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Old 05-29-2021, 06:24 PM   #21
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Brand: Thor Motor Coach
Model: chateau 23U
State: Florida
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THOR #1241
$1 solution to condenser coil cooling

I placed a 12VDC 3.5" cooling fan pulled from an old PC power supply below the outside coils and mounted it to blow upwards. It is quick spliced to the gas solenoid valve wires, so it operates whenever the flame is on. The convection air flow is assisted by this modest (250mA) fan. Though I have no empirical data to verify improved efficiency, it "seems" to make propane more efficient with a modest hit to the 12VDC budget. But that may be an illusion!

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Old 05-29-2021, 08:27 PM   #22
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THOR #12189
For the last fews days, I've kept the cover off and poked my head out there a few times a day just to see if I could catch it running 'hot'. I like the theromstat idea because it will continue to vent when the fridge is not running, bringing down the temp for the next cycle. I tapped into the 12v circuit board juice. I would have liked to do a neater job on the holes but wasn't about to by a 3" hole saw I'd never use again (he thinks). Running full time, space is a precious commodity (as is weight )

The lowest I've seen it is in the morning 23C (75F). I have it set to trigger at 30C (86F) and it usually runs all day. It's 91F now and the fridge cavity reads 43.3C (110F ). The hottest I've ever seen it was 47.7C (118F). I seem to recall a 120F reading with the cover on but I guess I didn't keep that data point.

I put the thermometer in the freezer one day, until Pete's suggestion gets here. The freezer maintained 28F and the second shelf in the fridge maintains 40F, where it was beginning to flirt with the 50's.

This is a norcold N611 on setting '3'. All in all, I'm happy with the way the project has been helping out. I wish the fan CFM was a little more but for a few bucks, I have a working prototype I can improve on and a few reusable parts.

As a bonus, the fridge fins have stoppped icing up and defrost as they should now too.

Over an out.
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Old 06-02-2021, 02:23 AM   #23
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Model: Windsport 29m
State: North Carolina
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THOR #9553
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Originally Posted by The_Breeze View Post
I built a set of thermostatically controlled fans to help move the air behind the fridge and out through the roof vent.

Does anyone know if there's an optimum temperature for within that cavity behind the fridge? I don't want the fans running needlessly 24x7 and hope for a balance between efficiency and practicality. Running fans 24x7 reduces their lifespan and needlessly draws down the battery (e.g. at night when it's cool).

Thanks.

I included pics below in case someone is looking for a solution and wants to consider this.

Measures 3.73"W(at widest point) x 24"L x .75"H - fits between coils and wall just above the bottom vent (only wall vent on my RV).

Fans, switch and thermostat purchased on ebay.

Positive wires marked with brown tape (weird setup)

PM me for more info if interested.
Not long after getting our 2018 Windsport 29m I had the great idea to increase the draw of air from the bottom vent at the back of the fridge up and out the top vent by mounting a 12v fan I got at O'Rielly's. It had an off/slow/fast switch with a plug that fits into the 12v socket in my front console. I mounted it on a small piece of 2 x 4" and glued it to the top plate facing out of the vent. Ran the wire down thru the bottom of the fridge area into the coach along the inside of the kitchen cabinet and behind the sofa then mounted the switch next to the drivers seat. When I think it needs some extra air draw I simply plug it in and run it on slow or fast until it's cooler. My next project is to hang a shade of some kind in front of the fridge vents to block the sun from getting that area hot as well. Will need to be removable and put it up when we get to a site or boon-dock location. You gotta do what you can to keep these things cool to be efficient!! Bob Trice
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Old 07-05-2021, 03:13 PM   #24
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THOR #12189
Quote:
Originally Posted by RVGeek View Post
I placed a 12VDC 3.5" cooling fan pulled from an old PC power supply below the outside coils and mounted it to blow upwards. It is quick spliced to the gas solenoid valve wires, so it operates whenever the flame is on. The convection air flow is assisted by this modest (250mA) fan. Though I have no empirical data to verify improved efficiency, it "seems" to make propane more efficient with a modest hit to the 12VDC budget. But that may be an illusion!
I prefer the thermostat approach. It kicks in whenever the fridge generates heat, regardless of source - LP, SP or gen.
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Old 07-05-2021, 03:22 PM   #25
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For those of us with absolutely no mechanical aptitude : can you provide a parts list, and an idea about where to put hem?
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Old 07-05-2021, 07:59 PM   #26
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I'll point back to post#1 and supplement below. I found everything but the wood on eBay and the L-brackets at Ace HW. You might find everything on Amazon too.

