Author Topic: Archive 3  (Read 5467 times)

Richard

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Archive 3
« on: May 03, 2012, 10:45:26 am »

Archive 3

insulation inside box
I am about to add Armaflex 1" to the inside of my box on an Irwin 37 CC built in 1982. There is an old FRIGABAR unit installed that runs about 80% of the time. The Armaflex is a closed cell foam used to cover A/C duct, it is very flexable so will follow the hull on one side. I realize the R 3.57 is not a lot and can lamanate another piece if needed. If 1" does well I probably will line the inside with Ventureclad sheet to give the box inside a white or foil finish to prevent moisture getting to the foam and add a reflective finish instead of the black foam. I plan to cut paper pattern(s) for the sides and top, cut the Armaflex from the pattern and attach to inside the box with Armaflex 520. I plan to do wet seams in corners and edges. Comments/suggestions would be appreciated. Blue board is not very flexable and about the same R-value. Armaflex is very moisture resistant and is not suposed to support mold growth when wet. I am full time live aboard Melbourne FL and do the Bahamas so warm water nearly year round. I have 2 120 Watt solar panels and a Windbugger with a Balmar 110 Amp alternator to charge golfcart batteries 4 for the house and 2 for cranking. Each system has its own smart regulator. PEGASUSMC

Pipe Insulation for Refrigerator
Frigabar and similar Danfoss condensing units in 1982 lacked air cooling capacity to be efficient in warm climates. If you will enclose the fan with a shroud so that all of its intake air must be drawn through the coil and replace the fan with a 80 to 100 CFM volume fan the compressor run time will be greatly reduced. I have seen tube type insulation used in large chilled water air conditioning systems but these systems work at a much lower delta T than would be experienced in boat refrigeration. I would contact Armaflex and ask them two questions; which of their flexible insulation products do they recommend for a Refrigerator or freezer? And since the exterior membrane is only on the outside will the ends need to be sealed some how? I am afraid that my knowledge of the various types of insulation is limited to my own experience and those of boaters reporting problems with their refrigerated boxes. We all know that the amount of water in the air, humidity, will separate from the air on a cooler object when its surface temperature reaches its saturated dew point. A glass of ice water or a refrigerators exterior will collect moisture if the surface temperature is above the dew point. I believe that when the insulation keeps exterior skin of a boats refrigerated box within four degrees with a 90 degrees F ambient cabin air temperature, that amount of insulation is adequate. All insulation manufacturers list their products R value in the dry state almost no moisture content. Closed cell is a term used indicating each cell containing gas is surrounded by a water resistant membrane. Urethane insulations are defined as closed cell but have a faster rate of aging allowing moisture to enter cells. After insulating gas leaks out and moisture inters that cell, energy efficiency is lost. To help extend the life of urethane insulation a envelope of sealed plastic can be used. One can only guess how long urethane will be effective in a boats box, my belief is it looses 50% of its R valve in 20 years if not in direct sunlight. Extruded polystyrene products like DOWs Blue Board have a far greater resistance to moisture intrusion than urethane but have a lower R value.

armaflex
Thanks for the reply and thoughts. My plan is to use 3'X4' sheets of Armaflex and the Ventureclad (again sheet) should keep moisture away from the Armaflex. This stuf is 5 ply with a foil type finish, very expensive at $1.44 sq ft. The Armaflex was $18.00 per sheet, I will use 2 sheets. I have not found anyone who has tried this method, I do know 2 who have used the Blueboard with success. I do not think it would bend enough to contour my hull, it would break or have to be cut leaving a gap at the seams. pegasusmc

frigoboat / Sanden SD505
I have a frigoboat/frigomate unit in my relative new to me sailboat. There is a Sanden SD505 on the engine. I have not had the opportunity to use the refrigerator to this point. I did test it last year and it seemed to work. I am not 100% sure how to turn this thing on. There is one switch on the panel that turns on a fan that it part of the frigomate installation. There is a dial switch (timer) above the eletric panels. I think that the clutch in front of the Sanden should come on when I turn the timer on, but it does not. When I turn the panel switch on, the fan comes on by the frigomate. Am I doing something wrong to turn the unit on?

Engine Driven Refrigeration Power
I no longer have information on Frigoboats engine driven refrigeration but I will describe the electrical circuit as best I can. Are you sure the fan has something to do with the refrigeration system? The power source starts either at a circuit breaker or the engine key or engine warning switch. There may even be a fuse in this circuit. From the power source a single hot wire runs to the timer. When the power is on and timer is on power is sent to a high pressure switch on top of the refrigerator seawater condenser. This switch is designed to protect the system if water cooling is inadequate. Generally these switches are auto reset but some are manually reset by a red button on top. The single power wire is in series through the above then extends to the compressor clutch. Ounce the compressor clutch has power to it the circuit must be completed by grounding compressor to engine. There are some manuals available for boat refrigeration at: ttp://www.thermaldynamicssales.com/Manuals.html#, but I dont see the Frigomate model listed. Even if there were a manual I dough it would show the power source for your boats wiring. The normal troubleshooting for this problem is, without the engine running, to place a fused jumper wire across each component in the wiring until you hear the clutch snap closed. Do not run engine with any component bypassed.

