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Discussion Starter #1
I have read many of the refrigerator threads and my head is spinning!

I am at the design phase: 12v and cabinets, and would like some general information, please.

I would like to have a ~3.5 cf fridge. Freezer space is not important, as I store mostly fresh foods. Yes, this is small but I have had this size (and 3.0) in the past and it worked well for me.

I have not yet identified a fridge to buy -- suggestions in the "not top of the line" range would be greatly appreciated.

Q1: as I figure out my 12v system requirements what ballpark Amps would you suggest I use? 3.0A? 3.5A? And Sportsmobile suggests using 16 hours a day in calculating load -- that seems high but I guess it depends on ambient temps as well as insulation and air flow around the fridge ...

Q2: this will be mounted under a counter right beneath the countertop. How deep a cabinet/counter is typically required to accommodate a smallish fridge? Sportsmobile shows fridges in their 22" galleys, IIRC.

Sorry about these somewhat generic questions, but I am trying to do my high-level 12v and cabinet design before deciding exactly what unit to buy.

Thanks!
 

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Hi,

I'm using the Norcold NB 751 fridge -- have been happy with it. It uses the Danfoss compressor, which has a good reputation for reliability and efficienty.
If I were doing it again, I'd probably allow a little extra space for applying some external insulation.

I kept careful track of its electricity use over a couple days -- numbers here:
http://www.buildagreenrv.com/design-and-build-information-for-camper-vans/installing-galley/measuring-refrigerator-electricity-use/

Bottom line is that it used 42 amp-hrs per day on an 80F ambient temperature day.

Gary
 

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Trucker Fridge, I had one in my SMB, worked great! I actually will be puling it out for my new van. I had my RV battery hooked up with solar and also charging from the van. Never had a problem running the battery down......kt
 

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Discussion Starter #5
Thank you.

If I use 3.5Amps and 16 hours (as Sportsmobile suggests) that's 56Ah for the fridge. Yikes! GaryBIS (is that Best In Show?) has data that shows his fridge pulling as teady 3.6Ah, but for fewer hours a day at 80*F. FarOutRide assumed many fewer hours in their load calculations, but they will be in cooler climates, even in the summer.'

'I could panic at the thought of more than 40Ah per day for the fridge, and the implications for a 210V house battery. Or I could remember that whilst the fridge is pulling electricity, the van's alternator and/or solar panels are replenishing the battery, so it is never really drained 40+Ah. In fact, if my solar bank has two 100W panels, then during the 5 sunny hours of a day they should generate 50 Ah, so I might be OK....

BTW, my fridge budget is about $600 + shipping.

The Norcold NR751 seems to run $729 + tax at WestMarine, dimensions: 20 1/2" H x 18 1/2" W x 21 1/16"D (23 1/4"D flush mounted) So price wise it is do-able, but a stretch.

Counter/Galley size: my second question is, how deep does a counter typically need to be to accomodate a 3.5cf-ish fridge? 24"? And should I leave the back off the cabinet in order to allow good air circulation?

And if I put polystyrene boards around the fridge (and allow space for that), do I have the polystyrene touching the walls of the fridge, or do I insulate the cabinet walls and have an air gap between the polystyrene and the fridge?

Or, would it be OK to stuff extra Thinsulate betweeen the walls of the fridge and the walls of the cabinet?

Sorry for all of these questions, but as I said I am at the 10,000 foot design stage and need some basic measurements.

Thanks.
 

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Orton's build thread mentions venting the heat off the fridge with convective airflow using a floor vent below carrying air in behind the fridge and up to the vent in the roof. Moving the heat out of the cabinet will help reduce the amount of time the fridge runs to keep the beer and guacamole cold. The hot air rising will pull cooler air in from the shade below the van. In that thread he emphasizes how effective the method is in regulating the temp in the van. An excellent application of physics to milk more value from the energy in the environment. Regardless of what size unit you select this strategy should extend run time / reduce battery drain.
 

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Thank you.

If I use 3.5Amps and 16 hours (as Sportsmobile suggests) that's 56Ah for the fridge. Yikes! GaryBIS (is that Best In Show?) has data that shows his fridge pulling as teady 3.6Ah, but for fewer hours a day at 80*F. FarOutRide assumed many fewer hours in their load calculations, but they will be in cooler climates, even in the summer.'

'I could panic at the thought of more than 40Ah per day for the fridge, and the implications for a 210V house battery. Or I could remember that whilst the fridge is pulling electricity, the van's alternator and/or solar panels are replenishing the battery, so it is never really drained 40+Ah. In fact, if my solar bank has two 100W panels, then during the 5 sunny hours of a day they should generate 50 Ah, so I might be OK....

BTW, my fridge budget is about $600 + shipping.

The Norcold NR751 seems to run $729 + tax at WestMarine, dimensions: 20 1/2" H x 18 1/2" W x 21 1/16"D (23 1/4"D flush mounted) So price wise it is do-able, but a stretch.

