Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Kent Speers on June 04, 2011, 12:20:14 pm

Title: Refrigerator Auxiliary Cooling Fan
Post by: Kent Speers on June 04, 2011, 12:20:14 pm
I think some time ago I remember some posts regarding increased cooling of the Dometic refrigerator in very hot weather. A fan was placed in the refrigerator exhaust area to move more air over the cooling coils. I have searched the archives but have found nothing. Does anyone remember this subject and the the details on the alteration?
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Bill Willett on June 04, 2011, 12:30:05 pm
Kent, search under refrigerator fans, I just finished my fans yesterday, I removed the roof vent, made a bracket to hold 2 Ultra silent1500 rpm fans, with a thermodisc on the top boiler pipe that turns on the fans at 120 degrees, it has also reduced the temp in the fridge by 3 degrees.The fans I used are made by Ultra and you cannot hear them running.
 Ultra silent fans from Compusa, thermodisc stc-20 from Mouser Electronics.
 Hope this helps.
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Kent Speers on June 04, 2011, 12:38:01 pm
It sounds like the info I needed. I tried that search before to no avail. I may not know how to search properly.

Did your frig have problems with staying cool enough when outside temps were over 95? Freezer stays frozen but the frig is too warm, sometimes gets up to 42 degrees.

Any other tips on keeping the frig cool when in high outside temps would be appreciated!!! We are running near 100 degrees in the afternoon every day.
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Michelle on June 04, 2011, 01:45:06 pm

Any other tips on keeping the frig cool when in high outside temps would be appreciated!!! We are running near 100 degrees in the afternoon every day.

Move to a cooler climate.  That coach has wheels, right?  :P

On a more serious note, Barry had posted a photo of a sun shield he made for his fridge

The selected media item is not currently available.

Michelle

Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Bill Willett on June 04, 2011, 03:53:45 pm
Kent, a little more info,the fans are Ultra Model ULT40141, 120mm case fan,52.88CFM, another option is to Google Dometic thermister adjuster,this will change the resistance in the the thermistor and will lower the temp in the fridge, at the present time it is 95 degrees on the fridge side of the coach and the fridge is at 36 degrees.
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Kent Speers on June 04, 2011, 04:08:52 pm

Move to a cooler climate.  That coach has wheels, right?  :P

On a more serious note, Barry had posted a photo of a sun shield he made for his fridge

The selected media item is not currently available.

Michelle

We hope to catch up with you guys. Send a buyer for our house ASAP so we can get out of here.

Bill, thanks for the valuable info. Did you mount the fans on the screen at the top of the vent?
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Dave Cobb on June 04, 2011, 04:17:21 pm
Kent,

Have read about a system of fans that go into the ref. and sit on top of the cooling fins.  Was 4 small fans, pushing or pulling air thru the coils.  Remember reading how it dropped the ref. temps when needed.

Not to remember where I read the link.  But it would be on this site, or the Bluebird site, or the FMCA site.  Have been on them for months and hours of reading to get up to speed with the new coach.

Remember also that Camping World had some system for sale to do the air movement thing, but for many more dollars than the suggested home built solution.
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Kent Speers on June 04, 2011, 04:37:29 pm
Thanks Dave, but as I recall that was to stop the frig from frosting up. Steve Cook was the one that first posted about it. We aren't really having problems with frosting up its just I would like the frig to stay cooler in the hot summer. If I find the right fix I think you may want to use it also as your frig did the same thing. I think it is the nature of the Dometics but I'm betting some of our Forum Engineers have figured out how to make them work better.
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Michelle on June 04, 2011, 04:55:46 pm
I think some time ago I remember some posts regarding increased cooling of the Dometic refrigerator in very hot weather. A fan was placed in the refrigerator exhaust area to move more air over the cooling coils. I have searched the archives but have found nothing. Does anyone remember this subject and the the details on the alteration?

I did a forum search for fridge fans and came up with a possibility

Fridge fans (http://www.foreforums.com/index.php?topic=11669.msg59019#msg59019)

