If your heating
needs are confined to dockside I would get electric
heaters. But if you have a power down or you leave the dock
you will be without heat.
I have an Espar Airtronic4 which is a diesel fired forced air heater. The install itself is not complicated but there are a lot of parts
to it. The exhaust
hose is a high tech insulated hose about 4cm ID and must be no longer than 2 meters from heater to thru hull
. You run another 3" diameter hose around that because it gets hot and you want to protect anything which might be in contact with it.
You will have to connect the small pump to a pick up in your diesel tank or add a seaprate tank. My tank was already drilled for a second pickup so dropping that in place was a piece of cake.
is a piece of cake since it all harness and made up cables
except the main power which you connect to your 12v system. It has a thermostat and a program to drop it down to a very lower power and consumption
mode once things reach design temp, as opposed to cycling on and off in temp swings. This is a nice feature and keeps a balanced room temp.
Then there are the ducts which you need to run and connect to the supply grilles. We have 3 which I believe is the max number for this unit: one in the head
, one in the main cabin and one in the aft cabin. Running the duct can be challenging. Mine runs under the aft cabin, then under the the galley
then under the stbd settee in to the head
with the outlet grilles along the way with "Y" branches. The duct is 3" flexible insulated high tech and rugged yet easy cut.
And finally you need to connect a separate 3cm fresh air hose for combustion air. You can connect a separate return air duct or as I have done draw the air from the bilge
under the aft cabin berth where the unit is mounted.
Forced warm air mitigates the accumulation of moister because the moister is removed from the air as it's heated.
This system is very comfortable and attractive since it does not take up interior
real estate, but uses (in my case) inaccessible volumes for the components. It's very quiet, but not so quiet that you would not hear it go "off".
The fuel consumption
is less than .1 gal / hr. It heats the cabin from very cold to comfortable warm in 1/2hr or less depending on the starting room temp. If you ran this 24/7 it would not be cheap
at about $6-8/day. But chances are that you would use it not more than half that except on passages I suppose.
The other consideration is electrical
consumption. In start mode it draws about 4 or 5 amps to heat up the glow plug
to ignite the fuel, but after than the power use drops and then drops again as the motors which move the air go into the quiet/maintenance low draw mode when design temp has been reached.
The unit has some sophisticated monitors which will shut it down (properly) when a fault condition is sensed. The shut down sequence takes several minutes and is completely automated.
Once installed, I have found the unit trouble free and it enables me to work aboad in the coldest winter days with the unit set a mid setting. The settings are variable, but the scale does not have temp indications it more like the settings on a cook top burner.
I got the unit as a kit from a supplier UK and it was about $1,500 IIRC and then there were the odd bits that I need to get locally which amounted to a hill of beans except some additional duct from a supplier in PNW IIRC.
Having heat really extends my sailing, makes my wife very comfortable when the weather
is not perfectly warm and that is the Spring, Fall and even some summer days and keeps the boat dry when it's cold, rainy and humid.
I like not having to deal with another fuel source. I like that it does not take up space. I like that I can close and direct the grilles to balance the system to my heat needs. I like that there are no open flames or flues going through my deck
is on the transom). I like that there are no very hot things to burn someone if they touch it accidentally. I like the thermostatic control. I like the forced air which keeps the interior
air moving and mitigates mildew growth.
Is this system worth the cost? In my opinion is it. This is a complete furnance and heating
system, including ducts, furnace, fuel pump
, thermostat, wiring
harness, grilles and so forth. Yet it's small and fits inside the unused spaces in my boat. Since I get more use from my boat, and I am using this heater a lot, it's cost / use keeps going down and down. Let's see how long it lasts. Going on 5 years now. It replaced another one that lasted about 8 or 10 of the same make, but a more primitive design.
I recommend this unit, but not Ocean Options who sells them on the US East Coast