# Refrigeration-Frigoboat Keel Cooled vs. others?



## T37Chef (Oct 9, 2006)

I have been researching refrigeration systems and had the chance to see a few at the boat show. 

I want the most efficient system at the most reasonable cost (of course right ). It looks like the Frigoboat keel cooled system fits my needs best? 

A Frigoboat keel cooled system sized for my box (about 6-7 cu/ft) using a bin shaped evaporator will run about $2,000 + another $250 for the thermostat and the Merlin Smart Speed Control and maybe the spillover fan for $150? 15% off plus free shipping during the show, so I would like to decide very soon.

They also have a combined keel cooled & air cooled system for when the boat is on the hard or a back up, for an additional $200? Worth it?

I also looked at CoolBlue and Sea Frost but found the pricing is similar and neither offer the keel cooling option. The CoolBlue air cooled system is pretty efficient though at 24 amp hours a day using a holding/cold plate. If I recall, its also can easily be recharged with a kit which can be used at sea, others require a professional service call = $$. 

Are there any other systems that are similar in cost and efficient that I should consider?


----------



## svHyLyte (Nov 13, 2008)

Shawn--

We went through a similar process awhile ago and decided against the keel cooler option. Several of our friends opted for the system and had the experience of having the lubricating oil in the coolant collect in and obstruct the keel cooler which disables the system. One of our friends has abandoned a FrigoBoat system after two+ years of efforts and repeated malfunctions.

We did go with the FrigoBoat air-cooled option simply because it replaced the system that originally came on our boat and I did not want to have to change the cabinetry to fit a different arrangement. Thus far it has worked very well and we're satisfied with it although, believe it or not, the new unit is not quite as efficient as it's 1986 era predecessor which may be a function of the new refrigerants verses R-12.

In addition to the FrigoBoat for the refrigerator, we also have a separate SeaFrost for the freezer and I have found that to be somewhat more efficient. If we could have fit another SeaFrost in the space we had available, I would have gone with another.

The "expert" on refrigeration is a fellow by the name of Don Kollmann. See KollmannMarine Boat Refrigeration Specialist

FWIW...


----------



## JonEisberg (Dec 3, 2010)

I've had the Frigoboat with the keel cooler for about 10 years now, and am very happy with the choice... I've yet to have any significant issue with it whatsoever, it's been pretty flawless...

it's virtually silent, the only time I ever notice it is the very faint "shudder" the compressor emits when it shuts off... Only maintenance is to keep the keel cooler free of marine growth, pretty simple chore if it's located reasonably close to the waterline...


----------



## Alive3and3Well (Aug 16, 2010)

My frigiboat keel cooler has a zinc that must be checked and replaced when needed. I have seen a boat with the consequenses of zinc neglect on the keel cooler.


----------



## smurphny (Feb 20, 2009)

Am in the same decision process and think I'll probably wind up buying one of the Isotherm coldplate units. Have not yet decided to go water cooled or air. I don't like the extra layer of things to break on any of the water cooled exchangers although they are slightly more efficient. Just seems I remember seeing a few posts over time about various problems with water cooled units either getting clogged, corroding, etc. http://www.defender.com/product.jsp?path=-1|406|10789|322423&id=58870


----------



## svHyLyte (Nov 13, 2008)

JonEisberg said:


> I've had the Frigoboat with the keel cooler for about 10 years now, and am very happy with the choice... I've yet to have any significant issue with it whatsoever, it's been pretty flawless...
> 
> it's virtually silent, the only time I ever notice it is the very faint "shudder" the compressor emits when it shuts off... Only maintenance is to keep the keel cooler free of marine growth, pretty simple chore if it's located reasonably close to the waterline...


FWIW I think the older FrigoBoat units were much more robust than the current editions. Our original unit was a 1986 version installed by the builder when the yacht was manufactured and it worked very well for 24 years. We finally replaced it when the compressor died and although we could obtain another compressor, that would have been with "no guaranty" and would have cost about half of what the replacement system cost. I have heard the same sentiments from other owners of the older units...


----------



## SVAuspicious (Oct 31, 2006)

I'm a big fan of any of the keel-cooled variants. The two most common choices are the Frigoboat keel-cooler and the Isotherm SP. My experience with both has been very good, even when neglected. Both do have their own zincs to watch after. 

The Isotherm SP has its heat exchanger wrapped around a thru-hull (galley sink drain on Auspicious) so it can be installed in the water. In addition, as long as you don't accidentally put a drain plug in the sink drain acts as a chimney and cooling is quite reasonable (albeit at higher power consumption) on the hard. 

I would not hesitate to purchase either a Frigoboat keel-cooler or an Isotherm SP. Both are very reliable and significantly quieter than a classical water cooled unit. The air-cooled units are reliable but can be noisier than a keel-cooled/SP although quieter than a classic water-cooled. They do become one more source of heat in the cabin.

When looking at stand-alone Engel air cooled freezers for a friend I did some calculations that clearly indicated that the heat from an air-cooled refrigeration unit was significantly less than the heat shed by a person down below from breathing and body temperature, so while an air-cooled unit does add to heat loading it is much less than people. *grin*


----------



## wingNwing (Apr 28, 2008)

Our keel cooled Frigoboat has worked nearly flawlessly for 8 (?) years; interesting to read the above comment that the older systems are more robust than the newer ones. Their website has a table to calculate your power use that, if anything, OVERestimates what you'll need. We use about 25 silent amp-hours per day for two good-size cold boxes plus a shoebox-sized freezer. 

