The Worst pleasure boat refrigeration.

[waterman46]

Originally Posted by Uncle Bob

Hey, you are right (don't let it go to your head ) but solar power is just so easy, silent and usually available every day for when you are chilling in a nice quiet anchorage enjoying the scenery and/or company.

And so we see those monstrous solar arrays hanging on the sterns of small monohulls. What happens when they meet a gale at sea? Just asking, I am not sure if the windage is a problem.

[skipperguy]

Not by any means an expert but I will say that I was very pleased with my conversion on a 20-year-old icebox to a Danfoss 12v system . The only dock voltage power was through my regular battery charger on board and this system sustained good refrigeration for long periods on the dock. Use off the dock would drain the batteries in 24 hours With no engine running.Our house battery was a single 8D but not Deep cycle

[robert sailor]

Originally Posted by waterman46

And so we see those monstrous solar arrays hanging on the sterns of small monohulls. What happens when they meet a gale at sea? Just asking, I am not sure if the windage is a problem.

If an arch is built properly you shouldn't have any issues with it offshore. Everything you add to the deck and higher adds to wind age but your a cruiser so while it all decreases performance a bit, in the end a well designed and built arch is not going to be an issue.

[RaymondR]

Originally Posted by robert sailor

If an arch is built properly you shouldn't have any issues with it offshore. Everything you add to the deck and higher adds to wind age but your a cruiser so while it all decreases performance a bit, in the end a well designed and built arch is not going to be an issue.

The problem is that our perceptual base line for assessing refrigeration is created by our experience with domestic refrigerators - you buy them, plug them into the reliable old grid and cold beer for life.

Then you buy a boat, which mostly stays tied up in a marina plugged into shore power and for years the refrigeration is satisfactory for the relatively short periods you use it.

Then, full of optimism and enthusiasm for the new life you are beginning you pull the plug and cast of from the marina, and, with all the demands on your inadequate electrical system the ice cream melts, the beer gets warm, and the hot dogs go bad.

Then the battle begins. You add batteries, then you need to add more panels, then you need top ups with a genset, then you're lugging more fuel. It's enough to drive a man to drinking straight water and living on dried beans.

After many years of this I have come to the conclusion that if one wants a reasonably peaceful co-existence with refrigeration on a boat you need at least 600 amp hours of storage and 800 Watts of solar and at least 60 amps of engine driven recharge capability and then you have to keep the whole mess working. If eutectic helps exploit your panels to the max and minimizes battery decline and engine driven recharge then it's worth having.

There is no worst in pleasure boat refrigeration, once you abandon the two door and the grid, there's only least worst and life was a hell of a lot simpler with that big old two door plugged into the grid. But then, someone's got to do it.

[Davo1404]

Originally Posted by GILow

There may be a demographic problem here. I’ve met dozens of happy Ozefridge users here in Australia, but few, if any of them have heard of Cruisers Forum, and of those that have, most do no more than skim-read here from time to time.

I think it is a reasonable assertion to say that Cruisers Forum is predominantly North American membership and posting.

GILow, you are exactly right. 2 yachts next to us here in a Queensland marina have recently installed an Ozefridge system & both are very happy with them after their previous system. We installed ours in 2007 after arriving in Queensland & the old system struggled with the heat. The water cooling using the freshwater that is stored on board is an advantage over outside cooling that barnacles up quickly in 30c water temperature. The auto start up when excess power is available & the holding tank can take some more freezing is also a good use of sun or wind power. 13 years & still performs well in the tropics. One of many happy Ozefridge owners in Australia.

[Uncle Bob]

Originally Posted by waterman46

And so we see those monstrous solar arrays hanging on the sterns of small monohulls. What happens when they meet a gale at sea? Just asking, I am not sure if the windage is a problem.

I guess that owning a pilothouse which gives me sufficient room to mount the 190 watts of solar panels that I have without additional support has spoilt me.
That 190 watts of solar supports all my electrical needs most of the time although it does get a little skinny when on passage with all instruments running as well.

