I'm a lifelong resident and
liveaboard in
Alaska (three winters on a boat, so far--when the hell are we sailing south again??)
We have an Espar (Eberspacher by another name, FYI) Airtronic D4. I've been drafting a post for it on our blog, but *shrug, I'll sketch some of the contents out here. It is noisier than a drip stove, for sure, though properly installed Espar heaters should have a
muffler which makes them whisper-quiet. But for some reason, people will pay in excess of a $K, then balk at paying 100-200 for a
muffler. We would probably be one of those people, but the heater came with the boat (1989
Catalina 36). Lower-priced units are sold by Planar, among others.
It takes up to 40w to run the fan and
fuel pump, and puts out 4KW or 13,600BTU.
Based on our records (at average winter temperatures of about 20F, windspeed 10-15 mph) we use 0.06 gal/hr diesel. Or approximately 10 gal per week. Before we started insulating our boat, the heater would be running flat out to maintain a 30 degree temperature differential. So at 30F outside, we can keep the boat at 60F inside. Any colder, and we HAVE to use our
electric space heater. Although we didn't count these as
insulation, we did shrink wrap the windows, and block off the unconditioned spaces from the main
cabin.
Our last trip (October 2017), we left Seward with 70 gallons of diesel aboard, and motorsailed to Cordova. We worked our way back slowly, gunkholing in a few stunning
anchorages along the way, motorsailing, running the heater when we were cold. Upon our return to Seward a month later, we still had 35 gallons of diesel.
We've just finished adding closed cell foam
insulation to as much of the vberth as feasible. The heater can now maintain a 32 degree temperature differential, and the ambient temperature in the vberth is 3 degrees higher than before. Considerably reduced
condensation to boot. We are planning on insulating other areas when time permits, though our priority is kicking off for three months of sailing in Prince William Sound in February. Insulating the whole boat will really decrease the load on the Espar, and potentially lower the runtime, fuel, and power
consumption overall.
We have dined with friends on their boats who have, respectively, a Reflecs, a wood stove, a diesel drip stove, and a diesel cooker/heater. These are all great, except for two issues: they MUST be located centrally Iin extremely valuable
liveaboard real estate) to partially address the poor heat distribution in the classically long narrow volume of a sailboat, and installing the chimney both correctly and clear of all
rigging and the
dinghy on the foredeck is a real challenge. Every one of them has had smoke fill the
cabin when the notorious Seward winds kick up from the wrong direction. The hot
water jacket on the diesel cooker perks my ears, but I'm an avid cook, and the responsiveness of propane is hard to beat!
If and when we go to a wood/biofuel heater, I want a gasifier stove, similar to the Kimberly. I think Venture Lives, originally based out of Juneau, installed a Kimberly. Don't do the install the way they did, but the stove itself looks like a great idea. I have loved the camping downdraft gasifiers, and several aquaintances use rocket mass heaters to heat their greenhouses and cabins. Similar concept--secondary combustion of exhaust gases means cleaner burn, higher BTU/hr, smaller kindling size wood, less/no soot topside or backdrafted. Much easier to collect and store dry kindling/sawdust than dry
logs.
Propane and alcohol heat are terrible ideas in cold climates. I once had a Force 10 propane bulkhead heater on a 25ft
Ericson, and the first night I slept aboard in winter,
condensation literally rained in the main cabin. Propane combustion involves the release of enormous quantities of
water.
If anyone wants pics, message me through the turtletravels.com contact page, sending
images through Cruisersforum drives me nuts!