Date:         Fri, 24 Aug 2001 20:57:25 EDT
Reply-To:     Kellmg@AOL.COM
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Brian Kelly <Kellmg@AOL.COM>
Subject:      Re: Refrigerator cooling: Do extra fans help?
Content-Type: multipart/alternative;

In a message dated 08/23/2001 11:49:13 AM Central Daylight Time, 
EVEHART33@AOL.COM writes:



> I always read the refrigerator threads hoping to pick up tips to improve the
> cooling ability. Some of the tips involved adding an extra cooling fan or
> fans to remove more of the hot air that builds up behind the refrigerator 
> and
> presumably aid cooling.I don't know how I overlooked this before but I read
> in a recent post that the Dometic RM 182 is designed to cool a maximum of
> only 40F below the outside ambient temperature. I've been checking mine on
> 120VAC and propane and find this figure to be roughly accurate. Has anyone
> added the extra fans and improved on this figure?
> 



Hi Ken and Listers,

I have just recently, this month, installed two fans to the refrigerator 
circuit. One inside and one additional at the rear of the unit. My 
information was gathered from the following informative site.

http://vanagon.com/info/articles/Refrigerator/Reefer_Madness.htm

Thanks to Derek Drew for the articles and all the leg work.

I also installed the two reading thermometer that is mentioned. One probe 
situated in free air at the top of the fridge. The second ambient van temps. 
Here are the results, taken a couple of weeks ago when it was really hot.

120 volt system.  
Ambient in van. .             Fridge
      95                                45.8          
      88                                39
The thermometer registers the min. and max. temp. also. As follows.
Min. 75.                               24.1
Following day.
      96.                               32.3     10AM.
      99.                               43.2      4.30 PM
      91.                               40.6.     8.30 PM
      85.                               31.       10.00 PM
The Max for the day was103.
Min. 70.  [overnight.]             24.0

I did the trial last night, again, on 120volt.
      86                                30.        11. AM
      81                                30          1.00 PM.
The day is overcast, no direct sun on the van. These figures would increase 
if the sun was beating down on the left side panel, I'm sure.

The propane figures were close, unfortunately I didn't record them.
Having the thermometer makes you more obsessive with the temp in the fridge. 
I did a test today. Had the door open for 10 seconds and it increased the 
temp. by 8 degrees. So if you want any thing out of the unit do it PDQ. 
All the above figures are with an EMPTY fridge.

Here are Radio Shack parts numbers that I used.
273-240   Micro Fan, 1- 9/16" square. 5.3 cfm. Fitted above the cooling fins 
inside.
273-243B  Cooling Fan 3" Airflow  26cfm
Rated at 0.08A and 0.16A.
Note. Radio Shack offer more options for fans on their web site. Cheaper too. 
Mine are from their stores.. Not all on the web site are available at their 
stores

The rear fan was connected to the load side of the heatswitch then controlled 
by it's own switch, which I mounted on the fascia panel of the fridge inside. 
This gives me the oportunity to switch off the additional fan at night, if I 
wish.
The inside fan is controlled by a second switch again mounted on it's fascia 
panel.
Nothing is visible from the outside. The noise level is minimal. Though I 
haven't spent over night. On removal of the unit, I increased the insulation 
at the rear of the fridge.
Foil covered insulation from Ace.Hard.

Prices aprox,
Fan 1 $15
Fan 2 $15
2 micro-switches. $5.00
Thermometer. $20.00.

Well worth the effort in my view. 

Brian Kelly.
86 Westfalia.



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