Isotherm Cruise 195 AC/DC Refer

Time to ditch the old Norcold DE728. It only lasted 35 years damn it! I'm looking at an Isotherm Cruise 195. Anybody got experience with this model, or with Isotherm in general in terms of their reliability, customer service, etc.? I'm not 100% sold on an AC/DC replacement and am still researching a household AC unit. So you guys who fall on that side of the fence, any make/model recommendations you'd care to offer would be greatly appreciated (yes, I have researched at previous threads along this line). Thanks!

We have an Isotherm Cruise 130 fridge only - no icebox. It's nine years old, works perfectly and is super efficient (uses the Danfoss BD35 compressor). Cannot recommend more highly.
The only issue has been the internal light switch which failed and kept the light going. The bulb is close to the thermostat and the heat kept the fridge running so that it froze everything. I took the bulb out, being too lazy to replace the switch, and everything works fine again. But it's nice to know I can convert it back to a freezer by reinstalling the lightbulb!!

I had an Isotherm in the old boat with the Danfoss 135. Ran perfectly for the 11 years we had it. It was 12 volt only.

Rob

Datenight said:

I had an Isotherm in the old boat with the Danfoss 135. Ran perfectly for the 11 years we had it. It was 12 volt only.

Rob

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My fridge has a remote Danfoss compressor in the ER. I have ASSumed to this point it was 110 vac only. Do you or anyone else know if they are commonly one or the other or could some of them both AC and DC? Never have thought to check until this post caught my eye.

Craig,

Isotherm gave me the option of 12 volt only or AC/DC. I went with the DC (remote compressor) only for simplicity as that is what the compressor was designed to run on. I think I read on a former thread that 110 operation inverted 12 volt DC to wierd voltage AC in the fridge circutry in the Norcolds. Don't know how Isotherm does it. That is my recolection. I'm sure I will be corrected if not.

Does your freezer have a Danfoss 135?

Rob

p.s. I also replaced a Nevercold.

Datenight said:

Does your freezer have a Danfoss 135?

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Frankly beyond knowing it is a Danfoss I have not a clue. You can bet I'll be checking at my next boat visit though. Thanks for the info

Sorry for the thread hijack Captain K

Craig, you should have a dedicated breaker for your refrigerator either on the DC or AC panel (maybe both). If you do it should give you a clue.

Bay Pelican has both the Isotherm 130 - Drink (Refrigerator only) and the Cruise 90 Freezer. Both are AC/DC. I find the AC very useful when I am in the yard and also when the generator is running. In both cases the two units are not drawing their usual 3 to 9 amps DC.

Very satisfied with the units. The Freezers top shelf will not freeze. We use it for bread storage. Also love the flap over each of the shelves in the freezer which reduce the loss of cooling when the door is open.

Suggest that unless you rarely use the generator or shore power that you get the AC / DC.

Marty Campanella
Bay Pelican KK42

Aquabelle has an Isotherm as one of two galley fridges. The automatic AC/DC changeover unit failed after 5 years, apparently not uncommon. Expensive to replace and not needed if you have a modern inverter/charger anyway. Key thing with the Danfoss compressors is to keep the voltage up them...heavy cabling with short runs important. The other fridge is an AC domestic....I would go all AC domestic if space permitted, but the Isotherm's size worked for the space available

Aquabelle said:

...I would go all AC domestic if space permitted, but the Isotherm's size worked for the space available

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I feel the same way although I've experienced some slings and arrows as to the capacity of my frig.

Bay Pelican removed two ac domestic units to install the isotherm units. The AC domestics were taking almost 400 amp hrs (12 volt) per day to operate.
The Isotherms take a fraction of that.

We are generally at anchor 24/7.

Marty

Marty: I'd say that was an unusual result. The big difference between domestic AC and marine DC fridges is usually cycle time (due to superior insulation of the domestic gear). Cycle time on Isotherms is usually 50%; on modern domestic, 25%. So even if the amp-draw of the AC domestic is somewhat higher when cycling on, this is usually more than offset by the reduced cycle time.Then again, poor ventilation around the compressor can completely screw up the cycle times & therefore the total current draw of either type. (Of course the other big difference is cost: the production volumes of the AC domestics are huge so they are often less than 1/2 the cost of a marine DC model)

.:Cycle time on Isotherms is usually 50%; on modern domestic, 25%. So even if the amp-draw of the AC domestic is somewhat higher when cycling on, this is usually more than offset by the reduced cycle time.:

The hassle with most domestic units is the insulation and door seal gaskets are heated at times. This is not accounted for in the sellers literature.

