Heat and refrigeration for part time liveaboard

[hoehnt]

I am in the process of purchasing a CD30 ketch here in the Pacific Northwest.
I plan on living on the boat part time for now, then sailing to the south Pacific in a couple years.
Right now the boat has no cabin heater and just the ice box it came with.
What is the most efficient form of cabin heat for winter temperatures around here (mostly 30s and 40s)
I like the diesel bulkhead heaters but is there something better these days?
Is there a way to convert the existing ice box to a real refrig/freezer?

[Russell]

For heat I really like my Espar I installed last year. Its forced air diesel heat rather then a bulkhead. On a CD30 you could probably get away with the smallest unit they make. It is not cheap though, but works better then a bulkhead heater and does not take up cabin space. Though considering your long term plans for the south pacific, I wonder if you really want to spend that kind of money for heat. If you just need heat at the dock, ceramic space heaters or oil filled radiators will do the trick. A 30amp dock power connection can run two space heaters on low or one on high, which should be plenty for a CD30 in the PNW.

For a fridge, there are a number of brands that make easy icebox conversions, I have had good luck with my frigoboat, but there are many other brands as well, all using the same 12v danfoss compressor. The nice thing about the frigoboat is the optional keel cooler, which is a nice passive heat exchanger that makes the fridge run more efficiently without using additional power (such as a air cooled fan or water cooled pump).

[Kevin Kaldenbach]

I second the frigiboat with keel cooler

[rorik]

I've lived aboard in Puget Sound, on this boat, for 2-1/2 years.
I have an oil filled radiator to leave on during the day in winter months and an old Hi Seas diesel heater for when I'm home and it gets really cold.
If your ice box is built anything like mine was, it's basically junk because there's almost no insulation.
I ripped mine out and started with a clean slate.
I used a polypropylene water tank, suspended in 3" - 6" of foam.
Before I finished it, I did a test to see if I was on the right path.
With insulation surrounding the lower 2/3 of the sides and all of the bottom, but with no insulation on top and no lid, a 10# block of ice lasted for 49 hours with temps in the mid 70's.
Granted, ice boxes and old style diesel heaters aren't for everyone, but they do work well.

[Steve Laume]

I have used one of those 1500 watt ceramic heaters aboard Raven in the winter. This is New England where it can get pretty cold. I don't leave it on all the time but use it when I am on board the boat. I usually keep the door to the head closed if it is really cold. The only time it could not bring the main cabin up to a very comfortable temperate was when the outside temp was in the teens and it was very windy. That night I rather enjoyed my sleeping bag with inside temps between 50 and 55* F. Those kind of extremes are rare and if you wanted to be toasty warm you could always run a second heater.

I do have a diesel bulkhead heater that I picked up on e-bay and installed on Raven. I needed a rebuild kit for the burner at first and then found a beautiful stainless tank with built in pressure pump and gauge that fits in the locker under the settee. All of this seemed to take me a couple of years to deal with. It is all hooked up at this point but I am sorry to say that I have never used it. The little electric heater is just so much easier. I really need to play with it because it would be very nice for late fall or winter sailing trips or just to take the chill and dampness off of things in milder weather.

The nice thing about the ceramic heaters is that they are very small and stable. It would be very hard to tip one over and if it ever did it has a switch that shuts it off immediately.

I still use ice but insulating the ice box made a huge difference in how long it lasts. I drilled a grid of one inch holes and filled all the surrounding area with low expansion spray in foam then epoxied the holes back in. There is a thread on here that goes into more detail on the process. No matter how you decide to cool your ice box, extra insulation should be the first step. I also keep a couple of pieces of that bubble wrap insulation and a wool stadium blanket over the top of everything I am trying to keep cold. This system seems to last about 5 days if everything starts out cold.

I am tempted to install a refrigeration system now that they seem to have become much more efficient and reliable. The problem is that they are still not cheap. If I was heading south for an extended period of time I would definitely plan on it. Cold beer and not worrying about things going bad or getting wet with ice melt would be very nice, Steve.

[Steve Laume]

I just cruised Defender's site looking at fridge units. When you talk about keel coolers are you referring to the water cooled through hulls or is there something else on the market that I neglected to notice?

It looks like you could have cold beer and more for around $1500.00, Steve.

[Russell]

I just cruised Defender's site looking at fridge units. When you talk about keel coolers are you referring to the water cooled through hulls or is there something else on the market that I neglected to notice?

It looks like you could have cold beer and more for around $1500.00, Steve.

A keel cooler is basically a bronze plate mounted on the outside of the hull, the refridgerant passes through it. There are no actual holes per se. You have to put a couple holes in the hull to mount the heat exchanger (keel cooler) but then it covers them up. So its not like a water cooled system where you are adding another thru hull.

http://frigoboat.com

It needs to be bought from a dealer, no retailers carry it.

[rorik]

How well does a keel cooler work when the ambient water temp is 70-80 vs. the 50~ of New England? How much more power does it consume? How much more often do you need to run the engine to recharge and how much more diesel do you have to buy?
Just items to factor in.......

