CPVC water storage up top

[VanTalk00]

My target vehicle is a mini-cargo van (Promaster City, most likely). Reason: fit in my garage, which means keep height low (no more than 7 additional inches up top) and every bit of possible storage space used down below.  So, I've been considering a water storage system that resides on the roof. To distribute the weight, I'm thinking of 6 inch CPVC.  See the figure attached. The PV panel will sit between the CPVC tubes and create a storage space underneath (warm and not waterproof for lightweight items that can stand some heat). The CPVC tubes could be enclosed with plexiglass and insulation to create a solar hot water collector.

Here are my concerns, and I'd like comments.

1. Slosh effect. When braking, this could be a lot of weight (total capacity = 15 gallons or 126 pounds)
How could I design it (compartmentalize?) to reduce slosh effect?  Is slosh effect really a worry?  Could be a stressor on my roof rack system.

2. Potability of water heated/stored in CPVC.  Ideally, I'll have a Berkey water filter gravity-fed by this tank up top.

Thanks,

Jim

 

[highdesertranger]

I personally would go with a 1 ton if I was putting water up on top. the slosh effect is real. that much weight up that high is going to raise your center of gravity. any off camber driving might get scary. highdesertranger

 

[VanTalk00]

I personally would go with a 1 ton if I was putting water up on top.  the slosh effect is real.  that much weight up that high is going to raise your center of gravity.  any off camber driving might get scary.  highdesertranger

So which 1 ton would fit in my garage?  The door opening is 81" high.  I don't think the weight is a problem.  Lots of tradespeople put that much weight up top. However, the dynamics (sloshing) are concerning.  Not sure how to manage that.  Maybe break it up into several connected sections, but that increases the likelihood of leaks.  Hmmm....

 

[tx2sturgis]

Tanker trucks often have baffles in the tanks to limit the weight transfer when braking and accelerating.

You could use shorter sections connected with tubes or small pipes to lessen the weight transfer.

The sloshing effect is greater when the tanks are about 1/2 full...when completely full there is very little movement when braking.

As far as I know, CPVC is not UV stable, so a protective coating might be a good idea.

 

[VanTalk00]

Tanker trucks often have baffles in the tanks to limit the weight transfer when braking and accelerating.

You could use shorter sections connected with tubes or small pipes to lessen the weight transfer.

The sloshing effect is greater when the tanks are about 1/2 full...when completely full there is very little movement when braking.

As far as I know, CPVC is not UV stable, so a protective coating might be a good idea.

Good thoughts.  Thanks!  Maybe cut some 1/4 " plastic into CPVC diameter discs, drill a half-inch hole in the bottom, then couple the sections with the disc between them together with a normal CPVC coupling.

What kind of UV blocking coating would you recommend?

Jim

 

[highdesertranger]

"What kind of UV blocking coating would you recommend?"

Paint.

highdesertranger

 

[VanTalk00]

"What kind of UV blocking coating would you recommend?"

Paint.

highdesertranger

:blush:

 

[tx2sturgis]

I was actually thinking about RV type roof-coatings....thicker, and a bit more tolerant of UV, and expansion and contraction.

But sure, I suppose paint will work.