We're only on the hard a few weeks per year, so rather than adding the air-cooled option, we just use block ice for that short time.


----------



## smurphny (Feb 20, 2009)

Wow, 25 amp hours is great for that amount of cubic footage. That would add up to only about 2 hours of output/day from my 2 solar panels, an acceptable amount. The thing that seems to be difficult to find is the predicted cycle time. The amperage range is in the specs. of these units but there is no estimate of theoretical run-time. This would give a much clearer idea of actual amp/hours. It would be nice to see a chart with variables of cubic feet, R-value of the enclosure, ambient temp, and cycle time. This would give a much better basis for sizing a unit. Have not seen the Frigoboat table you mentioned, maybe they have done this.


----------



## wingNwing (Apr 28, 2008)

Smurphy, yes, they've done exactly that: you tell it box volume, amount of insulation, water temp, and they tell you usage. We can run indefinitely off our solar panels in 70-degree water. Better in summer with longer hours of daylight, worse in autumn when the water's still warm and the days are short.


----------



## smurphny (Feb 20, 2009)

Yes, their calc. page gives a good idea about actual amp hours. At least it's a basis for coming up with a guesstimate. My calc comes up to only 19.9 for 4 cubic feet, using a keel cooler. I like their opinion piece on coldplates as well which has convinced me to scrap the old coldplate. Although a couple of hundred bucks more than the Isotherm unit I was looking at, the Frigoboat looks at least as good and they have put together a very nice website. I really like the design of their keel cooler and the fact that it does not depend on salt water intake like the Isotherm.


----------



## T37Chef (Oct 9, 2006)

OK gurus...

Ideas on "oversizing" the unit a little? Or is it just a waste?

Thanks for all the replies.

I think I'm leaning towards a Frigoboat and will make the purchase soon, but what about NorCold by Thetford? Not a keel cooled unit but pretty inexpensive, around $600 + http://www.defender.com/product.jsp?path=-1|406|10789|322424&id=10854


----------



## SVAuspicious (Oct 31, 2006)

Do you oversize the chiller on a walk-in? I know that heat-pumps and aircon experts generally discourage significant oversizing. I expect reefers would be the same. 

The Norcold is air-cooled I think so you would have to be sure you can get good ventilation of the compressor location, both intake and exhaust without circulation of the hot exhaust air back into the intake.

No personal experience with the Norcold to offer that I know of.


----------



## JohnRPollard (Mar 26, 2007)

Hi Shawn,

Not sure if you decided already, but I just thought I'd throw in for the Frigoboat. Ours was installed by the previous owner, so I don't know the exact age. But it has run flawlessly for the past 8 years or so that we've owned our boat. It is VERY miserly on power consumption, too. That being said, ours is configured as a fridge -- not a freezer -- which likely contributes to the lower power draw.

I really like the idea of the air-cooled back-up (which ours does not have). Over the years I have consistently commented that the inability to operate the fridge while hauled-out is the one down-side to the keel-cooler. Sounds like they've come up with a good solution.

Good luck!


----------



## deniseO30 (Nov 27, 2006)

svHyLyte said:


> We went through a similar process awhile ago and decided against the keel cooler option. Several of our friends opted for the system and had the experience of having the lubricating oil in the coolant collect in and obstruct the keel cooler which disables the system. One of our friends has abandoned a FrigoBoat system after two+ years of efforts and repeated malfunctions.
> 
> FWIW...


SV, that condition is called "oil migration" it's caused when a component is colder then the compressor. It's hardly ever a problem in very small systems like used in boats. It should not require replacement of the keel cooler and could be corrected. I'd suspect the system not being used for very long periods of time as the cause.


----------



## svHyLyte (Nov 13, 2008)

deniseO30 said:


> SV, that condition is called "oil migration" it's caused when a component is colder then the compressor. It's hardly ever a problem in very small systems like used in boats. It should not require replacement of the keel cooler and could be corrected. I'd suspect the system not being used for very long periods of time as the cause.


Denise--

I do not have the detailed particulars on these cases tho' the folks are members of our club. Two are boats in our basin, one--the fellow that abandoned his system--being a sister-ship to ours. The boats are active and the cooling systems are left operating (and here in Florida they do get a workout). In all cases the keel coolers reportedly became obstructed with oil. In the one case the owner went through all kinds of shenanigans to try and clear the device without success. Based upon these reports, we decided to remain with an air-cooled system that is, admittedly, not as efficient as a keel cooler. In general we have been very happy with our system although I must say that the new unit does not seem to be as efficient as our older one (24 years old!) although that should not be the case.

All one can offer in response to inquiries is one's own experience. If the cases I have referred to are anomalies then so be it, but it is "interesting" that there would be a cluster of that nature in one locale.

FWIW...

(PS: I should add that I know very little about refrigeration and so had to rely upon the opinions and judgment of other more knowledgeable folks when I was replacing our own system last Spring.)


