Solar, off grid and heat problem

[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

[mr-canada]

My only winterizing I need to do is ensure any freshwater systems are not going to burst in freezing weather (head, faucet) and to find a way to deal with moisture issues in the swing season.

Regarding moisture I have a seriously kickass dehumidifier that, if left on full blast with shore power for a day, will dry the boat out to like tinder, so a night at a marina here and there isn't that big of a deal, its the seasonal I'd like to avoid but an overnight transient here and there wont exactly blow the bank.

Other than those two things there isn't much to winterize. Heat or potable antifreeze to keep the freshwater systems from bursting, and humidity to keep the small amount of electronics from getting damaged which are all turned off in my absence at the breaker - with exception of the handheld GPS which sits off and only draws a few mAh to keep the waypoints.

I don't really use the boat much in winter because honestly, here winter means rain rain rain rain but I do go hang out on it regularly to check and pump the bilge, ensure moisture hasn't brought on mould or accumulated, etc. However my situation has changed significantly so this may change as well. I sat frustrated without a working motor for several years with shore power in a freaking wind vortex called Squamish where 20-60 kt winds were the norm, now I'm in a much calmer area. Winter isn't exactly paradise here but there are nice days where it's crisp and clear or light rain.

With a 6 ft draught I dont really like the idea of pulling it out into the hard over an extended period. Haulouts are good but paying marina grade fees plus haulout and drop in sling charges, plus sailing/motoring all the way to Mosquito Creek (about 4-6h on a good day) doesn't make sense to me. I'd rather just clean the bugger on a grid. Plus the cold will still be there in the hard anyway so that doesn't really fix my woes other than access to shore power.

[rabbi]

A resistance heater running on 12v battery and solar will require way more panel area than will fit onto the boat, and a battery bank that might sink the boat. Plus a few thousand Euro. I could not heat my cat even if it was plastered with panels.
There is absolutely no way this can ever work so don't waste a thought on it.

Heating with 12V, and recharging from an auto-starting marine genset and rapid charger sounds like 10000 Euro or more. Plus its a stupid idea, as a decent heater will eat the battery capacity in a few minutes, so the genset will start every few minutes. Plus its a big installation for a small boat.

A forced air diesel heater costs about 1000 Euro for the smallest unit. With a remote control its more 1500 Euro. Plus installation isn't that easy and cheap with all the ducts, air inlet and exhaust.
We would need to do the math to see if a 150Wp panel can handle this load. On low setting the heaters don't use much electrical energy, its just a fan and a tiny fuel pump. But 150Wp doesn't produce much during winter.
So even this will cost at least 2000 Euro. Maybe half of that if you are lucky to find a used unit with all the ducts, exhaust, etc.
This could be a solution if you like to use the boat during nicer winter periods, and heat it during freezing periods.

The easiest solution is to winterize (not that much effort, just a can of antifreeze for the potable water, and one for the engine) or a marina berth for the two freezing months.

[mr-canada]

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

Interesting. I'm not far from Puget - I'm slightly NE of Vancouver in Howe Sound. What about last winter when it was cold as Fk (2016/17)? Nobody had any problems in your area?

[mr-canada]

Originally Posted by rabbi

The easiest solution is to winterize (not that much effort, just a can of antifreeze for the potable water, and one for the engine) or a marina berth for the two freezing months.

Can of potable antifreeze is $15CAD. Engine is a 2-stroke outboard, dont need to really winterize that, maybe pop some stabilizer in the fuel and pull the fuel line and let the float bowl run dry, start it once in a while.

You might be right on this one. I do have to account for the possibility that the marina might not have space for me when I need it most. The wait lists here can span years just to get a slip, they should really make more water leases, we are all coastal here it's rediculous but that's another matter.

[Pizzazz]

The electric blanket idea I mentioned only works for keeping you warm in bed when you are on board. It will keep you comfortable at 12V with minimum current. That is the only practical use for 12V heating. Forget about 12V heaters.

Keeping the whole boat from freezing is a different challenge but I do not think you need to address it. As others have mentioned, seawater is always 15 degrees or more above freezing, so it is very unlikely that the temperature inside the boat will fall below freezing. You can experiment with flooding the bilge (i.e. if you put there 30-40 gallons of water this will give you plenty of stored "heat" to avoid freezing the boat. But I do not think it is necessary. The inside of the boat will never get freezing cold in the PNW.

In terms of heating unattended, I think anything you do is dangerous. May be the diesel heater. You can get a Planar diesel heater with remote control for about $500. Installation is a breeze, just one 1" exhaust thruhull, the rest is basic. I believe it even has an anti-freeze setting to keep the boat at a specific temp.

