Pex or Silicone Hose for Webasto

[CindyandJohn]

I am getting ready to order some parts for my Webasto install and have a few questions... first i am concerned about the heat for tubing. I have read to use Oxygen Barrier Pex but all the papers for it only rate it at 180 degrees at 80 psi... Silicone is rated at 350 degrees or more but is real expensive. I will have a couple of heat exchangers in the system one between the engine and one between my generator. I am full electric and run the generator whenever not connected to shore power. So I figured I could use some of that heat in the hydro system. How hot does the Webasto actually heat the antifreeze? Is Oxy PEX sufficient? My next question is - how hot does a Webasto unit get? I have a DBW 2010 inside of an enclosure. Could it be put inside of a somewhat confined space - in with my fresh and grey water? I have an insulated Plywood enclosure within my water bay. Last question is - How noisy do the system run? should i be thinking of installing back with the engine? i have room there as well as in my generator bay, but that is in the middle of the bus and it would be on the passengers side of the bus - so we would be sitting next to it when sitting by the camp fire - not a problem in the summer and we don't sit outside much in the winter. It will mainly be used for heat and engine preheat while out and about in the winter.

Sorry for the long post. I searched a bit for some of the answers but still have many questions...

Thanks,
John

[Ednj]

John,
Use automotive heater hose.
It should heat the water to 180°
It will generate enough heat to keep your tanks from freezing.
They are noisy, you don’t want it under your bed, best spot is behind the front bumper.
Mount any side and run the exhaust out the driver’s side.

[luvrbus]

John, Dick Wright uses 3 ply heater hose but most people use CPVC pipe.I don't know about the 180 all I have been around are about 120 degrees.The Oais and Hurricane systems use PEX,copper,cpvc and rubber heater hose  good luck

[lostagain]

I have the service manual that a dealer emailed me last year when I had to fix ours on the hockey team bus. It says that it shuts down at 165F and back on at 68F. Rad hose should be OK. Yes it makes a noise, mostly from the fan for combustion air. It is not bad at all from inside the bus, just don't install it under your bed. It is a great heater!

JC

[makemineatwostroke]

My Hurricane unit (proheat) is adjustable from the 120 to 145 heat range and has PEX.With the price of fuel today I am looking into a different type of heat this winter at the ski resorts using 4 gals per day at $3.79 it is going to be expensive to heat,the grandkids may have to get a firewood permit and cut their own wood   have a great evening

[Jerry Liebler]

John,
     I went with what Dick Wright recomends, heavy duty radiator hose (3/4"), to get the same Id would require 1" Pex and I didn't trust it at 180 degrees, the coolant temperature.  Either location sounds fine.  You'll also want to onsider the exaust location.  I put mine in my engine compartment so my exaust is below my rear bumper.  Mine is real close to the head of my bed, just on the other side of the firewall yet form inside the bus I can hardly hear it running, certainly much quieter than any air conditioner.  However outside there is a sound sort of like a distant jet plane when it's going.  One more thing if you use radiator hose, don't use ANY nylon hose fittings, strictly brass.  I used a couple of nylon hose to pipe thread fittings & they leaked till I replaced them with brass.
Regards
Jerry 4107 1120

[Brian Diehl]

I have a DB2010 as well and it is setup to come shut off at 180 and come back on at 160.

[Skykingrob]

John
I just finished my install. I talked to Aquahot people and the recommendation is for 3/4" premium radiator hose. I have a 40' Prevost with 5 heat exchangers and used 75' of the hose. As Jerry says, buy brass connectors, I got mine at Lowes but any good plumbing shop will do and used steel hose clamps from an auto store, like O' Reillys/Autozone, etc. Strongly advised by Aquahot to buy radius tubes for the curves to keep them "gentle". Aquahot has them, kind of pricey at $7 each plus shipping but saw a new Prevost, sure enough they were on it so gave in and bought them from Aquahot. Aquahot also said I could use radius brackets to snap the radiator hose into rather than the radius tubes but the were more expensive.

BTW, I have an extra brand new never used box of  50', 3/4" premium gates hose that I was able to buy at store cost of 70 cents per foot. I would sell it for this plus shipping, if interested.

Rob
91 LeMirage XL
Missouri

[gumpy]

I guess I did mine all wrong. I used all PEX and copper in the install of my AquaHot.  Used 3/4" PEX to connect the engine to the AquaHot engine preheat, and to connect the heating system to the manifolds. All the heating system runs are 1/2" barrier PEX.

I'll let you all know when it fails from the heat. Heating system has been in for about 4 years now. The engine preheat has been in for a couple years. Don't hold your breath too long, it may be a while till you hear back from me on this one.

craig

[bottomacher]

Rob, I'd like to buy your hose. Can you email me at bottomacher at hotmail dot com please? Thanks
Don

[Brian Diehl]

I used 95% pex in my install as well.  It is working great with not a single leak in the pex.  On the other hand, I have had a few leaks in the radiator hose I used to make a couple of small connections.  Go with the PEX.  You won't be dissapointed.

[luvrbus]

My system is about 90% copper because i have radiant heat on each side it does have the molded rubber bend and that is the only place I have ever had a leak.Go with Pex it is used for floor heat poured in concrete it's good stuff and easy to work with but I have seen a lot of systems with CPVC and never had problems. No matter what you decide to use make it accessible for repairs   good luck

[CindyandJohn]

Thanks for all the great input. I will come to a decision soon. I will let you know how I make out.  I will definitely keep things accessible, that was in my plan already.  I kind of siding with the install in the generator bay. It is the most convenient spot and an area where the unit will mostly be protected from the weather and will still have venting if needed. Do you think the exhaust could be tee'd into my generator exhaust system? I have a flexible steel hose to a floor mounted elbow out under the bus - i have heard that these units have restrictions though on the exhaust length, etc... just a thought to throw out there. I will most likely run it out to the side near my generator's exhaust. Here is one more question to ask you guys - can I tee into my generator's fuel supply and return? rather then trying to access my fuel tank... Does it pay to install a separate tank just for heater fuel - I know this opens the door to that debate on heating fuel vs. on road fuel... I don't want to get that one going again, but I could do something like that for the heater...

[makemineatwostroke]

My Hurricane unit is restricted to max exhaust length of 8ft(no bends)  some of the diesel units are 5 ft max me I would use a separate exhaust the unit produces a lot of exhaust heat and shorter in my opinion would be best to get it away from the coach as fast as possiable 500+ degrees is hot  with a separate fuel line these units use about the same amount of fuel as a generator if not more

[Brian Diehl]

My unit is rated for .33 galons per hour.  That is very low fuel flow!