Two Propane Tanks for Storage - On End or Stacked?

[DenaliChuck]

I've been reading posts and don't see that anyone has concluded that one is clearly better than another. What is your opinion, or better, what have you done?

Option One: Two 500 gallon tanks stood on end...plumbed in series or parallel?

Option Two: Two 500 gallon tanks stacked horizontally...plumbed in series.

Space is not an issue for me, and it seems the driving factor would be maximum stratification.

Thanks,

 

[Northwoodsman]

I myself am getting ready to undertake the challange of installing a gasification boiler (EKO 40) with 1,000 gallons of storage.

I will be installing these with one on top of the other with the main goal of better stratification.

It has been discussed before and the overwelming opinion is that this orientation will provide for better stratification.

Thanks,

 

[Nofossil]

I'm also in the series / horizontal / stacked vertically camp. Don't know if my opinion is overwhelming, though. We don't have any actual data here that I'm aware of. That doesn't reduce the volume of opinions in any discernible way.

 

[DaveBP]

Most of the illustrations I've seen on european websites that show multiple tanks have them vertical with interconnections shown as into the top of the first then from the bottom of the first tank to the top of the next, etc., and out the bottom of the last. That makes the most sense to me for purposes of stratification but it makes a much taller array. In my case using 500gal tanks would need 10ft. of height in the basement. I just don't have it. So horizontal/piggy-back it is for a height of around 80". I'm still waiting for the perfect way to interconnect them to come to mind or to be suggested on this forum. At this point I'm thinking of feeding in at one end at the top and connecting them at the far end bottom down to the top of the lower tank and out the other end from the bottom: probably connected with 4" heavy pipe or larger if I can find some. I think it's important to minimize turbulence so as not to break up the thermocline. Some kind of baffles or diffusers make sense,too.

 

[sdrobertson]

I'm standing my four 500 gallon tanks on end. I'm doing this because the "footprint" of my storage will be smaller as I'm placing them in a 8 ft by 8 ft room and will have cellous insulation around them. I'll run from a manifold to tank with equal length lines so I'm not sure if that series or parallel. I built a new building so I made 10 ft sidewalls and then then made a 2 ft deep "basement" to place the tanks in to get a total vertical space of 12 feet to the bottom of the trusses and will then place about 2 additional feet of insulation over the trusses where the tanks are. The tanks are finally here so my father is wielding now so I hopefully will have them installed in a couple of weeks.

 

[DaveBP]

Damned if I can find it now, but somewhere in my harddrive is a pdf of a report done for DOE on loose fill insulation. Arlington National Labs as I remember. Infrared photos and all. When the temp difference gets above 100F or so serious convection currents can develop in fiberglass that can decrease the effective value up to 50% in northern US winters. Cellulose doesn't do this if you install it with a proper blower (fluffing it up is important). If your storage structure is outdoors in MI the temp difference could be several 100's! By all means use cellulose and rent the blower. About $40/day at Home Depot.

 

[taxidermist]

I'm standing my four 500 gallon tanks on end. I'm doing this because the "footprint" of my storage will be smaller as I'm placing them in a 8 ft by 8 ft room and will have cellous insulation around them. I'll run from a manifold to tank with equal length lines so I'm not sure if that series or parallel. I built a new building so I made 10 ft sidewalls and then then made a 2 ft deep "basement" to place the tanks in to get a total vertical space of 12 feet to the bottom of the trusses and will then place about 2 additional feet of insulation over the trusses where the tanks are. The tanks are finally here so my father is wielding now so I hopefully will have them installed in a couple of weeks.

Get your Dad going I will be coming up the weekend of the 6&7;of Sept to see yours and your Dads set up cant wait to see your setup.


Rob

 

[mpilihp]

I cannot stand my tank/s on end so the plan was to stack them horizontally but I was wondering if piggy backing them at an angle, as high up on one end as possible to allow for insulating (up to 2 ft folks here have recommened on other threads... Then piggy back other tanks on the back of the first one, would take up alittle more space than just stacking them horizontally but not too much, plumb them in series, top to bottom, Im thinking it would allow better stratafcation.

