Which Reefer System to Choose

[Richard Kollmann]

Originally Posted by Cpt Mark

My Grunert was a 3/4 hp 120 volt AC system. I have a 4kw get set on board and am adding solar and maybe wind.

The original box is out and gone. Replacing the 25 year old 4"foam with at least 4" and maybe as much as 6" depending on box final size.

As I read the specs, it appears that either the Nova Kool or the Cool Blue will not use that many amps per day. 50? Am I wrong in how I interpret their literature?

Thank you

No one can estimate your planed refrigeration system daily amp-hrs because there are too many variables that affect power usage. A duel refrigerator freezer box on a 35 ft boat in warm weather will consume more than 50 amp-hrs per day. Ounce you determine final box size I suggest you do the math building in those variables by watching the slide show on my web site at link.
Kollmann Marine ]

You also need to decide which system will provide the best temperature control through out the box dual temperatures. Divided box eutectic plates or fast response inexpensive evaporators? If the box is now to be 6 cu ft or less one BD50 compressor will be adequate.

[Cpt Mark]

Originally Posted by sailcrazy

Following. Our smaller boxes (4.5cf refer+2.5cf freezer) both run off a 3/4hp AC single compressor with a solenoid switching valve, but we need to operate our genset 2x ea day to pull the boxes down. Consideration of the holding plates physical size vs evaporator plates is also a real factor in a smaller box configuration; the extra space the holding plates occupy really reduces useable food storage space.

Very similar system to what I had.

[Cpt Mark]

Originally Posted by Richard Kollmann

No one can estimate your planed refrigeration system daily amp-hrs because there are too many variables that affect power usage. A duel refrigerator freezer box on a 35 ft boat in warm weather will consume more than 50 amp-hrs per day. Ounce you determine final box size I suggest you do the math building in those variables by watching the slide show on my web site at link.
Kollmann Marine ]

You also need to decide which system will provide the best temperature control through out the box dual temperatures. Divided box eutectic plates or fast response inexpensive evaporators? If the box is now to be 6 cu ft or less one BD50 compressor will be adequate.

I'm going to watch your slide show tonight and calculate my final box size. Somewhere between 6-10 total I would think.

Thanks

[Richard Kollmann]

Originally Posted by Cpt Mark

I'm going to watch your slide show tonight and calculate my final box size. Somewhere between 6-10 total I would think.

Thanks

The worst case totals for tropical condition can then be adjusted to your actual planed cruising sea water and ambient air temperatures with the 2% per degree rule. Example 25 degree cooler water than my tropical figures will reduce daily amperage for refrigerator by 50 percent. Remember my tropical totals include warm weather ice making, liquid and food product moving in and out of converted refrigerator box. If you never travel south of Latatude 26N you will not normally experience the worst case continuous high temperatures.

Email me if you need help my services have always been free.

[Siberian Sea]

I went through the same thing three years ago when the original freezer system died. As I spend much or my time in the tropics I wanted something that would not require the use of a generator, could freeze fish, and simple the maintain. In the end I removed the existing system and bought a self contained Engel chest style refrigerator/freezer. I seem to recall it was just under 1,500 dollars shipped to the marina. Honestly I could not be more pleased. The freezer will go -5 F, it holds food great and uses very little power. I bought the largest chest style they made at the time. I believe it’s made in Germany and very good quality, runs silent and has a wireless temperature gauge so you always know at a glance the inside temp.

[Cpt Mark]

Originally Posted by Siberian Sea

I went through the same thing three years ago when the original freezer system died. As I spend much or my time in the tropics I wanted something that would not require the use of a generator, could freeze fish, and simple the maintain. In the end I removed the existing system and bought a self contained Engel chest style refrigerator/freezer. I seem to recall it was just under 1,500 dollars shipped to the marina. Honestly I could not be more pleased. The freezer will go -5 F, it holds food great and uses very little power. I bought the largest chest style they made at the time. I believe it’s made in Germany and very good quality, runs silent and has a wireless temperature gauge so you always know at a glance the inside temp.

Yes, I did that too with the Snomaster. What doesn't work for me is the usable interior volume even with a 95 quart model and the fact that for my installation it needs to stick up 4.5" for the latches to work above what precious little counter space I have. Snomasters have a 5 year warranty and a bit better seals which is why I chose one. Great product, just not for my application.

