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Sounds like engine cooling might be ideal for charter boats.
I remember having one on a boat in the virgins eons ago.
Wouldn't work for me now
Engine is often not fired for weeks..evens months
I think it is a terrible thing for charter boats. Those guys never understand how to operate one, and almost always forget to when motoring, so they end up running the engine all night at anchor. We used to have them on all the boats we chartered back in the 90's. A real PITA for someone unfamiliar with them. 12V systems just work in the background with no operator involvement at all.

I was thinking the same thing about engine use. There are definitely weeks and months we don't use the engines, and then they are used for maybe 5min to get off an anchor. Then there are the layup times when we do some land travel where we don't want to get rid of the contents. There are even times we stay with friends in other places for a couple of days where the reefer would keep us pinned to the boat.

Just like the solar, the 12V reefer for us is a background system running without us ever thinking about it, or interacting with it in any way. Not many systems on a boat give you that freedom.

Personally, I only see an engine-driven system as being an advantage for boats that can't install sufficient solar and don't need a generator for other reasons, or boats with reefer systems so large they need the capacity an engine driven compressor can provide.

Mark
 

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Discussion Starter #22
I think it is a terrible thing for charter boats. Those guys never understand how to operate one, and almost always forget to when motoring, so they end up running the engine all night at anchor. We used to have them on all the boats we chartered back in the 90's. A real PITA for someone unfamiliar with them. 12V systems just work in the background with no operator involvement at all.

I was thinking the same thing about engine use. There are definitely weeks and months we don't use the engines, and then they are used for maybe 5min to get off an anchor. Then there are the layup times when we do some land travel where we don't want to get rid of the contents. There are even times we stay with friends in other places for a couple of days where the reefer would keep us pinned to the boat.

Just like the solar, the 12V reefer for us is a background system running without us ever thinking about it, or interacting with it in any way. Not many systems on a boat give you that freedom.

Personally, I only see an engine-driven system as being an advantage for boats that can't install sufficient solar and don't need a generator for other reasons, or boats with reefer systems so large they need the capacity an engine driven compressor can provide.

Mark
hot water?
 

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As with everything cruising, the right answer depends on the crew, the boat, the location, and what you want to achieve. For me, I love that I can run our unit indefinitely with virtually no dino-power assist. One season I basically anchored in one spot for nearly two months. Never ran the big diesel, and had to use the gas generator twice for a total of about five hours. Had cold beer and ice cubes throughout. That's freedom baby!
 

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hot water?
Yes, the tank water is the same temp as the air temp ~95F. :D

We heat our water using the inverter when needed. Our 11 gal tank on our other boat only took 15min on the engine heat exchanger to heat to shower temperature, which is probably too short to do much for a reefer on a daily basis. The engine driven reefers I've used in the past required an hour in the morning and an hour in the evening to stay frozen. This might not be typical, because I don't have a lot of experience with them.

Mark
 

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Our hot water tank gets hot in running the engine 15 minutes. Insulated so it stays temp for a couple days. If I stayed more times in cold weather I think I would look into a small propane unit.

The fact is very few people who sail like I do on weekends or a few vacations have taken to these plate coolers.
Even amongst the cruiser community it is a minority and I’ll bet those that do have generators.

So for the average sport boater 12 volt makes the most sense, plus you stuff is truly cold and you get ice cubes, an important ingredient in our Ninja frozen fruit drinks which are very appreciated in the brutal Chesapeake summers. 😀
 

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The fact is very few people who sail like I do on weekends or a few vacations have taken to these plate coolers.
You may be conflating holding plate systems with engine-driven or AC powered compressors. While they are used with those types of compressors, there are also DC powered compressors using holding plates instead of thin evaporator plates. Cool Blue is an example. Holding plates are just a way of storing energy for cooling, and aren't specific to the compressor type. They can actually be more efficient than thin evaporator plates, depending on the boat's electrical production system and usage profile.

Mark
 

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Discussion Starter #27
Technology for electrical devices is advancing... including litch batteries, solar, wind gen and more efficient heating and cooling systems.

The point about engine drive... was simply that engine use for cruisers is often a daily thing.... and so you can use the principal of co generation... use the running engine to do more than turn the prop! This takes virtually no more fuel. !2v systems which run continuously also continuously drain batts... often require large banks and alt sources... all of this is part of the "equation" when evaluating options.
 

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You may be conflating holding plate systems with engine-driven or AC powered compressors. While they are used with those types of compressors, there are also DC powered compressors using holding plates instead of thin evaporator plates. Cool Blue is an example. Holding plates are just a way of storing energy for cooling, and aren't specific to the compressor type. They can actually be more efficient than thin evaporator plates, depending on the boat's electrical production system and usage profile.

