Name my fridge!

[john61ct]

Originally Posted by NorthernMac

Do you have a link to this system, does it do fridge and freezer?

It just "converts" mains AC to the DC current native to the compressor and electronics

Freezer vs fridge (or both in a combined spillover design) is a design, sizing and usage issue, no difference in the power side other than a lower temp setpoint consumes more power.

https://store.danfoss.com/us/en_US/C...ply/p/080Z0053

https://store.danfoss.com/en/compare...0053,080Z0055#

[NorthernMac]

Originally Posted by john61ct

It just "converts" mains AC to the DC current native to the compressor and electronics

Freezer vs fridge (or both in a combined spillover design) is a design, sizing and usage issue, no difference in the power side other than a lower temp setpoint consumes more power.

https://store.danfoss.com/us/en_US/C...ply/p/080Z0053

https://store.danfoss.com/en/compare...0053,080Z0055#

So would that be two compressors?

Also what’s the best way to size the plates and all

[Richard Kollmann]

We can debate battery charging voltage profiles, affects of excessive battery stress do over charging heat as well as how all storage battery life is limited, based on amp hour throughput. This boater’s question is about selection refrigeration not the expendable life of batteries.

The boater’s questions are simple:

1. Looking at the best option for a fridge and freezer?
2. Seems like option 1 is cut out ether the top to install a top load fridge, or loose my cabinets for a front load fridge/freezer?
3. option two would be a cold plate setup and cold plate freezer, both in the existing iceboxes with the compressor in the dead space underneath?
4. I’d like something efficient as this is one a 33’ cutter, she’ll spend a good amount of time in the marina but also decent stretches in pretty remote areas?
5. Cooking wise, I’m not exactly a huge cook, maybe freeze some fish I catch, fruit and a little veg and some drinks type thing?

Anyone experienced in refrigeration installations on sailboats in the 27 to 34 foot size boats know space for refrigeration is limited and the electrical 12 volt power grid will not support refrigeration without an expensive upgrade. Manufacturers of these boats do provide an ice box insulated to operate at 45 to 55 degrees F on standard day temperatures of 69 degrees. Typical DC electrical power grids for these boats are two group 27 batteries, a 30 amp or maybe a 60 amp simple alternator. Experience would indicate with minimum insulation having an R value of ten at normal refrigeration temperatures will require 10 amp-hrs per cubic foot per day in warm weather.

The refrigeration application engineer who has the answer to what is the best refrigerator needs better advice than he has got so far. Unfortunately the boat owner is the engineer this time.

I listed earlier in this thread my observations to the above questions with the suggestion when purchasing a new refrigeration system that might be used at the dock to pick up the AC DC optional 101N0500 12/24V DC & 100-240V AC 50/60 Hz control module. Instead of the standard 101N0210 module, the difference being around $35. I also recommend on Live aboard boats refrigeration redundancy is important which is another benefit of the portable Freezer/Refrigeration I recommended.

I must admit I am confused with the above post as you must be.

[john61ct]

Originally Posted by NorthernMac

So would that be two compressors?

Also what’s the best way to size the plates and all

If you're set on a holding plate system, contact Rich above.

Proper sizing of the components is part of the extra you pay for proper design custom for yoir context.

It is definitely true you will need lots more Ah per day energy inputs, especially if freezing's involved.

[NorthernMac]

Originally Posted by Richard Kollmann

We can debate battery charging voltage profiles, affects of excessive battery stress do over charging heat as well as how all storage battery life is limited, based on amp hour throughput. This boater’s question is about selection refrigeration not the expendable life of batteries.

The boater’s questions are simple:

1. Looking at the best option for a fridge and freezer?
2. Seems like option 1 is cut out ether the top to install a top load fridge, or loose my cabinets for a front load fridge/freezer?
3. option two would be a cold plate setup and cold plate freezer, both in the existing iceboxes with the compressor in the dead space underneath?
4. I’d like something efficient as this is one a 33’ cutter, she’ll spend a good amount of time in the marina but also decent stretches in pretty remote areas?
5. Cooking wise, I’m not exactly a huge cook, maybe freeze some fish I catch, fruit and a little veg and some drinks type thing?

Anyone experienced in refrigeration installations on sailboats in the 27 to 34 foot size boats know space for refrigeration is limited and the electrical 12 volt power grid will not support refrigeration without an expensive upgrade. Manufacturers of these boats do provide an ice box insulated to operate at 45 to 55 degrees F on standard day temperatures of 69 degrees. Typical DC electrical power grids for these boats are two group 27 batteries, a 30 amp or maybe a 60 amp simple alternator. Experience would indicate with minimum insulation having an R value of ten at normal refrigeration temperatures will require 10 amp-hrs per cubic foot per day in warm weather.

The refrigeration application engineer who has the answer to what is the best refrigerator needs better advice than he has got so far. Unfortunately the boat owner is the engineer this time.

