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12V refrigeration
I may even have it from somewhere before, but the recent conversations on
reefers brought it to mind: Someone on these lists built a direct drive 12V compressor for refrigeration. My recollection has it connected to cold plates. It was designed to do what an engine drive would do, but not run the engine. At the time I saw it, it was new. If they're reading, I'd be interested to see a report on its efficacy. How much power did/does it take to operate? Was the size of the compressor notably less than one on the engine, and if so, what is the relative run time? In the end, are you happy with the outcome? If not, or even so, is there anything you'd have done differently if you were doing it again? Thanks. L8R Skip (and Lydia, by proxy), thinking of how to use the lovely cooling system on the boat without running the engine or the AC air-cooled system, either -- Morgan 461 #2 SV Flying Pig http://tinyurl.com/384p2 "And then again, when you sit at the helm of your little ship on a clear night, and gaze at the countless stars overhead, and realize that you are quite alone on a great, wide sea, it is apt to occur to you that in the general scheme of things you are merely an insignificant speck on the surface of the ocean; and are not nearly so important or as self-sufficient as you thought you were. Which is an exceedingly wholesome thought, and one that may effect a permanent change in your deportment that will be greatly appreciated by your friends." - James S. Pitkin |
12V refrigeration
Skip,
Some basics: First divide marine refrigeration into two classes, engine driven and electric. Engine driven systems on sailboats are always holding plate systems. The compressor can process a lot of BTUs in a short time while the engine is also charging batteries or propelling the boat which makes them very efficient. They are great if you are on board most of the time and the alternator is your primary battery recharging system. You can freeze the plates as you charge and/or motor. The down side is that you can't leave the boat for more than a couple of days to explore an island and box temps tend to oscillate. Electrically powered systems have one primary advantage: with good controls, shore power, a lot of solar panels or a wind generator and lots of wind they can be made to operate unattended. This can be a distinct advantage if you are off the boat for more than a day or two. They can be further divided into AC and DC systems. AC systems are usually a motor driving either an automotive or small commercial compressor either directly or through a belt. They are closely akin to engine driven in that they normally use a holding plate and can freeze the plates almost as fast but away from shore power the engine usually must be running to generate the power needed to run the motor which means it has the same limitations plus not being quite as efficient away from shore power due to losses in the alternator, battery charging and inverter. DC systems can be divided further into holding plate and evaporator systems and the compressors into discrete compressor/motor assemblies or hermetically sealed compressors. The discrete compressors are similar to the AC system being linked to the motor either directly or via a belt and usually freezing a holding plate. There is a practical limit to DC of 1 1/2 HP motor so they are not as powerful as AC or engine drives. They also tend to be noisy. Hermetic DC systems usually drive an evaporator and are more closely kin to a domestic refrigerator. Most are based on one of the Danfoss compressors which are gradually getting more efficient. They cycle on and off all the time and will therefore maintain a more constant box temperature and, with solar panels or other alternate charging source can operate constantly while the boat is not in use but they can consume 20% to 40% more energy. Skip Gundlach wrote: I may even have it from somewhere before, but the recent conversations on reefers brought it to mind: Someone on these lists built a direct drive 12V compressor for refrigeration. My recollection has it connected to cold plates. It was designed to do what an engine drive would do, but not run the engine. At the time I saw it, it was new. If they're reading, I'd be interested to see a report on its efficacy. How much power did/does it take to operate? Was the size of the compressor notably less than one on the engine, and if so, what is the relative run time? In the end, are you happy with the outcome? If not, or even so, is there anything you'd have done differently if you were doing it again? Thanks. L8R Skip (and Lydia, by proxy), thinking of how to use the lovely cooling system on the boat without running the engine or the AC air-cooled system, either -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
