Refrigeration of multiple coolers

[artbyjody]

I have two almost equal sized coolers on the Barberis. They approximately hold 8-12 cases of 18 pack beers (cans) with room to spare (one is slightly smaller). Both are separated by the propane stove. I am really tired of trying to keep these cool with ice.

Is it possible to use one condenser unit to feed both and still be able to control the temps of each separately - or do I have to go with dual compressors on this. I prefer to keep the built in coolers as they are already maximized for amount of storage.

My intent was to use a single remote Aldour compressor rated for use in the engine compartment - and two large evaporator plates (one in each) - but what I can tell from scoping this project out, there is no way to regulate the temps on the individual coolers...

So my macguverish thinking is for the one I want the coldest (and possibly freeze) use a large evaporator plate, and the chiller - use a smaller one...thus negating need for separate units and controls..

Has anyone attempted something like this or am I right to assume that I'll need individual units for each? It just seems ridiculous to spend 2.5 to 4K on this project which is what I am thinking it will run based on two separate units...

[Hartley18]

Jody, it is possible to rig the two coolers up to one compressor, but, apart from being complicated, I wouldn't recommend it:

1. Your existing compressor would most likely not be big enough.
2. The plumbling to separate Tx valves is horribly complicated (keep it simple).
3. Any refrigerant leaks will take out both coolers.

If they're only a few feet apart, how about turning one into a freezer and using the other as a cooler??

Run the nearest one to your compressor as a freezer, run some 2" reinforced water hose between the bottom of the two units glassed in at either end and wrapped with as much insulation as you can fit in the space, and install an electric cooling coil up the top of the other one for auxilliary cooling.

If you put a slight gradient on the hose and get the freezer temp right, cold air will travel from the freezer to the cooler, but the cooler won't freeze because of loss from the pipe...

Crazy, I know, but it might work..

[Stillraining]

And I thought I carried a lot of beer....no contest......Dude we really have to go sailing togather...

[Hartley18]

Originally Posted by Stillraining

And I thought I carried a lot of beer....no contest......Dude we really have to go sailing togather...

Bugger!!! I missed that completely!.. {grumble, grumble, mutter, grumble..) Must be having a bad day..

Don't you keep any food on board, Jody!?! Still, I suppose it's technically possible to eat frozen beer..

[Omatako]

Jody

I have two boxes, admittedly side by side, only one of which has any refrigeration gear in it. That gear consists of two eutectic holding plates 500mm x 250mm x 80mm. They are both driven off the same fridge unit (please don't ask for specs, I don't have any).

From one box to the other are two 50mm holes about 200mm from the bottom.

The box with the plates easily holds minus 25 degrees C and is a good quality freezer. The other box that relies purely on air flowing from the freezer holds an easy 5 degrees C.

So Hartley's idea of a pipe connecting the two boxes is a long way from crazy. I understand that all standard Morgan 44's are equipped the same as mine and I know that mine works really well. If a pipe can be fitted between your boxes and be properly lagged to prevent temp dissapation, one suitably specced fridge unit will make your beer cold and keep food frozen.

Andre

[sailingdog]

Actually, Hartley's idea is how a lot of modern refrigerators work, especially the ones with the refrigerator on the bottom and the freezer compartment up top. The biggest concern with it would be condensation and freezing of the hose. As pointed out, the single compressor would still be a weak point and if it fails, the whole system is shot.

[Gary1]

Island Breeze has a refrigerator and a freezer. Both have custom made holding plates (Rich Beers, Ft. Lauderdale). We have a single compressor and condenser mounted elsewhere.

Each unit has its own thermostat installed, and either one can command the compressor unit on. THe lines to the two evaporators (cold plates) are simply "T" d where the low pressure side enters the reefer.

For what it's worth, we can, after the whole thing is down to temperature, not run the compressor for a full day and the ice cream is still frozen. (The boss likes the good stuff, and it needs to be really cold!)

That's all a function of insulation, good seals, etc. (and keeping everyone out of the reefer for no good reason.)

[JimsCAL]

The ship's stores refrigeration systems on large ocean going vessels are very similar to what you desire - multiple boxes (sometimes 3 or 4) served by a one operating condensing unit. Actually they do have 2 condensing units, but one is a backup. You basically need a separate expansion valve and solenoid valve/thermostat for each box. The single condensing unit would have to be sized for the increased load of the 2 boxes.

[rewell6]

Our fridge (side x side) in our house just started acting crazy a month ago. The freezer side woudl be 0 degrees F and the fridge side would get up to 50 degrees F. Turns out the fridge side thermostat only turns on the compressor if it isn't already running for the freezer side and opens a damper to let air from the blower in the freezer side get to the fridge side. When the fridge side is cold enough the damper closes. The fridge side doesn't have a blower or evaporator. There must be some place for the air to recirculate back to the blower or no air would move to the fridge side.

Example of a damper Scroll down till you see the "Spill-Over Dampers" Check out the rest of the site too. The "Books and Manuals" section even has a book on Refrigeration for Pleasureboats - Nigel Calder

With a little creativity it would work.

[artbyjody]

Thanks everyone for the suggestions - definitely gives me the gist of what I need to do and I like the KISS method myself. Keeping one as freezer will be the route I take. Its a downhill gradient from one box to the other so it should work well with minimum labor (whom am I kidding here)..

As Still pointed out - kinda hard to keep food onboard for any amount of time without one and the diet of all beer and quick perishables doesn't work to well. It also seems to be the the quickest way to go as I want to get this done before Sept so I can take a few weeks and cruise the San Juans...

Thanks again...