Tank Insulation

[velvetfoot]

It looks like I'll be insulatiing a horizontal 1000 gal. tank at some point. I read a fair number of posts on the subject. It looks like I'll be putting it along a wall to a corner. I was thinking of a box of foam boards a foot thick. Somehow. I understand the XPS doesn't like the heat-does the polyiso like it any better?

The tanks can't be resting on foam, can they? Seems like a lot of weight,even spread out some. What's the alternative to getting some height? I saw someone use 6x6s under the tanks skids. Can you go even higher?

With the boards, there'll be the curved area around the tank to insulate, and I figure to stuff some fiberglass in there. Or maybe somehow use board foam there.

Is there a best way to do this?

 

[ewdudley]

The tanks can't be resting on foam, can they? Seems like a lot of weight,even spread out some. What's the alternative to getting some height? I saw someone use 6x6s under the tanks skids. Can you go even higher?

Heat rises, plus the there is not-so-hot water on the bottom most of the time, plus the tank curves away from the floor. So bottom of the tank is not as critical. Even so regular blue board is good for something like 35 psi, and the tank only weighs 10,000 lb, so two wooden cradles that would distribute the load down to two 40"x5.5" pads would be good for 15,000 lbs. High density blue board is good for 70 psi.

Around the tank just pack in high density cellulose and the styrofoam won't be seeing any high temperatures. I think cellulose would stop air movement better, which may be important with the higher temperatures.

FWIW I used cellulose inside a 4" thick airtight blue board box with 8" fiberglass outside that. (Plus 6" fiberglass in the outside walls of the building and 12" fiberglass in the ceiling of the building.)

On the bottom I used 3" high density blue board under the tank pads and about 10" of cellulose from the floor up to the bottom of the tanks.

 

[velvetfoot]

FWIW I used cellulose inside a 4" thick airtight blue board box with 8" fiberglass outside that. (Plus 6" fiberglass in the outside walls and 12" fiberglass in the ceiling.)

The 6, and 12 inches are for the building housing the tank?

Do I recall a thread of yours where you discussed placing the tanks on something or other? Can't recall the details.

 

[ewdudley]

The 6, and 12 inches are for the building housing the tank?

Do I recall a thread of yours where you discussed placing the tanks on something or other? Can't recall the details.

Can't find the thread, but I dug up the photo. Note that this not an example of 'how it's done', it just shows an example of the variety of solutions that will get the job done. The main factor was needing to place supports that wouldn't get in the way of the lower manifold.



(No, I didn't paint them, for what purpose?)

 

[velvetfoot]

Interesting.

 

[velvetfoot]

Geez, that polyiso is not cheap.

 

[peakbagger]

Too Bad you aren't closer to Maine. One of the members on Hearth, Tom in Maine has the best prices around for Iso board and a lot of experience with it

 

[velvetfoot]

Too Bad you aren't closer to Maine. One of the members on Hearth, Tom in Maine has the best prices around for Iso board and a lot of experience with it

That's good to know.

 

[goosegunner]

I bought the roofing style board with fiberglass paper on both sides for $3.20 for 1.25" 4'X8' sheets.

I used it on the walls and top. I put my tank on stacked treated 2X10's. The floor around the wood has 10" of the foam board.


gg

 

[maple1]

Ya - on the painting. I wouldn't bother either.

I did, and it sure made them look pretty - but they get covered up anyway, and they stunk like crazy for a couple of months once I got heat in them. The heat started some serious off-gassing from the paint. I used cheap paint, might of had something to do with it.

Get as much insulation on the wall as you can before you back your tank in against it, get what you can under them, then you can sort out the rest later. Mine are sitting on 3 - 6x6's, I just stuffed under them what I could, later.

 

[velvetfoot]

I bought the roofing style board with fiberglass paper on both sides for $3.20 for 1.25" 4'X8' sheets.

Is this used polyiso? If so, a great deal. A 2" sheet of polyiso is 28 bucks at Lowes. A foot around of this stuff on the tank would cost more than the tank.