12V refrigeration
Now, with the basics out of the way, MHO: This is not a good idea. It
looks like the worst of both worlds. 12VDC hermetic compressors are pretty well limited to 1/4 HP or less. That will take a looong time at full power to freeze a decent size holding plate. Several makers of hermetic systems do offer holding plates but strongly discourage their use. Skip Gundlach wrote: I may even have it from somewhere before, but the recent conversations on reefers brought it to mind: Someone on these lists built a direct drive 12V compressor for refrigeration. My recollection has it connected to cold plates. It was designed to do what an engine drive would do, but not run the engine. At the time I saw it, it was new. If they're reading, I'd be interested to see a report on its efficacy. How much power did/does it take to operate? Was the size of the compressor notably less than one on the engine, and if so, what is the relative run time? In the end, are you happy with the outcome? If not, or even so, is there anything you'd have done differently if you were doing it again? Thanks. L8R Skip (and Lydia, by proxy), thinking of how to use the lovely cooling system on the boat without running the engine or the AC air-cooled system, either -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
12V refrigeration
I have a 12V DC belt driven setup. Based upon the size of the
pulley on the motor and compressor, a direct drive system would seem to be rather tricky. My motor and compressor are both 3/4 HP. Draws 50A when running. Doug s/v Callista "Skip Gundlach" wrote in message ... I may even have it from somewhere before, but the recent conversations on reefers brought it to mind: Someone on these lists built a direct drive 12V compressor for refrigeration. My recollection has it connected to cold plates. It was designed to do what an engine drive would do, but not run the engine. At the time I saw it, it was new. If they're reading, I'd be interested to see a report on its efficacy. How much power did/does it take to operate? Was the size of the compressor notably less than one on the engine, and if so, what is the relative run time? In the end, are you happy with the outcome? If not, or even so, is there anything you'd have done differently if you were doing it again? Thanks. L8R Skip (and Lydia, by proxy), thinking of how to use the lovely cooling system on the boat without running the engine or the AC air-cooled system, either -- Morgan 461 #2 SV Flying Pig http://tinyurl.com/384p2 "And then again, when you sit at the helm of your little ship on a clear night, and gaze at the countless stars overhead, and realize that you are quite alone on a great, wide sea, it is apt to occur to you that in the general scheme of things you are merely an insignificant speck on the surface of the ocean; and are not nearly so important or as self-sufficient as you thought you were. Which is an exceedingly wholesome thought, and one that may effect a permanent change in your deportment that will be greatly appreciated by your friends." - James S. Pitkin |
12V refrigeration
The new Glacier Bay system uses a hermetic Danfoss (pretty sure
it is a Danfoss) compressor with cold plates. From what I can gather it works very well. Can even power a 6000BTU air conditioner as well. Doug s/v Callista "Glenn Ashmore" wrote in message news:mV%Ec.54$jp1.21@lakeread04... Now, with the basics out of the way, MHO: This is not a good idea. It looks like the worst of both worlds. 12VDC hermetic compressors are pretty well limited to 1/4 HP or less. That will take a looong time at full power to freeze a decent size holding plate. Several makers of hermetic systems do offer holding plates but strongly discourage their use. Skip Gundlach wrote: I may even have it from somewhere before, but the recent conversations on reefers brought it to mind: Someone on these lists built a direct drive 12V compressor for refrigeration. My recollection has it connected to cold plates. It was designed to do what an engine drive would do, but not run the engine. At the time I saw it, it was new. If they're reading, I'd be interested to see a report on its efficacy. How much power did/does it take to operate? Was the size of the compressor notably less than one on the engine, and if so, what is the relative run time? In the end, are you happy with the outcome? If not, or even so, is there anything you'd have done differently if you were doing it again? Thanks. L8R Skip (and Lydia, by proxy), thinking of how to use the lovely cooling system on the boat without running the engine or the AC air-cooled system, either -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
12V refrigeration
Hi, Doug, and thanks for the bounce.