----------



## Swb47 (Jun 14, 2010)

I'm not sure that oil logging would be the cause of failure. Hot gas enters the keel cooled condensor where its condensed into liquid refrigerant. Refrigerant oil entrained with the hot vapor will readily mix with the liquid refrigerant after the vapor has condensed. More likely cause might have been an overcharged system. I have to research the principle of operation in more depth. Refrigeration systems need some type of head pressure control to prevent liquid refrigerant from flashing to vapor before the metering device(not sure how frigo accomplishes this with their water cooled or keel cooled condensor). Slightly oversized med and low temp refrigerant systems are not as critical as oversizing an a/c or heat pump system, but should be avoided if possible to prevent flooding of refrigerant back to compressor. Air conditioning systems that are oversized will cool down the environment too quickly leading to short cycling equipment and not removing enough humidity resulting in high energy costs, shortened equipment life and a cold damp environment.


----------



## deniseO30 (Nov 27, 2006)

In older systems the oil could break down and form wax in high ambient conditions. SV there really is no way to know what really happened, I agree with you on that. My guess is that keel coolers are very susceptible to marine growth and loss of heat exchange when the boat is "parked" lol hence the addition for air cooling the refrigerant on the way back to the evaporator. 

SW, these systems are very small, with only a few ounces of refrigerant. Just hooking up gauges to "check the charge" is enough to drastically shorten the charge since the gauge hoses hold about an oz per 3ft hose. DIYers almost ALWAYS assume refrigerant is needed and ALWAYS (well almost always) overcharge systems. They are very basic systems also, no pressure controls, and the 12 volt (or 24) compressors have that controller that is hyper sensitive to everything; temp, resistance, amps, etc.


----------



## josrulz (Oct 15, 2006)

T37Chef, we're figuratively in the same boat as you, planning to make a purchase soon on the refrigeration we'll install over the winter. We had been planning on the keel cooler system, but haven't decided 100%. Have you made your choice?

Our goal is for the system to be as miserly as possible, even when it's hot. We don't have a ton of space for extra batteries on our Sabre 34, so our house bank will only be 2 Group 31s. If we get the results anything like WingNwing, then we'll be fine. But no guarantees there with different boat, insulation, etc.

Anyway, just wondering if you came a conclusion for your boat's needs?


----------



## JohnRPollard (Mar 26, 2007)

josrulz said:


> T37Chef, we're figuratively in the same boat as you, planning to make a purchase soon on the refrigeration we'll install over the winter. We had been planning on the keel cooler system, but haven't decided 100%. Have you made your choice?
> 
> Our goal is for the system to be as miserly as possible, even when it's hot. We don't have a ton of space for extra batteries on our Sabre 34, so our house bank will only be 2 Group 31s. If we get the results anything like WingNwing, then we'll be fine. But no guarantees there with different boat, insulation, etc.
> 
> Anyway, just wondering if you came a conclusion for your boat's needs?


Hi Jim,

We have 2xGrp31 AGMs also, and even now that they are 7+ years old, we typically can go 2+ days easily at anchor on just one of them running all domestics including fridge. We used to be able to get closer to 3 days. We are frugal, of course, with lights etc and careful about not opening the fridge unnecessarily, but we do have kids on board so probably open quite a bit more often than the average couple.

And as mentioned above, ours is a fridge, with no freezer capability. We also usually throw a bag of ice in the bottom, too, in case we need some for burns, sprains, bumps, etc. If I recall correctly, our fridge is about 6 cubic feet.

I think you'd like the Frigoboat, and if you don't need it to work when the boat is hauled, then you can save the expense of the air-cooled option. As erika mentioned, block ice is often an option if you need it when hauled.


----------



## T37Chef (Oct 9, 2006)

One of the major criteria in selecting a refrigeration system for our boat is power usage (we too have two group 31 AGM's = about 100 hours useable), nonetheless I think the time has come to increase the small battery bank we have.

I have, or had, pretty much determined I wanted to purchase the 12V *Frigoboat* keel cooled unit using a "bin" shaped evaporator. But it's pricey, about $2000 plus another $100 for a speed controller, $137 for their digital thermostat, plus I was also considering the keel & air cooled option for another $200 or about $2300 - $2500 total. Ouch! My Jen Air Stainless Side by Side for the house didn't cost that much!

A friend recommended I look at the *Norcold* system; its air cooled, runs AC or DC automatically, and cost $600 from defender Icebox Conversion Unit  It uses an "L" shaped evaporator plate. I could section off part of the box as a freezer and get a spill over fan?

We primarily sail on weekends with a week or two trip in the summer. I'm now thinking the Frigoboat may just be overkill and I'm not sure I can still justify the added cost. Adding another battery or two to the bank would provide enough power to keep it going for a long weekend, otherwise we would be plugged into shore power. Heck I could easily add a solar panel and controller and still come in for less $$ than the Frigoboat.

Thoughts?


----------



## josrulz (Oct 15, 2006)

T37Chef said:


> One of the major criteria in selecting a refrigeration system for our boat is power usage (we too have two group 31 AGM's = about 100 hours useable), nonetheless I think the time has come to increase the small battery bank we have.
> 
> I have, or had, pretty much determined I wanted to purchase the 12V *Frigoboat* keel cooled unit using a "bin" shaped evaporator. But it's pricey, about $2000 plus another $100 for a speed controller, $137 for their digital thermostat, plus I was also considering the keel & air cooled option for another $200 or about $2300 - $2500 total. Ouch! My Jen Air Stainless Side by Side for the house didn't cost that much!
> 
> ...


