FDA recommends 0 degrees F (-18 C) for freezers. But freezers use a lot of energy.... If you have a freezer on board: at what temperature do you keep it? Do you adjust the temperature according to what kind of cruising you're doing (e.g. lots of meat for long passages or stays in remote areas, versus shorter cruises where you're keeping ice and stuff that you'll be eating within a week or two)?
frozen meat and fish,bacon live at the bottom
,then frozen veg on top of that
,then frozen bread,pitta,pizza,s,
then the ice frozen on top in water bottels,
.all covered with a layer of insulating material,
then the lid
You need a lot of insulation to freeze for long periods of time. 6 to 8 inches would be nice. We tend to freeze for 2 weeks and you can get away with a higher freezer temperature if you think short sighted. Just the volume available will limit how long you can freeze. FDA standards would be nice but rarely affordable. I would worry more about keeping a steady 38 F in the fridge.
You also have to balance your energy budget or you lose the freezer just about 1st on the list. The fridge on most any boat is energy hog number 1. Making water would be up there too. How you make power and how much you can make determines how much ice cream you can keep for how long. Keeping ice cream long periods of time is the true test of a boat freezer FDA standards aside.
As with all things sailing you choose the battles you fight. Planning ahead is really a part of life on a boat. The better you get, the more often you can pull a rabbit out of your hat and come up with spectacular food in the most out of the way places. Freezers are only one tool to eating well. Eating well aboard is always a good idea! Food makes up for a lot of short comings aboard.
s/v Bright Eyes Gozzard 36
37 15.7 N 76 28.9 W
The freezer on my boat is separate to the fridge, but part of the one system. Its a set and forget 12 volt and even in my sub tropical part of the world is easy simple and totally reliable and uses about 20 amp hours a day, boat is three years old, fridge and freezer never gets turned off and I have no genset and the motorcharging output is minimal, and there is no shore power. The freezer and everything else on the boat happily runs off solar.
I have a spill over type system with a huge freezer. The frig section cold air is supplied by a fan blowing air from the frig into the freezer and a retun hole. Each has it own thermostat (the freezer runs the unit and the frig just runs the fan). All I can say is that last weekend the freezer was completly empty and the frig 80% empty and the temp in the frig was 32F with the unit drawing 4 amps and cycling off once in a while.
I mostly adjust the settings based on what is in the box. If the beer gets too cold and it freezes my gums when drinking it is too cold.
I tried to save energy and only run the freezer and turning the setting to a hugher temp; which resulted in soda cans blowing up the next day!
jobless, houseless, clueless, living on a boat and cruising around somewhere
I've found that to be a sweet spot. We did a two week trip in hideously hot temps and at the end we had some chicken from the first day left and it was solid as a rock and was fine. Not sure how long you can go at 27F but it looked good and it still is solid frozen. Items frozen when you put them in need less to keep them solid. I would not load up a freezer with un frozen stuff. A few items at a time should be fine though.
Ice cream won't last at 27F. It really wants sub 0 temps.
s/v Bright Eyes Gozzard 36
37 15.7 N 76 28.9 W
Temp varies greatly on the area you are in, in sub tropical area -22c will allow fresh items to freeze without effecting the rest of the products, it also depends on the amount of food in the freezer so what we do is keep a small icecream in the top or the freezer(our warmest area) if it gets soft then the freezer needs to be adjusted via the controller (buy a cheap thermometer and place it in different areas in the freezer to gauge the hottest area) At 0 degrees C it will take days to freeze items(in my area) try it with a plastic bottle full of water you will work it out quickly
I agree with the people in that thread, definitely the best bit of boat gear I have ever owned. When I dont have anything for the freezer, i.e. when we are not cruising just day sailing, I always leave a 10 litre water bottle in there to act as a cold sink. In summer that also means when we go for the day that we take it out first and have ice cold water all day.
Solar is 2 by 125watt panels, insulation is lots, (we are an australian company - we understand hot) on my boat the fridge and freezer are both custom cabinets, ie built into the boat. Roughly speaking there is around 100mm. On the larger boats the fridge is an upright type but the freezers remain custom in built with lots of insulation. I would not think an upright combined fridge and freezer is going to work well in our climate on 12 volt (fine on 240)