Reply
 
Thread Tools Display Modes
 
Old 08-24-2019, 02:27 AM   #1
Platinum Member
 
Join Date: Dec 2017
Location: Arizona
Posts: 312
Default Fridge cooling fan

About a year ago I built a bracket/housing that holds 2 120mm computer fans to promote airflow at the back of my absorption fridge. Seemed to work in the sense that I gained about 4-deg cooling in the fridge. But I have two issues/concerns:

1. One of the fans started making noise and died. It needs to be replaced. Okay, this was a $8 fan from Frys Electronics. Assume bearing failure. So my first question is can any of you recommend a good/quiet computer fan? Like one that you've had for several years and is still functioning. Don't need thermo control. I just switch it on/off.

2. While I'm making this replacement I'm wondering about position. My PW has an exterior vent/door at the bottom and an exterior vent at the top. The top of the fridge compartment arcs at the top to direct air to that upper vent.
Right now my fans are bracketed at the bottom pointing up at a 45-deg angle. Is it better to have the fans there or simply attached to the top vent to draw the air out? Or both?

thx.glenn
__________________

GallenH is offline   Reply With Quote
Old 08-24-2019, 02:33 AM   #2
Platinum Member
 
Join Date: Aug 2010
Location: Minnesota
Posts: 7,575
Default

Quote:
Originally Posted by GallenH View Post
About a year ago I built a bracket/housing that holds 2 120mm computer fans to promote airflow at the back of my absorption fridge. Seemed to work in the sense that I gained about 4-deg cooling in the fridge. But I have two issues/concerns:

1. One of the fans started making noise and died. It needs to be replaced. Okay, this was a $8 fan from Frys Electronics. Assume bearing failure. So my first question is can any of you recommend a good/quiet computer fan? Like one that you've had for several years and is still functioning. Don't need thermo control. I just switch it on/off.

2. While I'm making this replacement I'm wondering about position. My PW has an exterior vent/door at the bottom and an exterior vent at the top. The top of the fridge compartment arcs at the top to direct air to that upper vent.
Right now my fans are bracketed at the bottom pointing up at a 45-deg angle. Is it better to have the fans there or simply attached to the top vent to draw the air out? Or both?

thx.glenn

I think the most important thing is to make sure that the air that goes through the fan can't loop back and go through again and again. That might mean a baffle at fan level all the way across the cabinet that the fans mount to. You need to get the cool air in the bottom, over the hot places and out the the top without any side trips. You also have to deal with the heat from the boiler which you may need to separate with a baffle so it will keep it's heat off the coils. Aiming the fans right at the condenser is a good idea.
__________________

booster is offline   Reply With Quote
Old 08-24-2019, 02:48 AM   #3
Site Team
 
avanti's Avatar
 
Join Date: Jul 2013
Posts: 3,267
Default

Quote:
Originally Posted by GallenH View Post
Don't need thermo control. I just switch it on/off.
I would recommend that you reconsider this. A computer fan temperature controller costs like 8 bucks and (in addition to the convenience) will make your fans much quieter and they will likely also last longer, since the fans will almost always be running at a low speed.

I use one of these:

fan controller.jpg

There are many others.
__________________
Formerly: 2005 Airstream Interstate (Sprinter 2500 T1N)
Now!: 2014 Great West Vans Legend SE (Sprinter 3500 NCV3 I4)
avanti is offline   Reply With Quote
Old 08-24-2019, 04:51 AM   #4
Platinum Member
 
Join Date: Dec 2016
Location: America's Seaplane City, FL
Posts: 390
Default

Quote:
Originally Posted by avanti View Post
I would recommend that you reconsider this. A computer fan temperature controller costs like 8 bucks and (in addition to the convenience) will make your fans much quieter and they will likely also last longer, since the fans will almost always be running at a low speed.

I use one of these:

Attachment 8090

There are many others.
along that line, I bought a couple computer fans from Amazon that have a thermistor bulb attached to them that varies the speed on them.
__________________
2000 Roadtrek Chevy 200 Versatile
Fun stuff:
'15 Kawasaki Versys650LT
'98 Kawasaki KLR650
SteveJ is offline   Reply With Quote
Old 08-24-2019, 08:34 AM   #5
Platinum Member
 
Join Date: Feb 2016
Location: Portland, Oregon
Posts: 1,393
Default

I used this fan, the same manufacturer has PWM versions.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
__________________
George
2013 Sprinter VOILA
https://goo.gl/photos/2NCR3teXLSwNYSwN8
GeorgeRa is offline   Reply With Quote
Old 08-24-2019, 11:22 AM   #6
Bronze Member
 