I don't have my price sheet in front of me, so I'm recalling from the price sheet I saw a few days ago, but that sounds higher than what I spec'd out. Are you planning to go with the K50F as opposed to the K35F?
-J


----------



## T37Chef (Oct 9, 2006)

The price sheet I have from the show shows $1957 for the K50 with a Bin Shaped 340B, what they recommended for my boat. The other one I was considering was the Capri50K for $2206...

but I think they are offering a 15% off those prices plus free shipping till the end of the show, including the powerboat show, so this Monday


----------



## chef2sail (Nov 27, 2007)

My thoughts..insulate your box better. Alder Barber Super Cold machine, 4 new 6 volt AGM Lifeline low profiles at 440 ah or 220 usable. same footprint as your 2 group 31 for space. All this for the price of Frigoboat. Makes ice cubes too.

The other is overkill for your sailing profile and needs

Just saying..".

Dave


----------



## josrulz (Oct 15, 2006)

Hey Chef, I'm really not trying to give you a hard time--REALLY. But I keep hearing that four 6Vs have the same footprint as two Group 31s, but I don't see how that's possible. They're both about about 7" wide. The 6v is about 10" long and the 12v is 13". Am I missing something? On our boat, there's no way 4 6v would fit in the space of our Group 31s. Not even close. 

Don't get me wrong, you may still have a point about which refrigeration to go with, and I do agree with your point about insulation, in general. I'm just saying about the batteries...so seriously, am I missing something?
-J


----------



## josrulz (Oct 15, 2006)

T37Chef said:


> The price sheet I have from the show shows $1957 for the K50 with a Bin Shaped 340B, what they recommended for my boat. The other one I was considering was the Capri50K for $2206...
> 
> but I think they are offering a 15% off those prices plus free shipping till the end of the show, including the powerboat show, so this Monday


Ahh, yes the larger compressor and evaporator will make the difference. I was looking at the smaller in both cases. The recommendation I got was for the K35 and the bin shaped 250B evaporator.


----------



## fallard (Nov 30, 2009)

We installed an Isotherm SP/ASU system about 10 years ago and highly recommend it. It uses an in-water heat exchanger that is part of a bronze thru hull fitting that replaces your existing galley sink drain thru-hull. Needless to say, the boat needs to be on the hard to do this part.

The automatic start up process is particularly suitable for a sailboat. When the controller senses a charging voltage--like from the alternator when the motor is running--it kicks the compressor into high gear to quickly freeze the cold plate. Otherwise, the compressor runs off the house batteries at a lower speed. 

The manufacturer recommended that we use a special thru hull zinc for the first year on a precautionary basis. We did and it came out at the end of the season showing no noticeable erosion. We removed it and haven't had any problem with corrosion. Per the manufacturer's recommendation, we do not use any antifouling paint inside the thru hull and haven't seen any fouling. By the way, I don't think it's a good idea to run the compressor on the hard, as the heat exchange doesn't work that well in air.

In any case, the Isotherm refrigeration has been maintenance free all these years, with the only repairs being due to a lightning strike that took out all of our electronics last year.


----------



## T37Chef (Oct 9, 2006)

josrulz said:


> Ahh, yes the larger compressor and evaporator will make the difference. I was looking at the smaller in both cases. The recommendation I got was for the K35 and the bin shaped 250B evaporator.


and thats still a hefty $1850, not including the 15% discount


----------



## josrulz (Oct 15, 2006)

T37Chef said:


> and thats still a hefty $1850, not including the 15% discount


True, for sure. Although interesting that you say you have about 6 cu feet of fridge space--we probably do too--and they recommended the smaller of the two compressors for us, but the larger for you. Hmmmmm...


----------



## SVAuspicious (Oct 31, 2006)

Shawn - I tend to agree with Dave for a price-sensitive solution EXCEPT I don't like AGMs. If your battery box is at all accessible it is hard to beat lead-acid batteries for capacity/$-life. The greater charge capacity of AGMs is a red herring as few boats can generate the charge currents from either battery chargers or alternators to achieve the benefits advertised.

My box is under the main berth aft and I check the batteries for level and specific gravity whenever I change the sheets on the berth.


----------



## T37Chef (Oct 9, 2006)

Thanks Dave & Dave

Check it out, I think I have found the right system for my needs and wants  Isotherm Compact Refrigeration Systems 2554 Refrigerator / Freezer

Bonus; I will be replacing an old thru hull for the galley sink at the same time, I think? The $1400 price puts it right in the middle of the two extremes I was considering earlier, the Frigoboat and Norcold.

Dave, you mention you have/had an isotherm, was it this type with the water cooled thru hull option?


----------



## josrulz (Oct 15, 2006)

OK, so we took a few steps back and re-evaluated everything. We also took some measurements, did some additional research, and here's where we are. We're going with Frigoboat, 12v C35 or K35 compressor, smart speed control, digital thermostat (maybe even with the manual speed selection option--not sure), and a vertical "bin" style evaporator (size depending on what will fit). The only question now is air cooled versus keel cooled. 

I'm a big fan of efficiency, but I'm also a fan of simplicity (both installation and operation), so I go back and forth. I realized that part of the problem is that there isn't independent testing of the two against each other. All I know is what Frigoboat claims about the keel cooler, and that people who have it generally like it (although there have been some complaints about clogging of the tubes). 

The keel cooler will be more difficult to install, and more difficult to replace if needed. But if the efficiency gains are significant enough, then it's probably worth it. I just can't really quantify that gain for our intended usage...so again...I go back and forth on this one...

Anyway, just some thoughts on Frigoboat for today.
Cheers,
J


----------



## JohnRPollard (Mar 26, 2007)

josrulz said:


> ...The keel cooler will be more difficult to install, and more difficult to replace if needed. ...


