Reply
 
Thread Tools Display Modes
 
Old 09-11-2019, 10:35 AM   #1
Senior Member
 
Join Date: May 2007
Location: East Bay CA
Posts: 1,055
Norcold freezer and laws of thermodynamics

I've read that it's best to keep a refer full of cold items (and obviously buy already chilled stuff before putting it in). The idea being that there is more cold mass and heat coming in gets dispersed among the items so that your beer only drops a bit in temp over say the weekend.

But I wondered about say two weeks of refer use. How much more energy does one's refer use to keep one six pack cold vs say two cases? Seems it would make no difference, if this is correct: https://physics.stackexchange.com/qu...han-a-full-one

So now I'm wondering if it makes sense to put anything in the freezer. I suppose a few frozen meals would help in the first few days (I typically keep the thermostat quite low unless I've got something really critical like some dairy or prepared food). And then just consume them. It would seem that it would then have no effect on overall power consumption if I just leave the freezer compartment empty. Is that correct?
__________________

__________________
2001 Ford E250 Sportsmobile with Salem-Kroger 4x4 conversion
rob_gendreau is offline   Reply With Quote
Old 09-11-2019, 11:54 AM   #2
Senior Member
 
arctictraveller's Avatar
 
Join Date: Mar 2013
Posts: 2,909
Interesting article. One other thought though, as the refer is emptied, every time you open the door and the cold air poor's out the bottom and warm air enters at the top, I would assume this would happen faster when empty than when full, as the interior items would block some of the air flow. In the real world, unless you are on the very limit of battery capacity, it probably doesn't make any difference, far less than limiting the number of times and length of time the door is open, and the temp of items put inside. Add in a solar panel or two, and the beer should always be cold no matter what.
__________________

__________________
Arctic Traveller
KC6TNI
2001 GTRV
Advanced 4wd
Agile Ride improvement package
www.arctictraveller.com
arctictraveller is offline   Reply With Quote
Old 09-11-2019, 12:26 PM   #3
Senior Member
 
Join Date: Nov 2014
Location: Aurora, CO
Posts: 332
What about the Isotherm drawer style fridges? Do you think they would let all the cold air fall out of them? I would think they might be a bit better at retaining cold air inside the fridge than the standard cabinet door style fridges, but not quite as good as the ARB cooler lid style fridges, no?

Although, maybe the action of pulling out the drawer creates a little bit of a vacuum in the fridge that then pulls the cold air out of the fridge and it would be no better than the cabinet door style.
__________________
New Van: 2000 Ford E350 SMB RB42
Old Van(sold): 1995 Dodge B3500 SMB RB33
Ben10281 is offline   Reply With Quote
Old 09-11-2019, 03:04 PM   #4
Site Team
 
daveb's Avatar
 
Join Date: May 2007
Location: Turlock Ca
Posts: 9,819
Garage
With mine, if I need to crank it up enough to keep items fully frozen in the freezer, things on the bottom start to freeze. I tried to bring ice cream once but I had to turn it up much higher than normal so I'm guessing I was using more power. If I didn't store stuff in the freezer maybe one of those little battery operated fans might push colder air out into the main fridge???
I always put frozen food in both sections and at least it extends the thawing of items below as the days go on.
__________________
2006 Ford 6.0PSD EB-50/E-PH SMB 4X4 Rock Crawler Trailer

Sportsmobile 4X4 Adventures..........On and off road adventures
daveb is offline   Reply With Quote
Old 09-11-2019, 03:22 PM   #5
Senior Member
 
Join Date: May 2007
Location: East Bay CA
Posts: 1,055
I should carry my IR thermometer and do some observations. And maybe buy a lot of popsicles.
__________________
2001 Ford E250 Sportsmobile with Salem-Kroger 4x4 conversion
rob_gendreau is offline   Reply With Quote
Old 09-11-2019, 06:59 PM   #6
Senior Member
 
Join Date: Jun 2011
Location: Livermore, Ca
Posts: 351
If and only if the refer has a fan as in household ?

