My 37-C is a 1979. The icebox has about a one cubic foot in the deep section, then the top is much wider which ads about another one and one half cubic feet, for a total of approximately 3 1/2 cu. ft. I'm considering converting to refrigeration. Has anyone done this upgrade that can give me suggestions? Has anyone done much investigating regarding how well this box is insulated? It seems kind of small to me and appears nearly impossible to add insulation so I'm considering ripping the whole thing out and building a new box, but . . . this seems like a really big job. And, how about types and brands of refrigeration conversion kits, any experience or suggestions in this area? Any help is appreciated. Thanks, Morrie
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Starting point.
Think you are right Morrie, probably need to start from scratch. A good reference is the Related Link where Gene Gruender's projects are documented. See "Tore out the galley". My 37C has refrigeration, an old 110v compressor sits under the aft starboard coaming. Since I also have a dorm fridge where the oven used to be I only use the icebox with ice. I think my 110v compressor would be very inefficient and would rapidly drain the batteries through the inverter. But I have never tested that theory. My long range plan has always been to spray foam insulation where I can. Then improve the lid where most of the loss occurs. The lid in the starboard locker needs to be insulated and permanently sealed shut. You could also put insulation on the side that is inside the locker. Then I plan to install an Adler/Barbour with a vertical evaporator, probably the 'L' shape. But if I had the time and money I would do it Gene's way.
Think you are right Morrie, probably need to start from scratch. A good reference is the Related Link where Gene Gruender's projects are documented. See "Tore out the galley". My 37C has refrigeration, an old 110v compressor sits under the aft starboard coaming. Since I also have a dorm fridge where the oven used to be I only use the icebox with ice. I think my 110v compressor would be very inefficient and would rapidly drain the batteries through the inverter. But I have never tested that theory. My long range plan has always been to spray foam insulation where I can. Then improve the lid where most of the loss occurs. The lid in the starboard locker needs to be insulated and permanently sealed shut. You could also put insulation on the side that is inside the locker. Then I plan to install an Adler/Barbour with a vertical evaporator, probably the 'L' shape. But if I had the time and money I would do it Gene's way.
Went with AC/DC Refrig
I considered all the same options last year. I concluded that the amount of effort to properly insulate the 37C icebox wasn't worth it. Since the previous owner had removed the stove/oven, I used this space to install a stove top (electric/alcohol) unit and a built- in AC/DC Refrig below. To provide enough vertical clearance, I had to cutout and lower the bottom of the existing fiberglass oven enclosure. The refrig now sits on the lowered shelf. A new sheet of teak plywood stained to match with an opening for the refrig finished the job. I now have a built-in 2.3 ft3 refrig, a two burner stove, and use the ice-box for dry storage. This has been the best modification I have made to my boat! Mark
I considered all the same options last year. I concluded that the amount of effort to properly insulate the 37C icebox wasn't worth it. Since the previous owner had removed the stove/oven, I used this space to install a stove top (electric/alcohol) unit and a built- in AC/DC Refrig below. To provide enough vertical clearance, I had to cutout and lower the bottom of the existing fiberglass oven enclosure. The refrig now sits on the lowered shelf. A new sheet of teak plywood stained to match with an opening for the refrig finished the job. I now have a built-in 2.3 ft3 refrig, a two burner stove, and use the ice-box for dry storage. This has been the best modification I have made to my boat! Mark
big job, maybe worth it
As Ed mentioned, I tore mine out and started over. There is really plenty of insulation on the sides and bottom of the original one. The problems with the original one are: 1. The top is just plywood. 2. It's not shaped very well to be used 3. Access is difficult. The place where the drawers are is pretty much wasted. Mine box is now next to the engine, where the drawers used to be, and the outer area next to the hull is storage. I mocked up the shape of the area I had to work with in my garage, then made a box that would still leave me plenty of insulation on all sides (6") and 4" on top. If you do this, you have to either construct the new box inside the boat, or take care that it will fit through the companionway. (Seems basic, but I've overlooked basic things before!) After suspending the bos where it was to go I layered up blue styrofoam insulation board around it, filling voids with a spray can of foam insulation and presto, a new box. It's not advertised, but you can get your evaporator from Adlar flat, or custom bent in addition to the horizontal and vertical box shapes. I strongly recommend you get the larger sized evaporator, and suggest you consider getting it bent to fit your finished box so that you make better use of the space. When I got mine, it was a $50 surcharge to have it custom bent. I've talked to people who got them flat and bent them themselves, but I don't recomend it. Also, the supercold machine has no more cooling capacity than the cold machine, it just has a bit better corrosion protection, and it has the capacity of adding water cooling. The best choice for performance and cost is the coldmachine compressor and the larger evaproator. Consider mounting it where it can draw in cool cabin air instead of air from a small compartment, or re-circulating the engine air. Mine draws air from above the galley counter, and discharges it into the engine room. Do not consider the holding plate option, it's not for our type use. If you have questions, give Adlar a call, they will tell you what is what. It was one of the more useful mods we made to Rainbow Chaser, but as Ed also says, it is a lot of work.