Counter/Galley size: my second question is, how deep does a counter typically need to be to accomodate a 3.5cf-ish fridge? 24"? And should I leave the back off the cabinet in order to allow good air circulation?

And if I put polystyrene boards around the fridge (and allow space for that), do I have the polystyrene touching the walls of the fridge, or do I insulate the cabinet walls and have an air gap between the polystyrene and the fridge?

Or, would it be OK to stuff extra Thinsulate betweeen the walls of the fridge and the walls of the cabinet?

Sorry for all of these questions, but as I said I am at the 10,000 foot design stage and need some basic measurements.

Thanks.
Hi,
The fridge is by far our largest load, so I'd not get to concerned about it being pretty large. We have 220 amp-hrs worth of battery and 315 watts of solar, and that works out fine -- even for winter camping (hard on solar), it has been fine.

If you like the Norcold, I'd keep looking for a better deal -- I think we paid just over $600 with shipping. Can't remember where we got it, but it was a marine place in Seattle.
We have been happy with it. I've noticed that people who get Engels seem to like them. And Truckfridge seems to be picking up a lot of satisfied customers.

The way I've seen external insulation used is to attach it right to the fridge case. Polyiso would give you more R value for the inch than polystyrene or Thinsulate. Even half inch polyiso would give you an added about R3.
Some fridges have the condenser coil embedded in the fridge wall jjust under the outer wall of the fridge cabinet -- you don't want to insulate over the condenser coil.

I'm not home right now., so can't measure our galley cab depth. It might be mentioned on this page: http://www.buildagreenrv.com/our-conversion/promaster-camper-van-conversion-galley/
The guts are in the back of the fridge, and some venting is good -- the fridge does have an airpath under it.

Best in Show -- like it:), but it actually stands for Build-It-Solar which is my website on DIY solar projects. Just got used to using that UID, although it does not make a lot of sense here.

Gary
 

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Hi,
The fridge is by far our largest load, so I'd not get to concerned about it being pretty large. We have 220 amp-hrs worth of battery and 315 watts of solar, and that works out fine -- even for winter camping (hard on solar), it has been fine.

If you like the Norcold, I'd keep looking for a better deal -- I think we paid just over $600 with shipping. Can't remember where we got it, but it was a marine place in Seattle.
We have been happy with it. I've noticed that people who get Engels seem to like them. And Truckfridge seems to be picking up a lot of satisfied customers.

The way I've seen external insulation used is to attach it right to the fridge case. Polyiso would give you more R value for the inch than polystyrene or Thinsulate. Even half inch polyiso would give you an added about R3.
Some fridges have the condenser coil embedded in the fridge wall jjust under the outer wall of the fridge cabinet -- you don't want to insulate over the condenser coil.

I'm not home right now., so can't measure our galley cab depth. It might be mentioned on this page: http://www.buildagreenrv.com/our-conversion/promaster-camper-van-conversion-galley/
The guts are in the back of the fridge, and some venting is good -- the fridge does have an airpath under it.

Best in Show -- like it:), but it actually stands for Build-It-Solar which is my website on DIY solar projects. Just got used to using that UID, although it does not make a lot of sense here.

Gary
So you will loose how much power during the Solar eclipse? I guess that on Monday you can buy a few bags of ice to
keep you chill.
 

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I have a Vitrifrigo 85 liter refrigerator and a 255 amp-hr house battery. I also have a 300 watt solar panel with MPPT controller. The refrigerator is my largest power user.

The amount of power consumed by the refrigerator depends on the installation and the interior van temperature. My installation includes a 4" x 4" hole in the floor behind the refrigerator to supply cooler air to the condensor. I also have 2 1/2" of polyiso surrounding the exterior of the refrigerator except fot the door.

In my application in my climate the refrigerator uses about 3 to 4 % of the battery capacity ovenight. I had a 80 liter Dometic in the sold Sprinter and that used 5 to 6% of the same battery capacity. The Dometic had a serpentine condensor coil on the back of the refrigerator and the Vitrifrigo has a small radiator and fan. Both have the same Danfoss compressor. So I am guessing that the different condensor design is the reason for the better efficiency. That also is supported by other's comments that chest type refrigerators are more efficient. I do not believe the "cold air falls out" of a front door refrigerator theory. The chest type refrigerators use a condenser design like the Vitrifrigo because they can not have external coil. The Vitrifrigo installation does have 2" of closed cell foam insulation glued to the back of the refrigerator that the Dometic could not have due to the coil location.
 

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Don't know if this will help but I have a 6 cu. ft. refrigerator arriving any day now. It's big and tall, but it's only 20.5 inches deep.

It will also be my biggest current draw, and it will be significantly bigger than most. Which is why I am going large on the solar panel and the battery bank. It is also why I'm going to follow Orton's examply and install a vent at the back of the fridge cabinet. Initially I was reluctant to cut a hole in the floor, but the benefits of reducing the cooling cycle on the fridge while also getting induction cooling for the entire van is pretty compelling to me. My vent will be a 6" round duct with a large butterfly valve at the top to let me close it when I want to. I can provide more info. if desired.
 
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