"Doug Dotson" wrote in message ... I have a 12V DC belt driven setup. Based upon the size of the The one I had in mind (I saw pix of the setup, mounted on a breadboard; the shaft went directly to the compressor) was direct, not belt, driven. pulley on the motor and compressor, a direct drive system would seem to be rather tricky. My motor and compressor are both 3/4 HP. Draws 50A when running. 50A is a *BIG* load. How long does it run per cycle, and per day, typically? And, does that include the water pump, or is that an additional load? Another alternative I've seen, though it's a bit of an around-the-barn approach unless one is hooked up to shore power (recall from other discussions I really don't want to be running engines, whether propulsion or generator if I don't have to, and this would require an inverter). That's a washing machine or other similarly cheaply acquired motor with appropriately geared pulley driving the engine-driven compressor which has been set up with two/double pulleys and a means of quick-change on attitude so as to relieve the engine belt and engage the AC belt. You get the same output as with the engine but without running it. Ideal, perhaps for marina dwellers, but perhaps a bit of a kludge for everyday cruisers on the hook for days at a time, but not really long term. That, of course plus the accumulated draw with the inverter and pumps might be in the same ballpark as yours... L8R Skip -- Morgan 461 #2 SV Flying Pig http://tinyurl.com/384p2 "And then again, when you sit at the helm of your little ship on a clear night, and gaze at the countless stars overhead, and realize that you are quite alone on a great, wide sea, it is apt to occur to you that in the general scheme of things you are merely an insignificant speck on the surface of the ocean; and are not nearly so important or as self-sufficient as you thought you were. Which is an exceedingly wholesome thought, and one that may effect a permanent change in your deportment that will be greatly appreciated by your friends." - James S. Pitkin |
12V refrigeration
I have to hand it to Kevin. He can squeeze out more heat with less amps
than anybody else in the business but the bleeding edge comes at a price. That GB compressor does look sort of like a BD50 but I just can't imagine Kevin lowering himself to that. :-) Actually the compressor has some subtle physical differences that make some big differences in efficiency and he has licenced the production to one of the biggies like Tecumseh or somebody. The other main difference is the recovery system that sucks the last bit of heat out of the refirgerant. The numbers look impressive but so does the price. Doug Dotson wrote: The new Glacier Bay system uses a hermetic Danfoss (pretty sure it is a Danfoss) compressor with cold plates. From what I can gather it works very well. Can even power a 6000BTU air conditioner as well. Doug s/v Callista "Glenn Ashmore" wrote in message news:mV%Ec.54$jp1.21@lakeread04... Now, with the basics out of the way, MHO: This is not a good idea. It looks like the worst of both worlds. 12VDC hermetic compressors are pretty well limited to 1/4 HP or less. That will take a looong time at full power to freeze a decent size holding plate. Several makers of hermetic systems do offer holding plates but strongly discourage their use. Skip Gundlach wrote: I may even have it from somewhere before, but the recent conversations on reefers brought it to mind: Someone on these lists built a direct drive 12V compressor for refrigeration. My recollection has it connected to cold plates. It was designed to do what an engine drive would do, but not run the engine. At the time I saw it, it was new. If they're reading, I'd be interested to see a report on its efficacy. How much power did/does it take to operate? Was the size of the compressor notably less than one on the engine, and if so, what is the relative run time? In the end, are you happy with the outcome? If not, or even so, is there anything you'd have done differently if you were doing it again? Thanks. L8R Skip (and Lydia, by proxy), thinking of how to use the lovely cooling system on the boat without running the engine or the AC air-cooled system, either -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
12V refrigeration
It surely is expensive.