Insulation
Address for E Marine http://www.e-marine-inc.com/ You must decide on how much insulation is enough, in the tropics R 30 is generally acceptable. North of Latitude 30 N, R15 might be enough insulation. Whatever box liner material you use over insulation should be impact resistant and be able to support the weight of product put in box. Formica without a solid backing is not impact resistant.


I took another look at my system today. It may be possible that I have tow systems installed. Yes, the fan is mountedunder the sink area. It looks simular to a computer power supply fan and it blows over a radiator like grill. There is a little black tank (compressor?) and a box where the electrical connects that has a fuse, and a light for low battery. The other connections are marked for temp control I think. the compressor has lines that enter the ref. box and connect ot a flat like aluminum (condenser?) that wraps around two sides of the compartment. It is about 15" high. The only switch I see that looks lik it controls this unit is on the panel board. It is marked ref. When I turn it on, the fan runs but I cannot tell if anything else is happening. Now, for theother unit that has a compressor on the motor. I checked the compressor by turning the clutch by hand and it turns freely. I ran a wire from the positive terminal to the wire going to the compressor and it clicks the clutch into gear.When I start the engine and turn the frigoboat timer on, the clutch does not engage.I used an ohm meter to verify as many of the wires as I could and found them ok. One wire from the timer goes to the positive connection on the wire bank, and the other goet to what I think is either a relay, or switch. It has the name Cartier and 12 V 03104 on it. It also has a wire diagramof the five post that exit it. A blue wire leaves one of the post of this piece and goes through a reset switch and then to a white cylinder in the engine compartment. Here it goest to a device attached to the cylinder( maybe a sensor?) and then to the compressor. There is a brown wire that leaves theCatier and ends up not connected to anything by the compressor. A green and white wire leaves the Catier and goes to anothe device simular that is by the alternator whit several other wires. That pretty much describes the setup and the only part I could not figure out is how the power gets to the compressor to engage the clutch. Not sure what the green and white wire does at the alternator. Would this be somthing to do with the engine switch needing to be on to complete the connection? If so, I will need to trouble shoot some more.


Oh, I forgot that the other device in the ref. compartment looks like what Frigobot describes as a holding tank. It is rectangular, and about 3" deep.

Pictures
It sounds to me like you have two completely independent systems, an engine driven and a 12 volt system. If I am right there is no connection between the two. I am only guessing as your description is puzzling to me. If I am to help you I will need a complete set of pictures of all components in each area. As many pictures as possible and they dont need to be in focus. Once I see your systems I will be able to help you. This may sound like a difficult process but I have been using it all over the world for twenty years. Please number the pictures. The unit with the fan sounds like a Danfoss compressor powered condensing unit system, could be Adler Barbour as they are the only company that has red light on control module. With a picture I will be able to help. For now do a quick test; Do what ever you did to start the fan and let it run for 15 minutes. Then feel the thin plate in refrigerated box if it feels cold that system is probably OK. And there will be a thermostat control for that system in the box. If the fan stops see if the red light flashes, if it flashes once and pauses for four seconds the battery voltage is low.

Kal-lite alternative
In a post from a couple years ago, you recommended Kal-lite as a box liner, and at that time it was apparently carried by Home Depot. They appear to no longer carry it (also here in Ft. Lauderdale :) ). Will any of the plastic-like wall panels work? Do you have any particular product that you are aware of that you would recommend? Thanks again.

Box Liner Material
Maybe I made a mistake by listing a product name Kal-lite, what I should have said was impact resistance opaque white plastic or a Poltruded fiberglass. These materials are used for wall liners in walk in coolers, shower stalls and splash wall panels in industrial kitchens. This paneling comes in 4x8 ft. sheets with a thickness of 1/8 to inch thick. One boat box builder reported he used 3/8 in white plastic solid sheet that is used to make real-estate signs. In Ft. Lauderdale I would check with Bingham Insulation for liner advice as most people here buy their insulation from them. They are located three blocks south of Lesters Diner on Third Avenue.


Many thanks, Mr. Kollmann...for your books and for all your assistance to so many of us struggling novices. :)

Pull down time, etc.
I am the new owner of a 43' sailing cat with a custom-built freezer/refrigerator. The box is 7 cu. ft. total with a 50 % divider panel. An AB super cold plate is refrigerated by a water-cooled super cold machine and is installed vertically in the freezer section. I attempted to pull the unit all the down to the controlling range of the thermostat w/o success. The cold plate freezes and takes 3 or 4 hours to thaw. Suction pressure is 6 lbs. Insulation looks very good but is only 3 inches on the top (unknown on the sides and bottom but the evidence points to more substantial foam). The freezer side will only pull down to 26 degrees F and that only after insulating the plywood divider panel with RMax. I'm headed to the Bahamas in a week or so and am in Boot Key Harbor now. What should I do next?

additional information
I wrote the previous query late last night and forgot to mention that the box took 12 hours or so to pull down to 27 degrees. Everything in my experience points to insulation as the culprit but maybe I'm missing something. Where can I get a refrigeration diagram for the AB super cold machine so that I'll know what I'm looking at? For example, there is a diaphram control device that looks like a suction pressure regulator fitted but that is inconsistant with a freezer application in my experience (which is entirely with large shipboard units). How can order a copy of your books?