As Ed mentioned, I tore mine out and started over. There is really plenty of insulation on the sides and bottom of the original one. The problems with the original one are: 1. The top is just plywood. 2. It's not shaped very well to be used 3. Access is difficult. The place where the drawers are is pretty much wasted. Mine box is now next to the engine, where the drawers used to be, and the outer area next to the hull is storage. I mocked up the shape of the area I had to work with in my garage, then made a box that would still leave me plenty of insulation on all sides (6") and 4" on top. If you do this, you have to either construct the new box inside the boat, or take care that it will fit through the companionway. (Seems basic, but I've overlooked basic things before!) After suspending the bos where it was to go I layered up blue styrofoam insulation board around it, filling voids with a spray can of foam insulation and presto, a new box. It's not advertised, but you can get your evaporator from Adlar flat, or custom bent in addition to the horizontal and vertical box shapes. I strongly recommend you get the larger sized evaporator, and suggest you consider getting it bent to fit your finished box so that you make better use of the space. When I got mine, it was a $50 surcharge to have it custom bent. I've talked to people who got them flat and bent them themselves, but I don't recomend it. Also, the supercold machine has no more cooling capacity than the cold machine, it just has a bit better corrosion protection, and it has the capacity of adding water cooling. The best choice for performance and cost is the coldmachine compressor and the larger evaproator. Consider mounting it where it can draw in cool cabin air instead of air from a small compartment, or re-circulating the engine air. Mine draws air from above the galley counter, and discharges it into the engine room. Do not consider the holding plate option, it's not for our type use. If you have questions, give Adlar a call, they will tell you what is what. It was one of the more useful mods we made to Rainbow Chaser, but as Ed also says, it is a lot of work.
aren't you on a mooring?
Morrie: Did I remember that you are on a mooring? One major factor here is the need for DC power. You are going to need a good sized battery bank that will run off solar/wind generators. If I were you I would try to fix the basics of the box. Put insulation in the top, put some weather stripping around the lids. Then try doing some heat loss calculations. I think that you should consider a holding plate unit too. If you do some research you will find that there are a lot of options out there. None of them are cheap either. You are looking at probably $1200 - 3500 for a decent unit that is going to keep your food from spoiling. Unlike some of us in more north lats. your temps in Hawaii are much higher average temps so you want to make sure that you do this right (and only once).
Morrie: Did I remember that you are on a mooring? One major factor here is the need for DC power. You are going to need a good sized battery bank that will run off solar/wind generators. If I were you I would try to fix the basics of the box. Put insulation in the top, put some weather stripping around the lids. Then try doing some heat loss calculations. I think that you should consider a holding plate unit too. If you do some research you will find that there are a lot of options out there. None of them are cheap either. You are looking at probably $1200 - 3500 for a decent unit that is going to keep your food from spoiling. Unlike some of us in more north lats. your temps in Hawaii are much higher average temps so you want to make sure that you do this right (and only once).