Join Date: Jun 2017
Location: Calif
Posts: 25
Default

Hi: I did the same thing in my PW van a few months ago. I did not notice a significant decrease in temp. So I installed a fan inside the refrigerator. It is the one with two fans blowing directly onto the fins. This just increases the air flow inside the refrigerator. This helped a great deal. Actually kept total temp down to a reasonable level. I installed a cheap remote thermometer to keep an eye on the inside temp without having to constantly open the door.
Rlum is offline   Reply With Quote
Old 08-24-2019, 02:27 PM   #7
Platinum Member
 
Join Date: Oct 2010
Location: VA
Posts: 477
Default

Quote:
Originally Posted by GallenH View Post
Right now my fans are bracketed at the bottom pointing up at a 45-deg angle. Is it better to have the fans there or simply attached to the top vent to draw the air out? Or both?

thx.glenn
Glenn,
I have found attaching the fan to the top vent better. I previously had a fan in the center and I think it looped much of the air around inside the vent cavity. After reading about this setup:

https://www.arprv.com/rv-fridge-slide-out.php

I got a fan like the one they sell and put it in the top vent. That has worked much better for me.

I also have done several other mods, with the cumulative effect that the fridge works much better. In very hot weather it is borderline, so I move some frozen ice packs that I keep in the freezer to the fridge part.

http://www.classbforum.com/forums/f8...ance-8484.html
peteco is offline   Reply With Quote
Old 08-24-2019, 03:17 PM   #8
Bronze Member
 
Join Date: Jun 2017
Location: Calif
Posts: 25
Default

Hi: Agreed. In hot weather not much works. One needs to do as much as possible. There is another consideration. Make a shade cover for the outside of van. To increase or create shade for vent areas of the van so it remains cooler. I have not done this yet. I believe it will aid.
Rlum is offline   Reply With Quote
Old 08-24-2019, 03:47 PM   #9
Platinum Member
 
Join Date: Oct 2010
Location: VA
Posts: 477
Default

Quote:
Originally Posted by Rlum View Post
Hi: Agreed. In hot weather not much works. One needs to do as much as possible. There is another consideration. Make a shade cover for the outside of van. To increase or create shade for vent areas of the van so it remains cooler. I have not done this yet. I believe it will aid.
I used to have fridge temp in the mid 40s, even higher if in high 90s outside. Now temps are in 36-39 in hot temp and hit 40 in the 90s. So the mods have worked very well.

Covering all the exhaust openings except for the fan exhausting the top vent has made a huge difference when driving. On 12v it holds the temp pretty good. Before the mods when driving the fridge temps always went up. I believe the airstream over the vents prevented good airflow in the bottom and out the top vent.

A shade cover on the fridge side of the van should help. I made one but have not tried it yet because I haven't needed it.
peteco is offline   Reply With Quote
Old 08-24-2019, 06:39 PM   #10
New Member
 
Join Date: Dec 2006
Location: Central Texas
Posts: 3
Default

Quote:
Originally Posted by peteco View Post
I used to have fridge temp in the mid 40s, even higher if in high 90s outside. Now temps are in 36-39 in hot temp and hit 40 in the 90s. So the mods have worked very well.

Covering all the exhaust openings except for the fan exhausting the top vent has made a huge difference when driving. On 12v it holds the temp pretty good. Before the mods when driving the fridge temps always went up. I believe the airstream over the vents prevented good airflow in the bottom and out the top vent.

A shade cover on the fridge side of the van should help. I made one but have not tried it yet because I haven't needed it.

I had a Dometic absorption fridge that worked fine when stationary but began to increased in temperature when driving after it was 2 or 3 years old. The longer the drive, the higher the temperature increased. Added a bigger cooling fan on condenser, increased insulation around fridge, closed off condensate drain in fridge but nothing helped while driving but it continued to work fine while stationary. Finally in desperation after this continued for almost 2 years, I used cord caulk around the interior cooling fins in the freezer and fridge and that fixed the problem while driving. Apparently the high air velocity when driving was able to penetrate through the back side of the fridge and leak warmer air into the interior of the fridge causing the temperature to increase. Not sure why this happened after owing the fridge for 3 years but maybe the urethane foam used to seal the exterior of the fridge contracts with age or maybe just cracks from vibration. It does not take much outside air to raise the temperature of an absorption fridge and it cannot keep up with continuous leaks even if small.
__________________

__________________
Mike
mondmn70 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT. The time now is 02:21 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.