Fresh and gray water tank questions.

[posplayr]

This is the best reference I have found providing a survey of Thermoelectric Power generation from waste heat.

https://www.sciencedirect.com/scienc...59431121012175

Free version here:
https://www.researchgate.net/publica...n_applications


As mentioned before the main question is whether it is possible to get the heat out of the cold side sufficiently to maintain a 60 degC temp differential on the PTV.

This is a heat flow problem. Using a simple model it seems like it is not too hard to conduct the heat into the frame of an Econoline using some aluminum heat spreaders.

https://www.engineeringtoolbox.com/c...fer-d_428.html

On the thermoelectric side, here is a data sheet for the garden variety 12706 PTC.

https://peltiermodules.com/peltier.d...TEC1-12706.pdf

[dbhosttexas]

Still digging on the side saddle tank for gray capture. I have the dimensions and will be working on a sketchup drawning. Looks like the capacity is 12 gallons, less than what would be ideal, but about what I thought I would get. Will do some more serious measurements once the spare tire carrier is removed and the receiver hitch is installed. There is a post on here about someone that had two tanks, a 25 and a 20 gallon in the spare tire slot and had room to spre for an air compressor, but that was on an extended length van. It is possible if I re-route the exhaust I may be able to buy myself enough room for a 15 gallon gray tank but again, the exhaust needs a slight re-route and the spare tire carrier needs to go.

[dbhosttexas]

Okay, so measurements, done, I am not 100% certain. The 20 gallon tank will fit along with a 25 gallon in the space of the spare tire carrier. Off to ordering the 20 gallon tank now.

[dbhosttexas]

Correcting what auto correct did to me. I am NOW 100% certain the 20 gallon tank for gray water will fit along with the 25 gallon tank for fresh water. I will need to re-route the exhuast slightly but already talked to the exhaust shop about it and no big deal...

[posplayr]

Originally Posted by dbhosttexas

Correcting what auto correct did to me. I am NOW 100% certain the 20 gallon tank for gray water will fit along with the 25 gallon tank for fresh water. I will need to re-route the exhuast slightly but already talked to the exhaust shop about it and no big deal...

Well, let us know what you use to cut out the spare tire support bracket. I'm not looking forward to it because I'm not sure whether to use a pneumatic chisel, Oxy-acetylene cutter, plasma cutter or cutting wheel.

My tanks are 16.5 (18.5g gray)+1+12(9g Black) = 29.5" wide together and just fit with some spare room.

If yours are square (like the fresh) then you probably have more capacity than mine which are both black (in color as well) water tanks.,

[dbhosttexas]

So the measured dimensions are, 36" from 4" behind rear axle to the front side of the reciever hitch. 35" wide where the frame kind of flares towards the middle by the bumper, and 36" between frame rails behind that.

My tanks are...

Fresh water 25 gallon tank.
11.75 D x 11.75 Hx 32.5 L 25 gallon

Gray water 20 gallon tank.
17 D x 10 H x 33.5 L 20 gallon

I would like, due to its height, the 20 gallon toward the back, but that leaves me only 1.5" for fittings etc... I have threaded 90 to PEX fittings that may come into play here, WIth a close nipple installed the nipple and 90 add 1" width to the assembly meaning 34.5", which would be close, but manageable.

The big issue is going to be where the frame kicks up for the rear axle, and fabbing the tank supports.

Like I mentioned. I am no welder. My skills are in woodworking. But I am also willing to learn. so I will be taking up some time, some scrap material and some practice to get it right before I fab up the tank mount frame. Once it is done, clean all of it 100%, epoxy prime it and use a rust preventer / frame paint on it... Probably have to use one of the hitch mount bolts to hold it in...

Spare tire location is going to be a problem. I have a rear door mount for the spare, but it holds the tire tight to the door, all of the ones I have seen for oversize tires are swing away type mounted to a custom bumper. And I need to finalize 4wd conversion or no....

[posplayr]

Originally Posted by dbhosttexas

So the measured dimensions are, 36" from 4" behind rear axle to the front side of the reciever hitch. 35" wide where the frame kind of flares towards the middle by the bumper, and 36" between frame rails behind that.

My tanks are...

Fresh water 25 gallon tank.
11.75 D x 11.75 Hx 32.5 L 25 gallon

Gray water 20 gallon tank.
17 D x 10 H x 33.5 L 20 gallon

I would like, due to its height, the 20 gallon toward the back, but that leaves me only 1.5" for fittings etc... I have threaded 90 to PEX fittings that may come into play here, WIth a close nipple installed the nipple and 90 add 1" width to the assembly meaning 34.5", which would be close, but manageable.

The big issue is going to be where the frame kicks up for the rear axle, and fabbing the tank supports.

Like I mentioned. I am no welder. My skills are in woodworking. But I am also willing to learn. so I will be taking up some time, some scrap material and some practice to get it right before I fab up the tank mount frame. Once it is done, clean all of it 100%, epoxy prime it and use a rust preventer / frame paint on it... Probably have to use one of the hitch mount bolts to hold it in...

Spare tire location is going to be a problem. I have a rear door mount for the spare, but it holds the tire tight to the door, all of the ones I have seen for oversize tires are swing away type mounted to a custom bumper. And I need to finalize 4wd conversion or no....

This guy does a pretty good job of showing how to mount a rectangular tank.

https://www.youtube.com/watch?v=7xIoBeAAe08