Existing Box with Cold Plate...
Here is a little more food for thought... I really like Gene's installation and I will ultimately go that route as I feel it is the best way to get an efficient box, but here is what I did in the mean time and how it works. We lived aboard for some time and I needed some means of refrigeration. I ran some thermal effeciency tests using block ice and calculated the insulation value of the entire box as built by Hunter. This was done in Florida just before the winter season and the results were rather dismal. I added 3/4" poly insulation to the top of the box which was originally just plywood and this resulted in a decent increase of insulative quality. I went with a cold plate system built by E-Z Cold and placed the plate on the shelf directly under the opening in the cockpit lazarette. This works pretty well but is still a power hog. The unit uses about 20-30 amp hours daily during the winter months but can draw up to 60 on the hook in the summer. The box is hard to manuver around in but works OK for the most part. I have a small freezer section over the cold plate which will keep ice and ice cream frozen solid. We have no problem provisioning a couple of weeks worth of perishables in it and it is really closer to 8 cubic feet if you calculate it out properly. Unfortunately, that 8 feet isn't laid out well but if you keep it stacked well with food, re-insulate the top and keep a insulation blanket on the top of the food it'll work pretty well in the mean time. Tom Hadoulias S/V Lite Chop
Here is a little more food for thought... I really like Gene's installation and I will ultimately go that route as I feel it is the best way to get an efficient box, but here is what I did in the mean time and how it works. We lived aboard for some time and I needed some means of refrigeration. I ran some thermal effeciency tests using block ice and calculated the insulation value of the entire box as built by Hunter. This was done in Florida just before the winter season and the results were rather dismal. I added 3/4" poly insulation to the top of the box which was originally just plywood and this resulted in a decent increase of insulative quality. I went with a cold plate system built by E-Z Cold and placed the plate on the shelf directly under the opening in the cockpit lazarette. This works pretty well but is still a power hog. The unit uses about 20-30 amp hours daily during the winter months but can draw up to 60 on the hook in the summer. The box is hard to manuver around in but works OK for the most part. I have a small freezer section over the cold plate which will keep ice and ice cream frozen solid. We have no problem provisioning a couple of weeks worth of perishables in it and it is really closer to 8 cubic feet if you calculate it out properly. Unfortunately, that 8 feet isn't laid out well but if you keep it stacked well with food, re-insulate the top and keep a insulation blanket on the top of the food it'll work pretty well in the mean time. Tom Hadoulias S/V Lite Chop
Existing Box with Cold Machine
My boat came with Adler/ Barber cold machine and small evaporator mounted in the forward wall of the existing box. The box has 1 1/2" of styrofoam insulation glued to the top of the interior. I have the compressor/ condenser mounted as high as possible in the bilge just aft of the mast with a teak grating forward of the mast and a teak grating forward of the companionway steps. This creates a draft through the coolest part of the boat. It isn't the best frig. but it keeps the beer cold, frozen food frozen and you can't beat the scenery. Charles S/V Destiny
My boat came with Adler/ Barber cold machine and small evaporator mounted in the forward wall of the existing box. The box has 1 1/2" of styrofoam insulation glued to the top of the interior. I have the compressor/ condenser mounted as high as possible in the bilge just aft of the mast with a teak grating forward of the mast and a teak grating forward of the companionway steps. This creates a draft through the coolest part of the boat. It isn't the best frig. but it keeps the beer cold, frozen food frozen and you can't beat the scenery. Charles S/V Destiny
Mine
I added 2" of foam insulation to the top of box by removing the plywood piece in the stbd. cockpit locker and sliding cut-to-fit pieces in and glueing them in place. Then I put a large AB horizontal evaporater in the 'shelf section' of the box, revealed when I removed the cockpit locker plywood piece. Looks like a regular freezer compartment from inside the box now - you can even use regular ice cube trays!Reinstalled the the plywood, threading the copper lines through, and mounted the AB Super Cold Machine compressor on top, in the cockpit locker (where Gene put his). No complaints so far, but have yet to test the system in tropical conditions (from the Great White North, eh?) Good luck.
