Refrigerator/Freezer Replacement on GB 42

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JESSEDIVER49

Senior Member
Joined
May 2, 2013
Messages
187
Location
USA
Vessel Name
Good Vibrations
Vessel Make
Grand Banks Classic 42
I have a 30+ yr old GB 42 with a Grunert holdover plate-type refrigeration system, 110v AC air cooled w/404A refrigerant and two boxes, 24" wide by 30" high, one for refrigerator and other for freezer. Besides its age, the 2 problems are refrigerant very slow leak (last charge lasted 3 years) and control system for on/off does not work properly, it runs continuously 24/7. I thought about solving 2nd prob by putting a timer on the power supply but haven't done that yet. My thinking now is to replace the unit but is there a reasonable solution that will work for the two 24"x30" openings I have?
 
24” is standard width for a domestic unit. I bet you can find a separate freezer and a fridge that can fit. If a modern unit (as opposed to a typical dorm unit) then you might cut your power consumption drastically
 
As a veteran of several "marine" refrigeration replacments, I'd suggest thinking outside the box. Literally. Modifying cabinetry to accept a standard size piece of equipment is a one time operation. It doesn't require maintenance once it's done, and the cost relative to replacing that specialized "marine" refrigeration system multiple times is low.

After having replaced 3 marine 12V fridges in 10 yrs at a cost of nearly $6K, there's a strong case can be made for an apartment fridge that can be purchased at nearly any appliance source that handles domestic fridges.

You'll need to consider how you intend to cruise, domestic equipment will likely use more power than a marine 12VDC unit, but that marine unit may not do as well at the job of keeping stuff cold.

Pay premium prices for "marine" fridge that requires monthly defrosting, won't keep ice cream hard, provides stinky milk in a few days and slimy deli meat in a week. Or get a domestic frost-free that keeps frozen stuff frozen, maintains a box temp of <38F, and won't wilt your lettuce- and run it on your inverter, or fit a dedicated inverter for the fridge. Replacement cost probably <$600 vs up to $3K for "marine". So cabinetry maybe isn't that expensive in the big picture.

Now, all that cynicism aside, you could also opt for conversion of the existing boxes to evaporator plate operation, and oversize the system a bit. I did that for my holding plate freezer, but rebuilt the box with vacuum panel insulation, a big job, but it works. The biggest consideration is if the existing boxes are adequately insulated, and the insulation is intact- read: DRY. Old freezers have a tendency to develop air ingress into the insulation where the moisture condenses or freezes in the insulation, rendering it wet & non-insulating.

The guiding factor is how you're going to use the boat, and what works best for that use.
 
Sea Frost - Very Happy

We replaced the Grunert system in our 1990 GB 46 in 2012 with three separate systems from Sea Frost, 2 refrigerators and 1 freezer. One of the best upgrades we've done on Avalon and we've done many upgrades. The 3 compressors take up less than half the space the Grunert compressor did.

We installed with the digital controls and the units have operated flawlessly over the last 7 seasons. Being 12v dc makes them extremely efficient and very quiet. In addition if you have questions on installation or operation you can call Sea Frost and speak directly with the owner Cleeve. He was so helpful in designing our system and like I said they've operated flawlessly-very happy,

Since we located the compressors in the engine room we opted for the water cooled units and the March pump is super efficient and near silent.

Tim
 
As Maerin described, it might make sense to use your existing boxes and convert them to 12VDC with external compressors, if the boxes are in good shape and have adequate insulation. I just converted a 12 cubic ft Kenmore AC household power hog to 12 volts, the work being done by Sea Freeze in Bellingham. It gets just as cold as the AC version and I'm happy with the result.
 
Thanks all for the advice. BTW - my Gruenert system has a common 110v compressor/condenser unit in the engine room with the evaporators in each box. The freezer box and refrig box have separate controllers but as I mentioned, the system runs 24/7 due to a fault in the controls.
 
I just converted a 12 cubic ft Kenmore AC household power hog to 12 volts, the work being done by Sea Freeze in Bellingham. It gets just as cold as the AC version and I'm happy with the result.

Ken,

What was involved in the conversion? I'd imagine the compressor, interior light and controls. Can you give some details?

Thanks,

Rob
 
I have a 30+ yr old GB 42 with a Grunert holdover plate-type refrigeration system, 110v AC air cooled w/404A refrigerant and two boxes, 24" wide by 30" high, one for refrigerator and other for freezer. Besides its age, the 2 problems are refrigerant very slow leak (last charge lasted 3 years) and control system for on/off does not work properly, it runs continuously 24/7. I thought about solving 2nd prob by putting a timer on the power supply but haven't done that yet. My thinking now is to replace the unit but is there a reasonable solution that will work for the two 24"x30" openings I have?