"Glenn Ashmore" wrote in message news:vo3Fc.249$jp1.15@lakeread04... I have to hand it to Kevin. He can squeeze out more heat with less amps than anybody else in the business but the bleeding edge comes at a price. That GB compressor does look sort of like a BD50 but I just can't imagine Kevin lowering himself to that. :-) Actually the compressor has some subtle physical differences that make some big differences in efficiency and he has licenced the production to one of the biggies like Tecumseh or somebody. The other main difference is the recovery system that sucks the last bit of heat out of the refirgerant. The numbers look impressive but so does the price. Doug Dotson wrote: The new Glacier Bay system uses a hermetic Danfoss (pretty sure it is a Danfoss) compressor with cold plates. From what I can gather it works very well. Can even power a 6000BTU air conditioner as well. Doug s/v Callista "Glenn Ashmore" wrote in message news:mV%Ec.54$jp1.21@lakeread04... Now, with the basics out of the way, MHO: This is not a good idea. It looks like the worst of both worlds. 12VDC hermetic compressors are pretty well limited to 1/4 HP or less. That will take a looong time at full power to freeze a decent size holding plate. Several makers of hermetic systems do offer holding plates but strongly discourage their use. Skip Gundlach wrote: I may even have it from somewhere before, but the recent conversations on reefers brought it to mind: Someone on these lists built a direct drive 12V compressor for refrigeration. My recollection has it connected to cold plates. It was designed to do what an engine drive would do, but not run the engine. At the time I saw it, it was new. If they're reading, I'd be interested to see a report on its efficacy. How much power did/does it take to operate? Was the size of the compressor notably less than one on the engine, and if so, what is the relative run time? In the end, are you happy with the outcome? If not, or even so, is there anything you'd have done differently if you were doing it again? Thanks. L8R Skip (and Lydia, by proxy), thinking of how to use the lovely cooling system on the boat without running the engine or the AC air-cooled system, either -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
12V refrigeration
Skip,
Comments below. Doug s/v Callista "Skip Gundlach" wrote in message ... Hi, Doug, and thanks for the bounce. "Doug Dotson" wrote in message ... I have a 12V DC belt driven setup. Based upon the size of the The one I had in mind (I saw pix of the setup, mounted on a breadboard; the shaft went directly to the compressor) was direct, not belt, driven. I understand that. It is just that a 1:1 coupling would seem not to be able to drive the compressor at it's most efficent speed. That is just my gut feeling based upon my experience which is not extensive by any stretch. I believe my motor runs at 1800 RPM. The pully on the motor is maybe 3 inches in diameter and the one on the compressor is perhaps 10 inches. It requires alot of torque to spin a 3/4 HP compressor under full load. pulley on the motor and compressor, a direct drive system would seem to be rather tricky. My motor and compressor are both 3/4 HP. Draws 50A when running. 50A is a *BIG* load. How long does it run per cycle, and per day, typically? And, does that include the water pump, or is that an additional load? When on ships power I run it twice per day. Once in the morning and once in the afternoon. It generally runs about 40-45 minutes to freeze the plates. This is the most efficient mode. When plugged into shorepower, I allow it to run automatically with a thermostat controlling everything. It runs longer in terms of total running time since the first 5 minutes or so of running time doesn;t actually cool much. It generally kicks in every couple of hours for 15 minutes or so. This is supportting a 9 cu-ft freezer box and a 12 cu-ft fridge box in a spillover arrangement. The water pump draws a whopping half an amp I think. Another alternative I've seen, though it's a bit of an around-the-barn approach unless one is hooked up to shore power (recall from other discussions I really don't want to be running engines, whether propulsion or generator if I don't have to, and this would require an inverter). That's a washing machine or other similarly cheaply acquired motor with appropriately geared pulley driving the engine-driven compressor which has been set up with two/double pulleys and a means of quick-change on attitude so as to relieve the engine belt and engage the AC belt. You get the same output as with the engine but without running it. Ideal, perhaps for marina dwellers, but perhaps a bit of a kludge for everyday cruisers on the hook for days at a time, but not really long term. That, of course plus the accumulated draw with the inverter and pumps might be in the same ballpark as yours... That will work. Probably better to buy a small fridge at Home Depot if one is in a marina most of the time. L8R Skip -- Morgan 461 #2 SV Flying Pig http://tinyurl.com/384p2 "And then again, when you sit at the helm of your little ship on a clear night, and gaze at the countless stars overhead, and realize that you are quite alone on a great, wide sea, it is apt to occur to you that in the general scheme of things you are merely an insignificant speck on the surface of the ocean; and are not nearly so important or as self-sufficient as you thought you were. Which is an exceedingly wholesome thought, and one that may effect a permanent change in your deportment that will be greatly appreciated by your friends." - James S. Pitkin |
12V refrigeration
Skip:
Theoretical considerations aside, my advice would be to insulate your box to the hilt and then install one of the many DC driven Danfoss compressor systems with a direct evaporator coil, ie no holding plate. Alder Barbour and others make them. David |
12V refrigeration
Hi, and thanks for the response.
