.

I checked Corey and my Dometic NDR1292 doesn't have any fans. I took the cover off the vent on the roof and got a good look down the compartment - the condenser is in plain view. I also took the side panel off and with the help of a mirror and a strong flashlight I got a good look up the compartment. All the coils, condenser, and piping look good - clean, no rust, and good paint. My fridge has always worked well. It could be that by 2002 BB got the compartment specs right. There was good flow of hot air coming out the roof vent. In 9 years I've never turned my fridge off. The theory is that this keeps the rust inhibitors mixed and flowing keeping corrosion from forming on the inside of the cooling unit.

gondolaguy · 07-14-2013, 20:47

(07-14-2013 18:56)davidmbrady Wrote:
(07-10-2013 17:40)gondolaguy Wrote: Are you sure you don't have fans? My Dometic had two large capacity 12V fans on the back of the appliance.

I checked Corey and my Dometic NDR1292 doesn't have any fans. I took the cover off the vent on the roof and got a good look down the compartment - the condenser is in plain view. I also took the side panel off and with the help of a mirror and a strong flashlight I got a good look up the compartment. All the coils, condenser, and piping look good - clean, no rust, and good paint. My fridge has always worked well. It could be that by 2002 BB got the compartment specs right. There was good flow of hot air coming out the roof vent. In 9 years I've never turned my fridge off. The theory is that this keeps the rust inhibitors mixed and flowing keeping corrosion from forming on the inside of the cooling unit.

Vewwy intewesting!

I'm willing to bet our compartments are identical, I don't believe BB had my compartment wrong either. The standard plastic lower vent found on most RVs with the gas/ab reefer - standard upper oval vent about 18/20 inches long?

See view of fans:

Also, rust may not be visible, see back side of my cooling unit:

My cooling unit looks really clean too, and I ran it pretty constantly. I would sooner think Dometic or luck are the real differences. Surprised about the fans though....... Huh

***Arcticdude*** · 07-15-2013, 06:02

I have no fans on mine either. Those certainly appear to be po added fans. I wonder if they were moving too much air, not allowing proper cooling to occur?

gondolaguy · 07-15-2013, 08:33

I'm pretty sure these were from the Dometic factory as they were wired into the control board and the bracket looks factory made, not custom. Another mystery, but I can't see how too much cooling could occur unless they were blowing down and restricting the natural chimney effect. A squirrel cage blower at top or bottom would have been a better choice.

***Arcticdude*** · 07-15-2013, 10:42

If you move the air across the coils too fast, you won't get as much a thermal transfer as if you slow the air speed down some.

gondolaguy · (This post was last modified: 07-15-2013 11:50 by gondolaguy.)

(07-15-2013 10:42)Arcticdude Wrote: If you move the air across the coils too fast, you won't get as much a thermal transfer as if you slow the air speed down some.

This seems counter intuitive to me. I couldn't find any online literature that supports the idea, but did find a wind chill chart (isn't that essentially the same deal?). It pretty clearly shows more air flow - more cooling.
http://www.nws.noaa.gov/om/windchill/ima...chart3.pdf

I'm not really caring that much, just curious is all.

pgchin · 07-15-2013, 13:04

(07-15-2013 08:33)gondolaguy Wrote: I'm pretty sure these were from the Dometic factory as they were wired into the control board and the bracket looks factory made, not custom. Another mystery, but I can't see how too much cooling could occur unless they were blowing down and restricting the natural chimney effect. A squirrel cage blower at top or bottom would have been a better choice.

My 1292 purchased in 2007 came from the factory with the cooling fans......... all this time I have NEVER seen or heard them come on........ Angel

But, I am old, blind and deaf! Tongue