On Board Water?

B3-12A 30 Plate Stainless Steel Heat Exchanger with 1/2" Female NPT Ports Copper Brazed

$75 Duda Energy HX1230:F12 B3-12A 30 Plate Stainless Steel Heat Exchanger with 1/2" Female NPT Ports Copper Brazed, 2.9" Height, 2.9" Width, 7.5" Length

https://www.amazon.com/dp/B003EBSUEA/

 

Manifold complete. Fittings installed on exchanger. All I have left to do, is fabricate a mounting bracket and decide on exact placement for exchanger and pump.

 

Sweet. Bet those fittings werent cheap they don't look like hose barbs?

 

Thanks. I made more progress this afternoon. I cut the bracket from some 16 gauge sheet. I hope to finish that tomorrow. The stainless barb fittings were about $5 a pop. The 1/2" barbs are from duda deisel and they are slightly weird shape. Here is a picture of my test board. Going to pressure test it tomorrow.



EDIT: 10/28/2014 Pressure Test completed. Everything checks out. I made a diagram to illustrate how it works for some friends.

 

Been working my way through the pages here, and one question keeps nagging at me.

If one already has onboard air, why not use that to provide water pressure???

I mean, if the idea is to keep it simple, and minimize parts and their potential to break, and one already has OBA, it seems silly to me to be adding a pump and switch and all the other stuff. A tank is still needed, so why not get one that can handle ~25psi? Route an air line to a check valve (without looking, I imagine there's one that can be set to ~25psi [or whatever water pressure one wants to run]), and the rest of the plumbing would be the same as an electric-motor setup.

Anyone want to explain to me why this isn't feasible? Or maybe why no one has discussed it?

(Yes, this is the route I plan on going when I start developing my OBW system. For the water tank, I'm considering using an aluminum air tank [or stainless steel], or maybe go the cheap route and build one out of PVC pipe......maybe aluminum pipe).

 

Not a bad plan at all. I think the reason it hasn't been shown here is most of us don't have or want a water tank. Personally, I don't want to lose the space or add weight carrying water, not to mention the upkeep of making sure mold etc never grows in that tank... It'll happen once sooner or later unless you keep chemicals in or can remove it to totally dry it out...
That's why I have a little water pump and a stinger I just drop into the nearest cooler & bam. To me, keeping it simple is making more purposes for crap you're already carrying. Like the cooler is now your water tank & my shower parts also have air fittings to use my air hose for water as well.

But for an on board water tank, that'd be awesome! Plumb a pressure line in past a check valve & you're good to go!
This also means you need a valve on the fill port but I don't see an issue.

 

It's been done before. Mr. Grimm used his OBA to pressurize a NATO water tank on his tire gate. It does work. However, for pressurizing a tank of water, you need to have some air in the tank to pressurize, so it can never actually be completely "full" of water. Also, there is the risk of over pressurization and busting your container or hoses. If you go this route, you'll have to manage the pressure in the tank which is where your complexity lies. The only other downside I can think of is that, air compressor air is dirty (oil). The good thing is you don't need much pressure to make it work, maybe 10 lbs. is fine.

Also bear in mind that a water pump is about $50, weighs 2.6 lbs, and is fairly compact. The water pump (in my case Flojet) can be quickly reconfigured to for general fluid transfers using quad port fittings. What this means is that I can on a whim, pump water from one source to another @ 3 gal/minute. That's a nice option to have!

I already own a vehicle mounted shower, called a Road shower. It's totally self contained, it has a schrader valve for pressurizing, and radiator cap for filling. It does work well, but showers must be made when water is warm. i.e. It does not work well in winter months for showers, but great for general camp cleanup, etc.

With my new heat exchanger and a bit of hose I can recirculate the water in the road shower to heat water at any time. Setup time is about 5 minutes to do this.

 

Some of us are desert rats, and really don't have many/any options but to carry our own water. Right now I carry 2 Scepter cans, plus my spigot. Would LOVE to consolidate them all into one or two, mounted out of the way (frame, bedsides, rack).

Good points about mold. But that's the case with any water container, is why I occasionally give them a good soaking in bleach water (tip: to get the bleach taste out of your hiking bladder, soak the mouthpiece in some scotch).

As for dirty air, well, that's what filters are for (post compressor).

I will say the downside to OBA-pressurized water is the inability to pump from a lake/creek/tub/etc. Maybe a backup pump, maybe hand-crank?

 

Here's the inside of a plate heat exchanger looks like. Pretty cool.

Has anyone else here finished up their project?

 

Nope was on the lamb for a couple months. You cut that open?

 

I'd like to take credit for that but it was on some stupid gizmodo article
10 awesome things cut in half or something like that.

Get on with it! I keep looking for excuses to use mine now but the ol lady isn't too keen on me bathing in the driveway these days...

 

Cool photo! I'm trying to find time to finish cutting the mounting bracket. I got sick for a week, and the time change limits me to working on weekend only. All that, plus more have made it very difficult to make time. I did pressure test everything and it all works dreamy. I am looking forward to wrapping up.

 

My friend dropped by with his buzz box and coalesced my mounting bracket. I'm so glad for his help. I can finish the project on my own now.

 

Never heard of a welder called a buzzbox

 

buzz box is reference to cheap ac welders because they buzz when they are on

 

Oohhhh that's clean! Much nicer than my mount.
Someday I'll redo mine...
Glad mines done though.

 

Thanks. In happy with it so far. The design and original blueprint is tweeks.

So funny, earlier you wrote. You were on the lamb, I had to look that one up.

I painted, applied a silicone backing material to the mounting bracket, and finally got it bolted up.



I'm struggling with where to mount the heat exchanger though... I want it on the passenger side close to the manifold. I have room there but nothing is square, it's oddball space.

 

Yes, I wasn't fuskcing a sheep or anything like that. LOL - I an only imagine what goes through peoples heads...

Plate and system look solid now.

 

Hey remind me again why do you have two inputs to the mixing valve?

 

It's actually a Tee. One is cold input from pump, the other is out to heat exchanger. Then connects to hot side of manifold.

I posted a full illustrated system diagram on post #269, can't seem to link it with Tapatalk.

Lol. No worries, i found the correct reference.