I listed earlier in this thread my observations to the above questions with the suggestion when purchasing a new refrigeration system that might be used at the dock to pick up the AC DC optional 101N0500 12/24V DC & 100-240V AC 50/60 Hz control module. Instead of the standard 101N0210 module, the difference being around $35. I also recommend on Live aboard boats refrigeration redundancy is important which is another benefit of the portable Freezer/Refrigeration I recommended.

I must admit I am confused with the above post as you must be.

Apologies, what was confusing?

So what would I need to do to my electrical system to have this running properly, the boat isn’t a live aboard that’s living at the dock all the time and I need the system to work while cruising.
I really have no desire to have portable coolers, I’d like to use the existing space and layout for a proper system. My thoughts are to figure out my needs and ruff design and work from that, size and layout I like the ice box layout and it will work for me, just need to know what I’d be looking at systems wise to refrigerate it and get the small part below 0C and if I have to I’ll junk the entire electric system and start over, not a big deal.


I purchased the size boat I did for a few reasons, one was to leave 100% of the acquisition cost to a refit, I don’t mind spending money if its going to give me a good ROI.

[john61ct]

Have you got any solar yet?

Do you have an inboard engine? What sort?

What alternator? Stock VR or external? How many hours motoring would you do every 2-3 days

I assume no genset, but some carry a quiet little Honda rather than running the diesel while living on the hook.

The key is multiple energy sources, maximise each "within reason", lot depends on you preferences.

If you're not using a portable then think hard about the holding plate idea, evaporators will give more usable space. Rich can give you a pretty close idea, pick his brains. . .

[NorthernMac]

Originally Posted by john61ct

Have you got any solar yet?

Do you have an inboard engine? What sort?

What alternator? Stock VR or external? How many hours motoring would you do every 2-3 days

I assume no genset, but some carry a quiet little Honda rather than running the diesel while living on the hook.

The key is multiple energy sources, maximise each "within reason", lot depends on you preferences.

If you're not using a portable then think hard about the holding plate idea, evaporators will give more usable space. Rich can give you a pretty close idea, pick his brains. . .

Inboard diesel, alt on a V belt, not sure the output though

Little solar on the back, but I’ll be upgrading that but I haven’t decided yet as that’s depending on what I need (hence this thread )

No gen and not looking to have to run one or the engine for the fridge, water maker maybe, but not a fridge.

[john61ct]

So each of these is of course a decent project and deserving of a dedicated thread.

A strong alternator setup combined with a LFP bank will likely give you all you need running a couple hours at a time, maybe 3-5 times a week.

But a decent solar setup, if you're willing to mount say 4-600W worth, will cut that way down, maybe even be enough except when insolation conditions are very poor. Depends on your other consumers of course

If so, then likely a lead bank will suffice, simpler and will save a fair bit up front, but need replacing more often.

Obviously if you do get a gennie for making water you'll also use that for charging when you aren't motoring much, but with enough of both above may not need it at all, there are darn efficient DC RO units out there if you don't mind running them many hours per week.

The bigger AC ones Rich sells are high gph, only a few hours per week, but not energy efficient.

[laika]

Forgive me if I missed some of the finer points of Richard's post, but my Sterling Batt charger doesn't seem to have any issues handling the fridge loads in float when connected to shorepower. The charger just adjusts the input amps and rolls with it. In my case, the charger will be feeding, say, 3A @ 13.3V into the house bank and will simply jump to 6A @ 13.3V when the compressor kicks on to make up for the difference. Whether or not the fridge is not doesn't change the battery float profile.

I have an Engel on our small boat and one of the projects I'd love to tackle is converting the icebox (currently dry storage) into a built-in fridge. The engel is reliable and efficient, but the insulation values leave something to be desired, plus it takes up valuable space inside our already small cabin.

We have 244W of solar, cruising grounds are W Caribbean. We make ~50A on a typical mostly sunny winter day here, and the engel in fridge mode probably takes up about 2/3 of that. I bet we would nearly half our energy needs if we beefed the hell out of icebox insulation and threw in a small Danfoss compressor.

Insulation is the cheapest and easiest energy you will come by.

[john61ct]

Yes in general optimizing efficiency gives a very high ROI if it saves adding input capacity

[Richard Kollmann]

NorthernMac, It seams you do need more experienced intelligent guidance than you are receiving if you want satisfaction and return on investment. You need quantified direction to avoid mistakes. Maybe Rich at Technautics or John at CoolED refrigeration will see this thread and ignore it do to its ramblings. You should call and talk to both of these boat refrigeration application specialists.

[Peter Mackay]

Hi Mac,
Suggest you have a 'Heat load, Duty Cycle and Daily power consumption' estimate done specific to your project. I have created a spread sheet which computes these outcomes instantly upon us entering your cabinet and usage details.
This data will allow you to acquire equipment that is able to meet your specific needs and with a known power consumption. PM me if you (or any other member) wants to use this no cost / obligation service. (send email address with PM)

Cheers Pete