Storage Tank Foam Thickness and Type

[Tennman]

I'm sure I could do a search and get the answers, but I'm being lazy. About what foam thickness is a diminishing return? In my boiler barn I'm not really space limited so if 4" is much better than 3" I'll do 4 or even 5. AND since it's indoors do you usually use polyurethane closed or open cell? Any other advice I should know before I cover my two, vertical 500 gal tanks is very, very welcome. As usual, thanks in advance. Soon gonna have me 1000 gal storage.....

 

[woodsmaster]

You still haven't got that storage going yet ? Oh, you have it hooked up and need to insulate it. Just giving you a hard time. It all takes time and money.

 

[Coal Reaper]

seriously tennman, get that going!
i asked for at least 4 and ended up with 5-6". surface of foam is always the same as ambiant temperature, but i have not seen cold temps int he barn yet. i read somewhere recently that 80% of the effectiveness from spray foam comes in the first inch. this may apply more to buildings since it blocks air infiltration.

 

[maple1]

I went with just building an enclosure around my tanks then insulating with fiberglass & roxul - there's some foam board in there too in places.

I liked being able to still access everything if needed (like replacing a temp probe - or fixing future leaks if one appears - or whatever), and if I crack open the enclosure on one end I have a great radiator to warm my basement up with. I also stuffed about two coils of pex inside around the tanks to preheat my DHW with - I think that alone actually does most of my DHW heating during heating season, except during heavy usage like multiple loads of laundry.

Whatever you do, get those puppies hooked up & running.

 

[Tennman]

You know JT that when I get this all hooked up I'll sucking the brain's dry of all BioMass storage guys.... or ANYONE with storage smarts. Yeah CR, I was thinking the same, shoot for 4" min. Maple, I may eventually build an enclosure around the tanks just for protection. I'm welding long nipples on the tank so about the only thing under foam is welds no threaded joins. We're gonna pressurize and leak check before blowing foam. Oh yeah.... I'm playing catch up to you long term storage guys. But I gonna be struttin' this winter! When you stand those 500gal propanes up they are impressive! Shoot I just may enclose them in glass I'll be so proud!

 

[hobbyheater]

This is a thread by Huffdawg with pictures of his foamed storage tanks. I believe he said that he used 3" but cannot remember for sure.

https://www.hearth.com/talk/threads/1st-night-with-1150-gals-of-heated-storage.84213/#post-84213


Foam was not too common when we insulated our storage but there is 6" of this high density fiber glass plus a reflective blanket next to the tank giving a heat loss of about 1,200 BTUs per hour.

 

[Coal Reaper]

You know JT that when I get this all hooked up I'll sucking the brain's dry of all BioMass storage guys.... or ANYONE with storage smarts. Yeah CR, I was thinking the same, shoot for 4" min. Maple, I may eventually build an enclosure around the tanks just for protection. I'm welding long nipples on the tank so about the only thing under foam is welds no threaded joins. We're gonna pressurize and leak check before blowing foam. Oh yeah.... I'm playing catch up to you long term storage guys. But I gonna be struttin' this winter! When you stand those 500gal propanes up they are impressive! Shoot I just may enclose them in glass I'll be so proud!

smart to no put threads under foam. i did the same. and noted where welded plugs were so i hopefully dont have to fish too much if a leak does ever develope. ::knocks on wood::

 

[Tennman]

Sounds like you have a pretty energy tight system Allan. I'll be doing some measurements to check my energy leakage. I just read Huffdawg's post you noted and it's full of useful information for a storage newbie. But he never mentions thickness. I'm shooting for 4" like CR did. No one's said whether they've used open or closed cell yet. Not sure it makes any difference in this application. In reading that old post there's discussion of temp probe wells. I'll be using some of the electronic temp monitors from... AZtech.... not sure if I have that name just right.

Anyway... good link Allan, thanks.

Yep planning on only welds under foam Coal.

 

[JP11]

I asked for 5, to get 4. He gave me over 6 to make sure I got the 5 I asked for.

in my case.. I had zip ties that I had used to secure probe wires. they worked perfect for him to 1. judge depth by using tail of the zip ties sticking out. 2. let me know where to dig to replace a probe.. Which I had to do already.

JP