Mark
Right.
I’m speaking about engine driven...
 

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Technology for electrical devices is advancing... including litch batteries, solar, wind gen and more efficient heating and cooling systems.

The point about engine drive... was simply that engine use for cruisers is often a daily thing.... and so you can use the principal of co generation... use the running engine to do more than turn the prop! This takes virtually no more fuel. !2v systems which run continuously also continuously drain batts... often require large banks and alt sources... all of this is part of the "equation" when evaluating options.
All of these points are valid and part of a decision matrix. The exception might be the statement of cruising boats using their engines daily. Most that we know (and us) don't change anchorages or make passages every day, and often stay in one place for days or weeks. When the engine is used, it is often for no more than 5-15min getting off anchor or coming to anchor.

In the past (decades ago), engine-driven reefer compressors were probably the majority of installs because DC compressors were horrible and solar/battery systems vestigial. I don't know what the market share now is for most 30-50' cruising boats, but I've never met any with one yet. I've met a few with engine-driven watermakers, though.

Mark
 

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Discussion Starter #30
This discussion has got me wondering... how many hrs do use use your engine per month or per season?

I went back to my log to check the last few sailing season's engine use from march/april thru october/november about 25-30 week(end)s which include several 2 weeks 24/7 live aboard cruises.

2015 engine use - 70 hrs
2016 engine use - 77 hrs
2017 engine use - 85 hrs

So the average engine use / week was less than 3 hrs. This makes sense to me. And it's more than enough to make hot water, cool the box and charge assorted batteries. Engine was very rarely operated with no load just to make hot water or cool the refer.

Engine use / season is going down because there were 4 years when I lived 24/365 on board including motoring one 12 day zero wind passage from St Martin to Greenport (YIKES) I don't have detailed hr use logs from 1992
 

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Discussion Starter #31
All of these points are valid and part of a decision matrix. The exception might be the statement of cruising boats using their engines daily. Most that we know (and us) don't change anchorages or make passages every day, and often stay in one place for days or weeks. When the engine is used, it is often for no more than 5-15min getting off anchor or coming to anchor.

In the past (decades ago), engine-driven reefer compressors were probably the majority of installs because DC compressors were horrible and solar/battery systems vestigial. I don't know what the market share now is for most 30-50' cruising boats, but I've never met any with one yet. I've met a few with engine-driven watermakers, though.

Mark
I didn't up the anchor every day when I lived aboard in the Eastern Caribbean. But I did move a lot... for sure every week as I liked going from one Island to the next.... change of scenery. But when you stay put there is no need to use the engine... except to get fuel or water (if you don't make water).. or change anchor location. I also wanted hot water and the tank water was not really hot enough for what I needed.... nor would it last long enough.

No need to change technology when what I have is working fine. I am not going to add more solar... nor get a gen set... or make water in a LIS harbor where water is free and a 20 - 30 minute round trip to the dock. We use water generously because it's free and available.

Hopefully I will not have to do upgrades... and let the next owner have that fun!
 

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3hrs/wk was enough for reefer, hot water, and charging? Were you living on it all week? That seems low to me. I understand that it is all done simultaneously with no penalty, but it implies a reefer box that is incredibly well-insulated or gigantic holding plates, and charging needs under 50Ah/day.

Our engine hours don't tell the real story wrt the above. While they may be a couple hundred hours each year, they are generally obtained in 25-50hr increments, when we are motoring in dead calms on passages. Our most recent passage was 96hrs of motoring in a mirror-surface gulf stream.

Mark
 

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Engine use is a funny thing.
Where you have a slip in relation to where you start / finish sailing
Traveling on vacation or trips

Haleakula engine gave up the ghost this year after 12,000 hrs. It was the original 3GMF installed in 1983. Well taken care of she succumbed to old age after years of faithful use.

Here are some eye opening numbers

37 years of use. That’s 324 hrs per year !!!!
324 hours X 5 miles per hour is 1620 miles per season. That’s a lot. However the meter runs as soon as the engine come on.

If we had refrigeration like Jeff’s, 100 days of use per year means at least 100 hrs of engine use only using it once a day. At the average cost of diesel. $400 per season.
 

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Discussion Starter #34
I can't follow Chef's math.
I have 110 watts of solar and 2 - 8Ds when they keep topped up. We also have a 120 amp alt with smart charging... and an echo charge for the start batt.

I can only report my use. AND there are weekends when I might just use ice and not the refer...
My total engine hrs for 35 yrs 5,291 on the original MD 17D.
 

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All of these points are valid and part of a decision matrix. The exception might be the statement of cruising boats using their engines daily. Most that we know (and us) don't change anchorages or make passages every day, and often stay in one place for days or weeks. When the engine is used, it is often for no more than 5-15min getting off anchor or coming to anchor.

