Adding a bus heater

[trace elements]

All,

I am working on rewiring the boat now, and have also decided to add a hydronic bus heater to the boat. My boat is simple with minimal electronics, no gen, gas 454s, and no AC. I would like to add heat to make fall and spring trips a little more comfortable. I selected a 40,000 btu hydronic unit with three outlet air ducts. The unit pulls hot water from the freshwater side of the engine cooling system, circulates it through a heater core, and then returns it to the engine.

I am planning on installing the heater core under the dinette seat and routing 2/3 heater ducts into the cabin and would like to (if feasible) run the third duct to discharge on the flybridge right at the helm, (no lower helm, yet).

Has anybody done this before? Any tips? Any advice on running the heater duct to the bridge?

Thanks in advance.

[mike ohlstein]

I did this years ago. I put the heat exchanger / fan unit in the head, under the sink. I ran flexible duct behind the fridge. One vent goes to the V-berth. One opens in the cabin, just forward of the head. The third connects to 4" pvc pipe that runs up to the bridge and then out just below the helm.

Two years ago, I tore it out and added an Espar diesel furnace in it's place (located under the starboard gunnel) and use the same duct work. Now I don't have to run one engine for heat.

[trace elements]

I did this years ago. I put the heat exchanger / fan unit in the head, under the sink. I ran flexible duct behind the fridge. One vent goes to the V-berth. One opens in the cabin, just forward of the head. The third connects to 4" pvc pipe that runs up to the bridge and then out just below the helm.

Two years ago, I tore it out and added an Espar diesel furnace in it's place (located under the starboard gunnel) and use the same duct work. Now I don't have to run one engine for heat.

MIke,

How well did the heater heat the cabin? Happen to remember how many btus your system was?

[mike ohlstein]

It worked very well. I don't remember the btu's. It was 18 years ago.....

[bob lico]

mike i did my heat slightly different but works great but must keep generator running not engines (no noise and less fuel) i used the A/C reverse cycle with heating coils in ductwork when the temperature of the water drops below 50 degrees.special A/C made for 65' viking bridge so has high speed fan for open back of bridge . the unit is located just inside cabin at main bulkhead inside bottom of bathroom vanity to balance generator on opposite side in port engine box.ductwork 5" goes thru top of vanity (under sink) in to a sealed air box then splits into 4" ductwork to bridge (A/C and headed bridge) and a 4" to V-berth and another 4" under cabin floor to outlet on top of cloths locker in salon forming a perfect quiet air circulation to compressor return in head vanity slotted door . the sliding head door is kept open with interlock while heat or A/C is running.works for me.

[bob lico]

mike i did my heating problem slightly different but works great ,but must keep generator running not engines (no noise and less fuel) i used the A/C reverse cycle with back up heating coils in ductwork to be used when the temperature of the water drops below 50 degrees.special A/C made for 65' viking bridge that has a high speed fan for open to the air back of bridge . the unit is located just inside cabin at main bulkhead inside bottom of bathroom vanity to balance generator on opposite side in port engine box.ductwork 5" goes thru top of vanity (under sink) in to a sealed air box then splits into 4" ductwork to bridge (A/C and headed bridge) and a 4" to V-berth and another 4" under cabin floor to outlet on top of hanger locker in the salon forming a perfect quiet air circulation to the compressor (return air) in the head vanity thru slotted door . the sliding head door is kept open with interlock while heat or A/C is running for the return air this system works for me.

[trace elements]

Anybody have any other ideas for getting heat to the flybridge? I was thinking something along the lines of what Mike said with the 4" PVC going up to the bridge.

[Todd Pearce]

Iam running a webasto diesel heater, BEST BEST BEST investment ever, totally quiet, burns 300-400 mils diesel an hour and the whole boat is warm, adds 6 weeks either side of the season to our boating, i cant say enough abut how great this has been, we get amazingly still winter weather but friken cold,but these last few seasons i boat in the dead of winter and its awesome, at night we are in shorts and tee shirts and its an absolute pleasure,,
Skip the rest, put in a small diesel tank and enjoy

[mike ohlstein]

Exactly. Like I mentioned earlier, I went with Espar, but Webasto is the same thing. Both companies make gas versions of their heater, but I would go diesel. They each burn about a gallon in 24 hours of use. Put in a 3 gallon diesel tank and fill it once a year.

I installed mine under the starboard gunwale, behind the panel, with the exhaust going straight out the transom. Digital thermostat in the cabin. It's quiet, efficient, and makes the cabin a pleasure to sleep in.