Good luck. Do not leave your boat unattended for long. She will miss you and complain.

[Panope]

Originally Posted by mr-canada

Interesting. I'm not far from Puget - I'm slightly NE of Vancouver in Howe Sound. What about last winter when it was cold as Fk (2016/17)? Nobody had any problems in your area?

Last winter I was ON THE HARD and the cabin most certainly froze. However, the water system was not damaged as all parts are nylon/plastic/flexible.

My boat has spent over 20 winters on the hard here (another 20 in the water) and the water system has never been winterized, drained, or deactivated.

The original (from 1977?) Whale foot pump still works fine having been frozen solid countless times.

Steve

[Privilege]

Some people over-estimate the abilities of a solar panel. Creating hot air (or cold) is a huge drain on any battery system. Here are some calculations for you so you can run the figures yourself. Please excuse me but I have simplified it.

Most all appliances are rated in watts. That rating doesn't change whether you run them on 110v AC or 12v DC. In order to work out how many amps it takes to run the appliance, simply divide it by the volts. Say you have a hairdryer rated at 1500watts. To work out how many amps will be needed to run it on your 12v boat system, divide 1500 by 12 = 125.

Your $100 battery is rated somewhere around 100ah? (Amp hours). You want to avoid running it below 50% discharge rate so you have 50ah available. Therefore, you could use your hairdryer to warm the air for 24 minutes before your battery needs recharging.

By the same principal, your solar panel putting out 150watts in perfect conditions, will only be able to replace 1/10th of the power that it takes to run a 1500w hairdryer. Although a hairdryer might not be the ideal appliance for heating your boat, you can see that the maths of any heating element just doesn't allow it to run on a small solar grid.

I hope this helps.

[Bullshooter]

This suggestion is only made to be helpful, but I do not really know if it is feasible.

Can you just drain the water out of all lines? Nothing to freeze that way, except the tanks and it seems like they would not freeze solid either. Or drain everything including tanks and re-fill after summer. Do you really need water on the boat over the winter?

[Colin A]

Either some potable water antifreeze or drain is your best bet. Cheap you can rig things like water heater bypass and drains to do it even quicker. Much simpler solution. That said in general my experience with winter on boats is the water will keep them a bit above freezing until air temp gets down below 25 degrees. Of course it varies alot depending on boat etc. A freak cold snap in TN a few years ago cause more freeze damage then you would think for instance.

You could also make a solar water heater and pump the water into a radiator in the cabin but I'm not sure how effective that would be in this size. I had a friend do that with a pump house for a off grid well. He used a couple of solar collectors designed for heating a pool (coils of black hose in a enclosure) and ran hoses to finned copper near the pump. He had a timer with a 12V circ pump.

[Paul Elliott]

Originally Posted by Pizzazz

The inside of the boat will never get freezing cold in the PNW.

I think you need air circulation inside the cabin to ensure this. I have a small powerboat in Friday Harbor, and before I started using a space heater (and shorepower) in the winter, it did get cold enough inside to freeze the standing water in my galley faucet. It cracked a fitting in the spigot. My sailboat a few slips away had some cabin fans running and there were no freezing problems. In neither boat did the water tanks freeze (they are against the hull).

Even with the fans running in the sailboat, both boats did have bad condensation, with water dripping off the metal portlight rims.

Since then I've used electric space-heaters on the boats over the winter and these have kept the condensation and freezing temperatures under control. I also try to drain the water lines feeding the fixtures, and leave the faucets open, but I don't think that is necessary as long as I've got a little heat. If I didn't have shorepower, I would have to go the antifreeze route, or use a fan to circulate the bilge air and hope that was good enough.

[alctel]

I live in the same area year round (inc winter), and basically you'll need to either be hooked up to shorepower or have a diesel heater. Electric heaters off-grid are a non-starter.

It's less about the cold (though it gets cold, I just wear PJs and have hot water bottles at night) and more about getting rid of the damp. To do that, you either need AC power to run electric heaters and dehumidifier or have a decent diesel heater. I have a Dickinson Newport that does the job nicely when I go away from the dock.

Look at chemical dehumidifiers - they are pretty crappy but better than nothing. It's really worth installing a diesel heater if you can though - winter sailing around here is pretty great, it's cold and damp but lots of wind and no-one else is around - and pulling into an anchorage and lighting the heater to dry everything off at the end of the day is wonderful.

[taxwizz]

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

45 degrees? Would you want to swim in that ??
Does NOT sound cozy and warm to me.
And I am from the frozen North (Toronto, Canada)

[ramblinrod]

Originally Posted by mr-canada

Hi there electrical junkies.

I am planning on buying a 150W 8A solar panel and a controller (good for up to 30A) for the boat as I am waiting on a waitlist for a marina and so I am moored off grid.

