Insulating stacked 500 gal propane tanks

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kuribo

Feeling the Heat
Dec 10, 2007
388
SW WI
Has anyone spray foamed their stacked 500 gal propane tanks? Wondering what is reasonable to have this done? I had one guy quote be $700 for 4" of close cell foam, 2 lb I believe. Don't have any idea if that is fair or not....
 
if the tanks are in a heated building then heat loss is not as important. build a plywood box around them lined with 2 inch styro, fill all the inside with loose fill cellulose and youre done. leave an end or the top accessable if you ever need to repair or modify anything. thats about 500 saved right there.
 
That's what I was intending to do but I wanted to get an idea of what spray foam would cost.
 
I wonder how many cans of great stuff it would take.
 
I framed and covered my tanks in a box. Inside the box is 6" of Polyiso insulation and Roxul blankets. I even insulated the floor as best I could. Everything is numbered in case I have to remove the panels. I have some inspection doors that I can open to see my water temps and pressure plus adjust my pump if needed.
I have a storage area above for items not used often and hung wall cabinets on the face that were at one time on the wall behind where the tanks are.
 
That's basically my original plan.

I should have added that buying cans of foam is going to get very stupid expensive but DIY kits are available on line but I moved away from that route because: a) it was going to look like crap thus needing a box anyway and b) if I ever have to get back to the tank for any number of potential issues I'm going to be digging for a while as that stuff really doesn't like to be removed.

I was able to find a salvage yard for all sorts of rigid sheets of insulation. In my case these were marked scrap from DOW on the foil face. It looked like these had too much distortion on the faces but brand new otherwise. Saved a lot of money there. My 1/2 MDO sheets were left over from a job so free to me.

I still need to box in my piping run from the boiler to the tank area but I'm waiting till I can cut the sheets on my portable table saw outside.
 
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I would never consider doing it with cans of foam, that would be nuts.....I have a bunch of rock wool batts already so some poly and I am good to go.
 
I covered my 1000 gallon with used foam board. I found a place which had used roofing material - expanded (EPS)/expanded(XPS) polystyrene board as well as polyisocyanurate are popular roofing insulation in commercial roofs. My storage is not inside my primary heated space, so I went kinda nuts on it with a total of 6" of foam. I would have gone with 8" given a second chance. I figure at the discount prices, this cost about $400. As your tanks will be in the basement, insulation requirements are not nearly as strict. That said, I'm a believer of storing heat in the tank and using the (intentional) heat distribution system to put it where you need it.

I'm sure spray foam is great, but I didn't want that for many reasons, some of which are cited by the folks above. I did, however very tightly seal the box, using great stuff as glue. The box is essentially airtight which is quite important, IMHO. Air tightness is one thing spray foam buys you.
 
I threw the kitchen sink at it when I moved the garn from one house to the other. I first covered with 3 inch batt insulation, then spray foamed over that with a 600 board ft kit, worked out to about 3 inches. The batts create a small air pocket and isolated the foam from the garn metal, the foam traps potential air movement. Then I covered with metal building insulation wrap, 6inch fiberglass with a tough scrim covering.
This worked well but after resting a towel over it one day I noticed it was warm underneath when removed.
At that point I wrapped with 12 inch attic batts and built a plywood box around it, now my boiler barn radiant kicks on more frequently. Did I win or loose?
 
I’m sure what I did was excessive, however at the time I was regularly charging storage to 185+, baseboards and poor house insulation, I’m slowly converting to radiant and dual element baseboards, adding house insulation and outdoor reset, thus not needing to fire storage as high, reducing the delta between the garn tank and room temp.
It looks like nhtreehouse is actually insulating the room air from heating the bottom of his storage!
 
It looks like nhtreehouse is actually insulating the room air from heating the bottom of his storage!

Good point... I bet at certain operating conditions, this is perhaps close to true. But once I get the pipes insulated, it'll be a definite false.

One thought that I did have, only as an afterthought, was to add more insulation on the upper portion of the tank. I typically charge the top half of the tank, and the thermocline is quite sharp. So insulation on the bottom half of the tank is somewhat wasted, as @TCaldwell rightly points out.
 
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storage tanks.jpg
 
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