Marine refrigeration recommendations

[JESSEDIVER49]

I have a '84 Grand Banks (just bought 18 mos ago) with an old, cold plate-type refrigeration system with water cooled condenser. The Ice box and refrigerator run off the common compressor/condenser skid. Recently had refrigerant re-charge and a temp switch on ice box changed out. The unit runs 24-7 without shutting off which tells me either refrigerant slow leak or controls system still not right even though refrig guy says the new switch put control system back in order. I'm now thinking any further work is just throwing good money away and I should bite the bullet and get a new refrigeration system. I'm looking for recommendations from experienced cruisers. What refrigeration system would go well in this 30 yr old Grand Banks?

 

[Andy G]

Yes, I was in the same position about a year ago.

My system is similar to yours in that it is a Eutectic system with a series of plates, run by a raw water cooled condenser. Originally the compressor was driven via the engines ,however my PO replaced that with a 240 volt system(yours of course is 120 volt) which runs off shore power and the Genny when on the hook.

There are obviously pro's and con's with the eutectic system, and most modern boats don't go down this route anymore.The big plus for your system is that it will bring down temp very quickly( a big minus is it will freeze anything that is stacked up against the plates).

Eutectics can be temperamental and it sounds like your system is cycling on and off, which if you have replaced the regulator usually means you have a leak. It is pretty easy for your refrideration guy to confim this , however sometimes tracing the leak can be a little tricky.

One of those tricky areas is where the copper pipe comes up through the ER bulkhead in to your cabinets.This is a common area where the copper pipe fails and is hard to detect.This happened to me and it took a fair bit of time to find the problem.

Luckily I had a good eutectic mechanic and he sorted the whole thing out by replacing the complete 30 year old copper pipe run, which is not that expensive, and once that was done it solved my gas leakage issues.

I costed replacing my fridge and cabinet freezer with the newer 12 volt electrical units, however after allowing modifications to the cabinets etc, it was cheaper to stay with my existing system and have it overhauled.Mind you my condenser and compressor were both in very good condition, that is something you may need to factor in.

If I had a no cost choice of which system to use I think I would go with the newer 12volt units and extra batteries, but it certainly would not make my fridge/freezer any colder.

All in all I am pretty happy with my decision(touch wood)

Hope that helps.

 

[Peter B]

My eutectic system died not that long after I bought the boat, so in the end, as the system was very old and would have needed virtually everything replaced, the tanks being the only parts that were ok, I did a 12v conversion. The inside frig and the cockpit chest type enclosures were well-insulated, so I kept those and did a 12v conversion myself with a kit provided by Waeco. It was not that hard, retained the original compartments, and works well, and the Danfoss compressor in the frig unit (installed in a cabinet next to it), is very efficient and light on power drain.
The cockpit chest was seldom needed unless on an extended cruise, so if needed we just place large ice-filled bags in the bottom, under the racks, and it performs well as an ice-chest. The lid also acts as a half-way landing on the way up to the flybridge, and but for that useful function, I think we would have just ripped it out, and added the space to the cockpit, as the frig inside holds so much anyway.

 

[bnoft]

refrigeration

We have a '91 GB and when purchased 7 years ago the Grunert holding plates didn't wok, the compressor wasn't even on the boat. After an extensive search, which in hindsight I wish had gone a little further (more on this in a minute) I removed everything except the refer and freezer box (have one of each) and replaced with Sea Frost systems. The compressors are located in the ER just aft of the forward bulkhead on the port side. The units are cooled by air drawn from vents leading into the forward hanging locker. These units can also cool with a strainer and raw water intake but I don't like holes in the bottom of the boat. The air cooled system has performed very well; the freezer makes ice and will keep ice cream solid. Running the lines from the ER was easy and the DC draw is minimal.
Now for the hindsight; my only complaint lies with the basic design of GB refrigeration. One must approach the refrigerator or freezer in a "prayerful" manner, on your knees, as these boxes are floor mounted under counter style. Our son, a yacht broker, told me after the fact that we could (should?) have considered drawer units which would permit walk up as opposed to crawling access.
I highly recommend Sea Frost refrigeration but encourage you to investigate drawer units. The later will be more costly especially if you want to maintain teak doors.

 

[FF]

What do you want to save is the question?