Jim,

I'm not certain that's the case. I have installed an air-cooled fridge, and have inspected our keel-cooled Frigoboat installation very closely. One of the things I've noticed about the Frigoboat is how comparatively simple the installation is. Aside from needing to haul the boat, the "keel-cooler" seems a much more straightforward, compact, and tidy way to exchange the heat from the system. I have some photos that I will try to get up for you so you can see what I mean.

I'm not trying to sway you one way or the other. I just wouldn't necessarily assume that the air-cooled installation will be easier. There's a good chance the opposite is the case. That said, neither should be too hard provided you have a good location.

One other thing about the air-cooled is that you will be dumping that heat back in the cabin -- which might not be a bad thing in some locales but could be unwelcome during the Chesapeake summers.


----------



## josrulz (Oct 15, 2006)

JohnRPollard said:


> Jim,
> 
> I'm not certain that's the case. I have installed an air-cooled fridge, and have inspected our keel-cooled Frigoboat installation very closely. One of the things I've noticed about the Frigoboat is how comparatively simple the installation is. Aside from needing to haul the boat, the "keel-cooler" seems a much more straightforward, compact, and tidy way to exchange the heat from the system. I have some photos that I will try to get up for you so you can see what I mean.
> 
> ...


I do see your point. Possible ducting for ventilation, etc. could make it more difficult actually to install the air cooled version, depending on location. I suppose it's just that I've never cut a hole in the bottom of the boat!

Any pics that you think may be helpful are greatly appreciated, JRP.
Thanks!
-J


----------



## JohnRPollard (Mar 26, 2007)

josrulz said:


> ... I suppose it's just that I've never cut a hole in the bottom of the boat!...


Jim,

The neat thing is I'm pretty sure you don't have to "cut" any holes in the bottom of the boat. At least, not in the sense of using a hole saw or anything. As far as I can tell, all that's needed is a couple of small holes (maybe 1/4" or so in diameter) that get drilled with a bit. In other words, it's nothing like putting in a through hull (for instance.)

I may end up sending those photos to you via email if that's okay. Or, we could meet at the boat some day and you could take a quick peek.

No matter what brand/configuration you end up with, it's really nice to have a fridge on board. It's an upgrade well-worth the cost.


----------



## deniseO30 (Nov 27, 2006)

In your planning guys. these units do not really make "tons" of btuhs like AC units. I think most are around 300-500 btuhs an hr. not allot of heat to vent


----------



## SVAuspicious (Oct 31, 2006)

JohnRPollard said:


> One other thing about the air-cooled is that you will be dumping that heat back in the cabin -- which might not be a bad thing in some locales but could be unwelcome during the Chesapeake summers.


I ran the numbers some time ago and determined that the heat load of an air-cooled refrigerator is less than a person sleeping below.

I still like the keel coolers.


----------



## JohnRPollard (Mar 26, 2007)

SVAuspicious said:


> I ran the numbers some time ago and determined that the heat load of an air-cooled refrigerator is less than a person sleeping below.
> 
> I still like the keel coolers.


As far as the heat in the cabin form the air-cooled versions....

As I said above, this might be welcome in some situations. I've often thought I'd want it vented to the wet locker, to help dry foulies, etc.

But my impressions are colored by my experience with an air cooled unit in hot conditions. The one that I mentioned having installed above, was used when cruising in the Med. During much of the 10+ weeks we spent in and around the Aegean, a persistent heat wave had descended on southeastern Europe, with temps topping out at 49C (120F) during the worst of it. It was HOT, and the air-cooled fridge struggled to keep up with even the bare minimum of cooling in the fridge.

We never scientifically quantified the heat being dumped back into the cabin, but there was no question it contributed noticeably to our discomfort. We now sail with 5 aboard our 31 footer here on the Chesapeake during the summer, which can get pretty uncomfortable at times due to the heat/humidity. Anything to reduce heat belowdecks is always welcome.


----------



## T37Chef (Oct 9, 2006)

What about running duct work to the bilge, get some air circulation down there? UM, decisions decisions...still muling mine


----------



## josrulz (Oct 15, 2006)

JohnRPollard said:


> Jim,
> 
> The neat thing is I'm pretty sure you don't have to "cut" any holes in the bottom of the boat. At least, not in the sense of using a hole saw or anything. As far as I can tell, all that's needed is a couple of small holes (maybe 1/4" or so in diameter) that get drilled with a bit. In other words, it's nothing like putting in a through hull (for instance.)
> 
> ...


Thanks JRP for the info, and I'd be happy to see the pics OR meet you at the boat one day--whatever works for you!

One thing I'll point out--and it may be that the design has changed--but even the "stud mounted" version of the keel cooler requires a 1 1/2" hole, according to Frigoboat. Not huge of course, but new for me. I know I can manage that (I've cut larger holes in the cabin top and sealed the core and all that)--no core in our hull--so it should be fairly simple. Again, just new for me.

Of course, I should add that when we bought our boat, pretty much everything about maintenance and installations was new to me!