 

[velvetfoot]

I used it on the walls and top. I put my tank on stacked treated 2X10's. The floor around the wood has 10" of the foam board.

So, how many 2x10's did you stack? Assuming the tank already had some feet and you placed the feet on the 2x10 stack?

 

[goosegunner]

Is this used polyiso? If so, a great deal. A 2" sheet of polyiso is 28 bucks at Lowes. A foot around of this stuff on the tank would cost more than the tank.

It is the same as tuff R the foil faced foam it just has a different covering.


gg

 

[goosegunner]

So, how many 2x10's did you stack? Assuming the tank already had some feet and you placed the feet on the 2x10 stack?

I can't remember exactly but it was a pretty good height so I could get foam board on the floor and also 2 6" layers of fiberglass insulation.

gg

 

[goosegunner]

Here are a few pictures of what I did.

These 2'X 4' pieces are free cut offs from factory that I used on floor under the tank. The full sheets were used on the walls and the top.




The wall stud cavity also got pieces of foam. This is interior wall.




Exterior wall has 6" fiberglass, 1.25 foam, osb, 3/4" pink board.



The top has 2 layers of 6" fiberglass around tank and all voids filled, 2" blanket over that, 6" in stud space framing of cover, 1.25" foam board, osb.

 

[velvetfoot]

I can't remember exactly but it was a pretty good height so I could get foam board on the floor and also 2 6" layers of fiberglass insulation.

gg

Wow. That's 1.25 + 6 + 6 = 13.25". That'd be about 9 of 'em.
Really great that you could get that polyiso for a good price.
Some hybrid of foam and fiber or cellulose is probably in my future.
I didn't think I'd need all that framing, but maybe there's no way around it.

 

[goosegunner]

Wow. That's 1.25 + 6 + 6 = 13.25". That'd be about 9 of 'em.
Really great that you could get that polyiso for a good price.
Some hybrid of foam and fiber or cellulose is probably in my future.
I didn't think I'd need all that framing, but maybe there's no way around it.

The foam is around the 2X10's. I did go over them with a layer to slow the minimal heat transfer from the wood. You gain a little height from the legs also.

My tank is in a enclosed lean to on the north wall of my building, that is why I have so much framing. I also made the top sturdy so I can use it as nice rodent proof storage. If I was building it now I would not do the lean to. I would make the building wider in that area. It would have been much easier to deal with tank. I also would have had the height to add a second tank on top. Or 4 vertical 500's.





I made a Foam box that covers the extra ports in the center of the tank. They are for future heating of the shed. The far end in this picture past the light is also boxed with foam board now.

gg

 

[velvetfoot]

Very nice! It looks like you built the building around the cars and tank!
How high would you say the top of your tank box is? Even with my original idea of a foot of foam, it still comes out to, like, 6' high. Most of the basement is almost 9', so I guess access to stuff above (pipe and wire) would still be possible. I'm conflicted about how sturdy to make it.

And, 2000 gallons? Wow!

 

[goosegunner]

The tank was put in place before the building was built. I did provide areas to remove if needed. the tank cover and wall coverings were screwed together to make removal easier.


I think the top of the cover is close to 6'.

Amount of storage can be tricky, 2000 would be nice at times. But sometimes I think 1000 is too much. It real depends on type of emitters. WIth my forced air its best not to mix the tank. In the shoulder time of year its hard not to mix the tank if you just burn a small amount of wood to put some hot water on the top of the tank. When your load uses supply the return to the bottom of tank is most likely hotter than the bottom of the tank.

With forced air heat I think it might be helpful to have 2 or three 500 gal vertical tanks. Valve off to just one and have one small fire a day. Just remember I did say "Might be" it is hard to know at times what would work best.

gg

 

[velvetfoot]

If one builds a well insulated, like with good thickness of foam boards, is it even necessary to stuff the voids? I'm thinking of an image that Effecta Boiler User posted. Makes it a lot easier to service.