[Russell]

How well does a keel cooler work when the ambient water temp is 70-80 vs. the 50~ of New England? How much more power does it consume? How much more often do you need to run the engine to recharge and how much more diesel do you have to buy?
Just items to factor in.......

The whole point of it is that it does not take anything more to use. Its entirely passive, the refrigerant is being pumped through those lines anyway, the small detour to the keel cooler has a near zero effect on its efficiency. This is a passive system, you are not adding any pumps, fans or anything, you are actually removing such things. As opposed to running a fan on the compressor for an air cooled system, or a water pump for a water cooled system. Thus is uses the least amount of power of any alternatives, so you buy less diesel and run the engine less. Granted, compared to an air cooled system, given the efficiency of 12v fans these days, the power savings is not huge, its not like you can have a smaller house bank or anything. But the other attraction to this system is its simplicity, as long as the compressor is running fine, the system works, you are eliminating a pump and/or fan from the system and thus a potential item to break.

As for efficiency is higher ambient water temps. Well, sure, its going to be less efficient in the tropics. I have used my keel cooled system all through the caribbean, its not an issue. In those same warmer locals, consider that a water cooled system, well, the water is still warmer, in an air cooled system, yep, air is warmer there too, any fridge is going to be less efficient in warmer climates. Keep in mind you are cooling something that even in the warmest climates is still far above the normal ambient temps, otherwise we would be worrying that our engine heat exchangers wouldnt work in the tropics either. Remember, a keel cooler is very simply nothing more then a heat exchanger.

[rorik]

Thanks for clearing that up for me, Russell.
For me, dead - really, really - dead simple is best. That approach isn't for most people. There are some tradeoffs. I suppose if you're going to use a powered system of some sort, keel cooled - per your description - would be the next most simple thing to a plain ice box.

[Russell]

Thanks for clearing that up for me, Russell.
For me, dead - really, really - dead simple is best. That approach isn't for most people. There are some tradeoffs. I suppose if you're going to use a powered system of some sort, keel cooled - per your description - would be the next most simple thing to a plain ice box.

I didnt take your quetion in the context of your prior post when I responded. Looking back now, yeah, compared to just using the icebox as an icebox, any refridgeration is going to make a huge impact on power consumption. The single biggest power consumer on any cruising boat is always the fridge. Keeping it running is what leads to big battery banks, solar panels, wind generators, etc... If you can live without a fridge you can certainly cruise much cheaper and keep your boat more simple and manageable, there is no question about that at all. It really does come down to, when living aboard full time and cruising (ie away from the dock) the difference of thousands of dollars, not just "oh I can install a 12v fridge for less then $2000".

Its a very personal decision, do you need a fridge or not? Do you want one? How badly do you want one? Myself I love my fridge. I have gone as long as 6 months without one, when my original compressor died and getting a new one simply was not convenient. But, away from normal US cruising locals, its not like you are going to find block ice, in fact, even finding cubed outside the US is difficult at best (and block ice non existent). So from a cruising point of view, beyond the standard snowbird type cruising, you need to decide on a lifestyle either with, or without, ie, warm beer, no cheese, no meat that isnt canned, etc...

I know more then a handful of people who could not cope with cruising a boat without a microwave, its, to them, a necessity. On the flip side I know people circumnavigating on boats less then 30' with kids and no fridge, no oven and barely workable stoves.

Most people, if they can afford the expenses involved, that is the fridge and the means to keep it going, I think would opt to have one. But there are plenty of people out there cruising around the world, to whom the act of cruising is more important then the fridge (or many other toys such as watermakers, chartplotters, etc). Everyone needs to make their own personal choices. I dont like people suggesting "You cant go cruising around the world without a 50' boat filled with all the latest gear" any more then people who suggest "If you have a 50' boat with all the gear you just are not a real cruiser". Its personal, what matters is doing it. The guy asked about converting his icebox to a fridge, I assume he knows he can put ice in instead, but he wants a fridge.

[Russell]

Sorry, I dont mean that to sound snarky, I really dont. As mentioned, I have many friends cruising on very simple boats, people who would lust after even a bare bones hurricane damaged Cape Dory. Also people cruising on whatever they have, very simply, who lust after nothing more then what they have. Too often I have seen armchair cruisers on the internet jump on people for "doing it wrong". I know that was not your intent, it is important to point out to people new to this that there are alternatives, and that is all you were doing. You are not "Wayward Wind" who told us all if we sailed with a dodger we were doing it wrong .

[rorik]

No worries, Russell.... you didn't sound snarky.
When I post here, it's to relay what works for me, even though I know full well that I am mostly in the bare bones camp and that that lifestyle doesn't work for most people.

[hoehnt]

Come to think of it, around here you can just put stuff out on deck in the great wide refrigerator

[Steve Laume]

I mesh bag hanging over the side works pretty well if the water is cold. It also keeps things from freezing if the air is very cold, Steve.