----------



## JohnRPollard (Mar 26, 2007)

josrulz said:


> Thanks JRP for the info, and I'd be happy to see the pics OR meet you at the boat one day--whatever works for you!
> 
> One thing I'll point out--and it may be that the design has changed--but even the "stud mounted" version of the keel cooler requires a 1 1/2" hole, according to Frigoboat. Not huge of course, but new for me. I know I can manage that (I've cut larger holes in the cabin top and sealed the core and all that)--no core in our hull--so it should be fairly simple. Again, just new for me.
> 
> Of course, I should add that when we bought our boat, pretty much everything about maintenance and installations was new to me!


Jim, Okay, maybe mine is different, or possibly I have misunderstood how it was installed. Looking at it, I have always assumed the studs and cooling lines were individually drilled. But it's possible there's a larger hole under there. It can't be all that large, though. If it is -- I would be a little worried that there is no way to close it if the keel cooler were somehow lost.

I'll send those photos to your sailnet e-mail of record unless you say otherwise.



T37Chef said:


> What about running duct work to the bilge, get some air circulation down there? UM, decisions decisions...still muling mine


Shawn, On my boat, that would be tricky but not impossible. I could see some benefits, though. On the other hand, it's expensive hardware and I might be a little reluctant to give bilge water a path up to where it's mounted. Hmmmm.

I'll copy you on those photos if you'd like.


----------



## deniseO30 (Nov 27, 2006)

The condensing needs of these "marine" refrigeration units so small that you could glue about 25 ft of copper tubing to the hull below the water line on the inside and it would work, Look at your home units, the condenser is the outside case. However per-engineered and sized condensers are better then "playing" with design.


----------



## josrulz (Oct 15, 2006)

JohnRPollard said:


> I'll send those photos to your sailnet e-mail of record unless you say otherwise.


Thanks JRP! I'll look for them in my in-box.


----------



## chef2sail (Nov 27, 2007)

Jos,

The footprint of the new Lifeline GPLCT is 10.28X7.06X12.98...two of these give you about 300ah. To achieve the same in Grp 31 you need 3 of them..They go 12.90X6.75X9.27 Lifeline 6V AGM volume is 1884 cubic inches vs Lifeline Gr 31 AGM 2421 cubic inches.

To achieve 600ah like we have you need either 5 Group 31 ( 4035 cubic inches and 560 ah) or 6 Group 31 (4843 cubic inches and 660 ah). The 600 ah Lifeline are 4- 6 volt agm are 3768 cubic inches.

The way we measured the fit was to make cardboard models and fit them in our battery compartment as I didnt just trust the mathematic information, I had to see how they practically would fit.

Dave is right, the wet cells are way cheaper. However they cannot be laid on their sides. The nice thing about the AGM is that they can be laid on their sides which helps in efficiently using the space. In addition our battery area is under our quarater berth and not easily accessable, so maitainence was a ***** for wet cell.

To Daves other point AGMs of the size battery bank we have make your standard 55-60 ah alternator run to hot and crazy and will burn it out. We have circumvented this my buying an elctomax 140 high capacity marine alternator, sepentine belt, and smart max external regulator with temp sensor for the engine charging. This system was recommended to us by Mainesail who is not a big Balmar fan. We also have 90amp 3 stage IOTA charger for when we are at the dock

We will be adding some passive charhing capabilities with solar in wind in the comming years.

While adding all this stuff to our boat ( electronics, refrigeration, etc it is important to consider spending as much time on upgrading you energy syatems as well.


----------



## josrulz (Oct 15, 2006)

chef2sail said:


> Jos,
> 
> The footprint of the new Lifeline GPLCT is 10.28X7.06X12.98...two of these give you about 300ah. To achieve the same in Grp 31 you need 3 of them..They go 12.90X6.75X9.27 Lifeline 6V AGM volume is 1884 cubic inches vs Lifeline Gr 31 AGM 2421 cubic inches.
> 
> ...


Those GPL CTs are cool stuff! I wasn't familiar with them. I certainly agree with your point, and if we could fit those specific batteries, then maybe we could gain something. In general though, we can't fit more than two house batteries on our boat.

When talking about volume, it is totally valid to compare dimensions. But for us, we have very limited vertical space. In the end, we could never fit more than any two house batteries. It could be two Group 31s, or maybe even two GPL CTs (big maybe, but possible on their sides). We can fit 3 regular 6Vs, but 3 doesn't help us!

Our battery compartment is THAT small.


----------



## SVAuspicious (Oct 31, 2006)

chef2sail said:


> The nice thing about the AGM is that they can be laid on their sides which helps in efficiently using the space. In addition our battery area is under our quarater berth and not easily accessable, so maitainence was a ***** for wet cell.


Good point.


----------



## JonEisberg (Dec 3, 2010)

JohnRPollard said:


> Jim, Okay, maybe mine is different, or possibly I have misunderstood how it was installed. Looking at it, I have always assumed the studs and cooling lines were individually drilled. But it's possible there's a larger hole under there. It can't be all that large, though. If it is -- I would be a little worried that there is no way to close it if the keel cooler were somehow lost.
> 
> .


Just to clarify, you definitely do need to cut a larger hole (1.5", if memory serves) to install the Frigoboat keel cooler. It is more or less the equivalent of the installation of a thru-hull fitting...

Here's a pic of an installation done by a cruiser named Dave McCampbell, aboard the CSY 44 SOGGY PAWS:










One important consideration on the choice of location - You do NOT want to pick a spot where a travelift sling might possibly get placed, that obviously could damage the fitting, or compromise the watertight bedding/seal...