I added 2" of foam insulation to the top of box by removing the plywood piece in the stbd. cockpit locker and sliding cut-to-fit pieces in and glueing them in place. Then I put a large AB horizontal evaporater in the 'shelf section' of the box, revealed when I removed the cockpit locker plywood piece. Looks like a regular freezer compartment from inside the box now - you can even use regular ice cube trays!Reinstalled the the plywood, threading the copper lines through, and mounted the AB Super Cold Machine compressor on top, in the cockpit locker (where Gene put his). No complaints so far, but have yet to test the system in tropical conditions (from the Great White North, eh?) Good luck.
Gene ?
You wrote: > Do not consider the holding plate option, > it's not for our type use. Can you tell me more about your reasoning for this? From the reading I've been able to do I was thinking that holding plate systems were more economical to run. Can you (or anyone) say a little about the pros and cons of the two types of systems? Thanks, Morrie
You wrote: > Do not consider the holding plate option, > it's not for our type use. Can you tell me more about your reasoning for this? From the reading I've been able to do I was thinking that holding plate systems were more economical to run. Can you (or anyone) say a little about the pros and cons of the two types of systems? Thanks, Morrie
Propane Refrigeration
Propane is definately an option for those of us who are away from shorepower for long periods, and who don't want to chase amps every day. Shown is a Dometic fridge placed "under" the nav table. It is gimballed for long tacks, but otherwise sits upright, and operates for about 4 weeks (with the stove and water heater) on a 5-gallon bottle of propane.
Propane is definately an option for those of us who are away from shorepower for long periods, and who don't want to chase amps every day. Shown is a Dometic fridge placed "under" the nav table. It is gimballed for long tacks, but otherwise sits upright, and operates for about 4 weeks (with the stove and water heater) on a 5-gallon bottle of propane.
Attachments
Propane?
Dave, Where I live (out in the boonies on the Big Island of Hawaii) there are a lot of people who live off-grid, miles from any conventional power source. I know a number of people who run their homes, quite comfortably, on a 12 volt solar system with propane refrigeration and a propane Paloma on demand hot water heater. My first thought for refrigeration for my boat was to use propane. But, I've read several statements that essentially said "propane refrigerators won't work on sailboats because they have to be kept level." I'd like to hear more about how well that works for you. Your post read like there is a picture you meant to post with it ??? Thanks, Morrie
Dave, Where I live (out in the boonies on the Big Island of Hawaii) there are a lot of people who live off-grid, miles from any conventional power source. I know a number of people who run their homes, quite comfortably, on a 12 volt solar system with propane refrigeration and a propane Paloma on demand hot water heater. My first thought for refrigeration for my boat was to use propane. But, I've read several statements that essentially said "propane refrigerators won't work on sailboats because they have to be kept level." I'd like to hear more about how well that works for you. Your post read like there is a picture you meant to post with it ??? Thanks, Morrie
Cold machine & cold plate
I recently replaced my refrigeration unit with a Alder-Barbour Cold Machine with the cold plate unit. It is a little too big to mount on the side of the stock box, so I set it across the box for now. It has been installed since the summer and will keep the food frozen in the small section of the box. The back section is cold but does not freeze. No problems when it was 100 degrees outside, it was down to 5-10 degrees. I plan on changing the size of our box soon, so the cold plate will fit better.
I recently replaced my refrigeration unit with a Alder-Barbour Cold Machine with the cold plate unit. It is a little too big to mount on the side of the stock box, so I set it across the box for now. It has been installed since the summer and will keep the food frozen in the small section of the box. The back section is cold but does not freeze. No problems when it was 100 degrees outside, it was down to 5-10 degrees. I plan on changing the size of our box soon, so the cold plate will fit better.
To plate or not to plate.
