Webasto heater

[S/V AMITY]

Any one install a Webasto (or equiv) air heater?  How/where did you install it and where did you exit the exhaust?

[Skookster]

I put a similarly-sized Wallas Dt40 in the aft third of the starboard sail locker. Ran the exhaust about 3' to the upper part of the starboard transom (fitting at top right in photo). Zero problems.

[S/V AMITY]

  Be interested in more info./pictures on your installation... duct routing, wiring & whatever else good-to-know info. you learned from your installation.   Cheers!

[Dale Tanski]

I cannot comment on the Webasto unit (although I am a dealer) however I do own a ESPAR forced air unit and it is wonderful.  The unit I own is a model D4.  I originally purchased it when I was working on the boat down in the Chesapeake during the winter.  Make no mistake it gets cold there, damn cold.  Often I would arrive to the boat late at night and it would be in the low teens.  During the day one would see 45 or so but at night it was chilly. 

My original installation was simply in a plywood weather board that I slipped into place when I got there.  I dropped it in, threw the fuel hose into a 5 gallon jug, clipped the battery leads onto a battery and away it would go.  My worst weekend of cold it only burned about 2-1/2 gallons and the boat was shirt sleeve warm (70 on the T-stat).

Everything you have read about smoke, noise and unreliability is in my opinion unfounded.  The thing was super quiet, put out a ton of heat and burned very little electricity and fuel.  It has a multispeed fan that ramped up and down depending on how much heat it had to generate.  My recommendations for mounting revolve around the exhaust pipe route.  Keep in mind the exhaust does get hot, very HOT.  It should be shielded so something doesn't melt or worse to it.  The hot air discharge should be as close to the floor as possible (hot air rises). I found with the discharge up high, the boat would stratify and the floor would get cold.  Often there was ice in the bilge.  I added a section of duct hose to direct it to the bottom of the boat which helped keep the air more uniformed in temperature.

Would I buy another on?  YES. If I had to do it over I would consider the hot water version.  With the forced air getting a outlet in the main cabin, head and V-berth will not be easy (impossible).  You almost need multiple forced air units to assure total comfort.  With the hydronic version you run a hot water loop around the boat and install little forced air heat exchangers where you need them.  Each separate heat exchanger is a "zone" and be controlled separately via a thermostat. The cost of the hydronic unit is much more but if you lived aboard it would be fantastic.  The beauty of a diesel unit is you can use it out of the water unlike a heat pump unit.

Dale

[S/V AMITY]

  Thanks Dale.  Since hot air rises, would it be practical/advisable to vent the hot air from the heater directly into the bilge and install cabin sole registers to regulate warm air distribution?

[84westy]

I installed a diesel heater in my 365.  The heater is mounted in the starboard sail locker exhaust out the stern.   Duct runs forward through wet locker and under navigation station to an t just forward of the water tank.   One duct enters the main cabin near the main bulkhead, 3" duct continues to a splitter which routes 60mm webasto duct to both the head and V-berth.  I also mounted a fitting in the aft bulkhead above the alcohol locker and oil return air to the heater there.  Mine is quiet, economical (fuel and battery), and keeps the boat very comfortable through the winter. 

[S/V AMITY]

84westy,

   What make heater?

[84westy]

Mine is the cheap Chinese knockoff of an espar.  I bought it to see if it had enough capacity vs the webasto 5kw air top.   Planned to replace it with an espar, but it seems to work very well and haven't gotten to it yet.   If you go that route, check into the afterburner controller.   Allows remote heater operation and vessel monitoring.    I can check temperature and battery voltage with my phone using MQTT.   There are four configurable input/outputs.   I've used two so far.  One tied to my high water bilge alarm and another to a relay that senses AC voltage present.   It is nice to preheat the boat before going down there.  I think espar or webasto is a better product and the hydronic systems are basically better.   I did use webasto exhaust and duct work.   Exhaust as shipped with China heater are a great way to win a Darwin Award.  Total installed cost with me performing labor and the afterburner is around $800.   Most of that is exhaust and duct work.

[S/V AMITY]

  I stay away from "Made in China" gear as much as possible.  There's a reason their prices are low besides the dirt-cheap labour.  When we pull the trigger it will be Webasto; we have too much invested in the boat to mess around with an economy heater.

[84westy]

Agree on Chinese stuff ( as I reply on my Made in China Iphone)I have the espar already, really just trying to get through other projects first.  I'm a mechanical engineer and spent some time doing calculations on what the boat would need.  The espar D4 is 4kW (13,683BTU/hr) and webasto makes a 5.5kW.  I wasn't sure that the 4kW version would be enough for the boat, but also wanted the low setting to be low enough to now heat the boat up too much (minimum setting on the webasto is 150% of the D4).  The Chinese heater, which you can adjust fueling and fan curves for allowed me to figure out sizing without potentially wasting the price of the others.  Cabin Sole is next in the queue. 

