Wabasto

[chazwood]

Who knows about a wabasco water heater hooked into the main heating system?

[Bill B /bus]

Do you want to tie a Webasto boiler (hydronic heater) directly into the bus cooling system?

Common mode failure would take out engine cooling and house heat.  Of course you could use the engine radiator to also cool the generator.

After being a smart a**, I would recommend a heat exchanger to keep the two systems seperate. A 40K BTU unit is not large, 24" long and about 5" diameter.

Bill

[Geoff]

My Scholastic Series DBW2010 is hooked directly into the heater lines coming from engine to the front of the bus.  The system works fine, and I can isolate the Webasto from heating the engine while keeping the interior warm.  You do not need to separate the two systems with a heat exchanger.  I do not understand Bill's answer without some personal experience.  Webasto has instructons on how to tie your Webasto into the engine heater lines.  It is Aquahot that uses the heat exchangers for a more complicated system that costs much more money.

--Geoff

[luvrbus]

All those units like Wabasto,Espar and Pro/Heat can be tied to bus heat from the engine

[Brassman]

I like Bill's idea about the heat exchanger. That way you could use a friendlier coolant for the house side.

[buswarrior]

Mine is simple and brutish.

It can pre-heat the engine, heat the coach interior, and supplement engine heat if trapped in idling traffic for extended periods in winter weather.

A large DBW 300 plumbed in-line into the forward direction piping, in the middle bay, towards the big stock heat exchanger and the stock defroster.

A bypass switch is installed to allow the stock coach blowers to engage without the engine running. A source of battery charging is required or the big fans will shortly deplete the batteries.

A Trace 4024 will consume 10amps of 120 AC to make the 24 volt power for the big Webasto and fans in this configuration.

From an efficiency standpoint, it is a poor performer: Draws in outside air, heats the coach engine block, burns relatively a lot of fuel, BUT it can take the interior to 80 degrees in the middle of a Canadian winter, if you please.

And will raise the engine temp from stone cold to above 100 degrees in 20 minutes with outside temps hovering around -20.

Lots of ways to do a more efficient job, depending on how you will use the coach.

Cost benefit calculation, how many days of use versus the costs of changing things, versus acquiring different parts...

If parts are on hand, you can burn a lot of fuel before you break even on spending more money on other parts.

Generally speaking, if many days of heating a year are anticipated, a coolant boiler (Webasto) type system is likely more expensive to operate than a propane furnace. It all depends on what you get the coolant boiler to do for you.

An article of interest: http://busnut.com/forum/index.php?action=articles;sa=view;article=43

The glory of bus converting: Whatever you do will be right for you!

happy coaching!
buswarrior

[Paso One]

I'm another vote for tying the webasto system into the cooling system.

Maybe it's a Canadian thing or just that when it's cold here it's cold.

My DBW 2010 Webasto  sends the heated water to a manifold  from this manifold I can send it to the engine and heat the engine only. or

Open up another valve and it is sent to a heat exchanger and fan to heat the interior of the bus. (old defroster Unit.)

It can also be directed to a side arm on the side of my electric water heater and the hot engine water safely transmits the heat to the electric water heater's  water.

The same loop (thru the side arm) heats the electric water heater as I'm driving down the highway.

I use a tempering valve on the top of the water heater to prevent "hot " water coming from the  electric water heater after driving.

I'm happy with the system as the engine is either making heat or the webasto is making heat.  The water free flows thru everything including the webasto when not in use.

The other benefit is the Bus radiator removes any air locks.

[Sam 4106]

Hi Pasco One,

What is a side arm? That is a term I am not familiar with, but sounds like something I would like to incorporate into our bus with an electric water heater. I like the idea of heating water with the engine heat but don't want to spend the money to get a water heater with engine heat incorporated into it.

Thanks, Sam

[luvrbus]

A side arm is a water to water heat exchanger Sam some hot water heaters in the marine world like Seward those are built into the heater fwiw Matt's Eagle has one I never hooked up lol 

Very easy to build all it is is a pipe in a pipe

good luck

[Paso One]

Yes Clifford is right it is a water to water heat exchanger. The best website I have ever seen  showing and utilizing a side arm heat exchanger is on the Central boiler website.

The outside wood boiler people use the side arms the most.

Lots of beautifully made stuff that can be easily used in a bus conversion.  www.centralboiler.com

It's free safe heat from the engine to heat your water heater while driving.

The techincal term for the heat transfer escapes me but someone will chime in.

[plyonsMC9]

I've been looking for references on this subject (Webasto) and how to learn about them & work with them.  Does anyone have a good reference site?  I've looked at the Webasto site before hoping to bring down PDFs to study so I could do my own work but hadn't had a lot of success.

Thanks! Phil

[expressbus]

Here is a link to another bus site. It has a detailed article on repair of webasto units.

http://www.prevoman.com/index.html

Happy Heating in the New Year!

[plyonsMC9]

Hey Will!  Thanks for the link.  That looks really helpful.  Reading now. 

Kind Regards, Phil

[expressbus]

Phil,

Only too glad to help out when I can. I was at a POG Rally in Oklahoma City and Mike Anderson disassembled and rebuilt a Webasto unit as one of the tech sessions. I wish I had made a video of the session for future reference.

Happy New Year.

Will

[plyonsMC9]

Wow!  That really sounds like a great session.  My plan is to eventually run all diesel (vs propane) heaters, maybe put the webasto burner (correct term?) up in the front compartment where the front a/c unit is behind the driver.   

Kind Regards, Phil