Refrigerators (2-way) 12v & 110v? - Page 2

larrie · 10-28-2012, 10:14 PM

Jim

Yes there is a cooling fan on the back of the unit that I can barely hear. I can only hear the compressor and that is really quiet.

I usually hear my next door neighbor start his car, a sedan, at 5:00 am. That is much noisier than the fridge.

robtbritn · 10-28-2012, 10:55 PM

You can try a search for marine refidgerators...this link has a fridge with an air cooled Danfoss compressor.
http://www.defender.com/product.jsp?pat ... id=1770570

billwilson · 10-29-2012, 05:23 AM

another vote for truckfridge

i never turn it off

two years now

12v/110v

yvrr · 10-29-2012, 09:26 AM

I'm very pleased with our Isotherm refrigerator. Here is a link to the install:

http://www.sportsmobileforum.com/vie...sotherm#p25770

It is very quiet and there would be no need to try to install the compressor, etc. outside the van, even if you could. (I'm assuming that you are thinking of that modification in order to control noise.)

The efficiency of any refrigerator is going to be related to the insulation and air flow to the coils. If I were home-building a rig, I'd consider adding additional insulation to the outside wall of the van around the refrigerator...when you get problems is when the van is parked with that side of the van toward the sun and it is hot outside. The van exterior transfers heat inside the van while the coils are trying to get rid of heat from inside the refrigerator. You will get higher efficiency with good wall insulation and good air flow from under the refrigerator, up to the coils, and out.

JimHefner · 10-30-2012, 08:14 AM

It appears I've narrowed it down to the Truckfridge (TF130 - $695) or the Isotherm (CR 130 - $1,500). They both sound like great units. The Truckfridge being 1/2 the price of the Isotherm makes me think I'm missing something with their unit. I'm inclined to buy the Isotherm because it's more expensive which is def stupid thinking. I'm going to call each to get the sales spiel...

**BroncoHauler** · 10-30-2012, 08:27 AM

Quote:

Originally Posted by JimHefner

It appears I've narrowed it down to the Truckfridge (TF130 - $695) or the Isotherm (CR 130 - $1,500). They both sound like great units. The Truckfridge being 1/2 the price of the Isotherm makes me think I'm missing something with their unit. I'm inclined to buy the Isotherm because it's more expensive which is def stupid thinking. I'm going to call each to get the sales spiel...

Does the Isotherm you are looking at include their ASU? It's essentially a cold plate that gets frozen when you have "extra" electrical power available (driving, shore power, solar) and the fridge then uses that stored coldness to keep the fridge at optimal temperatures rather than your house batteries. How long you enjoy the benefit of the ASU before it needs to get re-frozen I can't really say. I know I was really eyeballing an Isotherm with ASU when I thought my Norcold was toast.

If you are going to be driving every day or every other day, it might not be worth getting the ASU system, which does add considerable cost.

Herb

yvrr · 10-30-2012, 08:36 AM

One of the advantages of the Isotherm is that the ASU continually monitors the house battery voltage and shuts off the compressor when the house battery drops to 12.2v (50% service level) and then keeps things cold via the frozen gel pack. It thus doesn't drag the battery down at night. (It helps to have solar to recharge the battery in the morning.) I've found that, when it is hot outside during the day (and warm at night), the house battery will be at 12.2v in the morning. But, when it is cold, the refrigerator doesn't need to run that much and the battery will be at around 12.5v or more in the morning.

The Isotherm also doesn't have an adjustable thermostat. When we had the original Norcold, we were continually adjusting the thermostat to compensate for the air temperature. We'd turn it up during the day to keep things cold enough and turn it down at night to keep from freezing the lettuce. Where we put the lettuce was also critical. There is nothing to adjust with the Isotherm.

(I'm not sure/can't remember if the Isotherm runs directly from 120v. We have a inverter so it isn't a problem.)

The only problem with the Isotherm is the need to keep the ASU and control module from coming apart. My post on my install shows how I did it...I'm sure there are other solutions.

I believe that you get what you pay for...

billwilson · 10-30-2012, 07:06 PM

Quote:

Originally Posted by JimHefner

It appears I've narrowed it down to the Truckfridge (TF130 - $695) or the Isotherm (CR 130 - $1,500). They both sound like great units. The Truckfridge being 1/2 the price of the Isotherm makes me think I'm missing something with their unit. I'm inclined to buy the Isotherm because it's more expensive which is def stupid thinking. I'm going to call each to get the sales spiel...

I called em before i bought my first one for my westy
they laughed when i asked em if i could keep it running and on bouncy roads

they infereed that they were built to be mounted in big rigs and run non stop
and bounce quite a bit

i have 360 watts solar panels and 400 amp hours of AGM

on Bill Wilson's Tour de Utah 2011-2012 we had snow on the panels for days
no problem with lights, suburban, fridge or led/dvd player......

JimHefner · 10-30-2012, 07:48 PM

The guy at Isotherm told me today that the Truckfridge is actually built by them and is identical to their non ASU unit. (Exactly the same Danfoss compressor, etc.) It's just sold in a different market with a different price. Also, apparently the ASU can vary the speed of the compressor via voltage control. Variable speed compressors are the shnizit nowadays in home A/C units so I'm intrigued. Last, the whole cold plate idea, to me though, doesn't sound much different than keeping an extra quart of water chilled in the fridge.

I stopped by West Marine in Newport Beach today to check out the Isotherm but they don't stock any.

A couple more calls tomorrow to get more info on the variable speed.

I'm still blown away the 3.6 cu ft Norcold is a bit larger in overall size than the 4.6 cu ft Isotherm or Truckfridge. Thinner walls and less insulation I guess...

chromisdesigns · 10-30-2012, 11:43 PM

Quote:

Originally Posted by JimHefner

Last, the whole cold plate idea, to me though, doesn't sound much different than keeping an extra quart of water chilled in the fridge...

There is a big difference. It takes a lot of heat to change ice to water (or vice-versa). A bag of cold water will start warming immediately. A block of ice (or a frozen cold plate) will stay at the same temperature until all the frozen solid converts back to liquid, absorbing a bunch of heat in the process.

Cold plates contain a eutectic solution which freezes at a lower temp than water, making them even more efficient at cooling your ice box.

Cold plate systems have been used in refrigerated trucks and boats forever. The cute part about Isotherm's approach is a smart monitor that pumps down the cold plates whenever the energy is available, rather than you having to remember to do it.

We had mechanical cold-plate fridge and freezer on our sailboat, pumped down by a compressor belted to the main diesel. An hour running recharged our batteries and pumped down the plates. We could then go for several days without running the engine again. Engine-driven compressors have a lot more capacity than the little Danfoss units, though. We had 3 big cold plates and a lot of freezer space.