[hellosailor]

Numbers are always a good game. A long time ago my friend was proud of getting 28mph in a Beetle. I pointed out that the 21mpg I got in a V8 Mustang was actually better mileage, way better mileage, considering I was pulling 50% more weight and could run rings around the Beetle while I was doing it. (Not to mention, carry much larger people & such.)

The numbers with reefers are all suspect. Who is to say that a mass-market boat builder installed a box optimally? Or, perhaps they just threw in cheap insulation, not what a custom builder would do. And they threw the evaporator under the sink and next to the stove, without proper ventilation? And of course keel cooling, which would seem to follow the laws of thermodynamics, is so widely panned by so many people.

I just find that box builders are debating how much insulation is enough...but somehow, that's always way more than the best portable boxes offer. And of course, you can't just "skin" the portable to add two inches more. sadly.

Warm beer and Snickers. Problem solved.

 

[RegisteredUser]

....you can't just "skin" the portable to add two inches more. sadly.

.....

But you can 'blanket' them very easily.

 

[deniseO30]

As I pointed out on another thread. this discussion on the minor differeances in amp draw would not be possible prior to the development of dc powered refrigeration compressors.

So you can all take a chill pill. whatever 12/24 volt refrigeration unit any of you may choose you are still light years ahead of the "old" way of doing boat refrigeration.

 

[deniseO30]

q; what to do about that ice box lid in the counter top?
a; put a cutting board on it!

 

[hellosailor]

Yes, and any Brit will tell you how to add a tea pot cozy to keep the tea warm. Sorry, that's just not the same as a properly insulated box with the evaporator vented outside and the insulation all in one piece, and not made of quilting.

I know, Chairman Mao once said "Black cat, white cat, all same. Catch mice." still, catching mice is not the issue here.

 

[SVAuspicious]

"Work triangle" should apply to gallery layout imho

In principle I agree with you. In practice on smaller boats it's often a "work point." *grin*

Since I wedge myself into the galley I regularly end up with some interesting bruises from the safety bar in front of gimballed cookers. I am still looking for a more elegant and thermally robust padding solution than a pool noodle.

What I've looked at is amp draw for both built ins and portables to keep a certain temp level, regardless of the thickness of insulation.

You can see insulation quality directly in current draw, measured in amperes (amps, A). Disregarding insulation is ignoring a primary factor.

Again, only considering current is insufficient. Duty cycle, directly affected by insulation and compressor efficiency, is important. Box size is important. Consider an Engel MT45F-U1. 1.5 cu ft box (pretty tiny) drawing 2 A at 50% duty on a warm summer day. That is 16 Ah/day/cu ft. Compare that to an Isotherm SP2051 cooling a 4 cu ft box, well insulated, drawing 2.5 A at 20% duty cycle on that same 72F day. 3 Ah/day/cu ft. Clearly a more efficient solution. Even more exciting is that the solution scales. Don't need 4 cu ft? A couple of big insulation blocks in the bottom of your box will decrease duty cycle, increase insulation, and make food easier to reach.

I've not yet found solid info that the built ins are surpassing the latest portables, but that's something to check...and to post about, please.

You haven't looked very hard. Five minutes on Google provided a wealth of specified, tested, and anecdotal data. The two links above are the merest tip of the iceberg.

Keel-cooling is far from new. Frigoboat has been selling keel-cooled refrigeration for about 20 years and Isotherm for at least 15 years.

Without engaging in yet another dissertation, the thermodynamics are quite simple: liquid-to-liquid heat transfer is more efficient than liquid-to-air so any water-cooled refrigeration will be more efficient than an air-cooled one. Consider further that a conventional water-cooled system has the electrical load of the sea water circulation pump that keel-cooled systems do not have and the specified efficiency of keel coolers is apparent. Obviously there is one less noise source as well.

@deniseO30

The numbers with reefers are all suspect. Who is to say that a mass-market boat builder installed a box optimally?

I agree that some skepticism is appropriate, particularly since some production boats don't have the option of factory refrigeration - that makes buyers dependent on whoever the brokerage selects for commissioning.

And of course keel cooling, which would seem to follow the laws of thermodynamics, is so widely panned by so many people.

Some people can be quite vocal without understanding what they are talking about. "I heard" is not a credible footnote.

q; what to do about that ice box lid in the counter top?
a; put a cutting board on it!

Sure. I have a cutting board that drops onto the gimballed cooker which gives me a level cutting service in any conditions. I also have small boards glued to the bottom of the sink covers so I can turn them over and have more prep/cutting space.