I have traditionally ran a dehumidifier and ceramic space heater on very low over the winter when connected to shore power. Obviously the dehumidifier is completely out (it's big enough to dry out a huge house) and the space heater I currently have is going to be useless (120V AC, 750/1500W).

The goal is not to make the boat nice and toasty, but rather to have the heater kick in when it reaches near freezing. It doesn't usually get brutally cold here in the PNW but in the dead of winter it usually reaches about -5'C for a little while. In the odd winter (like last winter) it can drop to -15'C but that is pretty abnormal, if it got cold like that I might just wait for a calm day and plug er into shore power and run the AC unit.

It is a Columbia 26 MkII, the cabin is roomy but it's not a huge boat. I am mostly just wanting to make sure my fresh water system doesn't freeze up and burst.

The 150W solar w/controller at 8A should not have a problem charging the battery and keeping it solid, but as we all know when it gets cold you're usually not getting the best sunshine for very long even on a good day. Mostly overcast happens here and rain. Rain is good because it's not freezing, but it does reduce the output of the panel.

I've been digging around for 12V small space heaters and I keep turning up reviews where people are calling the things junk that are blowing their fuses. Maybe they're expecting too much from a 75-150W 12V space heater, maybe the things just dont put out enough heat to do anything, I don't know.

Drilling exhaust ports for a diesel heater, running the propane stove to heat the inside, the upside down flower pot hack are all things I'm not really too comfortable with. Oftentimes in the winter I check on the boat, pump the bilge (manually... :-( ) and stay the night on board before going back home as I'm not moored that close to my home. I mostly use the boat for summer sailing but hell if it's nice out I would gladly go and drop crab pots and fish and make use of it if I'm there. Obviously I'd be dressed warm.

Anyone have any ideas? I was thinking that a low power space heater on 12V below the solar panel's rated wattage would be able to at least keep the boat from freezing up if it dips below freezing in there, with some battery drain if the light source isn't optimal but that the panel would recharge over time because it would always be on with a controller.

Hi, I consult and modify boats for winter liveaboard on the north shore of Lake
Ontario. I winterize boats every year for the Ontario deep freeze.

Forget heating with photo-voltaic.

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. Seal all seams with clear plastic packing tape. Slope down at front to reduce windage when weather cocked. Cut up black tarp to to lay on top of boat surfaces. 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.

Now install two solar vents in the boat, one forward drawing in, one aft blowing out. Ensure these are not covered by black tarp or shadowed by greenhouse frame, but draw from and discharge to the greenhouse. Leave doors and locker lids open to all areas that have anything that can't freeze; if necessary cut passive venitation holes.

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.

[mr-canada]

Mmmm..

The tank itself I'm not worried about, it's aluminum. If the water in it froze it would not turn into a brick and the tank could probably take the strain as it isn't full. I could drain it with much pumping, I think it's about 3/4 full. Its more the water pipes I'd be worried about. I blew a gasket first winter as a previous poster noted. Now I have to give the boat a blow job (lol) where I have my fiancee pump the water while I blow positive pressure into the tank to get it primed, other than that it works fine.

I once had a horrific moisture problem in the swing season, it was literally raining inside the boat - hence I bought the dehumidifier and the space heater. But those will only work with shore power. The previous owner managed to keep things going with an incandescent 110V light bulb mounted in some strange contraption to circulate air and bring a bit of heat onto the boat. That wont work on a 12V solar, the bulb is 60-120W and the panel wouldn't be able to output that 24/7 even if I jury rigged it to work off the 12V especially in winter. I never figured out how to make it work despite it's simplicity hence the moisture problems and my resolution to them.

The electric 12V blanket seems like a good idea if I overnight during the winter. Unfortunately moisture outdoors is cumulative, I learned that in the military. If it's cold, and you get wet, there is not a whole lot you can do to get rid of the moisture until you have means to dry clothes, bedding, etc. and it just keeps building. That's why I have killer rain gear, gloves, boots - to stay dry as I can personally so I am dry. The boat unfortunately doesn't have such luxury.

For those not here in the PNW, Summer is beautiful, the swing seasons are wet as hell, and the short winter is wet and cold and dips below freezing. Swing season is actually worse than the freezing, because it gets quite warm in the day and quite cold in the night, with very high ambient humidity, causing condensation against the hull like no other resulting in moisture problems and full bilges.

Good luck. Do not leave your boat unattended for long. She will miss you and complain.

Haha I know. During a period of personal issues she destroyed the stereo, stuck the VHF to channel 16 only, rained inside the boat once, and now she keeps trying to turn off and drag me into the Georgia Straight so I can't leave her.