BTW, I met Sherry and Dave on SOGGY PAWS down in the Bay Islands of Honduras a few years ago, very cool people... They're in the Pacific now, and their blog is worth a look, it's a good resource filled with a lot of good technical advice on stuff like boat systems and communications, from a pair of very capable and self-sufficient cruisers:

S/V Soggy Paws - CSY 44 - Circumnavigate with Dave and Sherry McCampbell

And, their Frigoboat installation notes:

S/V Soggy Paws - CSY 44 - Dave and Sherry McCampbell


----------



## josrulz (Oct 15, 2006)

JonEisberg said:


> Here's a pic of an installation done by a cruiser named Dave McCampbell, aboard the CSY 44 SOGGY PAWS:


That's the same pic I saw. Now if I could only decide between air cooled and keel cooled! Maybe I can get Practical Sailor to test them against each other, in the Chesapeake Bay, near my home waters, and provide me the data by...say...Thursday this week. Riiiight! :laugher


----------



## ArcherBowman (Jul 1, 2009)

My instincts just scream "don't put more holes in the boat!" But perhaps that's just me.



josrulz said:


> That's the same pic I saw. Now if I could only decide between air cooled and keel cooled! Maybe I can get Practical Sailor to test them against each other, in the Chesapeake Bay, near my home waters, and provide me the data by...say...Thursday this week. Riiiight! :laugher


----------



## smurphny (Feb 20, 2009)

JonEisberg said:


> Just to clarify, you definitely do need to cut a larger hole (1.5", if memory serves) to install the Frigoboat keel cooler. It is more or less the equivalent of the installation of a thru-hull fitting...
> 
> Here's a pic of an installation done by a cruiser named Dave McCampbell, aboard the CSY 44 SOGGY PAWS:
> 
> ...


It's also important to make sure that the cooler is not out of the water when heeled over. When deciding where to drill through, make sure you are clear inside and have clearance to get lines from your cooler to the compressor without major structural hacking. Use a small pilot bit first to confirm both sides. Depending on hull thickness, it may also be wise to install a backing block or thicken the glass from the inside with a few layers of heavy roving.


----------



## josrulz (Oct 15, 2006)

So, T37Chef, did you come to a decision?


----------



## T37Chef (Oct 9, 2006)

Arggg...not yet.  You?


----------



## josrulz (Oct 15, 2006)

T37Chef said:


> Arggg...not yet.  You?


Actually, we're going with the keel cooler. Just placed the order today. There are pros and cons to every solution. We think this one is the best fit for us. Who knows if we're right? Practical Sailor didn't take me up on the personalized, localized, customized test, so I just had to pick something. 
-J


----------



## T37Chef (Oct 9, 2006)

Still haven't made a purchase...but the defender sale is this weekend


----------



## smurphny (Feb 20, 2009)

Double arrrrgh! I'm in the same boat here. Would like to get the Defender sale price but still torn over which unit to use. I like the amp rating of the Isotherm SP Evaporator but don't like the fact that it stops working if the boat is out of the water for a few days. Same w/ keel cooler models. Am thinking of just going with the smallest fan unit for about 1/2 the cost, about the same amp/hr rating.


----------



## SVAuspicious (Oct 31, 2006)

smurphny said:


> I like the amp rating of the Isotherm SP Evaporator but don't like the fact that it stops working if the boat is out of the water for a few days.


I have an Isotherm SP refrigerator and separate freezer. They work fine on the hard. Power consumption goes up but you are usually plugged in so that isn't a big deal. You have to be sure not to leave the plug in the sink drain as it acts like a chimney for the heat exchanger.


----------



## smurphny (Feb 20, 2009)

SVAuspicious said:


> I have an Isotherm SP refrigerator and separate freezer. They work fine on the hard. Power consumption goes up but you are usually plugged in so that isn't a big deal. You have to be sure not to leave the plug in the sink drain as it acts like a chimney for the heat exchanger.


Thank you for that info. This is the way I'll go, with the smallest unit. I just assumed the heat dissipation went to zero when out of the water. The only thing I need to check out is the feasibility of cutting off the sink drain which is fiberglass tube molded right into the hull. It's not a thru-hull fitting.


----------



## SVAuspicious (Oct 31, 2006)

smurphny said:


> Thank you for that info. This is the way I'll go, with the smallest unit. I just assumed the heat dissipation went to zero when out of the water. The only thing I need to check out is the feasibility of cutting off the sink drain which is fiberglass tube molded right into the hull. It's not a thru-hull fitting.


Definitely feasible. Although it may sound like major surgery I would cut out the entire tube and put in a thru-hull and run hose from the sink drain to the thru-hull. It will be easier to run from the hole in the sink to the hole in the hull than to try to work with the fiberglass drain.


----------



## smurphny (Feb 20, 2009)

SVAuspicious said:


> Definitely feasible. Although it may sound like major surgery I would cut out the entire tube and put in a thru-hull and run hose from the sink drain to the thru-hull. It will be easier to run from the hole in the sink to the hole in the hull than to try to work with the fiberglass drain.


Found a new sp2055 on ebay for a really good price, right from Indel. Went over to boat to assess the location and there is just enough space to drill out the old fiberglass standpipe and replace with the new heat exchanger unit. I don't like drilling a 2 1/2" hole but the .55 amp rating on this unit is too good to not do this. It'll leave me amp/hrs to spare. Also, just above where it will come through is a small hatch area in the counter that will work great as a completely new fridge location which I can super-insulate with some polyisocyanurate. The original box on the starboard side is WAY too large anyway, probably 6 cu ft. Project underway....finally! Thanks for your input.


