Solar, off grid and heat problem

[mr-canada]

Originally Posted by ramblinrod

For a 15 degree design delta, you would need 500 W of heat or super insulation (reducing interior space dramatically) and 100W of heating. You would need one }%{%{load of PV Panels and batteries to support this.

Instead, for heat, build a greenhouse of lumber and clear polyethylene over the entire boat. ... Now the entire boat is a passive solar heating panel. The black tarp converts suns radiation to heat, and the greenhouse holds that heat in.

...
In operation, warmer air will be drawn into the boat, pick up moisture and expell it into the greenhouse where it will condense and run toward drains.

Before first frost, blow all water lines with a 12 VDC air mattress pump. For seawater intakes/discharged, just blow the line and close the valve. Run propylene glycol through the engine, all pressure water lines, and blown lines.

Wow, that's quite the well thought out system and very passive. Might be a bit extreme for my needs as here we deal with on average no more than a week at a time of below zero weather. Ontario gets COLD AS FK so you obviously know what you're doing. I like the black tarp idea though.

Sun > Photovoltaic > Battery > Heater there are so many losses. Black tarp on the deck will just get warm in sunlight and add passive heat to the boat, albeit not much but much cheaper.

I might go that route. Potable antifreeze, solar panel for the battery, and black tarps all over the boat maybe with a small fan. There's enough air leakage through the drop boards that I could just pop a small fan in the head and exhaust air from the boat through the vent and let the boat suck in the air from the hatch at the cockpit; hit the marina and use a sht ton of shore power for a night once in a while and crank the dehumidifier and heater while I go out for beer or fish and chips waiting for the crab pots to fill up with goodies from the sea.

[Martkimwat]

Unless the water your boat is sitting in is going to freeze, you are unlikely to get below freezing in your boat, even if the air temperature is below freezing. The seawater will have a much larger effect on your boats temperature than the air, it has something like 30 times the thermal effect than the surrounding air. just keep it snugged up and not allow too much air circulation around the water tank and engine and the seawater should keep the frost at bay.

[Excalibur5]

Winterizing a small boat like that is simple, and if it is in the water you have very little to worry about anyway. If the lines & tanks are below water line they will not freeze unless it gets REALLY cold (well below zero F)

I am assuming you have no hot water system installed on a boat that small. Just pump the foot pump until the tank is empty, pour half a gallon of RV antifreeze (the red stuff that is drinking water safe) into the tank inlet and pump the foot pump until you see a little red. Then pour a bit down the sink drain.

Close the sink drain through hulls and you are done. It should take less than 20 minutes total.

If you have a raw water cooled engine and are concerned, you can flush that with fresh and use RV antifreeze again in the raw water intake. Again pretty simple, but in a monohull in the water it shouldn't be an issue until it gets much colder than you are experiencing. I would again be sure to close all your through hulls just in case while she sits though.

FYI I live aboard my boat in Juneau, Alaska year round - it gets a lot colder than you are talking about, and as long as the boat is siting in the water with the block below the water line the engines don't have freezing issues.

[ramblinrod]

Originally Posted by Excalibur5

Winterizing a small boat like that is simple, and if it is in the water you have very little to worry about anyway. If the lines & tanks are below water line they will not freeze unless it gets REALLY cold (well below zero F)

I am assuming you have no hot water system installed on a boat that small. Just pump the foot pump until the tank is empty, pour half a gallon of RV antifreeze (the red stuff that is drinking water safe) into the tank inlet and pump the foot pump until you see a little red. Then pour a bit down the sink drain.

Close the sink drain through hulls and you are done. It should take less than 20 minutes total.

If you have a raw water cooled engine and are concerned, you can flush that with fresh and use RV antifreeze again in the raw water intake. Again pretty simple, but in a monohull in the water it shouldn't be an issue until it gets much colder than you are experiencing. I would again be sure to close all your through hulls just in case while she sits though.

FYI I live aboard my boat in Juneau, Alaska year round - it gets a lot colder than you are talking about, and as long as the boat is siting in the water with the block below the water line the engines don't have freezing issues.

Depends on current and wind. With lots of current and no wind, no problem. With no current and water at 6C, and high wind at -15C, the wind will suck the heat out of the boat in no time if there is no insulation.

[mitiempo]

Panope is correct - any boat in the water in southern B.C. will not freeze. I would drain any water lines and leave the taps open but not bother with anti freeze as its not necessary. Ideally leave a few openings for ventilation with cover over with a tarp to stop water getting in. I know of no boat that has had an issue in the Victoria area with freezing - and your water in Howe Sound is warmer than ours here.

Now if you were on the hard winterizing is important as you do not have the warmth of the water.

