June 22, 2015

Thoughts on Heating Systems for High-Latitude Cruising

We occasionally comment on other cruiser's blogs. [See our Sailing blogs/sites we enjoy... sidebar for links...]

Some of those topics may be relevant here, so once in a while we will repost for reference. 

The following may be one of those... [Original post on the Zero to Cruising blog...]

Regarding a request for feedback about Heating Systems for High-Latitude Cruising I responded with the following:

Original Forum Post [22-Jun-2015]
I have lived aboard/cruised several boats above 60N year-round over the decades- each with a different, effective heating system. 
We are now preparing our current boat for high-latitude cruising. It came with diesel forced air which works very well for us currently cruising the Inside passage of Alaska. Before going to even colder climates, we will install a hydronic system as well. 
From experience, if you only choose 1 heating source, go hydronic. Set it up with a thermostat controlling the heat register(s) in each zone. Include a loop for your hot water heat exchanger, and a valve to preheat your engine(s) and generator. [I forgot to mention in my original post that this allows the engine to provide heat to the hydronic loop while motoring...] It doesn’t get any better than this, and the lockers/bilge where you run the hoses are heated and dry as well. A bit overkill for just taking the chill off occasionally, but very robust for the coldest of conditions. 
As a back-up go with a forced air system. Use this when constant heat is not required and/or moderate temperatures. 
Either system will do the job if properly engineered and installed. 
Having had a stand-alone diesel drip unit in a 37ft boat at 61N over several winters, I can tell you you need one that balances intake draft so it won’t back-wind and soot up your cabin. (Sigmar was the only brand I found back then that had a separate combustion air intake among the diesel drip heaters… there may be others now…) I can also state that even with fans and air circulation, you won’t achieve even heat through-out the boat when it is cool outside. My boat was insulated and conditions often reached -20F with 40+ kt winds for weeks on end… I stayed warm, but not every nook on the boat was cozy…
I also installed a Dickinson solid fuel heater inline [above] with the drip heater [Sigmar]- sharing the same exhaust flue. [Essentially, the solid fuel heater became a part of the diesel heater exhaust stack.] 
I had to drill a hole through the bottom of the ash drawer of the solid fuel heater the size of the flue pipe [3in?] to allow the diesel exhaust to pass through. I had a piece of heavy gauge [11ga?] SS sheared to the inside ash drawer dimensions that I set in the bottom of the drawer during the season when the oil burner was too much, but the solid fuel was just right. [I had a note I placed inside the diesel heater firebox reminding me to remove the SS ash drawer bottom piece before lighting the diesel...] 
I was living aboard in Prince William Sound at the time, and kept easy lighting [wax impregnated] compressed wood logs that I broke into ~3in lengths for quick morning fires in the summer, and often burned driftwood as well.  
Coal also worked, but was difficult to source locally... 
These days the compressed fuel for pellet stoves [with an aerated basket to hold the pellets in the burn chamber] might be appealing as well as the ~2in diameter compressed logs [without wax] from the pellet manufacturers.
This set-up worked well and was very safe. If there was a downside, it was the inside of the wood stove would build-up a bit of soot [no more than the inside of the flue...] from burning the diesel drip all winter. I would wipe the 'glass' and insides near the door with a dry paper towel, and use that to light the fire... Any remaining soot quickly burned off after a couple of hot wood fires. 
Since Morgan’s Cloud was mentioned, in case you aren’t already aware, they are conducting a High Latitude workshop this Oct in Halifax where this topic is one of many that will be covered over a 2 day period. (In case that is of interest…) 
Enjoy the journey. 

1 comment:

  1. I really wish Galapagos was insulated. It seems such an oversight to not insulate any boat. We have forced air diesel heat on her, but the 'forced air' is really loud. If we were to have the opportunity to cruise in higher latitudes, we'd need to refit this system and look at how to retrofit some insulation, a daunting task on a boat like Galapagos.


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