 

[TropicCat]

I just went through the new fridge selection process. A buddy bought one of the new Engle coolers and I was suitably impressed with it's performance, so I started my search with the Engle portables, and then compared features and benefits with the top loading counter build in solutions. For me, the 1.5 cubic ft of the lower end portables just wasn't enough. After loading wine and beer, there's little room for anything else, let alone a weeks worth of food.

I ended up with a 4 cubic foot top loading build in using an Isotherm BD50 model with a large L-shaped evaporator and the box divided horizontally. Good insulation. Upper lever stays at 33 degrees with a cabin temp of 100 degrees (yes, I live in the tropics) and the lower half is 6 degrees cooler and the unit is on 40% and off 60%. Solar handles it no problem.

Not perfect, as it was a bit pricey, but.. it works great..

 

[deniseO30]

Most of the "keel cooled" units I've seen use the keel or drain the cooler as an addition to the fan cooled condenser. The reason for this is; if by chance the boat were on the hard the keel cooler would not work very well and cause high condensing temps thereby causing high amp overload on the sensitive 12 volt compressors. "But I'd never run it on the dry" right.. and no one ever forgot to open the seawater valve to the engine

I wonder if this conversation was going on in the 40s50s and 60s when people wanted cold beer and started adapting land based machines to boats?

No affiliation;
General Marine's History
General Marine Refrigeration Corp. - About Us
General Marine Refrigeration Corporation is a third generation family owned business in the field of marine refrigeration and air conditioning. After sailing for years as a Chief Engineer, founder William F. Anderson started General Refrigeration Company Inc., in 1925. This Swedish immigrant worked diligently to give excellent and experienced service to his customers. He instilled these honest, hard-working principles in all his employees. To better serve the growing marine community of the Delaware River, General Marine Refrigeration Corporation was established in 1947. In 1969, Viking Supply Corporation was created to provide air conditioning and refrigeration equipment suitable for marine use.

Just a note.. recreational boating HVAC is a very tiny part of the marine hvac industry. Think of the freezer size they have on ships! and factory ships where they process the fish at sea.

 

[SanderO]

I didn't read the thread.... I apologize... my experience began when I was fitting out the new 36s over a 5 year period to get her to live aboard off shore capable. Changing by cold box to a fridge was one of the projects.

I also had to consider battery storage and power usage as a live aboard cruiser. I did a calc of all my loads in different conditions... offshore passage... at anchor and so on. I had a couple of solar panels... and moved up to a pair of D size batts.

I was concerned about electrical draw from a 12v fridge. And someone suggested an engine drive. Assuming the cooling worked well the advantage to me was that I could recharge the batts as I cooled down the fridge. I would typically use the engine an hr or two a day... say entering and anchoring and departing... or a dock stop to take on fuel or water... I couldn't see NOT using the engine and its alternator was the main charging source...I added a smart reg and high output alternator.

I installed a Grunnert "caribbean" with a freezer cold plate. If I ran the compressor a long time the plate would go very cold... and turn the box to a freezer. This worked for passage.... I usually took pre-coooked frozen meals and a used a separate portable cooler for drinks and so forth. As I used the meals I transfer food and mostly drinks into the box.

At anchor the minimal few hrs kept the box at frig temps and sometimes liquids next to the plate would become iced uo... slurrified orange juice or milk... No problem. The install was in 88 or 89 and I've only had a few repairs... replaced the clutch maybe 2 times... not even sure if it was twice. Works fine lasted a long time.

Weekending I often bring a block of ice and still run the fridge when we head out to sail or come into port... This has worked very well for me... batts are usually topped up... And the only fridge noise is masked by the noisy Volvo and boy do we hate the noise and smell... Most people I suppose do. But it's part of how the boat works.

If you have the power... you can with a 12v system.... I am sure they are fine... We're not at a dock... so shore power is not part of our power management regimen. If we were... we'd go 12v.

 

[hellosailor]

denise-
Thermodynamics can be easy. Consider, you live with central air conditioning and perhaps set the thermostat to 74F. Funny thing, after extensive research the USN also set the thermostat on board nuclear submarines to 74F, it works pretty well to keep people in their shirtsleeves awake and comfortable. Or even comfortable asleep.
Now take the same people and drop them in a relatively warm ocean, like off the Florida Keys. They may go hypothermic and die in 3-48 hours. AT THE SAME 74F AMBIENT TEMPERATURE.
Kinda proves what "water cooling" can do, without needing any pointy math.