With eutetic ,saving frozen brine is a great solution IF you have the ability to refreeze the setup in your normal engine /noisemaker run time.

A lack of operational understanding is the death of most eutetic installs.

Saving DC electric and using an efficient DC compressor also is OK but best if a custom well insulated box is created so the losses are smaller.

An RV or house fridge can be DC powered , but are usually big energy hogs as the insulation is thin for marketing purposes .

Sun Frost is one exception.

To me the service , anchor out 90% of the time , or dockside 90% of the time would be the decision maker.

WE of course avoid all the hassle with a nice big RV propane unit.

Ice cream , great volume and a 20# bottle goes almost a month in FL.

 

[Skinny]

I love my portable chest fridge/freezer. It has two units which can be seperately controlled. It runs on both 12v and 120v. When AC power is on, it takes that. If power goes off (unplug shore or genset is off), the unit reverts to DC. Pretty quiet operation, comes down quickly in temp, and runs less than $800. Not to mention its portable!


Sure it may not look at home on a Grand Banks or with a Teak interior so may not work in your application.

 

[dwhatty]

Now for the hindsight; my only complaint lies with the basic design of GB refrigeration. One must approach the refrigerator or freezer in a "prayerful" manner, on your knees, as these boxes are floor mounted under counter style. Our son, a yacht broker, told me after the fact that we could (should?) have considered drawer units which would permit walk up as opposed to crawling access.
I highly recommend Sea Frost refrigeration but encourage you to investigate drawer units. The later will be more costly especially if you want to maintain teak doors.

Retrofitted a Sea Frost into our previous boat's ice box. Easy install. I put the compressor in a rarely used corner inside and under a settee about six feet from the ice box. Worked well but did use a fair amount of battery, partially due to the ice box not being well insulated and front opening.

Two years ago we took the Nevercold front opening fridge out of our present boat and installed a Vitrifigo two drawer unit. We like it a lot. No more "prayer position", good looking, very quiet, greater holding capacity (especially in the freezer section) in the same footprint and it uses a lot less battery. And, since we also installed two 240 watt solar panels, we can now leave the fridge on 24/7 without having to worry about running the batteries down (we keep the boat on a mooring so don't have shore power).

 

[siestakey]

I love my portable chest fridge/freezer. It has two units which can be seperately controlled. It runs on both 12v and 120v. When AC power is on, it takes that. If power goes off (unplug shore or genset is off), the unit reverts to DC. Pretty quiet operation, comes down quickly in temp, and runs less than $800. Not to mention its portable!


Sure it may not look at home on a Grand Banks or with a Teak interior so may not work in your application.

these things are great we have 2 fridge freezers but we have a spot below the galley floor for one of these ours is not nearly this nice I would love to replace ours with a newer one like yours

 

[obthomas]

In my opinion marine refrigeration type and style should be dependent on how the boat is powered most of the time. Holding plate refrigeration has one strength; that is to stay cold for periods of time without power, and then to recover in a short time when power is available again. If you use a boat like me that is mostly on shore power or underway, holding plates do not make much sense. What makes more sense to me is an AC/DC refrigerator/freezer. Of course when I do anchor out for a night or two I have to run the generator often. In summary I would not consider holding plates unless I anchored out a lot more than I do.

 

[Carolena]

If you plan to keep the current box, I will echo the suggestion to check out Sea Frost. We converted the ice box on our sailboat to a refer with a Sea Frost system. It is a family owned company and they have both great products and service. We worked with the owner to figure out the best system for our boat and, unlike some of the fits all fits none conversation units, Sea Frost worked with us to get the correct lenght cooper runs between the plate and the compressor for a nice, custom fit. We also spent the money for the variable speed compressor control. It allows you to dial up the compressor speed when you have excess power (shore, genny or alternator) and are filling the refer with warm stuff, then turn it down to use less power once you are on the hook and everything is cold. I also liked that it gave me a remote temp readout for both the box and the plate. Great company from our experience.

 

[Alaskan Sea-Duction]

I plan to buy a new frig this January at the Seattle Boat show. I currently have an old Norcold that draws 12amps. I reserached all the differant manufactures and we have decided to go with Isotherm becuase of thier low amp draw. I will have to modify the cabinet it is going into, but it helps to have a cartenter and cabinet maker as friends....

