12V only versus 12V/120V fridge

[BroncoHauler]

I may need to replace my 2.7cu-ft dual-voltage Norcold if it's not a simple fix (for me it wasn't cooling at all, SMBw tells me its cooling but won't shut off). I don't know if it's the fan or the compressor that's not shutting off. Hopefully, it's a simple fix, since it seems it's either a simple fix or no fix at all with the Norcolds.

Since I have the smaller Norcold, there's not a great Isotherm fridge match, but there is a 2.3 cu-ft version (Cruise 65) that might fit. I think there is a 12V only version and a 12V/120V version. So what's the advantage of the dual voltage version? If I'm plugged into shore power, my 12V batteries will charge, and the batteries will powering the fridge. What am I gaining by having the fridge be able to run off 120V, aside from maybe some efficiency gain?


Herb

[jage]

My understanding is the fridge is more efficient on 120v, cycles less often. Apart from that... nothing I've ever heard. I put a switch on my to be able to force it to 12v for running the invertor while not on shore power- only thing is I almost always forget to turn the fridge outlet back on so I've been on 12v only almost since doing the wall rebuild.

[billwilson]

Truck Fridge's ROCK

I have the 4,2 cf in Wilson

http://www.truckfridge.com/acdc_models.html

meant to be run 24/7/365

OF course get the 12v/110v, price virtually same and great for places that ya might have a hookup like your house or visiting the relitives

"Since I have the smaller Norcold, there's not a great Isotherm fridge match, but there is a 2.3 cu-ft version (Cruise 65) that might fit"

Isotherm Cruise 65 = $800 usd
Truck Fridge 65 = $600 usd

hmmmm........

[BroncoHauler]

Originally Posted by billwilson

Truck Fridge's ROCK

I have the 4,2 cf in Wilson

http://www.truckfridge.com/acdc_models.html

meant to be run 24/7/365

OF course get the 12v/110v, price virtually same and great for places that ya might have a hookup like your house or visiting the relitives

"Since I have the smaller Norcold, there's not a great Isotherm fridge match, but there is a 2.3 cu-ft version (Cruise 65) that might fit"

Isotherm Cruise 65 = $800 usd
Truck Fridge 65 = $600 usd

hmmmm........

Thanks Bill. Definitely another, well priced option.

One thing I did notice was that the Truck Fridge's average power consumption is 24W/hour, where the Isotherm is 0.7A x 12V = 8.4W.

That said, the 0.7A is listed as the Average current, where the peak current is 2.7A. That and I treat all specs with suspicion.


Herb

[billwilson]

Originally Posted by Bronco_hauler

Thanks Bill. Definitely another, well priced option.

One thing I did notice was that the Truck Fridge's average power consumption is 24W/hour, where the Isotherm is 0.7A x 12V = 8.4W.

That said, the 0.7A is listed as the Average current, where the peak current is 2.7A. That and I treat all specs with suspicion.


Herb

I will dig out a real life power consumption report from The Samba
TF rating is IF it ran CONTINUOSLY

The truth is it does not, therefore less power drain

Did not turn off my TF in my Westy for 3 months
running 0ne 130 watt kyocera and One 110 amphour battery
allways had juice

Have slept with my new 4.2 cf TF and set on #4 cold setting (i think 6 is max)
it cylcles on for @ 5 min every 15 minutes

over

[billwilson]

Truck Fridge stats from TF 49 then Real World numbers… Courtesy The Samba
ps
You guys really gotta look at The Samba mods for Westys, they have a TON of good ideas...

Model TF49 AC/DC
Size - H x W x D 20 ½" h x 15" w x 18" d
Gross Capacity 49 litre/1,73 cu. ft.
Nominal voltage 115 Volt AC/12 Volt DC
Nominal imput 60 Watt
Refrigerant R 134 a
Internal Light Yes
EMC conformity Yes
Air-cooling Forced with fan
Average consumption 24 watts/hour
Net Weight 35 lbs.





Posted: Sat Jun 06, 2009 1:25 pm Post subject: Vitrifrigo performance

________________________________________
Time for some real-world testing. I'm sitting in VA at a campout, running the fridge since 7pm yesterday. Out of curiosity, I tested amperage before I left--3.7 A on startup, dropping to 2.5 as it runs. THEN, I added an analog clock to the fan power wires to time how much it runs in 24 hours. SO FAR, at this time, it has run 6 hours and 22 minutes. Fridge is 40 degrees inside at the mid point, van in the direct sun, 89 degrees inside. The thermostat is at the 7:00 position.

More tomorrow night.



Posted: Sun Jun 07, 2009 5:25 pm Post subject: Final run-time tally, Vitrifrigo

________________________________________
Just back from my camping weekend with a timer attached to the VF fridge fan: The fridge was started on Friday at 7 pm, turned off Sunday at 8 pm, total run time was 16 hour 20 minutes. That translates to exactly 1/3 'on' time. Temps ranged from the mid 60's at night to high 80's during the days, and the fridge was cranked up to the next mark past vertical on the dial (daytime), maintaining 38 to 40 degrees. Froze an ice-pack in the freezer last night, solid.

