Engine coolant hot water heating tank design idea

[James86004]

In the spirit of getting many ideas out there, try this far-fetched one:

I have thought of doing something similar, except by running the water I want to heat through the copper tubing, wrapping the copper tubing around the exhaust pipe near the back of the truck, and have it plumbed into my water tank. It would be nice if the water would circulate though free convection, but it probably won't, and it would probably need a thermostat to keep it from boiling, and there could be issues if the tubing gets hot when there is no water in it, etc.

Another thought was to permanently attach a water tank to the frame rails near the exhaust pipe and see how hot the water gets at the end of the day.

 

[Desert Dan]

I like having a portable hot water shower unit so I can use it in different vehicles or leave it set up at camp and not have to run or start up the truck to get hot water.

 

[chasespeed]

I have an idea, that I will be messing with shortly, as the major things(closing on this house, with its 4 car garage, and shop, yes, the garage is bigger than the house I think).,... and a few other things.

BUT, the best bet, is.. to make or FIND a coil(preferably a tankless hot water coil from a boiler)... add it to a container,,, and have the coolant cycle through that, while its in a well insulated water tank....

Find a mixing valve, to control the temp of the hot water...

Any RV/Marine water pump would be sufficient at this point, as you could use it UPSTREAM of the heating tankm to maintain a slight head pressure. If you find a big enough pump, one pump can operate the hot and cold water....

A #8 or #9 Silver Solder should be more than sufficient in this as well. Lower temps than brazing, and, its stronger than copper itself....less resistant to vibration, etc... personally, tested this on a system to 550psi...

Anyway, braze does take to different metals easier, and without as much surface prep....

Chase

 

[cruiseroutfit]

...Much like those that have tried various lengths of copper tubing, tightly wound around there exhaust manifolds or header pipes... to realize a 5-10 temp increase. Would a foam shell have increased the heat transfer in their cases, sure... but the logistics, cost and serviceability often lead them to other means...

In the spirit of getting many ideas out there, try this far-fetched one:

I have thought of doing something similar, except by running the water I want to heat through the copper tubing, wrapping the copper tubing around the exhaust pipe near the back of the truck, and have it plumbed into my water tank. It would be nice if the water would circulate though free convection, but it probably won't, and it would probably need a thermostat to keep it from boiling, and there could be issues if the tubing gets hot when there is no water in it, etc.

Another thought was to permanently attach a water tank to the frame rails near the exhaust pipe and see how hot the water gets at the end of the day.

Its worth an experiment, but those that have tried it in the past have found it very lackluster on actual heating when moving a decent volume of water through the coils. You have a very finite heat transfer contact and exhaust pipes are not all that hot near the back of the vehicle. Even those that tried wrapping them around their exhaust manifolds didn't realize the heat gains they were hoping for. Different procedures and installation might yield very different results but the thermodynamics just don't favor heated gases, heating a metal, which then heats a dissimilar metal through a finite contact point... which then attempts to move a fast moving fluid. Your results may vary

 

[78Bronco]

I have thought of doing something similar, except by running the water I want to heat through the copper tubing, wrapping the copper tubing around the exhaust pipe near the back of the truck, and have it plumbed into my water tank. It would be nice if the water would circulate though free convection, but it probably won't, and it would probably need a thermostat to keep it from boiling, and there could be issues if the tubing gets hot when there is no water in it, etc.

BMW had concept like this a few years ago except the purpose was to generate steam than use that to power a small generator to power the cars accesories. This energy translated into fuel savings of almost 15%.

So it could work but you would want the HE coil very close to the combustion process. It might not work so well in cold climates!

More here:
http://www.motortrend.com/features/editorial/112_0606_technologue_hybrid_qa/index.html

 

[Bogo]

I have an idea, that I will be messing with shortly, as the major things(closing on this house, with its 4 car garage, and shop, yes, the garage is bigger than the house I think).,... and a few other things.

Only 4 car??? I only need to widen the door another 10 feet to be able to park my 2000sq ft house in the garage. I attached my house to a former hay barn and now use it for a garage.

BUT, the best bet, is.. to make or FIND a coil(preferably a tankless hot water coil from a boiler)... add it to a container,,, and have the coolant cycle through that, while its in a well insulated water tank....

Standard part and they even come in double walled varieties in case the coolant tube leaks.

Find a mixing valve, to control the temp of the hot water...

Any RV/Marine water pump would be sufficient at this point, as you could use it UPSTREAM of the heating tankm to maintain a slight head pressure. If you find a big enough pump, one pump can operate the hot and cold water....

Take a look at the PDF file I linked in post #6 in this thread. Isotherm already makes that for the boating industry. They just have the hot water port plumbed to draw from the top and expect it to be in a pressurized water system. That's a bit much for a small vehicle, but doable for a bigger one.

 

[Bogo]

I like having a portable hot water shower unit so I can use it in different vehicles or leave it set up at camp and not have to run or start up the truck to get hot water.