One reason the original VW Beetle was so cheap and simple, the engine was air cooled. And the efficiency (not to mention the heater) was crap compared to water-cooled designs. The second law of thermodynamics is it? Is inescapable, just like the rest of them. Little bits like plumbing leaks, return on cost, and critical parts in unreachable places, that's quite another story.(G)

 

[deniseO30]

why I advise clients to leave the ac "on" when they leave the house. yep 74 is a a sweet spot temp for most humans.

but let's not confuse water as a medium to heat transfer in heat ex-changers with "swamp cooling" evaporation coolers used most often in desert conditions (hot dry heat)

 

[SVAuspicious]

Most of the "keel cooled" units I've seen use the keel or drain the cooler as an addition to the fan cooled condenser. The reason for this is; if by chance the boat were on the hard the keel cooler would not work very well and cause high condensing temps thereby causing high amp overload on the sensitive 12 volt compressors.

Your point is well taken regarding conventional keel coolers. The Isotherm SP series use modified seacocks as the refrigerant to sea water heat exchanger. Isotherm specifically addresses the use of their products on the hard. As long as you don't put the plugs in the sink drains the drains act as chimneys. You suffer the inefficiencies of air cooling of course but on the hard where shore power is generally available at least part time that is less of a factor.

And someone suggested an engine drive. Assuming the cooling worked well the advantage to me was that I could recharge the batts as I cooled down the fridge.

I think the day of engine drive refrigeration, indeed any holding plate refrigeration, is past. 12 VDC is a better solution. As with anchors, the availability of something better does not make the previous solutions less good. I personally would not replace a working holding plate system but I wouldn't install a new one either.

A 12 VDC refrigeration system with an L- or J-shaped evaporator takes up less space in the cold box, keeps the temperature in the box more stable (good for the food), does not require manual intervention to maintain temperature, and can be pretty energy efficient. A 12 VDC system also allows using battery power originally derived from a number of sources: main engine alternator(s), generator, shore power, solar, wind, even water. That provides a great deal of energy redundancy. While if the battery bank fails entirely there is a problem, that problem is a whole lot bigger than just refrigeration. Battery banks are pretty reliable and if a single cell fails you can take that battery or pair out of the bank and soldier on.

 

[TropicCat]

....
One reason the original VW Beetle was so cheap and simple, the engine was air cooled. And the efficiency (not to mention the heater) was crap compared to water-cooled designs. The second law of thermodynamics is it? Is inescapable, just like the rest of them. Little bits like plumbing leaks, return on cost, and critical parts in unreachable places, that's quite another story.(G)

I agree with everything you wrote here, but .... the failure points double when water cooling is involved. Air cooling is definitely less efficient, but it's the KISS principle. Use air cooling, ... Go to a larger compressor/evaporator and the increased current draw and you have a bulletproof refrigeration system. Just add another solar panel!!

My point is, if any of these components fail, it's not going to sink the boat!!

 

[SanderO]

I think the day of engine drive refrigeration, indeed any holding plate refrigeration, is past. 12 VDC is a better solution. As with anchors, the availability of something better does not make the previous solutions less good. I personally would not replace a working holding plate system but I wouldn't install a new one either.

A 12 VDC refrigeration system with an L- or J-shaped evaporator takes up less space in the cold box, keeps the temperature in the box more stable (good for the food), does not require manual intervention to maintain temperature, and can be pretty energy efficient. A 12 VDC system also allows using battery power originally derived from a number of sources: main engine alternator(s), generator, shore power, solar, wind, even water. That provides a great deal of energy redundancy. While if the battery bank fails entirely there is a problem, that problem is a whole lot bigger than just refrigeration. Battery banks are pretty reliable and if a single cell fails you can take that battery or pair out of the bank and soldier on.

At the time I set up a refer... in 1989 12v refers were not what they are today I believe. I am not recommending MY solution to others... and concluded that if we were to replace we would go with a 12v system. This solution worked me and it continues to be acceptable for the way we sail... and as it remains in good working order... I see no reason to rip it out and install a new one. But like so many of the boat's systems... electricity is mission critical..