[Dave22q]

I suspect that if you cut off the fresh water at the tank and drain the hoses you will be protected for at least a few days of sub zero. you might also insert a submersible, low amperage fish tank heater with a small inverter if you cannot find a 12 v one. That might buy an extra day or two. It seems like the tank is the main issue so general heating solutions seem inefficient.

[Dockhead]

Originally Posted by taxwizz

Why in the world would you want to be on a small boat in winter?

The only time to be sailing is when the gals want to wear their bikinis.

But, if you need to keep warm can you install a small propane heater. Properly vented, of course.

Winter sailing is a special joy, understood perhaps not by all sailors.


One other comment -- don't use propane heaters on a boat! Most of them They are forbidden by ABYC -- for good reason! -- and may void your insurance.

In the UK more sailors are killed by propane explosions or being suffocated by using improperly vented heaters, than any other cause.

[taxwizz]

Originally Posted by Dockhead

Winter sailing is a special joy, understood perhaps not by all sailors.

In the UK more sailors are killed by propane explosions or being suffocated by using improperly vented heaters, than any other cause.

Sorry...I have never wanted to sail with someone hanging over the bow breaking ice with an ice pick. Or having to first shovel the decks clear of snow. LOL

Question...Propane explosions from propane heaters or stoves? I think that many of us have propane stoves.

[Rorzech]

Your best bet in the winter time is to get yourself one or two of those 600 watt wind generators. At least you can get power 24 hours per day.They put out 25 to 100 watts usually and the good thing is that its usually windy when it's cloudy and winter wind likes to blow all night. Any extra power should be put towards heating your battery to 60 F at least so you will double it's capacity. I would keep all heat close to the floor and cover it with a sheet of the foil bubble wrap to reflect the radiant heat back downwards where it's mist needed. Trying to heat something not insulated is just pi$$ing it out the window. You may get better results if you tape heat tracing wire along everything you don't want freezing and insulate over top of that and tape it around also. You don't have a lot of heat to play around with so you better get creative. Good luck ! Cheers.

[Stu Jackson]

Originally Posted by Panope

Boats in the Puget Sound have an excellent source of "heat" all year long - The water.

No part of the (below water line) hull will ever get below 45 degrees. Leave the bilge access panels open and let that warm(er) air rise into the cabin.

My boat spent the winter of 2015-16 in the water (Port Townsend) with no shore connection or heat. Cabin never went below freezing.

Steve

Steve's right. Last winter was my very first one here having sailed up from SF last summer. The first time it snowed was my birthday, so I remember it, plus it was the first time my boat had ever seen snow! One of my gifts was an electric heater (we have shorepower, only 15A, at our dock). It was RAINING inside. Because the ater was warmer than the snow on the deck above.

THAT'S what you have to guard against, in addition to just temperature.

Resistance heating without external power production, will simply not happen.

Good luck.

[Dockhead]

Originally Posted by taxwizz

Sorry...I have never wanted to sail with someone hanging over the bow breaking ice with an ice pick. Or having to first shovel the decks clear of snow. LOL

To each his own!!

Originally Posted by taxwizz

Question...Propane explosions from propane heaters or stoves? I think that many of us have propane stoves.

Propane explosions happen when LPG leaks into a boat and sinks into the bilge. Gram for gram, propane is far more explosive than TNT. If you read through the cases you'll see that it happens to all kinds of LPG systems. Every device you add, adds joints and pipes and hoses and increases the risk of leaks. Propane heaters designed for use on land are particularly bad.

There ARE propane heaters which are suitable for marine use (sealed burners and so forth), but they are rare and expensive. See here: https://www.practical-sailor.com/blo...s-11860-1.html

[GILow]

A little webasto diesel preheater of the sort used to preheat cars in Europe is dirt cheap secondhand on fleebay. Set one up to heat a big drum of water in the cabin and you are good to go. One cycle a day for maybe half an hour would be heaps. Solar power should be plenty for that and the continuous run is good for them, much better than short pulses. Look for CF user "typhoon"'s posts on the subject.

[john61ct]

The thermal mass can be below, easy to rig a little case fan + radiator, with passive circulation don't even need a pump.

Same unit for hot water service, preheating the engine block for the Arctic sailors 8-)

[smac999]

If you are on the boat. You need diesel heating like esbar. It takes minimal dc power.

If you're off the boat. It needs to be plugged in.

Or move it south...

[john61ct]

A minimal solar setup will keep the diesel heater going 24x7 unattended until it runs out of fuel, about a gallon per day.

Yes safety issues, but no more than any other active solution.

But we've already seen not needed, at least for OP's location.