Storage tank quandary

[VtRv]

I keep reading on here that the more storage you have the better. I just picked up two used 500 gallon LP tanks, one for me and one for my brother. I have access to more tanks with options to get 500, 330 or 250 gallon sizes. Here is what I'm trying to decide.

My boiler is in my basement and I have room for a 500 gallon tank in my basement and/or garage along an adjoinin wall that is 6' higher then my basement. I'm wondering if I should start with one 500 gallon tank and see how it goes or start right off with more storage. I could put one in the basement and one in the garage or stack two in the garage. I could stack two in the basement but I'm not sure how I would get one on top of the other down there and I'm a little concerned about weight.

There is a drain in the basement but if anything happen so that a leak developed the garage would be better. The garage is insulated but not heated where the basement is heated. I also have a 117 gallon tank that I was going to use as an expansion tank but that could also be thrown into the mix to give me 617 gallons.

Such a quandary, what to do, what to do.

1000, 830, 750, or 500 gallons? Stacked or seperate, basement, garage or one in each? What I'm not sure of is the actual advantage of the various volumes as it relates to length of time between fireings.

Any thoughts on the matter?

 

[WoodNotOil]

With high temp pressurized storage you shouldn't need as much. Having it in a heated space requires less insulation which is a very costly part of the project. The only advantage of more is length between firings. I would suggest going ahead with one 500 gallon tank in the basement using the 117 tank for expansion. I think you will be happy with the results. You can always add more later. Just my $0.02 on it.

 

[Nofossil]

Agreed. Start with 500, plan for the option to add more later if you want. The benefit of the first 500 gallons is huge. The next 500 is a much smaller additional benefit.

I have a bunch of people interested in tanks if you have access to extras.......

 

[VtRv]

Now that I have the tanks I have an appointment with a welder tomorrow. I'm planning to have a 1 1/4 nipple (I believe it called) welled on the top and bottom of each end along with a drain plug. I told him I wanted the bottom two to exted 3 or 4 inches into the tank so I wont pick up sediment. Should I have the top nipples flush or also sticking into the tank or does it matter. The reason for having 4 nipples in each tank is for adding additional tanks if desired. Does this sound right?

 

[Nofossil]

Sounds right. Think about introducing the water so that you minimize turbulence. If the tank is horizontal, see if you can introduce the water horizontally right along the top. If I were doing it, I'd consider cutting a bunch of holes along the pipe and inserting it along the top, sticking into the tank several feet. Don't know if that could work given the angle of the end bell as you get near the top, but worth asking your welder.

 

[stee6043]

Just an FYI - pallet racking can be had relatively cheaply for stacking 500 gallon propane tanks. Load capacities vary from 2000lbs all the way to 10,000lbs per level depending on the beams. I'm stacking two tanks with approx. $500 (delivered) worth of racking, new. Getting the upper tank in place is pretty simple with a few pulleys since they only way 1000lbs or so....

 

[ManiacPD]

Thanks for writing this topic. I'm the the same boat so this discussion is really helpful. 500 gallons of water with a 60 degree delta-T is worth 250,000 Btus. That should last a little while in the winter, longer in the spring and fall.

I started the MEMCO last weekend to play with it. It was warm and humid outside (Hurricane Kyle) so I had only DHW for demand. It was impossible to keep the fire small enough to not trip the dump zone but burn for more than 1 hour. It got old by Sunday morning so I shut it down and went back to burning oil for now. It is pretty clear to me why storage is the only way to fly with these systems. I'll have to start with 500 gallons and go from there.

What are you planning to use for insulation? I was thinking about building a box and lining it with 4" foam and keeping it 1" away from the tank to prevent thermal bridging. I'm gathering ideas on how to do it now even though I'm 6 months from doing any work.

 

[VtRv]

What are you planning to use for insulation? I was thinking about building a box and lining it with 4" foam and keeping it 1" away from the tank to prevent thermal bridging.

I'm still up in the air over that as well. I think I'm going to box it in and use either blown in insulation or spray foam. I figured if I don't use spray foam I would line the box with foam board and insulate from there. I've even thought some of wraping the tank in fiberglass to get started so I know there are no leaks as access could be a messy problem with either of the other options unless I box in access areas around the fittings.

 

[Vtgent49]

I usually think of heat leaking from a medium insulated tank into my cellar as not really "lost", so I'd skip the garage for tank 1.

Also, I would add a 117 gal expansion tank to my storage calculations. An expansion tank is all air til pressured, so of no value as storage.

Check for leaks before foaming in that tank! Maybe even thru a full heat cycle or two.

Al