Webasto H-type exhaust cap / flue cap

I have a Webasto DBW2016 diesel heater (to be installed) but I am having a hard time to accept the side exhaust that comes with all these types of heaters....reasons are the possibility of burning the neighbors gelcoat, the fenders, getting water into the exhaust, exhaust next to windows and the possibility of down drafts/blowbacks when the wind is blowing into the exhaust.

I was therefore thinking that the H - style exhaust caps, that exits vertical on the boatdeck, would be a good idea.*

But I cannot find anyone that has used this solution, neither discussed on the forums or advertised by the manufacturers..

So the question is if this is a good idea?

Can the 1- 1/2" Webasto exhaust be connected correctly to a 3" H - style cap (the smallest I can find) or would it be better to have one made that fits the Webasto exhaust pipe?

Why do you want to cover it? *If water does get in the exhaust has drain tube.* 13 years and I have not covered the exhaust tube.* When it cold/rain you will be running the webasto so the tube is hot, and its made out of* SS.

My Wabasto exhaust goes out the transom through a maximum length exhaust pipe. Your idea sounds good to me but I'd call Sure Marine in Seattle or Wabasto. On my previous boat my Wabasto exhaust went out the stbd side (we tied port usually w that boat) and only needed to locate the fenders accordingly. Was never a problem.

The reasons that I stated are all based on the experience that others have posted on the forums - I think they are valid concerns - especially the neighbors gelcoat and the possibility of starting a fender or rope fire...

Water in the exhaust tube is not that big a problem when moored due to the required drain, but it appears to be a concern for the blow boats when heeling. I guess that the drains cannot cope with a larger amount of water when they frequently have their exhaust under water.

I also like to be "double safe" as I would get in trouble with my better half if there were no hot water....

*

The next boat would have to be REALLY! close as the volume of exhaust air is small.

IF tied alongside a thin fenders width away , maybe a problem, bit in the next slip?

Our slip on Lake Union was a fixed dock.* In the winter the reduced the water level about 3 ft so the Webasto Exhaust was next to the wood dock.* So I had a SS 3 ft X 3 ft make and also hung welding blankets over the dock for safety.* With in one ft the air was warm but not hot.* The biggest complain is fumes, soot and noise.* So each year I have the Webasto service so it was soot and fume free.* Not much can be done about the noise.* We had a neighbor whose exhaust put out some soot, so I hung a welding blanket to protect our boat.*
*

If I had the to do the install over again I would have a longer exhaust so the exhaust cools down and reduce the noise.* I thought about having the shop make a extension to divert the exhaust down and back rather than straight out.

Suremarine and Navstore have Webasto installation explantions that says to place the exhaust as high as possible and as far aft as possible, max pipe run is around 15' with max 270 degrees of bends in the system.

This indicate to me that the H-type would be a suitable solution. The next question is then how to run it through the saloon.

My current thinking is to install a bulkhead thru-hull in the engine room ceiling. Suremarine * has a model for insulated bulkheads so it has extra heat protection.*

http://www.suremarineservice.com/W005-154.aspx

This thru-hull has an inner pipe that extends quite a long way out of the thru-hull - this is perfect for connecting an extension pipe (either welding it on or clamping it on).*

Then route the extension pipe up through the saloon and connect it to another of these bulkhead thru-hulls.

The exhaust will now be protruding on the outside roof on top of the saloon.Then connect a Dickinson 3" deck plate and a 3" H-style flue cap.

Then the issue of insulating the pipe: Would it be possible to place the exhaust pipe INSIDE another stainless steel pipe with insolation between the two pipes. Then build the pipe system into a wooden box.

Any comments?


-- Edited by Singleprop on Saturday 15th of October 2011 11:19:35 PM

Mount the Wabasto further aft and run the exhaust through the stern/transom.

That would be even more complicated since it will have to go through the lazarette and a water tank to reach the stern.*

I had a force 10 propane heater thet came with a deck flu cap. Google At Sig marine.

It could work.

Sd

Singleprop,

Mine goes right alongside one of my plastic 50 gal water tanks. Has lots of heavy insulation along the exhaust pipe. No problem.

nomadwilly wrote:
Singleprop,

Mine goes right alongside one of my plastic 50 gal water tanks. Has lots of heavy insulation along the exhaust pipe. No problem.

Click to expand...

*Mine would have to go through the water tanks - I don't like that idea.

I eventually found some recommendations from Webasto and others:

max 5 meters length without exhaust silencer,

as high as possible,

aft 1/3 of the boat,

it's OK to increase the exhaust pipe diameter, this reduces back pressure,

ensure no water ever gets into the exhaust .......a very good reason for using the H-type exhaust,

do not face the exhaust into the wind ..........this is impossible with a hull side thru-hull but never a problem with a H-type exhaust.

max 270 degrees bends in the exhaust....easy with a vertical stack, more difficult with a side exhaust.

use double walled pipes and thru-hulls if at all possible

On my previous boat with a Wabasto I put the exhaust amidships on the stbd side. It had a RH prop. I was worried about the exhaust heat there but it never was a problem. As I recall I put the exhaust between fender cleats. And also consider that the exiting hot gases are not hot enough to be a threat to the hull of your own boat 2" from the outlet.*

Does anyoneknow if the "Wallas" type heaters are the same type as the Webasto?