[GILow]

Originally Posted by Davo1404

GILow, you are exactly right. 2 yachts next to us here in a Queensland marina have recently installed an Ozefridge system & both are very happy with them after their previous system. We installed ours in 2007 after arriving in Queensland & the old system struggled with the heat. The water cooling using the freshwater that is stored on board is an advantage over outside cooling that barnacles up quickly in 30c water temperature. The auto start up when excess power is available & the holding tank can take some more freezing is also a good use of sun or wind power. 13 years & still performs well in the tropics. One of many happy Ozefridge owners in Australia.

You wouldn’t be next to a Ben Lexen designed Revolution by any chance?

I feel like a total newbie with my Ozefridge having only been installed for a few months. But I look forward to 10 or more years of cold beers and ice cream. (Provided the extra calories don’t kill me first.)

[robert sailor]

Originally Posted by RaymondR

The problem is that our perceptual base line for assessing refrigeration is created by our experience with domestic refrigerators - you buy them, plug them into the reliable old grid and cold beer for life.

Then you buy a boat, which mostly stays tied up in a marina plugged into shore power and for years the refrigeration is satisfactory for the relatively short periods you use it.

Then, full of optimism and enthusiasm for the new life you are beginning you pull the plug and cast of from the marina, and, with all the demands on your inadequate electrical system the ice cream melts, the beer gets warm, and the hot dogs go bad.

Then the battle begins. You add batteries, then you need to add more panels, then you need top ups with a genset, then you're lugging more fuel. It's enough to drive a man to drinking straight water and living on dried beans.

After many years of this I have come to the conclusion that if one wants a reasonably peaceful co-existence with refrigeration on a boat you need at least 600 amp hours of storage and 800 Watts of solar and at least 60 amps of engine driven recharge capability and then you have to keep the whole mess working. If eutectic helps exploit your panels to the max and minimizes battery decline and engine driven recharge then it's worth having.

There is no worst in pleasure boat refrigeration, once you abandon the two door and the grid, there's only least worst and life was a hell of a lot simpler with that big old two door plugged into the grid. But then, someone's got to do it.

Unfortunate lots of what you have to say is true, that fridge is probably the most expensive piece of gear on the boat when you add everything up. Your alternator should be closer to 120 amps minimum but you've got the rest of it figured out.
The first year we went cruising, which was a long time ago we understood that we either started to write some big cheques or shut the fridge off. We shut it off and learned how people lived before refrigeration...it all worked out fine back then but these days we have spent lots of money to keep things cold. We humans find it easy to really complicate our lives, lol

[teneicm]

Any Isotherm water cooled system.

Reasons:

1) Raw water cooling is a pain for maintenance. We had 2 systems, one fridge and one freezer, both water cooled. Almost every other week I’d need to do something to clean/ unblock the water lines or heat exchanger coil. From oysters growing in the lines, to squid getting sucked up, to the coils getting blocked, it was a never ending battle. To be fair, this is not an isotherm issue but rather a problem with all raw water cooled systems.

2) Isothem positioned the voltage reducer for the pump immediately adjacent to the heat exchanger coil. Invariably, when having to clear blocked lines, no matter how careful you are some raw water gets on to the unit. This leads to the electrical connections eventually rusting and corroding away.

3) Isotherm runs the body of the pump through the heat exchanger coil. This means the pump is horizontal. We were talking with a guy who claimed to design water pumps and he said that this type of pump should be mounted vertically, otherwise the seals will fail. I’m not sure if what he said was true, but I do know that over an 8 year timeframe we replaced the water pumps on both systems at the rate of one every 18 months due to leaking seals.

4) So with having all this errant water from blocked lines and leaking pumps, where’s the best place to install this unit? In a nice dry locker? I guess if you don’t mind the spills and leaks so the locker is no longer dry. We chose to install it under the floor in the galley. Even though it’s up on a shelf, and in a bone dry large area with good airflow, Isotherm refused to help or consider warranty issues once I used the term “bilge” to describe where the unit was installed. The unit was going through a high number of “black box” control units, but Isotherm washed its hands of us and simply said it was our fault as the unit was mounted in a bilge.

