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pgarver · 20-03-2021, 14:40

HI I'm buying a Hunter 306 that has just an ice box. anyone have experience with such conversions? How hard is it to confirm there is enough insulation?

OzeLouie · 20-03-2021, 15:08

Quote:

Originally Posted by pgarver

HI I'm buying a Hunter 306 that has just an ice box. anyone have experience with such conversions? How hard is it to confirm there is enough insulation?

Start with the cabinets internal dimensions then external if possible. From those you should be able to determine insulation thickness. With this and other information regards where you will be sailing to, number of persons the fridge will serve etc., you can then obtain a properly calculated 'Heat load and power consumption' estimate to determine the refrigeration equipment needed and DC power required.

boatpoker · 20-03-2021, 15:39

Simple intallation of evaporator plate and compressor .... Black wire, red wire.
Insulation ... add as much as you can. Done.

silkie · 20-03-2021, 15:47

I've seen ice boxes that had space for insulation, but no insulation was added. Just left as air cavities.

**TrentePieds** · 20-03-2021, 15:53

In principle, very easy, in practice not so!

As I understand the layout of the H306 the icebox is located on the port side of the boat with the galley sink located inboard of it. Fore and aft its dimensions are constrained by the settee forward of it and the stove aft of it.

Therefore any desired increase in the "R-value" (insulation capacity) of the insulation in order to diminish the refrigeration load must be achieved by making the insulation thicker than it is and, as a consequence, losing a significant amount of storage volume.

You have said nothing about where you are located, so I can have no idea of the level of the need for refrigeration. If your concern is that the beer must be kept cold, then I suspect that in a H306 - like in my boat which is also a thirty footer - one of those 12V "refrigerators" intended to plug into a 12V outlet in a car would be a far simpler and more satisfactory solution, one that would also obviate invasive surgery having to be done on the boat.

However, electrical devices in cars are fed from the alternator which is always running while the car is moving. Not so in boats where they are fed, at least while sailing, from the battery(s). Cold plates and other devices required for refrigeration take a lot of power, and refrigeration is not, therefore, particularly efficacious in a sailboat. The demand such devices place on the battery capacity is best avoided altogether.

Cruisers learn fairly quickly to adapt their diets to something that doesn't require refrigeration. Intelligent meal-panning and provisioning can obviate the need for refrigeration, and even ice boxes, altogether. Bang-up meals - a la Escoffier if you like - are the result of careful planning, not of refrigeration :-)

All the best to you.

TrentePieds

OS2Dude · 21-03-2021, 08:50

Quote:

Originally Posted by pgarver

HI I'm buying a Hunter 306 that has just an ice box. anyone have experience with such conversions? How hard is it to confirm there is enough insulation?

Our Catalina 30 came with such a conversion, but I ruptured the evaporator and had to replace it.

We have a Norcold SCQT-4408F conversion unit. It comes pre-charged with refrigerant. You mount the compressor in a lazarette or some other space outside where the heat can escape, run the lines from the cooler to the compressor and attach them. This can only be done once, the seals holding the pre-charge in are pierced as you tighten the connections. The refrigerant lines are copper tubbing, and you need to be VERY careful you do not crimp it anywhere. You will need at least some access to the entire path between the cooler and where you plan to place the compressor.

Other than that, it is completely within the realm of a DIY project. As far as insulation goes, that is not directly related to the conversion. Insulation would help even if it was left as an icebox. If you can get to the outside of the enclosure, wrap insulation around it, spray some foam on it, or glue panels to it. Our enclosure is not insulated, as I can only get to two sides but we have no issue keeping items cold.

RSB333 · 21-03-2021, 08:52

I'm in the process of adding insulation to the inside of my old ice box. Interior volume will be reduced by about one third, but the smaller, well insulated box will reduce the drain on the house batteries. I'll have five inches of foam insulation in the floor of the box, and four on the sides, with only one inch in the ceiling.
good luck!
RSB333

jen1722terry · 21-03-2021, 09:55

We basically did what OS2Dude did, above. Our old Cape Dory 31 had a top-loading, 2-layer ice box, kinda like a thermos. We drilled the inner shell in an 8" grid and used canned closed-cell foam to fill the void, carefully, so as not to crack the fiberglas. Plugged the holes with thickened epoxy. Top loaders are very efficient.