Far be it from me to explain the difference between a thick cold plate and a thin evaporator plate. But there were two letters in the most recent Practical Sailor that lead me to agree with Gene, we are best served by the thin evaporator. And I have read this on some other forums. I would pose the question over on the A/B forum and get the expert answer. For Morrie it seems that propane would be ideal. I have no plans for any propane on my H37C so need a different solution.
Far be it from me to explain the difference between a thick cold plate and a thin evaporator plate. But there were two letters in the most recent Practical Sailor that lead me to agree with Gene, we are best served by the thin evaporator. And I have read this on some other forums. I would pose the question over on the A/B forum and get the expert answer. For Morrie it seems that propane would be ideal. I have no plans for any propane on my H37C so need a different solution.
holding plate
As usual, I just included enough information to confuse things. I was only talking about the Adler/ Barber cold plate, not cold plates in general. Adler/ Barber told me that the holding plate they offered was really for fishing boxes and so on, made to survive ice picks and other abuse. They told me that it really didn't cool nearly as well as the evaporators and unless it was subject to some abuse, they didn't recommend it. As others have mentioned, a good cold plate system is a good setup. And now, "OBX Sailor " tells us his Adler/barber cold plate works quite well. It certainly sounds like it works far better than Adler/barber suggested it would. I can say that whoever said that what ever you do, it's going to be expensive, is correct!
As usual, I just included enough information to confuse things. I was only talking about the Adler/ Barber cold plate, not cold plates in general. Adler/ Barber told me that the holding plate they offered was really for fishing boxes and so on, made to survive ice picks and other abuse. They told me that it really didn't cool nearly as well as the evaporators and unless it was subject to some abuse, they didn't recommend it. As others have mentioned, a good cold plate system is a good setup. And now, "OBX Sailor " tells us his Adler/barber cold plate works quite well. It certainly sounds like it works far better than Adler/barber suggested it would. I can say that whoever said that what ever you do, it's going to be expensive, is correct!
Evaporator vs. Cold Plate...
Morrie, Here are some pro's and con's about the different types of refrigeration. Cold plates use a eutectic solution in the cold plate to store cold and remove heat. This is similar to the product "Blue Ice" that is sold as a cooler accesory instead of ice. The cold absorbs heat until a temperature probe in the cold plate triggers the compressor to come on if it's 12 volt or you run your engine if it's engine driven. Most early systems were all engine driven and as a result are not realy suitable for anything but liveaboard use as if you're not there to run your engine every day your box get's warm. This has been remedied by the manufactures who make 12 volt systems that work great, problem is they cost a lot more than conventional evaporator systems. Evaporators use stored battery power to create cold as needed. They are somewhat less effecient in that the air in your box has a much lower co-efficient to conduct and store cold than does the eutectic solution in a cold plate. So if you don't keep your box full or if you open it a lot it uses more energy for a given temperature range. The key to both is good insulation. An evaporator works perfectly well and actually maintains a more even temperature overall as it cycles more and over less temperature range than a cold plate, but the cold plate is really a more effecient system for long term cruising if you have a well insulated box. It can use up to 50% less energy if the whole system is designed properly but at a significant cost up front. I'm sure this will stir some debate but the research I've done over whelmingly convinced me that this was the best application for my particular use. That said, I would have no problem living with an evaporator system as the Adler Barbour unit's are excellent and extremely easy to install. By the way... don't be fooled by the individual manufacturers claims that any one system is better that another by design, they all use the same refrigeration components just packaged and painted differently. I've seen the same basic components in different brand systems priced a thousand dollars apart. If I can be of any further help, email me at hadoult@bellsouth.net. Tom Hadoulias S/V Lite Chop