In the past (decades ago), engine-driven reefer compressors were probably the majority of installs because DC compressors were horrible and solar/battery systems vestigial. I don't know what the market share now is for most 30-50' cruising boats, but I've never met any with one yet. I've met a few with engine-driven watermakers, though.

Mark

The majority of boats with refrigeration are not cruisers though. The majority of boats with refrigeration are weekend/ coastal cruisers. I know very very few using engine driven refrigeration.

Of the 130 sailboats in our small marina . I would be very hard pressed to find 5. Next time I’m in Annapolis a visit to one of my friends who installs / services refrigeration is in order ( socially distanced of course)

The OP question of refrigeration answers seem to be focused on refrigeration of live aboard and cruising situations.
In today’s world if I did that I still believe I would go with my DC setup and add solar to meet its needs.
To me running the engine with its myriad of parts is inefficient when a simple battery/ solar/ solution is much more simplistic.

The newer refrigerators are quite reliable and with proper insulation of your battery box very efficient.
Plus I believe you get a steadier temperature gradient easily controlled by a thermostat. I can keep by box at a steady 38 degrees in the WHOLE box. I can keep my freezer section at 0 degrees all the time and can make ice. In terms of food preservation and storage the consistent stead temperatures allows us to keep STEADY RELIABLE temperatures thus controlling the moisture in the box and insuring all the food in it is kept a food safety temperatures no matter where it’s placed in the box.
 
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I can't follow Chef's math.
I have 110 watts of solar and 2 - 8Ds when they keep topped up. We also have a 120 amp alt with smart charging... and an echo charge for the start batt.

I can only report my use. AND there are weekends when I might just use ice and not the refer...
My total engine hrs for 35 yrs 5,291 on the original MD 17D.
 

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Interesting examples. I rarely anchor for only one night, even when we're underway. Anchoring for weeks is common, and occasionally months. My aim is never to have to run the main diesel, or the backup gas generator, just to charge batteries. And I also want cold beer :).

Our current system does this. We have enough solar/wind to maintain our 320 amp-hr bank, while running the 12v refer and maintaining all the other electrical needs on our boat.

As for hot water, we have an on-demand system; I put a pot on the stove and heat water whenever demanded ;).
 

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The majority of boats with refrigeration are not cruisers though. The majority of boats with refrigeration are weekend/ coastal cruisers. I know very very few using engine driven refrigeration.

Of the 130 sailboats in our small marina . I would be very hard pressed to find 5. Next time I’m in Annapolis a visit to one of my friends who installs / services refrigeration is in order ( socially distanced of course)

The OP question of refrigeration answers seem to be focused on refrigeration of live aboard and cruising situations.
In today’s world if I did that I still believe I would go with my DC setup and add solar to meet its needs.
To me running the engine with its myriad of parts is inefficient when a simple battery/ solar/ solution is much more simplistic.

The newer refrigerators are quite reliable and with proper insulation of your battery box very efficient.
Plus I believe you get a steadier temperature gradient easily controlled by a thermostat. I can keep by box at a steady 38 degrees in the WHOLE box. I can keep my freezer section at 0 degrees all the time and can make ice. In terms of food preservation and storage the consistent stead temperatures allows us to keep STEADY RELIABLE temperatures thus controlling the moisture in the box and insuring all the food in it is kept a food safety temperatures no matter where it’s placed in the box.
Yes, I understand your oft-repeated point about the majority of boats not being cruisers. However, I was responding to SanderO's specific comment about how cruising boats use their engines.

You may be misinterpreting my posts - I am not in favor of an engine-driven system, and have yet to personally meet a cruiser who had one.

A holding plate keeps a steadier box temperature profile than a thin evaporator plate. This has nothing to do with how the compressor is powered. An engine-driven compressor driving a holding plate can keep rock-steady box temperatures at any temperature level, out-performing a DC compressor thin plate evaporator, as long as it is run appropriately. That is a matter of planning, and not system type/design.

Mark
 

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I was looking at those simple ( less than $200) propane instant demand systems for the RV we are going to purchase.
Maybe would work on the sailboat too. I don’t want to run off the inverter.

Anyone heard any reviews of them

 

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I ditched a hi$ engel, because of a micro leak nobody could find, and went with a 40 and a 20 qt cheaper models, for much less than 1 engel.
The 40 fridge seems to run about 25% of the time. The 20 freezer runs 100%
I am looking at purchasing a fridge to take between truck and trailered boat. i am between Engel and Dometic. The Engel MR040 has the reputation of being super reliable and efficient. Is that the model you had to bad? Which cheaper models did you replace it with?
 
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