21 replies to this topic

[craig333]

They all seem to work just fine. It would great to have an unbiased comparison of energy usage, efficiency etc of the various brands.

[pods8]

They all seem to work just fine. It would great to have an unbiased comparison of energy usage, efficiency etc of the various brands.

 

I know my buddies front opening truck fridge pulls more amps that my top loader ARB but I'm not sure how the truck fridge top loader would stack up against, IE is it the fact there is a freezer section in the truck fridge that causes it to run a tad more or such?  Either way a bit of properly sized solar can neutralize that aspect.  I'd stew mostly on whether you want a top loader or front opener, I certainly see pros/cons to both.  Having a freezer for ice, drinks on the door, can be nice.  Top loaders can be portable, stuff doesn't fall out (but you have to dig at times), hold in their cold more when opened, catch spills.

[MarkBC]

The isotherm seems to have a separate unit that can reduce battery usage up to 50%? Is it that much better than the competition or are the other brands more efficient to begin with?...

 

Are you referring to the Isotherm ASU - Automatic Start Up option?

 

The ASU decreases battery usage (kinda...) by using "surplus power" -- when the battery is being charged -- to run the compressor harder to freeze a cold ballast -- a container of freezable liquid.

So, technically, it's not more efficient -- i.e., it doesn't use less power for the same result, it just has a way to put aside a reserve of "cold" when there's power to spare.

 

BUT: it may not really be power to spare: if the ASU is putting some of that "surplus power" into the fridge when the battery is being charged then the battery is being charged more slowly.  But the principle is still sound if "at the end of the day" you can still get the battery topped up despite the drain of charging power by the ASU.

 

I have the Isotherm Cruise 130 -- with ASU.

[kmacafee]

Love my National Luna Weekender.  Freezer is great and there is plenty of room for 2 people's food and drink.

http://www.equipt1.c...stainless-steel

 

I am trying to figure out how to make it work in my new (to me) Eagle Camper.

 

Cheers

[pods8]

MarkBC, interesting on the ASU, is there an option to bypass it if needed?

[MarkBC]

MarkBC, interesting on the ASU, is there an option to bypass it if needed?

 

pods8:  Note that my CR 130 is of mid-2011 vintage, and I don't know how later/current models are different, but I think they are.

 

I also should clarify what I said in the post above:  The ASU doesn't make the compressor run extra fast when there's surplus power, it just runs at full speed.  It's special ability is that it runs the compressor slower when pulling from a battery that isn't being charged. (like, maybe when it senses that the battery voltage is less than 13 volts..??...something like that).

 

Anyway...my 2011 model CR 130:

There is a 3-way toggle switch that, besides "Off", can select "Normal.Auto" -- meaning with ASU engaged, or "Man.Temp", meaning ASU is not working.  Here's how the manual that came with mine describes it:

 

2.2 Temperature setting ASU

The Isotherm refrigerators with ASU can be operated

in two ways. When energy saving is needed, switch to

”NORMAL.AUTO” position.

Optimal refrigeration temperature is than automatically

maintained while consuming the lowest amount of

battery power possible. When there is no need of energy

saving, switch to “MAN.TEMP” position on the panel.

The automatic function is now partially blocked and

refrigeration temperature can be manually adjusted. In its

centre position, the unit is switched off....

 

The thing is, when in "Normal Auto" -- with the ASU in control -- you can't set the temperature:  ASU knows best, apparently.  It's only when in Manual Temp mode (thus, the name) that turning the temperature setpoint dial does anything.

 

Speaking of the manual temperature control:  Unlike some other brands of compressor fridge that have a digital temperature setting, one that allows you to enter/select a specific numerical-temperature setpoint (e.g., 36°F), this CR130 with ASU doesn't have anything that sophisticated.  All it has is a little knob with a symbolic image wrapped around it, like this:

  (imagine it curved, which I can't draw easily)

 

Here's the full manual if you/anyone is really interested in reading more about operation of this model, but again, I think current versions are at least somewhat different:

 Isotherm_Cruise_42_130_Manual.pdf   1.4MB   126 downloads

[craig333]

Was probably referring to the smart controller upgrade.

http://www.defender....6232&id=2407016

[MarkBC]

Was probably referring to the smart controller upgrade.

http://www.defender....6232&id=2407016

 

I see... The description of this includes what my ASU does, but with other features/qualities added.  I see the last line in the "how it works is" sounds like the 2011 ASU: 

• The cooling energy is stored when a power surplus is available (engine on or connection to grid) and reused first, before the fridge runs on battery

It's a great installation video.  (even with the cheesy techno-pop soundtrack.  And apparently the installation is easy enough that you can do it even with a French manicure.  )

[norcalhusky]

Was probably referring to the smart controller upgrade.

http://www.defender....6232&id=2407016

Yep I was referring to that particular upgrade. Kind of looks like a pain to install...

 

I think I like the design of the Waeco/Dometic CR-1065 the best so far.. Does anyone know if it has something like a digital temperature adjustment or just a knob with some random numbers on it? It doesn't seem to indicate what sort of controls it has on the product brochure that I have found.

 

Though the price on the Engel seems nice too. Can almost buy a Fantastic fan with the difference (at least with Amazon pricing)...

[craig333]

It wasn't a bad install at all. I posted my install of it here somewhere. Its not cheap though.