So does it sound like I’m a bit bitter with Isotherm? Yep, a bit. Was really disappointed with the customer support.

So do we still have the same systems? Sort of... we had the refrigerator unit converted to air cooled. When it struggled with the high temps of the SE Asia tropics, we added the passive SP keel cooler and it’s working very well now. We converted the freezer to run off of the fresh water from the water tanks. The water pump was changed to a smaller seal free design (the type used in fountains or small ponds). The water in the tanks is a couple of degrees above the sea temp, but this doesn’t seem to effect the system’s performance and it is using less electricity then before.

[RaymondR]

Originally Posted by robert sailor

Unfortunate lots of what you have to say is true, that fridge is probably the most expensive piece of gear on the boat when you add everything up. Your alternator should be closer to 120 amps minimum but you've got the rest of it figured out.
The first year we went cruising, which was a long time ago we understood that we either started to write some big cheques or shut the fridge off. We shut it off and learned how people lived before refrigeration...it all worked out fine back then but these days we have spent lots of money to keep things cold. We humans find it easy to really complicate our lives, lol

I'm rebuilding my Honda gas powered auxiliary charging system at the moment and am putting two 12 V 85 amp Bosch Universal alternators, one either side of the engine, into the deck box. I'm thinking about an RO unit in the future and if I do it will remove one and put the HP pump on that side and a 150 plus amp alternator on the other. I already have the 2 x 85s from previous projects.

The image below are the two bain marie food trays I am going to use for the rebuild of my fridge. The two of them are 1,1000 mm overall length and I have a BD50 condensing unit for each of them. I'll use the tops of them for the freezer section and have a couple of levels of sliding trays above them. I'm also adding another 300 Watts of solar panels. Hopefully when it's all finished I'll have this refrigeration business by the throat.

[robert sailor]

Originally Posted by RaymondR

I'm rebuilding my Honda gas powered auxiliary charging system at the moment and am putting two 12 V 85 amp Bosch Universal alternators, one either side of the engine, into the deck box. I'm thinking about an RO unit in the future and if I do it will remove one and put the HP pump on that side and a 150 plus amp alternator on the other. I already have the 2 x 85s from previous projects.

The image below are the two bain marie food

Very intriguing!

[RaymondR]

Not sure what happened, maybe I broke the forum, but here's the other half of the post above.

The image below are the two bain marie food trays I am going to use for the rebuild of my fridge. The two of them are 1,1000 mm overall length and I have a BD50 condensing unit for each of them. If I use them to fabricate the tanks I'll use the tops of them for the freezer section and have a couple of levels of sliding trays above them. The alternative is to wrap the evaporator tubing around the outside of them and hang them in the bottom making the bottom of the box the eutectic tank and the bain maries the food storage part with insulated sliding tops. Damned decisions.

I'm also adding another 300 Watts of solar panels. Hopefully when it's all finished I'll have this refrigeration business by the throat.

[Buzzman]

RV-type fridges and fridge-freezers don't tend to need/want as thick insulation for two reasons:

1) makes them too bulky and difficult to use/fit into a vehicle, and or lift out of the vehicle

2) the "vehicle use mode" tends to involve a few hours of engine-driven power supply. So even with only a single 'main battery' when the auto cut-off kicks in at 10V (as most do to prevent running down (potentially) the vehicle's starting battery), there's *enough* charge from the alternator and subsequently the battery to keep everything cool during the day, and night time the compressor cycling requirement is lessened, hence less insulation is required.

So the "RV-cycle" is simlar to the "marine cycle" as far as power generation/consumption goes, which is why stand-alone 'boxes' (RV-stylefridges) can be utilsied cost-effectively.

The big advantage of doing so is the cost factor, as RV boxes are made in the millions globally, competition and manufacturer efficiencies make them MUCH cheaper than dedicated "marine systems".

One option I don't see canvassed is taking the guts out of the 'box' and placing it inside a MUCH thicker insulated fixed 'box' in the boat.