[stnick]

Yes re do the box insulation Use a holding plate make a divider spill over put the plate on the freezer wall. I went and drilled 3 3inch holes in my spill over eall one at the bottom one at the top. I have plugs to as stoppers when needed. With spill over i get 4 degrees warmer frig as freezer. I have a 1 inch fan in the refrigiator as a extra.
I like if battery low I can turn off the holding plate and at least 2 days im still cold.
When cruising i use dry ice in the bottom of each side and 20 pounds of ice cubes over top.
You will have cold for 13 days ! here in south fla in Summer water temp 92 air themp 100 !

[qwert]

Originally Posted by john61ct

To be honest in this niche, things are **so** competitive.

The sub-par got wiped out long ago.

Minor differences, slightly different factors.

Question is, which one picks up the phone 6am Vanuatu time on a Sunday and is happy to patiently step you through the troubleshooting process?

Doesn't charge for it?

What's that worth over the next ten years?

Well I did phone Ozepete at an odd time on a sunday and he was happy to step me through it .......and no he didn't charge for it

[Uncle Bob]

Originally Posted by qwert

Well I did phone Ozepete at an odd time on a sunday and he was happy to step me through it .......and no he didn't charge for it

Priceless, worth more than a few shekels at time of purchase.

[john61ct]

Originally Posted by Siberian Sea

bought a self contained Engel chest style refrigerator/freezer. I seem to recall it was just under 1,500 dollars shipped to the marina. Honestly I could not be more pleased. The freezer will go -5 F, it holds food great and uses very little power

And get two identical units, can use both or neither as freezers, change with conditions, as food runs lower etc.

[john61ct]

Originally Posted by qwert

Well I did phone Ozepete at an odd time on a sunday and he was happy to step me through it.......and no he didn't charge for it

Excellent!

Is he shipping out worldwide now?

[Maka]

Following here with interest.

[Richard Kollmann]

Originally Posted by Maka

Following here with interest.

I had hoped Cpt Mark would receive some better quantified suggestion and also surprised at the lack of responses from 40 to 60 ft sailboats more than 20 years old looking for down grading to smaller light weight 12 volt refrigeration units. These large pleasure sailboats at the end of the 1970’s were sold with large single or duel ice boxes. Crosby, Grunert, Fleming each developed large enough refrigeration suitable for large ice boxes by adapting available designs and parts from supermarket water cooled refrigeration units. Because of the limited hours a day when energy was available large compressors along with large eutectic ice storage tanks were installed. For a freezer one gallon of eutectic ice per cubic ft of box space could hold desired box temperature for 24 hours and refrigerator temperature boxes contained plates with ½ gallon of higher temperature melting eutectic ice per cubic ft of box space. There were various ways of driving these compressor, 12 volt belt driven motors, 110/220 volt AC compressors and belt driven compressors mounted on an engine. Grunert even sold a 90 volt belt driven unit with power supplied from a dedicated alternator mounted on engine.

It is easy to see why in 2019 there are so many boaters wanting replacement of these old refrigeration units in larger sailboats. In the 1980’s there was a high demand for these larger boats and large refrigeration do to their growing use in world wide chartering. It was estimated that 300 of these heavy sometimes called bullet proof refrigeration units were sold each year.

The dilemma facing anyone wanting to replace large icebox conversion units with today’s so called modern 12 volt Tecnical knowledge units faces three problems:
1. Old box insulation and lack of insulation R value.
2. Electrical power grids on older boats will not support the needed daily boats 12 volt needed daily power with the added refrigerator without running an engine alternator hours a day.
3. The small 12 volt compressors are over rated by creative sales marketing when any refrigerated box consumes over 100 amp-hrs per day. Complicating the energy problem on many of these boats is the fact that onboard generators on many of these boats were removed.

If you have gone through this change over to 12 volt refrigeration it would be of interest to others with large insulated boxes. So far this posted thread has covered three possible solutions. Use portable small refrigerator freezer 12 volt units, 12 volt compressors with eutectic cycling or maybe holdover plates. The third option to use two 12 volt icebox conversion units with many to chose from one in freezer and one in refrigerator both must have matching evaporator energy K value equal to compressor output.

[Coolerking]

I can't get too deep into specifics here, but our company has been producing cold plates and condensing units for boats of all sizes for more than 30 years, we (me) have recently retrofitted a few sailboats that had big, heavy, noisy belt driven eutectic plate systems, with a new style, 12/24vdc Masterflux driven units that we build, they are seawater cooled.

Most have solenoid panels to control multi zone systems.

Very quiet, variable capacity to fit a wide range of box configs.

They weigh less than half of what they replace.