 

[TomMaine]

I have pretty much decided I need to do a remodel / redesign of my Galley. One of my primary concerns is the icebox is under the starboard quarterberth and thinkin if i give up some storage under the galley i could fit it in the starboard galley and get more depth and room for better insulation maybe eventually goin to a holdover plar or some other type of refer system. With the change from the old stove with oven to a gimballed wallas 1000 with no oven i have alot of space below there perhaps if i moved some storage to there i would be able to fit the icebox in the counter top.
DISCOVERY 32 sailboat specifications and details on sailboatdata.com
any constructive ideas and suggestions would be helpfull.
I am not afraid to build new cabinets from scratch
Bill
SV Rangatira
Sailing the Rangatira

A galley redesign could be fairly simple. Adding refrigeration gets complicated. Plus refrigeration could change the way you sail when charging becomes a bigger part of the equation. Going to refrigeration, the charging - battery storage, etc. is a big project. A portable might be a good way to supplement your refrigeration and get a taste of how much energy you'll need with the way you sail.

Looking at the line drawing of your boat, it's hard to see where you could move the ice box from the starboard quarter berth (if I have this right), and fit everything in the port side galley.

I'd be more inclined to figure out a way to keep the icebox - starboard - and improve it.

However, I don't see much a way to do that except eliminate the quarter berth. You probably have thought of that?

 

[Pendragon35]

As to cooking being a "chick thing"...I (the male half of the crew) do almost all the cooking on Pendragon. It's just how we split up the duties. In theory we have room for an oven (Alberg 35) but the space is occupied by cabinets and it would take a lot of rebuilding not to mention insulating and buying an oven. So I stick to my two burner Origo which can produce quite amazing meals. (Not in the same class with @T37Chef but still good!).

A lot depends also on what sort of cruising you do. Ours tends to be sailing to some cove, anchoring, making a little dinner; not a lot of cooking underway, and a lot of making things that are essentially boiling water and heating something. Would we bake in an oven? not sure. We don't have propane and I have a feeling an alcohol heated oven would take forever. Still the idea of cookies would be wonderful

 

[hellosailor]

Probably 20 years ago, not long after the USSR was dissolved, there was a news story about some hunters (Siberia?) in the wilderness who were being treated for radiation burns. They had snuggled up next to a nice warm aeronautical beacon during a storm. It turns out the USSR supposedly had 2000+ of these, located in remote places for aircraft navigation, each being a strontium thermal pile. Like we use on some spacecraft. And out of the 2000, apparently ~1800 had gotten lost, forgotten, mislaid, or just "someone else's problem" after the split up.
So for the really enterprising sailor, while Reddy Kilowatt still hasn't delivered, there's always a chance to go looking for surplus in the old USSR. Surely there's a way to get refrigeration oit of a strontium pile. (Just stack the old lead acid batteries around it.)

 

[Faster]

A galley redesign could be fairly simple. ........

However, I don't see much a way to do that except eliminate the quarter berth. You probably have thought of that?

An Engel in a drawer oriented to slide aft and under the cockpit might work there.. You would lose the quarterberth but could retain a good sized seat; or sacrifice the berth, mount the engel (again in a drawer) athwartship and have a ton of extra counterspace/standup nav table and possibly more cabinetry and storage.

Accessing the newly created 'cockpit storage' might be trickier...

 

[Bill-Rangatira]

A galley redesign could be fairly simple. Adding refrigeration gets complicated. Plus refrigeration could change the way you sail when charging becomes a bigger part of the equation. Going to refrigeration, the charging - battery storage, etc. is a big project. A portable might be a good way to supplement your refrigeration and get a taste of how much energy you'll need with the way you sail.

Looking at the line drawing of your boat, it's hard to see where you could move the ice box from the starboard quarter berth (if I have this right), and fit everything in the port side galley.

I'd be more inclined to figure out a way to keep the icebox - starboard - and improve it.

However, I don't see much a way to do that except eliminate the quarter berth. You probably have thought of that?

i use the quarter berth alot on both sides the icebox is starboard as is the galley i can have 1/2 of the countertop still useable and the lid of the icebox will be flush as well i have about 24" of depth under the counter to put it in but want to get 4" of insulation to get better R factor with out going to the aerogel panels
the refridgeration would be a holdover plate running off the engine directly so no power involved just need to runn the engine twice a day for 15 mins each which is normal for setting and picking up anchor

 

[SVAuspicious]

the refridgeration would be a holdover plate running off the engine directly so no power involved just need to runn the engine twice a day for 15 mins each which is normal for setting and picking up anchor

My experience is that keeping holding plate refrigeration at appropriate temperatures takes much more than 30 min / day especially in warmer climes.