[jpendoley]

I installed a Planar 44D. The results have been mixed-I installed it forward in the starboard cockpit locker- just in front of the bulkhead seperating the engine room from the main cabin. I made a shelf of diamond plate and installed it high in the locker. The unit itself seems well designed and reliable. The problem I have is two fold:

1.  At 13000 BTUs I think it is undersized for New England winters- and my boat is partially
     insulated. I am in northern Mass.
     I'm considering selling the existing unit and getting the next size up.  If someone wants to make
     me an offer.....

2.  The mounting location I chose necessitates a long exhaust pipe run to the stern.  The exhaust
     pipe does get hot so I insulated the pipe with a pipe insulation rated for very high temps.  I can
     put my hand on the insulation and it barely gets warm on the outside.  I even welded up a long
     rectangular cage to house the insulated exhaust pipe so that objects in the locker could not
     abrade or damage the insulation.The exhaust run is 11' and that length causes the unit to not
     be able to expel the hot exhaust fast enough to prevent it from overheating and conducting an
     emergency shut down.  I am consiering remounting further aft-but the install specs don't want
     the hotair outlet to be too long either. Kind of flummoxed on whether he move would resolve the
     shut down issue or not.
Jim

[Dale Tanski]

Regarding your long exhaust run...
I suspect that if you increased the diameter of the pipe the problem would go away.  Too much restriction.  Remember every elbow and every fitting adds to that problem. Somewhere they must give you a maximum number on back pressure. You could also install a induced draft blower that "sucks" the exhaust out of the boat. That will add to the amps consumed but if you are on shore power most of the time it would be mute. 

Exhausting under the cabin sole...
The theory is correct however you would have to deal with heating the bilge area as well as heating the boat.  This would include heating the surface of the hull.  The good news is that the portion of the hull below the water line would never get below 28 deg F. (in salt water, 32 in fresh) unlike the hull that is exposed to whatever the outside air temp was.  I would rather insulate the "floor" and remember a great article in Good Old Boat where they used a foam play mat that were shaped like puzzle pieces.  The installed the soft foam pieces that would indeed be an insulator by cutting them with scissors to fit. Sounds like a great idea for the winter months. 

Dale

[S/V Deo Volente]

I have a very early Webasto forced air heater, about 50 years old. Since I have a Pilothouse there are some differences in ducting. It's mounted in the back of the port cockpit locker. I wrapped the exhaust in rockwool from a fireplace store and covered it with a galvanized stovepipe. It's not completely encased but enough to protect the rockwool. The ductwork in the locker is galvanized stove pipe insulated with foil faced bubble wrap, probably not the best choice but better than nothing. I am using a T so the main outlet is through the aft bulkhead at floor level. The other outlet is under the dinette. Normally we only run it in the morning or evening to take the chill off, but occasionally we have had to run it all day. The problem with this unit is it only has one heat output, on or off. That means each heat cycle the glow plug comes on for 1 minute before firing up. That consumes a lot of power when cycling on and off. I would like to have a dual btu output unit if I used it more.
I recommend using large wire to the heater to avoid voltage drop especially when starting.

[Skookster]

Ok, here are a few pics, sorry they're not the best lighting. The duct routing was further described in a 2012 post "Forced-air diesel furnace" (can't believe it's been 8 years since I put this in).
Two hot air ducts come out of the forward end of the Wallas. One I routed down via the bilge stbd of engine/drivetrain (photo 122457) all the way forward to the stbd hanging locker in the V-berth (122837). Insulated the whole way with the rubbery sleeve they sell, it delivers enough heat to drive you out of bed in the morning. I put one wye on that line and that branch goes to an adjustable register in the head installed beneath the locker door under the sink. I should swap out the registers one of these days, since the fixed open one would do better in the head where so much drying is a good thing, and I could reduce the amount delivered in the V-berth. The to-do list always gets bigger, right?

The other branch goes forward on outboard side of the stbd lazarette, and beneath it is a cold-air return from the hanging locker aft of the nav station to the aft end of the Wallas (122505). Yes, the support straps are kinda lame. But the routing allows me to still just fit into the stbd lazarette for systems work. That hot branch is split between an open register under the nav station (122658) and another register into the saloon in front of the head discharge through-hull. There is enough room outboard of the stbd settee slideout to run this branch beneath the nav station and stbd berths.

The fresh-air supply comes into the other aft inlet via a short run from the stbd coaming ventilator. If I did it over, I'd probably add one more hot air outlet on the port side forward of the double berth. I hope this is helpful--good luck!
-Tim