I am asking because "Wallas" has a thru-deck exhaust system and if the heater works the same way as the Webasto then at least there is a similar system that works, which would make my decision a bit easier.

Singleprop wrote:
Does anyoneknow if the "Wallas" type heaters are the same type as the Webasto?

I am asking because "Wallas" has a thru-deck exhaust system and if the heater works the same way as the Webasto then at least there is a similar system that works, which would make my decision a bit easier.

Click to expand...

*The Walls has a vent system that the exhaust exits thru the the flu and the combustion air comes in thru the same fitting.

The Wabesto is a direct exhaust with a seperate intake for combustion.

So not the same.

SD

I asked Wallas and they confirmed what you said - except for the DT40 - which has a seperate air intake.*

They didn't answer the primary question - that was if the "forced" Wallas heater exhaust works the same way as the "forced" Webasto heater exhaust (I believe they are the same type - but I just want them confirm it).

If they are the same then that would be a go-ahead for my longer vertical stack and H-type cap.........but only if I can get the other systems out of the way of the exhaust.

our boat had the webasto installed when we purchased her last September.* It exhausts amidships on the port side. We are in a double fingered slip and tie over to the starboard finger.* Standing on the port finger you notice a bit of warm air but there is no way it is hot enough to damage the neighboring boat a finger away.* Of course we would not run the heater if we were rafted up to someone on that side.* We would have to be in pretty heavy seas for water to possibly get into the exhaust.* Hasn't happened yet.* In any case, we are very happy with the heater.*

I ended up with the following exhaust from Sweden:

2m (6-7 feet) Glembring 70mm stainless steel insulated exhaust stack with thru-deck fitting and H-type exhaust.

Inside the insulated exhaust there will be a 50mm stainless steel exhaust pipe going straight through the Glembring pipe - from the engine room to the upper deck.*

The dual pipes ensures no heat damage at the thru-decks, reduces the exhaust noise in the saloon (increased diameter pipe slows down the gasses, the air gap between the pipes and the 10mm insulation on the outer pipe), and it is a really pretty looking exhaust as well.

Price for a complete exhaust is 400 US.

I will be happy with this system once it gets installed.

http://glembring.se/eng/index.htm

The link I provided doesn't work so here is another link for the Glembring exhaust.

70mm Flue Parts

here is another link that turned my "flue understanding" upside down, will post it on another relevant thread as well:

http://www.tigerboats.co.uk/images/forum/insulated-flues.pdf

Then the issue of insulating the pipe: Would it be possible to place the exhaust pipe INSIDE another stainless steel pipe with insolation between the two pipes. Then build the pipe system into a wooden box.

I would use a SS pipe if thru the cabin with a nifty SS screen to avoid burns.

IF the object is HEAT why throw the exhaust heat away with insulation?

I think this is a created problem , the side exhaust is no bother at all.

We have a Webasto 2010, 90,000 btu, the exhaust air about 6” hot but not enough to burn, and 1 foot away is warm. Our bumpers are the 12” X 34” so at the distance to the dock not that hot. I don’t think you need a H exhaust. I mean the exhaust pipe ring the fasten to the hull is not hot enough to damage the hull, caulking and/or paint. So a foot away it should not be hot enough to damage a boat or dock next to you. I would be more concerned about soot/than heat.

A local fab/metal shop should be able to make one for you. I would use the same hole pattern and screws as the existing exhaust ring. Why don't you wait to see if you need one.

FF said:

Then the issue of insulating the pipe: Would it be possible to place the exhaust pipe INSIDE another stainless steel pipe with insolation between the two pipes. Then build the pipe system into a wooden box.

Click to expand...

That's exactly what I'm doing. A stainless steel exhaust pipe inside an insulated Glembring exhaust flue.

The H-type cap is to avoid any issues with wind and weather. And hopefully brings sooth away from the hull...

Singleprop said:

Does anyoneknow if the "Wallas" type heaters are the same type as the Webasto?

I am asking because "Wallas" has a thru-deck exhaust system and if the heater works the same way as the Webasto then at least there is a similar system that works, which would make my decision a bit easier.

Click to expand...

The Wallas is a different exhaust type.

The Wallas uses a two tube design. The inner tube is exhaust out, and the outer tube is combustion air in.

The exhaust pipe is not very hot at all because of this design.

Also the Wallas furnaces are dead silent. Thats why I bought them

That's exactly what I'm doing. A stainless steel exhaust pipe inside an insulated Glembring exhaust flue.

That is why I quoted your setup.
INSULATED pipe will trap the heat inside , instead of having it aid the vessel.

That is why I suggest an uninsulated SS shield with holes to let the warmth into the cabin.

The reference file that I posted claims that it is more energy efficient with an insulated pipe than with an un-insulated pipe - in other words - that the extra heat gained by insulating the pipe is offset by less efficient burning of the solid fuel.

In my case, the fuel is diesel so it's not relevant - but I don't want extra heat inside my cabin for 48 weeks of the year at 23 degree N - that's why it will be good with the insulated exhaust on my installation. If my boat was staying in a colder climate the un-insulatd pipe would be good.