Michelle
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: PatC on June 04, 2011, 05:59:43 pm
A fan inside like Steve fabricated will help a lot with the cooling.  Here is one that is on Ebay.  DOMETIC NORCOLD REFRIGERATOR FAN FOR RV 12 VOLT | eBay (http://cgi.ebay.com/ebaymotors/DOMETIC-NORCOLD-REFRIGERATOR-FAN-RV-12-VOLT-_W0QQcmdZViewItemQQhashZitem3cb5926fe2QQitemZ260744310754QQptZMotorsQ5fRVQ5fTrailerQ5fCamperQ5fPartsQ5fAccessories#ht_8773wt_1165).  Works well.  Could be used to blow air on the tubes also.
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Bill Willett on June 04, 2011, 06:51:48 pm
The E Bay fans will work for a short time until the sleeve bearing becomes dry and it will start to whine,you will notice it at night when it is quiet, you can buy the E Bay fans at Tiger Direct or Compusa for around 5 bucks,I am working on a replacement with dual ball bearings or fluid dynamic bearings.
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Kent Speers on June 04, 2011, 07:04:11 pm
A fan inside like Steve fabricated will help a lot with the cooling.  Here is one that is on Ebay.  DOMETIC NORCOLD REFRIGERATOR FAN FOR RV 12 VOLT | eBay (http://cgi.ebay.com/ebaymotors/DOMETIC-NORCOLD-REFRIGERATOR-FAN-RV-12-VOLT-_W0QQcmdZViewItemQQhashZitem3cb5926fe2QQitemZ260744310754QQptZMotorsQ5fRVQ5fTrailerQ5fCamperQ5fPartsQ5fAccessories#ht_8773wt_1165).  Works well.  Could be used to blow air on the tubes also.

That was a great lead. I ordered one. I'm not sure if it will help with my current problem but it can't hurt and it will cut down on the frost. Its easier than making one myself and actually less cost.

I just installed a rather large 10", 12V fan meant for use in the coach and have it blowing across the heat exchanger as a test. It's probably too large for a permanent installation but at least it will give me an idea of the difference more air movement will make. This thing moves a lot of air. I will report the outcome.
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Dave Head on June 04, 2011, 08:06:23 pm
I bought the little double fan setup sold on ebay, mounts on the fins at an angle - 10.00. Does a phenomenal job moving the air around inside. The I bought the thermostat controlled fan assembly at Camping World for the back side, mounted with plumber's tape on the coils. Does a great job moving air up through the vent.
With both of those, we have no problems maintaining temps in any temp or humidity.
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Dick S on June 04, 2011, 08:40:26 pm
Is there any way to tell if the electric heating element is On or Off? Maybe a voltage somewhere? I thought I would measure & record the ambient and coil temps and refrigerator setting for awhile. But I assume the coils will be much hotter when the heater is On.
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Jerry Whiteaker on June 04, 2011, 08:58:11 pm
Did your frig have problems with staying cool enough when outside temps were over 95? Freezer stays frozen but the frig is too warm, sometimes gets up to 42 degrees.

I think this is normal for this type refrigerator, maybe even better than normal.  The freezer gets cooled first as the refrigerant passes through the freezer and then to the coil in the refrigerator.  Making ice or opening the freezer door tends to warm up the refrigerator.  With all due respect to Barry, placing something over the vent that would block air flow is not a good idea.  He also said that it was an experiment for a problem that he had while driving, he didn't say that he did that when parked.  An outside fan will help with the cooling, and parking so that side is shaded from the sun helps.  Remove the outside vent door and look up inside (may need a mirror); there should be a block of foam near the top between the finned heat exchanger and the wall so that rising warmed air is forced through the heat exchanger.  It may not have this if there is no space between the wall and heat exchanger which is okay.  The freezer and refrigerator doors should be open as little as possible.  Too much stuff in the refrigerator blocks air circulation reducing cooling.  Manufacturers advertisements will show you a picture of it stuffed to the gills, then tell you in the manual that you shouldn't do that!
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Kent Speers on June 04, 2011, 09:09:47 pm
Jerry, I think you hit on our primary problem. Our frig is very full. The milk was spoiling early due to higher temps. We keep the milk on the bottom of the frig. I trust the circulating fans for the cooling fins will help keep the milk cooler. It was 95 degrees here today and the middle shelf temp was 42 degrees. That should have been cool enough so now I just need to spread the cool air around.

As usual, thanks to all who provided just what I needed to know.
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: George Stoltz on June 04, 2011, 09:43:07 pm
The blue cube in our fridge is a fan we bought at an RV dealer for about $20.  It makes a huge difference in keeping food cold and the cooling fins do not ice up nearly as fast -- even in Nac.
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Barry & Cindy on June 04, 2011, 11:14:16 pm
We ran a fused wire-pair of wires from rear of fridge to inside motorhome that is connected to a Radio Shack neon light on the inside and the refrigerator heating coil terminals on the control board. Whenever the electric 120-volt heating element in powered, the neon lamp lights.

We have a wireless Chaney refrigerator thermometer that displays inside fridge and freezer temps and has high/low settable alarms.

Here is a photo of our fans that we clipped to our fins for many years. These same fans are now mounted behind our new 120-volt Whirlpool 9.9 cu-ft refrigerator that replaced our original Norcold fridge that served us well for many years.
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Barry Beam on June 05, 2011, 01:46:18 am
With all due respect to Barry, placing something over the vent that would block air flow is not a good idea.  He also said that it was an experiment for a problem that he had while driving, he didn't say that he did that when parked.  An outside fan will help with the cooling, and parking so that side is shaded from the sun helps.  Remove the outside vent door and look up inside (may need a mirror); there should be a block of foam near the top between the finned heat exchanger and the wall so that rising warmed air is forced through the heat exchanger.  It may not have this if there is no space between the wall and heat exchanger which is okay.
Jerry,
That is correct, it was an experiment to determine if air coming in the vent while driving was the cause of my problem running on gas. And it was because I was missing that piece of Styrofoam above the refer. it served its purpose.