30+ years on the original cold plate? ZOWNS
A home refrigerator wont last that long.
With the tech improvements with efficiency you should give serious consideration to total replacement.
Next, do you want 12vt or 120vt. 120vt can have an auto defrost. The 12vt, can live on batteries (if you have enough batteries) but requires manual defrosting. Each has certain advantages and disadvantages. 120vt needs either a really good maybe dedicated inverter and lots of batteries or running the gen for the 120vt necessary. The 12 vt cold plate freezer on my N46 had a timer.

My current AT has 12vt fridge and separate freezer, (NovaKool) supported by the 3x200amp house battery bank. There is a gadget called Stainless Lobster that is supposed to reduce the running time of the compressor and also, force a defrost cycle by shutting off the compressor based upon the manually setting.
I think I have space for another layer of foam insulation to the box. On the AT, the microwave cabinet sits on top of the fridge so, I will have to drill two 3 inch holes on the microwave shelf, a couple of 3 inch flex vent piping from the back of fridge to a collector box and vent the heat out behind the back of the microwave cabinet, with a small box fan in the vent hose. Yes, I enlarged the air inlet to the fridge cabinet too.
Yes, first thing I did was change out the door gaskets.
The fridge should be defrosted every week or two and the freezer once every couple of months. This leads me to believe the ice build up is a result of normal every day activity interacting with the fridge.

Tuesday, I have a tech coming out to verify the freon charge. We shall see how everything pans out after venting the back of the cabinet and installing the Stainless Lobster controls.
I shall try and remember to post an update here.
 
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Jessediver49,Doesn`t it depend where the slow leak is? If it`s in the compressor unit you can replace that,and it should come with controls. If it`s elsewhere, in the boxes or cold plate tanks, replacing the whole system may be the right option.
Once you do it and revert to 12v fridge and freezer, your refrigeration loads are on the batts instead of off them. They are major power users, which may require more battery capacity, or very good management, even some solar.
 
Ken,

What was involved in the conversion? I'd imagine the compressor, interior light and controls. Can you give some details?

Everything AC was removed from the box, replaced by a DC compressor and evaporator, plus a DC light, fan, thermostat and defroster. The Sea Freeze website has lots of specifics and details on conversions like this.
 
We replaced the holding plate system win our '91 GB with 2 Sea frost systems, one for frig and 1 for freezer. Utilized existing boxes. Worked for the 10 years we had the boat, freezer made ice and kept ice cream hard. We could turn the temp up on it and make it a 2nd frig if needed. We opted to air cool the system , drew air from the forward hanging locker with knowledge that if it didn't work we could water cool it later. Didn't need to. Vey efficientB
My only complaint was not with the system but with the style of the boxes, one must approach in a "prayerful manner", on your knees. If I did it again I would explore a drawer system using existing openings.
 
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Eutetic systems are great , but rely on the insulation to function.

To test the system empty one box , install a big hunk (30-40lb) of ice give the box a day to normalize , then weigh the ice block.

Wait at least 48 hours and reweigh the block of ice.

If you lost 5 lbs of ice per day the insulation is OK and you could simply repair the existing system .

A refrigerant leak is findable and better controls are OTS.


5lbs a day is ice melt also the cut off for DC refrigeration , removing the eutetic plates will make the reefer interior much larger and cost no efficiency .
 
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The OP`s compressor unit is air cooled. Water cooled is better, many a compressor sits in a hot ER and is starved of cool air for heat exchange. Took me a while to realize my ER exhaust fan sits over my air cooled compressor unit. Intentional or just good fortune,running the exhaust fan while running the fridge/freezer compressor pulls temps down way quicker,so much less genset run time. The fan pulls amps, I run the battery charger so the batts keep up.
 
Everything AC was removed from the box, replaced by a DC compressor and evaporator, plus a DC light, fan, thermostat and defroster. The Sea Freeze website has lots of specifics and details on conversions like this.

Thanks Ken, I'll check it out.

Rob
 
AMAZING GRACE - Can you tell me who you used to do the conversion and roughly the cost? My boat is currently in the Chesapeake Bay north of you. At this point I'm considering Sea Frost conversion vs doing a bunch of cabinetry work and using 12v Apartment size refrigerators.
 
