Questions About Sailboat Heating and Ventilation|Offshore Sailboat Voyaging|Attainable Adventure Cruising

Questions About Sailboat Heating and Ventilation

Is the Espar Heater Really That Hot? (01/2008)

Question: My experience with diesel heat is that it's hard to light, hard to control, it smells and the deck is covered in soot. That was 25 years ago with the stainless steel pot belly stove in [a] Westsail. You rave about the Espar diesel heater on your web site. Is the Espar really that good and does it address my previous experience with diesel heat?

Answer: Yes, the Espar (Eberspaecher) really is that good. Keep in mind that we set a very high standard to make it into our Stuff that works area. If the Espar had the problems you mention, it would not have had a chance. Our Espar D8 has run for about 4000 hours and has never let us down. Very occasionally, as it fires up, we get a slight whiff of diesel but that clears as soon as it completes the ignition cycle.

The key issues are good installation and to make sure you have it serviced at least once every two years. (If you are mechanically inclined and can pry the service manual out of the dealer’s hands, you can learn to do this yourself.) Also, you should make sure you run it regularly (not a problem for us).

On the installation, it is vital that the power cables are heavy enough and that you follow the instructions for the fuel pickup and fuel pump installation to the letter. Mess up in either of these areas and the thing will drive you crazy. Also, see below for our comments and photograph on a proper exhaust for an offshore boat.

If you will be far from service help, it is probably worthwhile investing in one of the little black boxes that allow you to read diagnostic codes and reset errors on the Espar, as well as a few spare parts including a glow plug. Also, keep in mind that on the air units the blower motors only last 2000 to 3000 hours. We carry a spare.

Having said all that, if we were to do it again with what we know now and keeping in mind our heavy usage, we would have installed a water, rather than air, circulation unit from Espar or possibly a Refleks from Denmark. The advantage of the Refleks is that it is a much less complex machine than the Espar and uses no electricity (the Espar is a power hog). The advantage of the Espar is automation: Need heat? Flick a switch and you got heat.

The disadvantage with both water circulation solutions is that they are more complex to install than the air unit we have. Also the Refleks requires a real chimney, rather than the simple exhaust of the Espar, and with a water coil to feed the radiators, which we would need to heat our aft cabin, it is very large.

Keeping the Boat's Interior Dry (2005)

Question: Is keeping the interior of the boat dry in the midst of prolonged damp, chilly weather, and/or sea spray just a matter of dorade vents, hull insulation and your Espar heater? DO you have success keeping the interior dry or does it inevitably get damp?

Note Morgan's Cloud's beefy dorade, outlined in yellow, just to Phyllis' left.

Answer: If you already have a boat, there are some things you can do to at least help the problem:

	Install an extraction blower over the galley. The stove is one of the biggest moisture generators, particularly since a byproduct of burning propane is water vapor. When we wintered over in Norway we installed a second bilge blower and a vent on the suck side of the blower over the stove and routed the blow side out a dorade. This really helped.
	When installing a heating system you have to decide how much outside air to let into the supply side of the furnace. For example, the Espar on Morgan's Cloud is installed in the lazarette right under a large dorade vent. If we close the dorade, the heater just re-circulates the air, which is more efficient than opening the dorade and letting the heater draw cold air in from outside. However, keeping the dorade at least partly open results in a MUCH dryer boat, since we are drawing in dry outside air, heating it—which drops its relative humidity—and forcing moist warm air out through other ventilators. The point being, you have to think about airflow and trade off efficiency against dampness. We found that in Arctic Norway, where we spent two winters, where the air was dry and cold, it was better to keep the dorades pretty much closed, but in London, England it was better to open almost all of them and get rid of the damp. (The winter in London was brutal for dampness, the worst we have ever experienced. In the end we bought a dehumidifier.)
	Our biggest problem on Morgan's Cloud, like most boats, is condensation forming on the hatches and ports. In Norway we covered both with plastic sheeting separated from the metal by bits of adhesive foam; in effect double glazing—not elegant but it worked like a charm. (Update, 2007: During the last refit we designed and had built wooden bezels around each port that accept Plexiglas covers, which will do the same thing and are more elegant.)
	Make sure you have a heater that can be run in any weather offshore. I can't tell you the number of boats we have met, even in the Arctic, that have to cap off the heater at sea because of worries about burning something on the chimney or getting water down it. Don't let anyone sell you one of those "toy" exhausts for an Espar that pokes out of the hull of the boat. Ours is on the aft deck, massively braced to the rails, and three feet high. The result is that we can run the heater in any weather. (See picture below.)

Note Morgan's Cloud's massive heater exhaust—outlined in yellow—that we had custom made and well braced to the stern rail.

Which Heating System? (2005)

Question: What do you use for heating on Morgan’s Cloud?

Answer: We have an Espar D8 8KW (I'm not sure of the BTUs). It is one of the bigger ones they make and keeps us toasty in all weathers. One thing I would suggest is not to use the exhaust exit in the hull that they normally specify. In heavy weather this will be very vulnerable to flooding. We had Mike Bowden at Ocean Options, where we bought the heater, fabricate us a 4' high chimney with a "Charlie Nobel" type top that is braced to the stern rail. With this set up we can use the heater even in very heavy weather, which is, after all, when you want to be toasty below.

If I were doing it again I would install one of the Espar heaters that uses hot water and radiators or heat exchangers. It would be more controllable and it would cut down on all the ducting though it would be more complex to install.

We also have a heater that uses the waste heat from the engine to warm the cabin—essentially free heating with no fuel cost. See our Stuff that works page and www.espar.com and www.oceanoptions.com for more information.

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Last edited on Wednesday April 30, 2008

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COPYRIGHT: All information on this website is the copyright of John Harries and/or Phyllis Nickel. All rights reserved. FAIR USE: Notwithstanding the above, it is perfectly acceptable for you to use quotes of a reasonable length from this website, as long as you include an attribution with a link to this website. DISCLAIMER: Nothing on this website or in direct communications received from us, or in our articles in the media, should be construed to mean or imply that the high latitudes are anything other than a hazardous place to take a boat. Dangers such as, but not limited to, extreme weather, cold, ice, lack of help or assistance, and poor charting could injure or kill you and wreck your boat. Decisions to cruise the high latitudes, where you go, and how you equip your boat, are yours and yours alone. The information on this web site is based on what has worked for us in the past, but that does not mean it will work for you, or that it is the best, or even a good way for you to do things.