Then we mounted the smallest NovaKool unit. The cold plate inside the box doubles as a small freezer box. We ran the tubing into the port cockpit locker and installed a 4x6" vent into the cabin for the compressor. Wired the unit thru a dedicated breaker. Built a little ventilated frame around the unit in the locker to protect it.

Granted, we sail in Maine and Nova Scotia, but the box uses very little energy. It runs maybe 10-15 minutes every two hours. Quiet. No maintenance other that vaccing the compressor each spring for dust. 6 summers and narry a problem. We love it and have cold drinks, fresh fish, meats, etc. all summer long.

It will make ice cubes in the freezer on a low setting, maybe 3 out of 8. We try to keep the box fairly full, which holds the cold and conserves energy.

Oh, one more thing. Your box probably has a drain to the bilge. Keep it plugged or covered unless you're actually draining water. Otherwise, much of your cold air will end up in the bilge.

I may have some install photos if you need them. PM me.

Cheers

Captjohn4 · 21-03-2021, 10:07

On my boat I had the traditional drop in fridge so I installed a 12dv refrigerator in the bulk head and simply changed the thermostat for the drop in fridge. Now I have a deep freeze unit and a refrigerator.

I should add that the original unit was a frigaboat compressor and the deep freeze thermostat cost me about $100.

Richard Kollmann · 21-03-2021, 10:11

Quote:

Originally Posted by pgarver

HI I'm buying a Hunter 306 that has just an ice box. anyone have experience with such conversions? How hard is it to confirm there is enough insulation?

Your best advice will come from Hunter 30 foot boat owners who have refrigeration on their boats. The evaporator that must fit in the box and produce what box temperature you are looking for must be your first decision. Ice boxes in 30 ft sailboats have less insulation but can be converted to either a drink coolers or a refrigerator or even a two temperature refrigerator with a small chamber evaporator. How well these refrigerators work depends on where the energy comes from this being the boats engine alternator maintaining battery charge. Experience on other 27 to 30 ft boats in warm climates need at least two 80 watt solar panels to prevent engine from running more than twice daily just to support refrigeration. All fan cooled available ice box conversion refrigeration units are equal in performance when properly installed.

Cheechako · 21-03-2021, 10:31

It's not that hard. All boat work takes time though. Insulation helps, but what's your usage? If you day sail or vacation only. You can live with what insulation you have fine.

Layout where you will put your compressor unit, and figure what size evaporator will fit into (and get through the opening!) your ice box.

Richard Kollmann · 21-03-2021, 11:50

Quote:

Originally Posted by Cheechako

It's not that hard. All boat work takes time though. Insulation helps, but what's your usage? If you day sail or vacation only. You can live with what insulation you have fine.

Layout where you will put your compressor unit, and figure what size evaporator will fit into (and get through the opening!) your ice box.

He is right if you added three inches of closed cell to all sides of box as small as it is there might be only a Fifteen percent improvement in energy consumption daily.

He is also correct in cutting a cardboard shape of the evaporators available from different refrigeration manufacturers and see if it fits through lid opening without bending it.

flyingfin · 21-03-2021, 12:34

Quote:

Originally Posted by pgarver

HI I'm buying a Hunter 306 that has just an ice box. anyone have experience with such conversions? How hard is it to confirm there is enough insulation?

Why convert? Just put 3/4 full water jugs in Ice Box. Put frozen jugs in a new mini-fridge every morning, put previous water jug in IceBox to refreeze. Now you have both. We use on deck Igloo cooler as the mini-fridge. Before a long voyage, we throw a dry ice pack in bottom of Igloo, will go a week if you keep adding a new frozen jug every morning

Cheechako · 21-03-2021, 12:35

When I took my 47 footer to the Caribe, I used a very small box. The boat had a huge SS lined refrig, but much bigger than I wanted. I was not crossing the S Pac, just cruising the Caribe. I wanted to use a lot of fresh food. So I converted the center storage in the big salon table to a fridge that was probably 1.5-2 cu ft. I put insualting foam around the center box. I used a small water/air cooled Coldmachine. Eventually I lined it with those vacuum panels that were popular at the time.

The end result, before vs after the vac panels, was I ran the engine to charge the batteries the same length of time each day before vs after installing the vac panels.