Really not difficult. the lines ran from forward in the ER, portside up to both units. The refrigerant lines basically followed the lines that lead from the old Groco units. Used black water hose (new not used) to guide tubing up above the port fuel tank. We cut 2 circular holes in the forward bulkhead into hanging locker and ran flex hose to them for fresh air cooling.The electrical was handled by a yard in Deltaville. Subsequent experience with this yard prevents me from recommending them.
 
After review of threads sent and talking to a marine refrigeration installer, I'm leaning toward replacing my old greunert system and boxes with a 12 volt 22"x30" marine refrigerator and similar size marine freezer. Mainly an economics decision. It appears the total installed cost difference is $10-11K versus about $4K or less. I'm looking on the Defender site at Isotherm, Dometic and Norcold. Does anyone have experience with these brands that can tell me which have the best reliability and lifespan?
 
In # 16 above Should read Grunert not Groco units
 
I have a 30+ yr old GB 42 with a Grunert holdover plate-type refrigeration system, 110v AC air cooled w/404A refrigerant and two boxes, 24" wide by 30" high, one for refrigerator and other for freezer. Besides its age, the 2 problems are refrigerant very slow leak (last charge lasted 3 years) and control system for on/off does not work properly, it runs continuously 24/7. I thought about solving 2nd prob by putting a timer on the power supply but haven't done that yet. My thinking now is to replace the unit but is there a reasonable solution that will work for the two 24"x30" openings I have?

JesseDiver, the leak can be located and repaired. That is assuming the coils are not plastic. Plastic may be more difficult to repair.
Finding a working control may be elusive.
Replacing the 2 units ..... I'm not sure they make the units anymore and therefore may require cabinet work....
 
re; Cost to replace with 12v apt size refrigerator & freezer. The marine quality types of small refrigerators and freezers, not Home Depot-type, run about $1200 each. And there will be electrical and cabinetry work involved. so, I rounded up to "less than $4k". If I have time to do say removal work, 12v electrical feed, any new installation supports needed and just leave cabinetry work for a craftsman, my cost will be less than $3k.
 
The Krogen we recently purchased has what I think might be the original (early 80's) AC side-by-side fridge and freezer. We are looking at a similar upgrade, probably to a DC unit.
I was at the Seattle Boat Show last weekend and spoke with several vendors that I know personally so I somewhat trust their input. For an air-cooled DC unit, it sounds like brand is not really that important. The compressors and insulation are all comparable among the major names, so it is more aesthetics and physical size. We have a DC chest freezer on the back deck so I think we are going to replace the fridge in the galley and convert the freezer space in the galley to a cabinet with shelves for storage. Our chest freezer is an Isotherm model with a smart controller and it works very well, so we may go with Isotherm even though they are more expensive. I also asked several vendors about the stainless lobster add-on, and was told that without the smart controller it could be a worthwhile purchase for a boat that spends a lot of time away from the dock.
The one thing everyone was in agreement about is that there is no reason to go with an AC/DC model for several hundred dollars more. Any reasonable battery charger will make that option unnecessary.
There are enough size options so we shouldn't have to do any cabinetry work, and I can easily do the wiring myself. I looked at smaller AC household units and am tempted by the pricing, but I am trying to remove as much of the AC equipment on the boat as I can, so will most likely go DC.
 
Refrigerator/Freezer replacement

Thanks for that info. Very helpful.
 
We replaced our original refrigerator on our 1997 Mainship three years ago with a Isotherm unit, and only wish we had done it sooner. Separate compressors for the frig/freezer, and everything stays cold. Milk lasts well passed expiration date, and my ice cream is rock hard.
The compressors are actually DC, so I operate mine from the DC panel. Current draw seems very low, although I have no specifics.
 
I second using Seafrost. 12v, common efficient water pump, very efficient, no cabinetry modification.
 
I always get AC/DC. I was in the Bahamas once and had a house battery issue and was glad I had AC too. I just bought two Isotherms and one dometic freezer. Am adding auxillary fans on the two Isotherms in addition to the fans on them. I want all the hot air out of the cabinet!
 
Also ad insulation on the sides and top if there is a gap in the cabinet
 
I recommend Coleman 120 quart coastal xtreme, I think the Coleman 120 Quart is best product with me. This cooler got more space and guaranteed to keep your fish, food and other chilled items for approximately 6 days even if the temperature is 90F. And one thing I like of this cooler is the drain plug wherein it allows the user to drain melted ice easily.
 
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