For real simplicity I really like the Zodi Extreme tank/etc.. I'd ditch their burner and use my MSR stove instead. People have home made similar with old fire extinguishers for the tank. I've also heard of people using small 2 to 3 gallon hand pumped sprayers. The stainless steel ones can be directly heated while the plastic ones require heating the water elsewhere.

 

[chasespeed]

ANOTHER thought, would be.. .some Marine exhuast manifolds. They have a water jacket around them, to keep them cool in a closed engine compartment.

On a gasser it wouldnt take long at all to get those things hot enough to make hot water.... a diesel on the other hand...

Chase

 

[chasespeed]

Only 4 car??? I only need to widen the door another 10 feet to be able to park my 2000sq ft house in the garage. I attached my house to a former hay barn and now use it for a garage.



Standard part and they even come in double walled varieties in case the coolant tube leaks.



Take a look at the PDF file I linked in post #6 in this thread. Isotherm already makes that for the boating industry. They just have the hot water port plumbed to draw from the top and expect it to be in a pressurized water system. That's a bit much for a small vehicle, but doable for a bigger one.

Well, the Garage, is 4 cars(deep enough to park my boat in), WITH a 15x30 shop on the end of it...runs the depth... set up for heat(propane and wood stove)... plenty of room for lathe, mill, benches, welding equip, etc.. WOOHOO... my dream garage... just need to make one of the bays set-up for an oversize door....

Tankless coil... yeah, I know they make them, most houses got their hot water from them for a long time... as far as for boats.. didnt know that...

Havent looked too much at marine plumbing.. since I on,y have a Cuddy at this point... not really an issue...if I am able to snag a 26-28footer this winter like I hope... then I will have plenty more of stuff to deal with...haha

There are plenty of efficient ways to make hot water... just need to use some care when doing it... I AM on the process of making a small tankless heater(which could store H/W in a tank if you had/have room)....

Since I have a diesel, and it takes forever to get hot, and if its cold enough, and I dont have enough load... may not get hot at all...

I will be using my stove... at least for the first experiment... I know it will work, just need to see how LONG it will work for, and how fast.....

Because personally, no one in camp is going to want to hear my truck fire off in the morning, go into hi idle, while I wait for it to make hot water....

Chase

Chase

 

[Bogo]

Since I have a diesel, and it takes forever to get hot, and if its cold enough, and I dont have enough load... may not get hot at all...

Control the airflow into the engine compartment on cold days. Ever look at the front of trucks when it is cold out. They partially cover the radiator. During the winter in MN I'd do the same with a sheet of cardboard tucked between the radiator and grill. With my toyota hilux I'd only cover the bottom half the radiator, but it helped allot in getting it up to operating temp quickly and keeping it there.

I will be using my stove... at least for the first experiment... I know it will work, just need to see how LONG it will work for, and how fast.....

Because personally, no one in camp is going to want to hear my truck fire off in the morning, go into hi idle, while I wait for it to make hot water....

They insulate the tanks well so they hold heat for hours. Read that PDF file. The Isotherm 24 liter unit could produce 23 liters of >40C hot water for a shower 12 hours after last being heated for an hour. Here is the final table with the results for a number of units.

The article is well worth reading if you are at all considering making a water heater. They cut open all the units to show the insides. If I had the space and weight budget I'd just buy an IsoTerm unit and use it. Unfortunately it would require a pressurized water system and I feel it would require a 15 plus gallon cold water tank. With a '94 Toyota Hilux mini truck as the basis I am severely weight limited. If my vehicle was Sprinter sized I'd do it.

As a side note a coolant heated water heater can also be heated by hot water off of an engine preheating boiler. I'd plumb it so the water flows through the water heater then through a kick space heater. At the same time it could also heat the cabin. Actually as the cabin is heated the hot water is brought back up to temp. During warmer times the kick space heater can be bypassed and just the water heated when needed.

 

[chasespeed]

I will certainly read it when I have a chance....

BUT, just for the record, I work on boilers and water heaters, and the such by trade.... so.. I have a bit of an idea how I want to do this. I have been working on some variations of portable Solar h/w for for my fathers boat...

I think for size, simplicity, and portability, tankless style set-up would be great.....

In my case, where I DO have the room, and no restrictions on weight, adding in a well designed h/w storage tank MIGHT be in the cards as well... but, even with this truck, I like to try to stay as light, and portable as possible....

Thanks... I think we might be able to spawn some good homebrewed designs from this....

Chase

 

[Bogo]

I think for size, simplicity, and portability, tankless style set-up would be great.....

To me that goes to ones like the Zodi Extreme. A simple pressurized tank heated on a burner. I'm very tempted to get a Zodi Extreme or maybe Solo Stainless Steel sprayer.:sombrero: Less tan $70 at Gempler's and they ain't a cheap place to buy stuff.

Thanks... I think we might be able to spawn some good homebrewed designs from this....

Part of the reason I posted the idea in the first place. I know it is over a year before I'm to that stage in my build. Part of it was also I figured out a method that required little to no machining. If somebody was willing the ends of the tube and the hoses they connect up could be bound to the tank. Then there is no machining needed.