Morrie, Here are some pro's and con's about the different types of refrigeration. Cold plates use a eutectic solution in the cold plate to store cold and remove heat. This is similar to the product "Blue Ice" that is sold as a cooler accesory instead of ice. The cold absorbs heat until a temperature probe in the cold plate triggers the compressor to come on if it's 12 volt or you run your engine if it's engine driven. Most early systems were all engine driven and as a result are not realy suitable for anything but liveaboard use as if you're not there to run your engine every day your box get's warm. This has been remedied by the manufactures who make 12 volt systems that work great, problem is they cost a lot more than conventional evaporator systems. Evaporators use stored battery power to create cold as needed. They are somewhat less effecient in that the air in your box has a much lower co-efficient to conduct and store cold than does the eutectic solution in a cold plate. So if you don't keep your box full or if you open it a lot it uses more energy for a given temperature range. The key to both is good insulation. An evaporator works perfectly well and actually maintains a more even temperature overall as it cycles more and over less temperature range than a cold plate, but the cold plate is really a more effecient system for long term cruising if you have a well insulated box. It can use up to 50% less energy if the whole system is designed properly but at a significant cost up front. I'm sure this will stir some debate but the research I've done over whelmingly convinced me that this was the best application for my particular use. That said, I would have no problem living with an evaporator system as the Adler Barbour unit's are excellent and extremely easy to install. By the way... don't be fooled by the individual manufacturers claims that any one system is better that another by design, they all use the same refrigeration components just packaged and painted differently. I've seen the same basic components in different brand systems priced a thousand dollars apart. If I can be of any further help, email me at hadoult@bellsouth.net. Tom Hadoulias S/V Lite Chop
Morrie......
I DID post a picture with my post.....see "Related Photo". And you can use a propane fridge on a boat. The Hiscocks used a "parafin" (English for kerosene) fridge for many years, and ours is over seven years on board Duet, the past two on moorings or at anchor. The trick is, the fridge has to "average" level; bobbing around in the ocean averages level. The little flame (about the size of a pencil eraser) is under the bulb of liquid ammonia, and if it burns a bit on the left, a bit on the right, some up, some down, it still averages in the middle of the bulb, and heats the ammonia very effectively. Where you may run into trouble, and where the confusion probably comes from, is if you are sailing and you get onto one tack for a longish time, the flame is concentrated on one side of the bulb and can do damage. That's why our fridge is gimballed athwartships. We only engage the gimballs when we are under sail. While at anchor or at a mooring, it is locked in place and does fine. If you wanted to skip the gimballing alltogether you could do so; just turn the fridge off when sailing and relight it when you come home. Our Dometic Model #2410 is so well insulated that we've forgotten to relight it on occasion, and found frozen ice cubes still there after 24 hours. Your intended use seems close to what we've been doing, and I can recommend this solution very hightly.
I DID post a picture with my post.....see "Related Photo". And you can use a propane fridge on a boat. The Hiscocks used a "parafin" (English for kerosene) fridge for many years, and ours is over seven years on board Duet, the past two on moorings or at anchor. The trick is, the fridge has to "average" level; bobbing around in the ocean averages level. The little flame (about the size of a pencil eraser) is under the bulb of liquid ammonia, and if it burns a bit on the left, a bit on the right, some up, some down, it still averages in the middle of the bulb, and heats the ammonia very effectively. Where you may run into trouble, and where the confusion probably comes from, is if you are sailing and you get onto one tack for a longish time, the flame is concentrated on one side of the bulb and can do damage. That's why our fridge is gimballed athwartships. We only engage the gimballs when we are under sail. While at anchor or at a mooring, it is locked in place and does fine. If you wanted to skip the gimballing alltogether you could do so; just turn the fridge off when sailing and relight it when you come home. Our Dometic Model #2410 is so well insulated that we've forgotten to relight it on occasion, and found frozen ice cubes still there after 24 hours. Your intended use seems close to what we've been doing, and I can recommend this solution very hightly.
Dave - - and all
Dave, Thanks for the details, they are very helpful. I read your first post just seconds after it was posted and it evidently took a minute or so before the 'related photo' link came through. Thanks everyone for your great suggestions and responses to my question. Aloha, Morrie
Dave, Thanks for the details, they are very helpful. I read your first post just seconds after it was posted and it evidently took a minute or so before the 'related photo' link came through. Thanks everyone for your great suggestions and responses to my question. Aloha, Morrie
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