"David&Joan" wrote in message news:9i4Fc.6732$151.2942@fed1read02... Skip: Theoretical considerations aside, my advice would be to insulate your box to the hilt and then install one of the many DC driven Danfoss compressor systems with a direct evaporator coil, ie no holding plate. Alder Barbour and others make them. David Ah - now we get back to the discussion of evaporators and cold plates. I've just got this thing for cold plates - and ours is an Adler Barbour system - but if evaporators worked well, and I felt comfortable about not having to worry about dinging them, I suppose I'd be ok with them. However, I'm still trying to come up with the most efficient overall electrical plan which doesn't use internal combustion any more than absolutely necessary. Stories of reefers running happily off the solar or wind make me happy, because most of the time they wouldn't need the battery during the day, which - at least in the high season - will be when we're gone most of the time. Depending on how much they cost, a belt-and-suspenders approach might be worthwhile to consider: We're going to redo the reefer. It's 19CF, with cold plates added some time along the way, with a single hatch (see URL pix in sig), as originally laid out as an icebox by Moorings, but divided so that a freezer section would be easy. When we redo the top to have two hatches, as it's so big, we'll add insulation and some fancy ceramic paint which adds some amazing R value for a coat of paint. It's plenty big to add some insulation material and leave the current cold plates (engine and AC on one of them, both 26* units), *and* add evaporator plates around the perimeters. I also intend micro fans (always on, in the bottoms) to move the air to even out the temps, and mega gaskets and way-insulated tops as well. (I recall reading that the only notable difference in the high-insulating coolers for the picnic/camper/RV-tailgater crowd is an insulated vs not insulated lid, and others in these fora and various mailing lists have cited the same in their boxes' efficiency.) Glenn was kind enough to give me a long dissertation on the merits of cold plates and evaporators long ago in this space, so we don't need a repetition, though others just joining the party might enjoy it/them. I'm still of mixed mind. In the end, I want it to stay cold in the most efficient manner. This will be our home, all year round, in the tropics, so doing it well is important. The specific means of achievement (cold plate, evaporator or mix)isn't really important. Part of my challenge is, I realize, a fetish about not running internal combustion motors if I can avoid it, complicated by our expected lifestyle of working ashore with the boat on a mooring for some months per year. I anticipate we'll have awnings and shades, but we won't run A/C, so it will be warm inside... Thanks again for the input... L8R Skip and Lydia -- Morgan 461 #2 SV Flying Pig http://tinyurl.com/384p2 "And then again, when you sit at the helm of your little ship on a clear night, and gaze at the countless stars overhead, and realize that you are quite alone on a great, wide sea, it is apt to occur to you that in the general scheme of things you are merely an insignificant speck on the surface of the ocean; and are not nearly so important or as self-sufficient as you thought you were. Which is an exceedingly wholesome thought, and one that may effect a permanent change in your deportment that will be greatly appreciated by your friends." - James S. Pitkin |
12V refrigeration
I have a 8 foot fridge and a 5 foot freezer cooled by a 1/2 hp Crosby holding
plate system. If I had to do it over again, I might go with two Danfoss base units. Redundancy and flexibility are good. "David&Joan" wrote in message news:9i4Fc.6732$151.2942@fed1read02... Skip: Theoretical considerations aside, my advice would be to insulate your box to the hilt and then install one of the many DC driven Danfoss compressor systems with a direct evaporator coil, ie no holding plate. Alder Barbour and others make them. David |
Alternative power Refrigeration
It is possible to have refrigeration on your boat without running the
