Espar hydronic mounting and exhaust options.

[javajoe79]

Any feedback here is welcome. I am trying to decide on where to mount my D5 unit. Should I mount it inside to protect it from the elements or is frame mounting ok? Can it be submerged for short periods without damage?

Has anyone plumbed the exhaust into the trucks exhaust pipe? My thoughts there are to eliminate the need for a separate muffler if I plumb it in upstream of the truck muffler.

Does anyone put filters on the fuel and air inlets?

 

[Joe917]

I am running a Webasto hydronic.
It is in an exterior enclosure, no issues. The previous unit ran 23 years in the same enclosure.
I would highly recommend you do not tie into the vehicles exhaust. The muffler and exhaust for the heater is pretty simple.
Submerging the unit would be a bad idea.
Air is unfiltered, fuel is filtered in line.

 

[javajoe79]

For what reason should I not tie into the vehicle exhaust? I'm envisioning a potential back flow issue which I could get around easy enough I suppose. It would eliminate any water back flow into the hydronic exhaust too.

If you're unit is enclosed, where did you duct the air inlet to? If I were to mount it outside the camper, it would have to be underneath on the frame as I don't think I will have engine bay space for it. So in that case I need a sealed box to prevent submersion. Then both the inlet and exhaust would have to be ducted up above potential water level. Not to mention sealing where all the plumbing and wiring passes into the box.

Really just makes me want to put it inside the camper to simply it all. It's so small it won't take up much space

 

[Joe917]

Tying into the exhaust just adds another layer of complication and if you mount the heater internally a great way to fill the camper with CO. Internal mounting is an option but the exhaust will have to be run with care.
My unit is enclosed but not sealed in a compartment under the camper frame. This puts the bottom of the heater over 3' off the ground.
What vehicle are you using?

 

[javajoe79]

To me, tying into the exhaust simplifies it and possibly kills two birds. I can fabricate just about anything so it's easy. Figuring out how to prevent back flow is the challenge I guess.

My vehicle is a Chevy S10 with soon to be significant upgrades. I suppose it would also be about 3' from the ground on my frame. Mounting it there is very tempting but it would complicate things

 

[fluffyprinceton]

Definitely do not submerge...these things depend on electronics - my opinion only as I've never dunked mine...It lives between the frame rails so gets splashed often, no problem with that although I had to clear the exhaust of iced mud one time.
Routing to the truck exhaust is a worthwhile experiment for someone else to try...main advantage being it might be quieter than the stock muffler which is louder than I'd like. But the stock muffler works OK and is dead simple so why go to the trouble? If you did maybe just a deflector inside the muffler to get enough of a venturi effect to avoid exhaust back pressure into the D5's exhaust. I doubt the D5's exhaust tube could handle much engine exhaust heat - it's pretty light weight. This assumes only using the D5 with the engine OFF. If you use it with the engine running I think it would screw up the D5's intake/exhaust balance. Moe

 

[javajoe79]

I could make a simple guillotine style valve to block it off while the engine is running.

 

[IdaSHO]

Have you read the installation guide?

Most of these types of units are not designed to be fitted to a vehicle exhaust.

They are a stand-alone, and designed as such.

Webasto units have a warning of:

DO NOT connect the heater exhaust into the engine or generator exhaust. Doing so will result in unacceptable back-pressure levels and may damage the heater or cause operational failure.

Im sure Espar is something similar.


Regardless, with such a specialty item, Id advise you follow the installation guideline to the letter.

 

[javajoe79]

I have read them completely. I don't see it mentioned anywhere. I wouldn't be running it at the same time anyway so back pressure wouldn't be an issue.

 

[IdaSHO]

I found what looks to be the correct installation manual. Most Espars seem to have the same paperwork.

I made BOLD what I feel is the key point here.


As follows:

A 24mm flexible tube exhaust pipe with a length no more than
2 m. long is required for the exhaust. A 27-30mm exhaust
clamp is needed to secure the exhaust to the the heater.