Kent , a few ideas you can look at
Refrigerator Not Maintaining Temperature (http://www.beamalarm.com/Documents/refrigerator-not-maintaning-temperature.htm)
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: hotonthetrail on June 05, 2011, 08:32:10 am
Barry with the 97 U270, could you elaborate on your refrig. mod., pics and details would be helpful. I am thinking about replacing a perfectly operating refrig. before its time of demise, that I know will happen at the worst time and place. For those who must replace with the same, check PPL big mark downs.  thanks jc
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Dave and Nancy Abel on June 05, 2011, 09:12:21 am
I bought the little double fan setup sold on ebay, mounts on the fins at an angle - 10.00. Does a phenomenal job moving the air around inside. The I bought the thermostat controlled fan assembly at Camping World for the back side, mounted with plumber's tape on the coils. Does a great job moving air up through the vent.
With both of those, we have no problems maintaining temps in any temp or humidity.

Hello Dave, 
  I've just ordered the little double fans for the fins from ebay and I've done a quick search on the camping world site, and I guess, I'm not finding the "thermostat controlled fan assembly at Camping World for the back side" that you are refering to.  Is it possible that the fans came from somewhere else?
Thanks for your help, Dave Abel
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Kent Speers on June 05, 2011, 10:17:47 am
Dave, I too could not find that product at Camping World. There are a number of listings under Google of similar products. Several cooling fans are solar powered which seems like a good idea. However, I think I will build my own fan like Bill Willet's post suggested at the beginning of this thread. I have a small solar panel I may use to power the fans.
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Dave Head on June 05, 2011, 11:33:24 am
Its made by Valterra
Valterra Products - Fridge Vent Exhaust Fan, 12V - Refrigerator Accessories - (http://www.campingworld.com/shopping/item/fridge-vent-exhaust-fan-12v/19709)
Sez not avail online anymore.
Here is Valterra's site:
RV Products & Accessories (http://www.valterra.com/rv/rv-main.htm)

Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Dave and Nancy Abel on June 05, 2011, 03:19:58 pm
Thanks Dave, 
    I'm not too far from a Camping World.  Think I'll check it out tomorrow..
Dave Abel
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Dave and Nancy Abel on June 05, 2011, 03:30:51 pm
Its made by Valterra
Valterra Products - Fridge Vent Exhaust Fan, 12V - Refrigerator Accessories - (http://www.campingworld.com/shopping/item/fridge-vent-exhaust-fan-12v/19709)
Sez not avail online anymore.
Here is Valterra's site:
RV Products & Accessories (http://www.valterra.com/rv/rv-main.htm)


Howdy Dave, 
  Checked out valterra's website and they have the Fridge Vent exhaust fan with solar panel for approx $72.  A quick Google search found the same product for about $52 at these two websites.  VALTERRA A10-2900VP - Valterra Solar Fridgemate A10-2900vp A10-2900VP - RV Plus (http://www.rvplus.com/valterra-solar-fridgemate-a10-2900vp-a10-2900vp.html)
https://www.makariosrv.com/products/Solar-Exhaust-Fan-by-Valterra-A10%252d2900VP.html.
Any comments/advice would be greatly appreciated. Thanks, Dave Abel
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Dave Head on June 05, 2011, 05:07:44 pm
My only issue is I have been in places (like Yuma, Laughlin) where it was 110 degrees AT MIDNIGHT. I took 12 v right off the back of the reefer.
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Dave and Nancy Abel on June 05, 2011, 06:13:08 pm
Thanks Dave,
  A very good point!!!  Dave Abel
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Bill Willett on June 05, 2011, 06:31:52 pm
I have ordered 3 coolink swif2-800 80mm fans from Quietpc Usa, they are 1100 rpm,19.1cfm at 9 DB for the inside of the fridge, I will also change the light switch to a SPDP switch so that when the door is open the fans will not run and blow the cold air out.
 More to come. ^.^d
Title: Re: Refrigerator Auxiliary Cooling Fan
Post by: Dwayne on June 05, 2011, 08:02:03 pm
I bought a 12v fan at campingworld that goes behind the fridge.  I wouldn't work based on their instructions or at least I couldn't get it to work using the attachment to the tubes with the thermocouple thing.  I tapped into the 12v always hot lighting wiring and put a switch above the refer so that I can turn it on or off from inside.  It is a box fan that mounts on the wood floor the fridge sit on and aims straight up the stack just to create a little air current going up.  Seems to help especially when combined with the little fan for inside the unit that circulates air.