engine. Here is a basic design concept that will allow wind or solar power to support onboard refrigerator. 1. The refrigerated box needs to have at least four inches of encapsulated urethane insulation. The size of the box and the temperature to be maintained inside the box will determine the daily energy required. 2. The decision as to wind or solar for energy depends on anchoring and cruising locations. Large heavy boats that like to anchor out where there is more of a breeze might be better suited to wind power. In South Florida Solar Power seems to be the preferred alternative power. 3. There are only two small 12 volt compressors today that can be efficiently adapted to wind or solar power, the Danfoss BD35 and BD50. 4. To take full advantage of the new Danfoss variable speed efficiency with alternative energy, manual or automatic speed switching controls are required. 5. It is also possible to save 3 to 6 amp-hrs per day in some cruising areas with a keel cooler. Here is an example of a system in a three cubic ft. box with four inches of urethane insulation, with a planed cruising area of the Bahamas: The condensing unit would be a Danfoss BD35 compressor either a WAECO 85 or a Technautics Coolblue. If the Coolblue were selected which is a holding plate system a voltage startup switch would be added This switch would bypass the thermostat when a charge current was available from any source exceeding 12.8 volts the compressor would run. Seventy five watts of un-shaded, adjustable solar panels is the minimum requirement for this example. Two additional gulf cart six volt batteries are needed to produce 12 volts and would be wired to solar panels and refrigeration unit. Between the gulf cart bank and the house bank there is a Battery Combiner to link them together when a charge current is available. To complete the system a battery monitoring instrument is required. There are several wiring diagrams of these systems in my 12/24 Volt Refrigeration Manual From the author of four books on boat refrigeration http://www.kollmann-marine.com "Skip Gundlach" wrote in message ... Hi, and thanks for the response. "David&Joan" wrote in message news:9i4Fc.6732$151.2942@fed1read02... Skip: Theoretical considerations aside, my advice would be to insulate your box to the hilt and then install one of the many DC driven Danfoss compressor systems with a direct evaporator coil, ie no holding plate. Alder Barbour and others make them. David Ah - now we get back to the discussion of evaporators and cold plates. I've just got this thing for cold plates - and ours is an Adler Barbour system - but if evaporators worked well, and I felt comfortable about not having to worry about dinging them, I suppose I'd be ok with them. However, I'm still trying to come up with the most efficient overall electrical plan which doesn't use internal combustion any more than absolutely necessary. Stories of reefers running happily off the solar or wind make me happy, because most of the time they wouldn't need the battery during the day, which - at least in the high season - will be when we're gone most of the time. Depending on how much they cost, a belt-and-suspenders approach might be worthwhile to consider: We're going to redo the reefer. It's 19CF, with cold plates added some time along the way, with a single hatch (see URL pix in sig), as originally laid out as an icebox by Moorings, but divided so that a freezer section would be easy. When we redo the top to have two hatches, as it's so big, we'll add insulation and some fancy ceramic paint which adds some amazing R value for a coat of paint. It's plenty big to add some insulation material and leave the current cold plates (engine and AC on one of them, both 26* units), *and* add evaporator plates around the perimeters. I also intend micro fans (always on, in the bottoms) to move the air to even out the temps, and mega gaskets and way-insulated tops as well. (I recall reading that the only notable difference in the high-insulating coolers for the picnic/camper/RV-tailgater crowd is an insulated vs not insulated lid, and others in these fora and various mailing lists have cited the same in their boxes' efficiency.) Glenn was kind enough to give me a long dissertation on the merits of cold plates and evaporators long ago in this space, so we don't need a repetition, though others just joining the party might enjoy it/them. I'm still of mixed mind. In the end, I want it to stay cold in the most efficient manner. This will be our home, all year round, in the tropics, so doing it well is important. The specific means of achievement (cold plate, evaporator or mix)isn't