Well, as this is the cruising forum, I felt it might be beneficial to discuss refrigeration techniques that have worked for us to keep your 12v costs at a minimum. I am not the final expert on this (or anything in life, for that matter), so I urge anyone with other ideas to feel free and chip in.
Refrigeration. It is one of those things that I have had old salts tell me you do not need, but I will be darned if I will do without. There would be a mutiny of kids, wife, and dogs (not sure who would lead it either!!). But, refrigeration has the distinction of being about the biggest electrical hog on a boat on the hook. Many of the modern coastal production cruisers use Adler-Barbor refrigeration, as I do. Short of sticking an ice-pick through it (no laughs... it COULD happen to you!!), it has served us well on our many trips. The general budget for a AB system is about 50-60 ah/day. With that in mind, even large 12v systems will begin to get taxed before long. Thus, here are some key ways you can do your own Refrigeration Conservation:
1) Stick your head inside the box and look around for holes. Sound silly? I bet if you own a production boat (or almost any boat) you will see the refrigeration lines come right into the box and are not sealed!! It is like leaving the door cracked or lid up! Depending on the size, you can use MG caulk or even the can of Foam Stuff to seal it in. If you use the latter, let it dry completely before you cut it to shape. Acetone cleans it up when wet. A putty knife cuts to shape when dry.
2) Plug the drain (foot drain) with a cork or similair object. It might not save you much, but I see no reason to cool the water under the boat. Keep the T-Hull closed too - though I am sure this is a practice most people do anyways.
3) Use thick plastic sheets to cover the inside of the front door. Remember when you would walk through the old grocery stores and you had to reach through hanging plastic to get something that was refrigerated? Make a similair system on your boat. Thick plastic, cut in strips, screw it just to the inside of the door at the top.
4) Resist opening the front door. Even with the plastic strips, when you open the front door the cold air comes straight out. On a passage, I drop a little screw through the "lock hole" so it cannot be opened by those who forget (ie, the kids). On long runs, pack the things you will need most on top through the top-load.
5) Double insulate. Styrofoam, for all of its negatives on the environment, is one of the best insulators and is dirt cheap. I would not do this unless the original box was not well insulated (as this takes up some room in the box), but it is a consideration.
6) Use a "heat blanket" on top. You know the aluminum emergency heat blankets you can buy at about any backpacking store? They keep in cold too. They are cheap. Put one aross the top of your box (on the inside) where you have to push it to the side to get the item(s) you need.
7) Keep your fridge stocked. The more stuff in there, the better. A super-stocked fridge (once it has gotten all of the items cold) will maintain its own temperature better. The cold items act as their own cold plate. You also seriously minimize the air inside, which is most apt to dissapear when you open the door.
I hope some of these tricks help some of you as you gear up to punch off - whether around the bay or around the horn. They have worked for us.
__________________
Sailingdog Telstar 28
New England
You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.
—Cpt. Mal Reynolds, Serenity (edited)
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I'd agree, some very good tips. On mine, I put a valve in the drain line, rather than using a cork or other stopper (one of those flat stoppers might make a better surface than a cork).
I've also been trying to think of the best way to insulate around the outside of the box, as the area between the inboard side and hull side of the box isn't really usable for storage. Any suggestions? Would be nice to just fill it up with foam, but I have some concerns about absorption and eventual deterioration of the foam.
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John
Ontario 32 - Aria
Free, is the heart, that lives not, in fear.
Full, is the spirit, that thinks not, of falling.
True, is the soul, that hesitates not, to give.
Alive, is the one, that believes, in love. JCP
In chemistry, we always said the best insulator was styrofoam - believe it or not. I would imagine styrofoam would be viable for a very long time, is cheap, is easy to get, easy to cut, easy to install (if you have acces to that space). Those are my thoughts, PB.
CD, I have a regular 12V 100liter refirgerator with ice maker.
As you know my house battery is only 70amp, but this summer I will upgrade and get another battery, maybe 140 amp, just for the cruising.
Twice last summer, we ran the house battery completely flat with the refrigeartor, because normally I run the diesel engine for 1 hour to charge the battery, and those days I forgot.
Assuming I have more amps next time...is there a way to make the refrigerator more power efficient???
I heard that switching on/off on a time basis uses more power than if I let the refirgerato'rs thermostat do the start and stop of the compressor.
I know about opening the door and all, but do you have more ideas?? There is no way the refrigerator is coming out. It was one of those things my wife chose and requested. (I remove it for racing, only) the rest of the time its inside.
It may not be possible for your application, but getting a top opening door setup would be the best suggestion I could give. A side opening door lets cold air spill out every time it is opened. Even the plastic strips will be parted to let this happen when a hand is stuck thru. Cold air sinks, hot air rises, the zone on top of the fridge when opening a top door doesn't exchange air immensly upon opening. It's definately a more neutral situation than a side opening door.
Just my 2 cents...
Don
__________________
I love being on an Even Keel WTF are YOU lookin at?????
Actually Giu, what you might consider when not racing, is using a cooler for things like drinks and snacks that you frequently get in the reefer for. A couple of gallon jugs of water, left in the freezer at home for a couple of days should last you a couple of days, and then you have water to drink as well. I have a small cooler that sits in front of the pedestal that I use just for drinks I'll want during the day.
__________________
John
Ontario 32 - Aria
Free, is the heart, that lives not, in fear.
Full, is the spirit, that thinks not, of falling.
True, is the soul, that hesitates not, to give.
Alive, is the one, that believes, in love. JCP
You're welcome Giu. Sometimes the simple answer works well, eh?
__________________
John
Ontario 32 - Aria
Free, is the heart, that lives not, in fear.
Full, is the spirit, that thinks not, of falling.
True, is the soul, that hesitates not, to give.
Alive, is the one, that believes, in love. JCP