[NakedCity]

Originally Posted by Richard Kollmann

I had hoped Cpt Mark would receive some better quantified suggestion and also surprised at the lack of responses from 40 to 60 ft sailboats more than 20 years old looking for down grading to smaller light weight 12 volt refrigeration units. These large pleasure sailboats at the end of the 1970’s were sold with large single or duel ice boxes. Crosby, Grunert, Fleming each developed large enough refrigeration suitable for large ice boxes by adapting available designs and parts from supermarket water cooled refrigeration units. Because of the limited hours a day when energy was available large compressors along with large eutectic ice storage tanks were installed. For a freezer one gallon of eutectic ice per cubic ft of box space could hold desired box temperature for 24 hours and refrigerator temperature boxes contained plates with ½ gallon of higher temperature melting eutectic ice per cubic ft of box space. There were various ways of driving these compressor, 12 volt belt driven motors, 110/220 volt AC compressors and belt driven compressors mounted on an engine. Grunert even sold a 90 volt belt driven unit with power supplied from a dedicated alternator mounted on engine.

It is easy to see why in 2019 there are so many boaters wanting replacement of these old refrigeration units in larger sailboats. In the 1980’s there was a high demand for these larger boats and large refrigeration do to their growing use in world wide chartering. It was estimated that 300 of these heavy sometimes called bullet proof refrigeration units were sold each year.

The dilemma facing anyone wanting to replace large icebox conversion units with today’s so called modern 12 volt Tecnical knowledge units faces three problems:
1. Old box insulation and lack of insulation R value.
2. Electrical power grids on older boats will not support the needed daily boats 12 volt needed daily power with the added refrigerator without running an engine alternator hours a day.
3. The small 12 volt compressors are over rated by creative sales marketing when any refrigerated box consumes over 100 amp-hrs per day. Complicating the energy problem on many of these boats is the fact that onboard generators on many of these boats were removed.

If you have gone through this change over to 12 volt refrigeration it would be of interest to others with large insulated boxes. So far this posted thread has covered three possible solutions. Use portable small refrigerator freezer 12 volt units, 12 volt compressors with eutectic cycling or maybe holdover plates. The third option to use two 12 volt icebox conversion units with many to chose from one in freezer and one in refrigerator both must have matching evaporator energy K value equal to compressor output.

OK Richard, here is my testimonial. I have not been sitting on the sidelines, I just saw this tread for the first time.

Our 1982 Freedom 40 was delivered new (TPI build) with 2 separate boxes, 5 cubic foot fridge and 3 cubic foot freezer. Installed during the build was a Grunert Holdover plate system with an automotive style belt driven compressor that could either be run from our Perkins 4108 or by a rather huge 120V electric motor. Wires, relays , switches, pumps & components everywhere ! Since we had no generator the 120V was only used at the dock. A very complicated system with lots of things that could go bad but it did a great job for it's first 32 years.
Our biggest mistake was not to take our first refrigeration tech's advice and remove the whole system and start over with new stuff when it started giving trouble in year 33. Instead we found someone who would repair our Grunert. To make a long story short over the next 2 years we wasted approx $1500 and ruined alot of food when 2 years in a row the system crapped out during our annual Bahamas cruise.
We removed all the Grunert stuff which opened up tremendous space in our engine room. We DID NOT remodel our 2 boxes although I'm sure the insulation has to suck after 34 years, all we were interested in was getting cold in time for our Bahamas trip.
The refrigeration tech who we liked recommended two 12v air cooled Vertifrigo BD50 driven units ( thin plate evaporators ) Vertfrigo only because thats who he had a good supplier relationship with but we also liked their very neat bulkhead mounted unit that worked out excellent for our install. That was 2 1/2 years ago and we love the system. I did upgrade our house batteries from 3 grp27 to 4 grp31. We already had a 135amp alternator. We also added a Smartguage battery monitor system. I can't tell you how many amp hours we use in this situation or that but our normal use of the boat which usually includes an hour or two of daily motoring restores our batteries. Sometimes if the batteries might be a little low at bedtime we simply turn the units off for the night. Also we now leave our fridge on all the time for the 10 months that the boat is mostly tied to a dock, always have cold beer on the boat.
I spent a total of around 6 months in 4 separate trips on a Beneteau in the Bahamas that had a Cool Blue holdover plate spillover system. The Cool Blue did a good job for us but overall I like the simplicity and the lesser expense of the 12v thin plate.The spillover was never perfect. Richard's idea of using the box evaporator is an excellent idea. If we did that we could get by using only one box when just doing weekend trips. Also the recommendation of a Nova Kool is probably worth listening to, I have their upright refrigerator 12v/120v in a trawler and I love it.