really important. Part of my challenge is, I realize, a fetish about not running internal combustion motors if I can avoid it, complicated by our expected lifestyle of working ashore with the boat on a mooring for some months per year. I anticipate we'll have awnings and shades, but we won't run A/C, so it will be warm inside... Thanks again for the input... L8R Skip and Lydia -- Morgan 461 #2 SV Flying Pig http://tinyurl.com/384p2 "And then again, when you sit at the helm of your little ship on a clear night, and gaze at the countless stars overhead, and realize that you are quite alone on a great, wide sea, it is apt to occur to you that in the general scheme of things you are merely an insignificant speck on the surface of the ocean; and are not nearly so important or as self-sufficient as you thought you were. Which is an exceedingly wholesome thought, and one that may effect a permanent change in your deportment that will be greatly appreciated by your friends." - James S. Pitkin |
12V refrigeration
We have an old system which by all accounts should not work. Sort of
like the bumblebee which should not be able to fly. It is a combined 110 AC system with an engine driven system. We run the system twice a day for about 40 minutes. Since it is an old system, it could probably use more insulation, and it is such a large space that it is hard to keep on top of what's actually in there. Plus it isn't on a thermostat so we have to be there on the boat to run it. We have to be very careful how long we run the engine driven or the compressor will freeze up - the 110 system can be go a bit longer without a problem. I'm sure it is a holding plate system. grandma Rosalie S/V RosalieAnn, Leonardtown, MD CSY 44 WO #156 http://home.mindspring.com/~gmbeasley/id2.html |
12V refrigeration
Hi, Grandma :{))
"Rosalie B." wrote in message ... We have an old system which by all accounts should not work. Sort of like the bumblebee which should not be able to fly. It is a combined 110 AC system with an engine driven system. We run the system twice a day for about 40 minutes. Since it is an old system, it could probably use more insulation, and it is such a large space that it is hard to keep on top of what's actually in there. Plus it isn't on a thermostat so we have to be there on the boat to run it. We have to be very careful how long we run the engine driven or the compressor will freeze up - the 110 system can be go a bit longer without a problem. I'm sure it is a holding plate system. Sounds just like what we have. Somewhere along the way, quite recently, a 110 air-cooled unit was added. The lines go into one of the holding plates. I didn't think to look to see if the other plate has input for them, but it's probably irrelevant, as I can't conceive ever running our 110 refrigeration except at the dock (unless the solar and wind output is so big that running it from an inverter wouldn't matter) - where we expect to be only extremely rarely. Along with the (one each new and older-style) Lectra-Sans, the 600 hour 6.5KW Onan/Kubota 3600RPM generator, the SS davits and whoknowswhatelse, this might be one of the items available to purchase as we refit! L8R Skip and Lydia -- Morgan 461 #2 SV Flying Pig http://tinyurl.com/384p2 "And then again, when you sit at the helm of your little ship on a clear night, and gaze at the countless stars overhead, and realize that you are quite alone on a great, wide sea, it is apt to occur to you that in the general scheme of things you are merely an insignificant speck on the surface of the ocean; and are not nearly so important or as self-sufficient as you thought you were. Which is an exceedingly wholesome thought, and one that may effect a permanent change in your deportment that will be greatly appreciated by your friends." - James S. Pitkin |
12V refrigeration
"Skip Gundlach"