So, the fridge in such conditions consumes 22.4 amp-hours (8 hours x 2.8 A, avg.) daily. Size your batteries accordingly and you'll have cold food.

[yvrr]

Originally Posted by Bronco_hauler

Since I have the smaller Norcold, there's not a great Isotherm fridge match, but there is a 2.3 cu-ft version (Cruise 65) that might fit. I think there is a 12V only version and a 12V/120V version. So what's the advantage of the dual voltage version? If I'm plugged into shore power, my 12V batteries will charge, and the batteries will powering the fridge. What am I gaining by having the fridge be able to run off 120V, aside from maybe some efficiency gain?

Herb

If you choose the ASU (Automatic Start Up) option, the Isotherm refrigerator monitors the house battery voltage and basically adjusts the cooling cycles in response to the available voltage level to minimize battery usage. This means that if you been running the lights and using the house battery in the evening (and thus lowering the voltage of the house battery), the refrigerator will go into a passive mode at night, keeping things cool via a "holding plate" without using any additional power. This may not be all that important when your house battery is new and can power everything for a couple of days without solar, shore power, or running the engine but can be extremely beneficial after the house battery is a couple of years old.

As far as the 12v/120v option, the Isotherm (with ASU) has both manual and automatic settings. When you are precooling the refrigerator and have shore power available, you can put it in the manual mode and cool the refrigerator lower than the normal operating temperature. This helps compensate for the inside temperature loss while loading it up. But, if you have only 12v available and put it in manual mode overnight to precool it, then it might pull the house battery down below your preferred voltage level.

Another nice thing about the Isotherm is that temperatures are controlled automatically...there is no adjustable dial as with a Norcold. When we had our Norcold, we had to turn the thermostat up as high was it would go for precooling and then try to find the right setting during the day to keep things cold. We'd then adjust it down at night to cold avoid freezing the lettuce. The correct setting was dependent on temperatures inside the van which could vary by 30 degrees or more throughout the day. Temperatures inside the Isotherm are controlled automatically...no dials or settings in the automatic mode.

[Gulliver]

So to conclude: A dual voltage 12v/120v fridge is better than a 12v only fridge, because it spares your batteries and your food, whenever you have access to shore power - Correct?

Hey Bronco, I hope you don't mind if I semi-hijack your thread on a closely related topic?

I also have a new fridge purchase in my near future. I'm building my rig for full-time RVing. Therefore, I require high quality 24/7/365 dependability. So Norcold and those silly dometic fridges are off the table. So far my research is pointing to one of these 3 brands:

1. Vitrifrigio (aka Truck Fridge): http://www.vfamerica.com/eng/index.asp Much thanks to Bill for his recommendation
2. Isotherm: http://www.isotherm.com/en/index.html?fixframe=1& Thanks to yvrr for the Isotherm info
3. Nova Kool: http://www.novakool.com/index.htm

Does anyone else have any info on the Nova Kool?

[BroncoHauler]

No worries Gulliver, seems like your question is very closely aligned. FWIW, if you full-time, look at getting one large fridge, or two small ones.


Herb

[billwilson]

Full time?
I would look at the "external cooling" offered by vitrifrigo
for the same weight, it gives you another 0.5 cf and the ability
to really cool down the cooling unit/placement ability
i DO NOT know how far away you can place the cooling unit
if you could tuck it away in a dead space very cool, no pun intended

if full timing it, that 1/2 cubic foot is alot

ck out www.thesamba.com
i remember seeing a install of a unit w/ remote/external cooling
i think the fridge was midships (westys have a rb50 floor plan)
and the cooling unit was under the driver seat
a couple of feet away....
(search under vanagons/truck fridge or virtifrigo)

Originally Posted by Gulliver

So to conclude: A dual voltage 12v/120v fridge is better than a 12v only fridge, because it spares your batteries and your food, whenever you have access to shore power - Correct?

Hey Bronco, I hope you don't mind if I semi-hijack your thread on a closely related topic?

I also have a new fridge purchase in my near future. I'm building my rig for full-time RVing. Therefore, I require high quality 24/7/365 dependability. So Norcold and those silly dometic fridges are off the table. So far my research is pointing to one of these 3 brands:

1. Vitrifrigio (aka Truck Fridge): http://www.vfamerica.com/eng/index.asp Much thanks to Bill for his recommendation
2. Isotherm: http://www.isotherm.com/en/index.html?fixframe=1& Thanks to yvrr for the Isotherm info
3. Nova Kool: http://www.novakool.com/index.htm

Does anyone else have any info on the Nova Kool?