Vertical / Horizontal Storage

This is a 720 gallon vertical tank with a stainless domestic loop. It should stratify better than a horizontal tank. This is a tank that was built for me by IPS in Wisconsin, Randy

Good Morning,

My two bits worth. I use a 1200 US gallon pressure tank for storage. The measurements are approx. 54 inches diameter and 9 or 10 feet long. I can't measure, it's buried in insulation. It is used horizontal. Stratifies fine. I am sure vertical would be better. The return lin has a baffle in tank so fluid does not flow straight up.

I wish I had more than top temperature and bottom temperature. A couple more measurements mid way on tank would have meant less guess work on when to re fire. When you are installing the cost is very low.

I am using 750 gal vertical storage. The tank is a cylendrical pressure vessel with domed ends, about 4 ft dia by roughly 10 ft tall (incl legs). Boiler return(hot) and load supply at the top and boiler supply(not as hot) and load return at the bottom. I find that my tank mixes after enough after running a few hours that the temp difference isn't that much. Probably because the return from the loads, even at full draw, is only about 25 degrees less than it left the top of the tank to supply. I think it would make a lot more difference if I didn't circulate through my loads constantly. If your system circs only when you have demand, you'd probably see more benefit.

I think, repeat THINK, that mixing is a combination of things. On my return line I added a T, inside the tank ( the tank is large enough it has a manhole, I dodn't fit but wife does) and slowed down the pump, just enough pump speed to meet heat demands. Seemed to stop mixing somewhat. The boiler to tank line does not have 3 speed pump and it will mix.

I'm going to use Noshok thermometers with 12" stems so I can reach through the insulation & get into the water a bit. I have 3 of them & this should be fine for this shorter tank. These were cheap & I didn't know enough about electronic ones, Randy

Mid Michigan said:

Thanks for the responses.
Sounds like there is some vertical storage out there. My interest is for next year. Shop has 14 ft. side walls with scissor trusses. Should be able to get 1000 gal. vertical.

How many censors?
Think 4 would be enough?
Are there any more pics of vertical tanks and their piping?

Anyone else?

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I stood mine on end with semi-rims welded on. My building was built with 10 ft side walls so I made a "basement" down 2 more feet to stand the tanks upright. https://www.hearth.com/econtent/index.php/forums/viewthread/18299/

For the sensors I used 12" pvc pipe to make wells to the side of one tank so I could reach in and tape a sensor directly to the tank. If it ever fails, I just pull out the insulation and install another one. I used 2 (top and middle) but if I was doing it again I would use at least 4 as its easier to monitor the tanks as the stratification moves up and down.

Theory suggests that tall & skinny ought to be better than short & fat, but actual practice as reported by our users seems to suggest that it doesn't make a lot of difference... More important seems to be designing the plumbing to minimize turbulence and mixing.

I would say that if you have the choice, vertical would be nice to have, but I wouldn' loose any sleep over not being able to get it, or spend a lot of extra money to get vertical when you have a lower cost horizontal option available.

Gooserider

Gooserider said:

Theory suggests that tall & skinny ought to be better than short & fat, but actual practice as reported by our users seems to suggest that it doesn't make a lot of difference... More important seems to be designing the plumbing to minimize turbulence and mixing.

I would say that if you have the choice, vertical would be nice to have, but I wouldn' loose any sleep over not being able to get it, or spend a lot of extra money to get vertical when you have a lower cost horizontal option available.

Gooserider

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I certainly agree with the above statements. I went with vertical as I was using new construction and by standing the tanks I had a smaller footprint. My footprint is a little over 8' by 8'. Turbulence is the enemy to any stratification.

After Jebatty's reports last spring on his stratification on a horizontal 1000 gallon tank (only slightly modified propane tank) I don't think the everyday performance difference between horizontal or vertical is a deal breaker.

The biggest advantage I see is that if the tank is vertical and IF you are using one of the loading units (combined return temp protection and circulator in one unit, more common in Europe) like Termovar, ESBE, or Laddomat offers, the added vertical height would make it easier to get the whole thing to thermosiphon when the power fails. These things are designed to thermosiphon with a directly coupled pressurized tank if it is higher than the boiler. One of our members here, Hansson in Sweden, has his set up that way and it works.

Other than that, if you can takes some measures to minimize turbulence and therefore temp mixing in the tank and keep it moderately well stratified, I'm not sure it makes that much difference. Multiple tanks could certainly take up a lot of floor space it they were all laid out horizontal and not stacked.

In my case I couldn't quite get a 1000 gallon propane tank to fit in my basement. Too long. So I'm working on 2 500s welded together horizontally on top of each other. And I do have one of those loading units.

Mid Michigan; Without installing the same tank both horizontal & vertical it's hard to tell the benefits of one over the other. The storage tanks I see from Germany,UK,Poland etc etc are vertical & this is what I went by when having my tank built. Many members are happy with their horizontal tank setup & this is what I would have used if not for the one built, because of limited height in my basement, Randy

Some tanks have a track device on the outside. This allows you to slide the sensor to whatever level and lock it there. This is a common method on Euro tanks for installing, and adjusting multiple sensors at adjustable levels.

hr

This thread reminds me of a mid-term in my undergrad studies. In a heat transfer course we had to write a proof for cooling soda cans in a refridgerator. The proof showed that a can of soda in a refridgerator laid on it's side will cool faster than a can of soda stood on end, all other things being equal. The proof took two hours to write if I remember correctly.

One could argue that in addition to the potential benefits of vertical tanks mentioned above it may (in a static condition) also bleed less heat to the outside environment. Measureable? Probably not....but still interesting to consider.

Mid Michigan said:

stee6034,

You want to pull those books back out and do a proof showing vertical hot water storage is more efficient than horizontal...probable not.
I can only assume that it is better, but to put a % on it would be difficult and it probable would turn out to be a small % better.
It comes down to what fits it your spot and how much did you pay for it. What good is it to pay $3,000.00 for the perfect take when the $250.00 one will work.
That pay off will never come.

Thanks again for all the replies!

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While it's fun to discuss ways to improve the systems we use, you are right about the payoff. When it comes down to it you are probably better off just
using a little more storage than trying to squeeze every little bit out of a smaller tank. For the most part as with many other areas of hydronic heating
these things seem to be fairly forgiving. Won't stop me from trying to improve it though.

Mid Michigan said:

stee6034,

You want to pull those books back out and do a proof showing vertical hot water storage is more efficient than horizontal...probable not.
I can only assume that it is better, but to put a % on it would be difficult and it probable would turn out to be a small % better.
It comes down to what fits it your spot and how much did you pay for it. What good is it to pay $3,000.00 for the perfect take when the $250.00 one will work.
That pay off will never come.

Thanks again for all the replies!

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That's why I finished up with "measurable? Probably not". And if you'll notice I have (2) horizontally stacked 500 gallon propane tanks myself. I was merely making conversation...