wrote: Hi, Grandma :{)) Hi "Rosalie B." wrote in message .. . We have an old system which by all accounts should not work. Sort of like the bumblebee which should not be able to fly. It is a combined 110 AC system with an engine driven system. We run the system twice a day for about 40 minutes. Since it is an old system, it could probably use more insulation, and it is such a large space that it is hard to keep on top of what's actually in there. Plus it isn't on a thermostat so we have to be there on the boat to run it. We have to be very careful how long we run the engine driven or the compressor will freeze up - the 110 system can be go a bit longer without a problem. I'm sure it is a holding plate system. Sounds just like what we have. Somewhere along the way, quite recently, a 110 air-cooled unit was added. The lines go into one of the holding plates. Our system came with both systems as OE. Some people replace them with just engine driven, or with genset driven or with something they can run off of solar or wind power. We keep on using our OE which is way cheaper than getting a replacement. It's way cheaper than replacing it, since it works for us for now. I didn't think to look to see if the other plate has input for them, but it's probably irrelevant, as I can't conceive ever running our 110 refrigeration except at the dock (unless the solar and wind output is so big that running it from an inverter wouldn't matter) - where we expect to be only extremely rarely. Along with the (one each new and older-style) Lectra-Sans, the 600 hour 6.5KW Onan/Kubota 3600RPM generator, the SS davits and whoknowswhatelse, this might be one of the items available to purchase as we refit! L8R Skip and Lydia grandma Rosalie |
12V refrigeration
"Doug Dotson" wrote in
: I have a 12V DC belt driven setup. Based upon the size of the pulley on the motor and compressor, a direct drive system would seem to be rather tricky. My motor and compressor are both 3/4 HP. Draws 50A when running. Doug s/v Callista You know, many times while sailing along watching the shaft pulling the shaft alternator at 20A or so, I've thought to myself, "Where will the little R-134A compressor go on a longer belt to that alternator?" "Why is the fridge running off power through so many "conversion losses"?"...... We'll need a liquid-thermostatic-controlled variable speed transmission....(c; Can we build one for your shaft? Larry If you don't think that shaft has the power to run it, try to stop it from turning at 8 knots. |
12V refrigeration
"David&Joan" wrote in
news:9i4Fc.6732$151.2942@fed1read02: Skip: Theoretical considerations aside, my advice would be to insulate your box to the hilt and then install one of the many DC driven Danfoss compressor systems with a direct evaporator coil, ie no holding plate. Alder Barbour and others make them. David AAAAACCCCCKKKKKK!!!! ADLER BARBOUR!! If you install an Adler-Barbour electronic 12V compressor, be SURE you put it into an RF shielded screen room! We had one on "Claire's Navie" that had this AWFUL pulsing RF noise ON VHF CHANNEL 16!.... Bzzt....Bzzt.....Bzzt,Bzzt,Bzzt.....Bzzt......Bzzt .......Bzzt, Bzzt, Bzzt....repeating the exact sequence of SQUELCH OPENINGS on both VHF radios for your entire watch! Drove us crazy until I turned the damned thing OFF~! Only bothered Channel 16...of all the channels....JUST 16. Larry |
12V refrigeration
Radio Frequency Interference (RFI) Is not an Adler Barbour
refrigeration problem as Larry indicates it is a boat refrigeration industry problem. It seems that only a very few boaters are concerned with RFI, the others are willing to set the VHF squelch high enough to silence it out. A few system manufacturers have received complaints from ham operators about RF from their refrigerators or other boat's refrigerator's parked nearby. On the few boats that are experiencing a problem the full box copper screen over the condensing unit does seem to satisfy at least three radio operators that answered my resent survey. Larry W4CSC wrote in message ... "David&Joan" wrote in news:9i4Fc.6732$151.2942@fed1read02: Skip: Theoretical considerations aside, my advice would be to insulate your box to the hilt and then install one of the many DC driven Danfoss compressor systems with a direct evaporator coil, ie no holding plate. Alder Barbour and others make them. David AAAAACCCCCKKKKKK!!!! ADLER BARBOUR!! If you install an Adler-Barbour electronic 12V compressor, be SURE you put it into an RF shielded screen room! We had one on "Claire's Navie" that had this AWFUL pulsing RF noise ON VHF CHANNEL 16!.... Bzzt....Bzzt.....Bzzt,Bzzt,Bzzt.....Bzzt......Bzzt .......Bzzt, Bzzt, Bzzt....repeating the exact sequence of SQUELCH OPENINGS on both VHF radios for your entire watch! Drove us crazy until I turned the damned thing OFF~! Only bothered Channel 16...of all the channels....JUST 16. Larry |
12V refrigeration
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