~ Phil

 

[stee6043]

Does everyone plumb their tanks in series? I was planning on plumbing two 500 gallon tanks in parallel this fall. Pump hot into the tops of both tanks and draw cold from the bottom of both tanks at the same time, same rate when heating to storage. All it would take is two T connections on your tank loop (I would think), one for the tops and one for the bottoms. I figured the most important part would be having the exact same distance of pipe and same pipe size to each inlet/outlet. Perhaps I'm out to lunch here? In my simple mind it seems you would get better efficiency doing it this way versus pumping all of the cold water from one tank into the top of the other tank to start the cycle each time....

 

[sdrobertson]

Does everyone plumb their tanks in series? I was planning on plumbing two 500 gallon tanks in parallel this fall. Pump hot into the tops of both tanks and draw cold from the bottom of both tanks at the same time, same rate when heating to storage. All it would take is two T connections on your tank loop (I would think), one for the tops and one for the bottoms. I figured the most important part would be having the exact same distance of pipe and same pipe size to each inlet/outlet. Perhaps I'm out to lunch here? In my simple mind it seems you would get better efficiency doing it this way versus pumping all of the cold water from one tank into the top of the other tank to start the cycle each time....

This is going to be the way I plumb. Each manifold will have 4 lines going to the tanks. One manifold from boiler to top of tanks and one manifold from tanks to feed boiler. If the lines are all the same length the flow should be the same to all tanks.

 

[Nofossil]

The advantage of series is that it comes closest to ensuring perfect stratification. Of course, you want to minimize turbulence and mixing in each tank.

 

[stee6043]

Perhaps I'll read up more on the stratification topic. If you can optimize both tanks using a series hookup I'll need to change my plan. Could save some copper as well...

What are you guys using to support the top tank? A structural steel support is going to run another grand painted. This hobby is expensive!

 

[DenaliChuck]

Nofo (and others),

What diameter pipe would you use to connect two tanks in series?

I guess I wonder if two tanks stacked horizontally (6' tall) and plumbed in series would have better stratification than two tanks on end (10' tall) and plumbed in parallel.

Would the best alternative be:

Most of the illustrations I've seen on european websites that show multiple tanks have them vertical with interconnections shown as into the top of the first then from the bottom of the first tank to the top of the next, etc., and out the bottom of the last. That makes the most sense to me for purposes of stratification but it makes a much taller array.

Thoughts?

 

[sdrobertson]

The advantage of series is that it comes closest to ensuring perfect stratification. Of course, you want to minimize turbulence and mixing in each tank.

In a ideal system I'd follow Nofossil's advise. I'm going w/4 tanks as this was available here so I'm doubling the water volume so I'll be standing them upright as this is what fits my situation. I wanted the smaller footprint but if I was using 2 tanks, I'd stack them. With the 4 tanks I hope that I'll have enough lines to split up the flow of water so the individual tanks will not stir up and I'll get stratification.

 

[DenaliChuck]

Based on DaveBP's observation that European tanks are often set up vertically and in series, I'm going this route. This also fits my space the best.

Using many ideas and suggestions found on this forum, this is the strategy du-jour.

I'll weld a round plate on the end of a 30" section of 2" forged black pipe, thread the other end, and then drill a bunch of 1/8" holes down one side of the pipe. Repeat 3 more times.

With the tanks vertically I'll use a hole saw to drill a hole on the side of the tank, just large enough to slip the closed end of the pipe in so it is horizontal and then weld it in place. There would be one at the top and bottom side of each of both tanks.

The top pipe would have holes pointing up and the bottom would have holes pointing down so water drawn from the bottom would be pulled from lower than the pipe and water inserted on the top would be directed upward.

The 2" pipe can be reduced to meet the incoming and outgoing pipes.

Please let me know what you think. I'm going to cross post to my welding propane tanks post too.

 

[Willman]

Someone posted this method of piping last year and had pics of his setup. Can't remember his name. He had a manway in it also. Anybody remember the thread ?

Will