----------



## AlanF (Feb 27, 2012)

I wonder if JonEisberg's lack of oil collection is related to the cooler being near the waterline? It would make sense that if the compressor is lower, that might solve the problem. I've met people who had the same blockage problem, btw. 

- Alan


----------



## deniseO30 (Nov 27, 2006)

refrigeration oils do migrate to lower and or colder areas of the system. the oil and refrigerant do mix and the oil actually does move through the system, not like in auto engines where most of it is supposed to stay put. Most of the time, when the system is running it's not an issue. On larger systems oil return traps are used in the suction (return line) Not something you would see on little 12 volt systems and domestic refrigerators


----------



## UnionPacific (Dec 31, 2013)

It is interesting that these systems can be had today for under $1000 online.


----------



## smurphny (Feb 20, 2009)

As long as this old thread has been revived, I'll report that the Isotherm SP flat plate evaporator unit works well. With the small (2cu.') space I built in for refrigeration, the biggest challenge seems to be in getting the stat setting low enough without being off. The placement of the thermostat sensor tube makes a tremendous amount of difference and there is NOTHING in the inadequate manual as to how to position it in a space relative to the evaporator for best efficiency. This could probably still be better.

Anyway, 200 watts of solar panels keeps the beer cold If it's completely overcast for 2-3 days, I'll need run the engine for about 1/2 hour but that's no biggie. With careful use of wattage for things like the SSB and computer charging, this system works but I am very stingy with use of electronic stuff and probably well below the average wattage of most boats.


----------



## deniseO30 (Nov 27, 2006)

Just a hint since I'm not loyal or have any fondness for Danfoss 12/24 volt wonder piston compressors with modules that cost hundreds.

"swing" compressor quite amazing little gadget they are. engel, norcold, and I think isotherm use them. 
ENGEL USA - AC/DC FRIDGE/FREEZERS | PERFORMANCE COOLERS - - Swing Motor Compressor


----------



## smurphny (Feb 20, 2009)

deniseO30 said:


> Just a hint since I'm not loyal or have any fondness for Danfoss 12/24 volt wonder piston compressors with modules that cost hundreds.
> 
> "swing" compressor quite amazing little gadget they are. engel, norcold, and I think isotherm use them.
> ENGEL USA - AC/DC FRIDGE/FREEZERS | PERFORMANCE COOLERS - - Swing Motor Compressor


That looks very innovative. I have virtually zero knowledge of refrigeration but it seems like this would be excellent for a power miserly marine installation. I know the Danfoss in my Isotherm system gets quite warm to the touch when operating which translates to me as battery bank charge used up


----------



## deniseO30 (Nov 27, 2006)

Air conditioning compressors used to be designed receive cooling from the saturated gas coming back. 

Refrigeration compressors all types will get warm, even hot from the motor windings and the heat of the refrigerant being compressed. The returning gas is not as "saturated"


----------



## smurphny (Feb 20, 2009)

I get the basic principles of HVAC. Had a lot of doubt about being able to actually have refrigeration with only a couple of solar panels and an occasional alternator charge. So far I give the Isotherm unit an A even though the installation lit. is poor.

Just noticed your bench link. Nice work!


----------



## T37Chef (Oct 9, 2006)

I ended up installing an Isotherm unit with a BD 50 compressor used in a 7 cu/ft box. Easy to install. I'very had it for about 2 months now and just returned from 18 day sail and found it to work very well. I like that I could attach a simple dryer hose to the fan and route it low in the bilge so it's pulling cool air from the bottom of the boat while the heat escapes through a vented door in the galley. I paid about $800 during a Defender sale. The standard thermostat is nothing more than a dial, I may upgrade that part at some point but for now it's fine...keeps beer cold and ice cream frozen.

I wanted to go with the Sea Frost but just couldn't stomach the $2,000+ for one. If we were full time cruisers or live aboard we probably would have chose something else, like the Sea Frost or Fridgaboat. 

Cheers


----------



## SchockT (May 21, 2012)

smurphny said:


> the biggest challenge seems to be in getting the stat setting low enough without being off. The placement of the thermostat sensor tube makes a tremendous amount of difference and there is NOTHING in the inadequate manual as to how to position it in a space relative to the evaporator for best efficiency. This could probably still be better.


If you are having to run your thermostat at it's warmest setting in order not to freeze the contents then your thermostat is probably intended to control the evaporator temperature rather than the box temperature. If the unit didn't come with clips to attach the sensing tube to the plate, then try putting it between the evaporator plate and the box wall so that it is pressing against the plate. That will serve to hide and protect the fragile cap tube, as well as giving it an accurate measurement of evaporator temperature.


----------



## smurphny (Feb 20, 2009)

SchockT said:


> If you are having to run your thermostat at it's warmest setting in order not to freeze the contents then your thermostat is probably intended to control the evaporator temperature rather than the box temperature. If the unit didn't come with clips to attach the sensing tube to the plate, then try putting it between the evaporator plate and the box wall so that it is pressing against the plate. That will serve to hide and protect the fragile cap tube, as well as giving it an accurate measurement of evaporator temperature.


Thanks for that info. because that's exactly what I wound up doing after a lot of experimentation. There were no clips included with the unit but I'll probably make something to keep the tube stationary. Now, it's just slipped in behind the plate and not fixed in any set position.


----------