[bob lico]

the advantage of mike`s system is you don't need generator running and up north the A/C on bridge is never used especially if the boat is moving with air coming into the bridge thru open front.

[trace elements]

Exactly. Like I mentioned earlier, I went with Espar, but Webasto is the same thing. Both companies make gas versions of their heater, but I would go diesel. They each burn about a gallon in 24 hours of use. Put in a 3 gallon diesel tank and fill it once a year.

I installed mine under the starboard gunwale, behind the panel, with the exhaust going straight out the transom. Digital thermostat in the cabin. It's quiet, efficient, and makes the cabin a pleasure to sleep in.

Mike and others,

where did you install your exhaust outlet for the diesel heater? Do you have any pictures?

[mike ohlstein]

I'll get a picture over the weekend.....

[Todd Pearce]

Hi , i used a Webasto Diesel heater, its great in that you have silent heat anytime you want, long after the engines have gone cold, absolutely the best edition to the boat ever, would highly recommend it

[Rocky]

There is also a more comfortable feel of radiant heat vs air vent heat. I installed a direct vent propane heater in our travel trailer (in addition to it's fan forced heater) and it heats all the surfaces inside, not just the air.
The BEST investment we ever made for that especially when miserable outside, very comfy.
On our commercial boats we always had a diesel fired furnace (direct vent), and always the best relief from the cold to the bone soaked clothes from on deck. Furnace all the way.

[Rocky]

https://rover.ebay.com/rover/0/0/0?mpre ... 3040952532
And apparently they have fuel fired bus/parking heaters too for your hot air up at bridge!

[mike ohlstein]

Those look just like the Espar / Webesto units, but at 1/6 the price. I have no idea what the quality or safety will be....

I can tell you that I have Espar units in my Van and my Boat and I sleep in both. No fear.

[Rocky]

Yeah Mike,
I don't know about the quality difference, yes it apoears very similar to your Espar unit (German)
compared to Vevor. Both look robust inside and the kit is very similar too. It also looks like they don't give you much direct vent tubing. How long of a run did you make for yours? Bought extra tubing?

[mike ohlstein]

I bought a Marine Installation kit from Espar which included marine exhaust pipe, marine grade fuel line, a hull fitting for the exhaust, stainless brackets, and perhaps a more robust fuel pump.

Intake is no problem, and I already had the warm air distribution plumbed in from the original bus heater.

It wasn't cheap, but it's fabulous. I've had one in my van since new in 2003. I use it quite a bit and it's flawless.

The bus heater is inexpensive, but no thermostat. It has a fan on/off switch (speed adjustable if you do that), and requires that the engine be running. Plus you have to re-plumb the FWC system. This is slightly tricky if the bus heater is above the level of the engine. It works well, but definitely not as sexy as the Espar.

[Carl]

This is one of those Hey Carl, mind your business things...


I think Trace has the heating unit dialed in, but wants to know where/how those of you who have 'em in their boats ran the exhaust.
It's nice to be warm n toasty, sucks to suffocate and be dead.

[Rocky]

Carl I think Trace has the simple heat exchanger run by engine coolant and a fan through ducting.
Correct Trace? I was trying to suggest the type you don't have to run engine with as Mike was, but I suppose if you don't mind running engine for heat it's OK. I had a simple one like that in my Skipjack25, but of course didn't work while anchored overnight or at dock. If just ducting to bridge that PVC idea of Mikes sounds like the bees knees.

[Carl]

Mike and others,

where did you install your exhaust outlet for the diesel heater? Do you have any pictures?

I was refering to this question.

[trace elements]

Carl,

Yes, I had originally inquired about the location of the diesel exhaust pipe. Thanks for reiterating it, but the conversation was consturctive nonetheless, so thank you all.

I think I am going to go with the bus/hydronic heater. I need heat mostly for early spring/late fall fishing, most of the time I am on the boat the engines are running. It would be great to have some heat on the bridge though!

[Rocky]

PVC baby!

[mike ohlstein]

I ran heat to the bridge from the bus heater. The heater itself was mounted in the head, under the sink. Two 2" holes in the bulkhead for coolant hoses. It had three vents. One ran behind the galley and into the berth. One ran into the space behind the fridge and vented into the cabin. The other ran into a piece of 2.5" PVC pipe that ran just out of the head, up through the headliner and into the space under the helm. Flex tube from there to a vent outlet which was positioned to warm the captains twig and berries.

[mike ohlstein]

https://imgur.com/gallery/7TFB4oh