Kinda like buying a "compressor + evaporator kit" from one of the 12V fridge makes (e.g. Novakool, Waeco), but getting the 'liner' as well.

Purchasing an RV-type box reefer (or event the larger spill-over-type fridge/freezer units) would appear to be a cost effective option for anyone who has DIY skills.

I've seen 80-100L RV-style fridge/freezer units sell on special (especially at 4WD and Boating shows) for 20-30% off RRP. This should be enough for all but the largest boats. Certainly enough for anything in the 30-45' range.

I'd be interested to hear for anyone who has 'built-in' an RV-style box into a boat, as opposed to Jedi's plan of using them 'as bought' but on a sliding shelf. [Not knocking his plan - good way to add extra bench space - or at least, not lose it].

One thing I can confirm - most of the better RV unit makers sell canvas "insulated covers" made to fit each unit, and these are not just desirable but essential in most 4WD and RV applications.

A non-air-conditioned boat in the tropics is, ipso facto, much like an RV or 4WD on land in terms of heat transfer into the salon, so perhaps that should also be an essential there too?

Will be interested to see how Jedi's 3" insulated (as opposed to the industry 'standard' 2" insulated box) fares in warmer climes, with or without 'insulated covers'.

[NB: When RVs or 4WDs stop for longer periods - e.g. at a campground - thereby replicating the 'at anchor for a few days' scenario of cruising boats, the lack of 'daily engine running to recharge batteries' puts a severe strain on available power. It's why most RV and 4WD applications involve the addition if a dedicated 'house' battery, or "dual battery" as it's called in 4WD terms. Much like cruising boats have separate start and house batteries.
It's also why portable folding PV panels have become so popular, as you can prop them in full sun and leave the vehicle in the shade (if any is available), and thus trickle-charge or 'drip-feed' the house battery to keep reefer running. Many 4WD owners and RV owners doing this also carry a portable gennie like a Honda eu22 that is 'near silent' so they don't have to start the vehicle engine.
This, I think, is comparable to the marine 'cruiser at anchor' scenario, except that the cruiser probaly has more available sunlight and sq m to put solar PV, rather than having to run a gennie or (worst case) the main engine.
Of course, having a watermaker further complicates this, and perhaps running the gennie or main engine to simply recharge the batteries makes more sense as the "shortest time with engine running".]

But, by and large, I see the "12/24V DC air-cooled RV-type fridge as being significantly cheaper for a DIY-capable boater to install.

Or am I missing something vital..??

[GILow]

I don’t know about the assertion that the fridge adds up to the biggest cost item on the boat.

Aside from the fact that I bought an engine recently that cost more than 7 times the fridge purchase price, there is also the observation that the 50 AH I need to find every day does not add all that much to the electrical system. Nominally one more 105 AH FLA battery, call it two for a good margin of capacity, one more 200 Watt solar panel and associated mounting hardware.

In my case I didn’t actually have to add any of these as I was set up with heaps of excess capacity already, but I still don’t see them as big costs.

[robert sailor]

Originally Posted by GILow

I don’t know about the assertion that the fridge adds up to the biggest cost item on the boat.

Aside from the fact that I bought an engine recently that cost more than 7 times the fridge purchase price, there is also the observation that the 50 AH I need to find every day does not add all that much to the electrical system. Nominally one more 105 AH FLA battery, call it two for a good margin of capacity, one more 200 Watt solar panel and associated mounting hardware.

In my case I didn’t actually have to add any of these as I was set up with heaps of excess capacity already, but I still don’t see them as big costs.

Sure, sure you had to win the argument by buying a bloody new engine. Wasn't on my mind when I was thinking about fitting out a boat, lol. Having said that by the time you build a large arch for panels and add in a set of davits as part of it then add a genset or a high output alternator or both plus a large battery bank...the fridge is pretty cheap in comparison, oh don't forget a high quality controller for that big array of panels and if your not handy the labor costs to put it all together....this is not the cheap seats. I've done it several times over the years and other than installing a new engine it's one of the most expensive parts of outfitting a base boat.