Connect the exhaust as follows:
• Connect the exhaust pipe to the exhaust port on the
heater and attach with clamp provided.
• Run exhaust to an open area to the rear or side of the
vehicle so that fumes can not build up and enter the
passenger compartment or the heater combustion air intake.
• Install exhaust pipe with a slight slope or drill a small hole
in the lowest point to allow water to run off. Any
restriction in exhaust will cause operational problems.
• Route the exhaust pipe from the heater using holders
provided

Looks to me like the maximum overall length of the exhaust can be no longer than 2m

That alone would pretty well eliminate the possibility of tapping into the vehicle exhaust for most installs.
All of it for good reason, as the units are sensitive (as I mentioned) and the pumping losses of an extended exhaust look to stress the system.


Regardless, if you intend to do this correctly and not void any potential warranty claim down the road, Id advise contacting the MFG directly.

 

[javajoe79]

Yeah I remember that. I will contact the manufacturer but to me, dumping it into the truck exhaust is essentially the same as dumping to atmosphere. They specify that length to maintain heat and velocity. Once it's past that point, as long as it's not backing up I don't see a problem

 

[javajoe79]

So I spoke to Ray at Espar of Michigan. I'm giving up on the combined exhaust idea because I would end up pumping exhaust from the Espar back into the engine. I could have a valve for both the espar and the engine exhaust to prevent either one from back flowing into the other but that is more complicated than I want to deal with.

Looks like I will box the unit into a sealed space inside the camper or under the camper or truck cab. Then I can run the exhaust and intake both up above the possible water line.

 

[loonwheeler]

On my Espar D5 Hydronic install, I chose to follow the manufacturer's installation instructions just like others have mentioned. I didn't route the exhaust into the truck's exhaust as I didn't see any major advantages and thought it would just add complexity. Instead I mounted and routed the D5's exhaust right next to the truck's exhaust just aft of the driver's side door.

You can also see from the picture that I purchased the "box unit" from Espar (aluminum housing). The box allows mounting location flexibility without having to worry too much about road spray. I have another D5 unit that wasn't boxed and it had to be serviced / rebuilt mainly due to being exposed to grit and grime from the road ($$).

These units are specialty items and aren't cheap. If installing them, it make sense to take your time to figure out the correct location and do the job right the first time. Other jobs you can just "wing it" but my suggestion is to plan and take your time on the install to achieve the best results for long term reliability.

 

[javajoe79]

On my Espar D5 Hydronic install, I chose to follow the manufacturer's installation instructions just like others have mentioned. I didn't route the exhaust into the truck's exhaust as I didn't see any major advantages and thought it would just add complexity. Instead I mounted and routed the D5's exhaust right next to the truck's exhaust just aft of the driver's side door.

You can also see from the picture that I purchased the "box unit" from Espar (aluminum housing). The box allows mounting location flexibility without having to worry too much about road spray. I have another D5 unit that wasn't boxed and it had to be serviced / rebuilt mainly due to being exposed to grit and grime from the road ($$).

These units are specialty items and aren't cheap. If installing them, it make sense to take your time to figure out the correct location and do the job right the first time. Other jobs you can just "wing it" but my suggestion is to plan and take your time on the install to achieve the best results for long term reliability.

View attachment 344357

On your boxed unit, how is it vented to allow the unit to breath?

My main issue will be sealing it all up as it will likely end up mounted below the potential high water line. I can seal the wiring by running it through a waterproof cord grip bulkhead fitting. I can duct the air intake up high but the exhaust is supposed to run down hill. That leaves me thinking I need a waterproof and high temp valve that I can use to close off the exhaust pipe while in transit.

 

[loonwheeler]

On the boxed unit, there is an opening in the box that allows air to pass into the air inlet of the D5 freely. No tubing etc. The box isn't sealed in any way and serves its role much more as a splash shield more than a sealed box.

Here is a photo of the box with the cover removed. Inside you can see all of the guts exposed. No sealing at all. If you dunk the hydronic heater, water will enter. Not a good idea and best if you can avoid it.