 

[BruceK]

I have a eutectic system, a fridge about 1/2 the size of a home one, and a separate freezer. Once cold, they maintain easily (genset) when cruising. Had to replace the whole compressor unit not long after buying the boat. I suggested to the service guy adding an engine driven compressor, he said no they give trouble, and the experience of 2 unhappy friends using one supports him.
We have an OEM built in 12v Danfoss powered under settee fridge, 34 yrs old, and still good. And "belt & braces"I carry a 12v/240v Waeco too. I take frozen stuff to the boat in it, run it in the car on route, so I may as well have it for back up cruising. Failed fridges can mess up a cruise.

 

[Insequent]

All up I have 5 refers on board. I measured the 'steady state' Ah use for 24 hours for the units, and the results are noted below. By steady state I mean stuff inside already cold (or frozen) and unit opened a few times during the 24 hour period.

When I discovered that the Norcold barfridge (DE-400C) was using 156 Ah per 24 hours I removed it and replaced it with an old 40 litre Engel (bought 1980, still operating perfectly) that holds almost as much and used a fraction of the power even though it is nowhere near as efficient as the newer Engels.

24 hour steady state Ah draw:
Norcold DE-0061R galley unit: 80 Ah (12V operation)
Uline icemaker BI-48: 93 Ah
Engel MRFT40: 55Ah for 0.5ºC hold, 101 Ah for -3.8ºC hold

I have 2 x Waeco CF110 units as well. I have misplaced their steady state draw, but from off (ambient 30ºC) pulled down and held to -5ºC the 24 hour draw was 250 Ah. I need to re-do their steady state performance - IIRC it was pretty good.

 

[windmist]

For your information, Sea Freeze in Bellingham, WA will custom build a unit to fit in your available space.


www.seafreezeinc.com

 

[JESSEDIVER49]

Thanks for all the refrig intelligence!!


Good Vibrations, Galveston, TX

 

[janice142]

If you plan to keep the current box, I will echo the suggestion to check out Sea Frost.

(snip)

I also liked that it gave me a remote temp readout for both the box and the plate. Great company from our experience.

Aboard Seaweed I bought a Weather station (brand Ambient, from Amazon for about $25) that came with and "outside" monitor gizmo. I put that inside my reefer and can tell the temperature and humidity at a glance.

Specifically, you'd want that brand as the cheap one sold in Walmart was not visible except if I was directly in front of it. Mine shows at most angles without issue. And the numbers are big enough for me to see without my glasses.

 

[Larry M]

For your information, Sea Freeze in Bellingham, WA will custom build a unit to fit in your available space.


www.seafreezeinc.com

Replaced 2 Sub-zeros with one unit from Sea Freeze.

 

[Sanjv9473]

Marine Refrigeration

Refrigeration cycle is a cycle of mechanical system in which transmission of heat allow from one place at a lower temperature (the source ) to another place at a higher temperature ( the sink or heat sink ) by continuously circulating, evaporating, and condensing a fixed supply of refrigerant in a closed system.

Or, Refrigeration cycle is thermodynamic cycle to generate refrigerating effect with the use of evaporator, compressor, condenser & expansion valve.

Thus, a heat pump is called as a "heater" if the objective is to warm the heat sink (as when warming the inside of a home on a cold day), or a "refrigerator" or “cooler” if the objective is to cool the heat source (as in the normal operation of a freezer).

In both case, the operating principles are close.Heat is removed from a cold place to a warm place.

Note :- Refrigeration cycle is also called heat pump cycle.

Diagram of refrigeration cycle.

Vapour compression cycle

Vapour Compression Refrigeration Cycle is the most widely used refrigeration system.

Vapor-compression cycle refrigeration is a process that uses the physics of phase change heat transfer and the unique properties of a refrigerant to transfer heat from a relatively cold source to a hot medium.

Basic Refrigetion cycle

The basic components of any refrigeration system working on the vapour compression cycle,are the compressor,condenser, expansion valve and evaporator and the refrigerant fluid which is alternatively vaporized and liquefied during the refrigeration cycle.

The temperature at which a fluid boils or condeses,is known as the saturation temperature and it varies with temperature.

Basic components of refrigeration cycle

The 4 main Components of Refrigeration cycle

1.Compressor
2.Condenser
3.Expansion valve
4.Evaporator

Selection depend on size of ship , space and quality.