The cycle time of a modern 12v unit is of almost no consequence as the DC unit has a brain that runs the compressor slower (more efficiently) as the cooling demands.

The reefer MFG would love to allow the fridge to be on 24/7 for lowest daily amperage draw , but it would panic too many owners.

++++
What is efficient to produce simply requires a full assembly line, not millions of sales.

A mfg like Dometic constructs 600-900 reefers a day , with efficiency.

The DC parts like a Danfoss setup and superior insulation add to DC reefer coats.

Domestic versus marine refrigeration

While I understand cycle time and production issues I am mostly concerned with amperage draws over a 24 hour period. When on DC my two Isotherms never draw more than 9 amps and frequently draw 3 amps. For the sake of discussion lets say that the draw is 9 amps for 24 hours or 216 amps per day.

On AC using a Kilowatt meter over a 24 hour period the two units draw (when converted to DC, less than 150 amps per day.

My two SubZero units drew over 400 amps per day.

I attribute the difference to the insulation in Isotherm units, and the more efficient Danfoss compressors.

I am aware of the maintenance issue with regard to the controller on the Danfoss compressors (a $300 item on line), but then 200 amps per day savings clearly makes up for this in generator run time.

The SubZero units were from 1999 and the constant 80+ degree temperatures in the Caribbean may affect the results.

Marty Campanella

Bay Pelican said:

While I understand cycle time and production issues I am mostly concerned with amperage draws over a 24 hour period. When on DC my two Isotherms never draw more than 9 amps and frequently draw 3 amps. For the sake of discussion lets say that the draw is 9 amps for 24 hours or 216 amps per day.

On AC using a Kilowatt meter over a 24 hour period the two units draw (when converted to DC, less than 150 amps per day.

My two SubZero units drew over 400 amps per day.

I attribute the difference to the insulation in Isotherm units, and the more efficient Danfoss compressors.

I am aware of the maintenance issue with regard to the controller on the Danfoss compressors (a $300 item on line), but then 200 amps per day savings clearly makes up for this in generator run time.

The SubZero units were from 1999 and the constant 80+ degree temperatures in the Caribbean may affect the results.

Marty Campanella

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During our cruising for the last month, I am finally getting a good handle on our power consumption and needs. Like Bay Pelican had, Dauntless has 1988 Subzero fridge and freezer. They consume about 17 amps per hour and the Inverter is using about 3 amps, so 20 amps x 24 hours is = 480 amp hours which is 50% of my total capacity. This boat was originally set up to live at the marina, the power consumption was not a problem, but now, in the past month, I have been having to go to a marina every 3-4 days just to fully charge my batteries over time.

So, now that I better understand what’s going on, I am thinking that my short term goal (this fall) will be to replace fridge and freezer with 12V system and make boat so that I can turn off inverter when anchored, unless I’m watching TV, Otherwise, just run inverter when running engine. Now, I am using gen more, but we seldom anchor in the same spot more than two nights, so when running my alternator is putting about 30 amps back into batteries every hour.
Thoughts, comments.

Richard

Richard

Assuming you have more than a 3 kw generator there is another approach which I used for years to reduce generator run time. I installed a second inverter/charger so that when the generator was on I was pumping 235 amps into the battery bank per hour. My bank is greater than 1000 amps so this rate of charge is OK for the size of the bank. This requires a battery switch, either manual or remote, which can split the bank into two banks so that each charger is charging one bank otherwise the chargers sense each other and reduce the rate of charge.

A second charger also increases the load on the generator which is beneficial as most cruisers under load their generators.

Marty

<so when running my alternator is putting about 30 amps back into batteries every hour.>

Sounds like a better marine style alt V regulator would be a great help.

Best would be a 130 ,150 Amp alt with marine 3 or 4 style V regulator.