If you click on the pics, it'll enlarge and then merely search for those parts on your vendor of choice.

From left to right: thermostat, on/off rocker switch, fans. I had to do the MM to inch conversions via the web to make sure everything would fit in place. Hint: mock it up on cardboard and test fit everything before laying into the wood.

I mounted mine using L-brackets just below the lower coils. The thermostat sensor (silver rod in 1st pic) is held in place with silicone and placed on the edge closest to the fridge's coils. Pic1 belwo is looking up through the botttom vent (only one on my RV except roof). The second shows it's position relative to the coils and the cylindrical thermostat sensor is up against the coils.

Power is derived from the 12v wires going to the control board on the fridge, though any constant 12v source will suffice. You want to use the on/off rocker if/when maintenance is needed (as in replacing the fans) and/or use/store switches to control on/off state when in storage.

Quick note: if rig is stored in temps above 80*F, the thermostat (in my case) will trigger and draw 12v if available. In that case, use/store switch will prevent that. The on/off rocker is there to kill power draw if the wires, which in this case, have to be disconnected for service. It prevents any surge or crossed wires from entering the control board and causing damage. It also allows bench tests before installation.

Lesson Learned: One fan burned out already so replacements are on order (re: https://www.ebay.com/itm/254171174394). I'll keep a few spares in case it happens again. Might have just be a bum fan. Other two still work. I have it to do over again, sso I'll use male/female connectors on the fan wires instead of soldering together.

All in all I'm very happy with the performance. Where temps were reaching 130-140* there, they have s=consistently stayed under 120 in this FL heat. Now, if I can only figure out a way to keep the freezer defrosted...

Hope this all answers your question(s).

https://www.thorforums.com/forums/sh...62&postcount=1

https://www.thorforums.com/forums/at...3&d=1621887096

https://www.thorforums.com/forums/at...4&d=1621887096

https://www.thorforums.com/forums/at...5&d=1621887096
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Old 07-07-2021, 01:46 PM   #27
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THOR #9553
Quote:
Originally Posted by RVGeek View Post
I placed a 12VDC 3.5" cooling fan pulled from an old PC power supply below the outside coils and mounted it to blow upwards. It is quick spliced to the gas solenoid valve wires, so it operates whenever the flame is on. The convection air flow is assisted by this modest (250mA) fan. Though I have no empirical data to verify improved efficiency, it "seems" to make propane more efficient with a modest hit to the 12VDC budget. But that may be an illusion!
That looks like an awesome job and it WILL HELP. I did something similar....ALSO, try putting a small fan inside the fridge as well. That to me works even better at keeping the entire inside cold and even temps. Also helps the freezer too, not sure why but that's what JC Refrideration told me!! Bob Trice
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Old 07-07-2021, 03:10 PM   #28
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Originally Posted by knucklehead View Post
That looks like an awesome job and it WILL HELP. I did something similar....ALSO, try putting a small fan inside the fridge as well. That to me works even better at keeping the entire inside cold and even temps. Also helps the freezer too, not sure why but that's what JC Refrideration told me!! Bob Trice
You're right, it does help. I have one of those little battery operated fans in there. It helps but I believ it could be better. I'm looking into to those fans that mount to the condensor fins. I may return to this post if I go in that direction. So far, cavity temps have not gone higher than 116* (that I could spot) in this FL heat.
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Old 07-07-2021, 07:49 PM   #29
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Model: Forest River Forester 235
State: Indiana
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THOR #6826
Quote:
Originally Posted by RVGeek View Post
I placed a 12VDC 3.5" cooling fan pulled from an old PC power supply below the outside coils and mounted it to blow upwards. It is quick spliced to the gas solenoid valve wires, so it operates whenever the flame is on. The convection air flow is assisted by this modest (250mA) fan. Though I have no empirical data to verify improved efficiency, it "seems" to make propane more efficient with a modest hit to the 12VDC budget. But that may be an illusion!


I don’t remember which wire it is but there is one, attached to the controller, that is hot whenever the fridge is cooling - gas or electric. The need for best cooling is the same regardless of how the boiler is heating.
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