The van has a chest type compressor fridge/freezer from Max Burton. I have found no unusual temp swings or power usage fluctuations at any time of year full or not.
__________________
Peace, Regis
2011 Express 1500
I'm a camper not a glamper
regis101 is offline   Reply With Quote
Old 09-11-2019, 08:43 PM   #7
Senior Member
 
arctictraveller's Avatar
 
Join Date: Mar 2013
Posts: 2,909
I think the whole question of cold air flow is strictly academic. Any appreciable reduction with drawers or other methods would probably be immeasurable. Refers these days are pretty efficient, so any savings might be on the order of less than one amp hours a day. Far bigger savings from better insulation, improved air flow over the condenser, and content management are readily available. That's not to say this isn't a fascinating discussion.
__________________
Arctic Traveller
KC6TNI
2001 GTRV
Advanced 4wd
Agile Ride improvement package
www.arctictraveller.com
arctictraveller is offline   Reply With Quote
Old 09-11-2019, 11:17 PM   #8
Senior Member
 
1der's Avatar
 
Join Date: Apr 2013
Location: San Francisco, CA
Posts: 1,940
I propose a six “cases” research effort be undertaken over a long weekend. IR temp sensors are mandatory. Proper sampling and data collection, but definitely not to the point of double blind levels. We should really get to the bottom of this once and for all.

We can provide some baselines since Beastie has both the door and chest fridges, the chest is used as a freezer. While waiting for the samples to properly chill, ice cubes can be dispensed into blended concoctions to help with the survey effort.
__________________
Ray
Beastie 3: 2002 7.3 EB Cargo: Agile TTB, CCV Mid Top, Custom Walk Through, Lots of stuff added. BlingMyRig.com
1der is offline   Reply With Quote
Old 09-12-2019, 12:20 AM   #9
Senior Member
 
arctictraveller's Avatar
 
Join Date: Mar 2013
Posts: 2,909
Quote:
Originally Posted by 1der View Post
I propose a six “cases” research effort be undertaken over a long weekend. .
Very good. I propose we do said research in Baja...
__________________
Arctic Traveller
KC6TNI
2001 GTRV
Advanced 4wd
Agile Ride improvement package
www.arctictraveller.com
arctictraveller is offline   Reply With Quote
Old 09-12-2019, 10:46 AM   #10
Senior Member
 
Join Date: May 2007
Location: East Bay CA
Posts: 1,055
Quote:
Originally Posted by arctictraveller View Post
I think the whole question of cold air flow is strictly academic. Any appreciable reduction with drawers or other methods would probably be immeasurable. Refers these days are pretty efficient, so any savings might be on the order of less than one amp hours a day. Far bigger savings from better insulation, improved air flow over the condenser, and content management are readily available. That's not to say this isn't a fascinating discussion.
Ha! easy to say when you're the ARCTIC Traveler....

But yeah, partly academic. And I suppose coming from managing big ice chests of food for say 10 day raft trips where it's more critical influences my concerns.

But if I can save some amp hours, fine. Perhaps more importantly it's having that bee cold. I'll start that research soon.

I did upgrade my refer recently, the original Norcold from SMB having kind of died (didn't take it apart, but it couldn't cool much anymore and sounded like a blender full of gravel). The new one is almost too much; it seems to get stuff really cold even on a 1 setting. I noticed too that it would hit 4.2A pretty frequently the first day and took longer than I expected to get real cold (the beer actually got colder by the next day over the temp it was when removed from my house fridge). It would then cycle less frequently, of course, and only at say 3.2A, which was nice. SMB said overall it was considerably more efficient than the old one ever was.
__________________

__________________
2001 Ford E250 Sportsmobile with Salem-Kroger 4x4 conversion
rob_gendreau 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

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by Sportsmobile SIP or any of its affiliates. This is an independent, unofficial site.


All times are GMT -6. The time now is 01:15 PM.


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