That picture appears in this thread:
https://www.hearth.com/talk/threads/is-there-heat-coils-in-a-storage-tank.104936/

 

[woodsmaster]

what do you need to service ? I built a wood box around mine and dense packed with blown cellulose. Works very well and was fairly cheap. If I had more money when I did it I would have sprayed an inch of foam on the tanks, then the cellulose.

 

[Floydian]

Heat rises

What?Since when?

If one builds a well insulated, like with good thickness of foam boards, is it even necessary to stuff the voids? I'm thinking of an image that Effecta Boiler User posted. Makes it a lot easier to service.

I don't like it. Insulation is going to work better right up against the tank. That set up does not look well air sealed and that along with big voids would really up the convective heat losses. Even with the tank in a heated basement, the point here is to store as much heat as you can for later, right?

I like the dense pack cellulose route-it's what I am planning when I redo my tank insulation. True dense pack cellulose means 3.5 lbs per cu ft and it will NOT settle. This takes a serious machine not the wimpy little thing you can rent from the big box stores. You could build an nice box around your tank and hire a local cellulose installer to dense pack it and while they are at your house get them to add 4 or 5" of loose fill in your attic, on top of whatever you already have. Especially if you have fiberglass-batts or blown in. Capping it with cellulose will really up the performance R value. I will be doing exactly this, hopefully before next winter.(after air sealing my ceiling as much as possible)

Noah

 

[EffectaBoilerUser (USA)]

Being the importer and distributor for Effecta boilers nationwide, I have had the opportunity to work with many end users on storage tank arrangements and have determined that insulating a 500/1000/2000 gallon tank with minimum 1.5" thick "Tuff R" polyiso board works great! In fact, right in my local town there are two Effecta users that have this arrangement and its been installed for 3+ years at each location (on tanks that are inside the living space-in a basement).

In Alaska there is another 2 Effecta customers with this arrangement, 1 in Idaho, and so on.

In the beginning (and currently on my Effecta 35kW system for the 5,000 hours of operation) I used blue board with the tanks wrapped in pink fiberglass on the inside of the blue board box). However, I noticed excessive heat loss after a short time and thus removed the pick fiberglass from the tanks and filled up the cavity on all sides with chopped fiberglass insulation and this has worked great.

Yes, if I ever have to access my tanks it will require removal of the chopped fiberglass before doing so and this is why we switched to recommending simply a 1.5" or greater thickness polyiso board. Polyiso board is a very dense foam board with fiberglass strands in it for re-enforcement and typically a black side and a shiny reflective side. We put the shiny reflective side towards the tank to reflect the heat back towards the tank.

It was amazing to us that this worked as well as it has but now that we found something that works were not messing with it.

If you want to discuss further please call my cell at 231.343.3271.

Thanks,

Brian Crawford, Up North Energy
(broken link removed)

 

[goosegunner]

Being the importer and distributor for Effecta boilers nationwide, I have had the opportunity to work with many end users on storage tank arrangements and have determined that insulating a 500/1000/2000 gallon tank with minimum 1.5" thick "Tuff R" polyiso board works great! In fact, right in my local town there are two Effecta users that have this arrangement and its been installed for 3+ years at each location (on tanks that are inside the living space-in a basement).

In Alaska there is another 2 Effecta customers with this arrangement, 1 in Idaho, and so on.

In the beginning (and currently on my Effecta 35kW system for the 5,000 hours of operation) I used blue board with the tanks wrapped in pink fiberglass on the inside of the blue board box). However, I noticed excessive heat loss after a short time and thus removed the pick fiberglass from the tanks and filled up the cavity on all sides with chopped fiberglass insulation and this has worked great.

Yes, if I ever have to access my tanks it will require removal of the chopped fiberglass before doing so and this is why we switched to recommending simply a 1.5" or greater thickness polyiso board. Polyiso board is a very dense foam board with fiberglass strands in it for re-enforcement and typically a black side and a shiny reflective side. We put the shiny reflective side towards the tank to reflect the heat back towards the tank.

It was amazing to us that this worked as well as it has but now that we found something that works were not messing with it.

If you want to discuss further please call my cell at 231.343.3271.

Thanks,

Brian Crawford, Up North Energy
(broken link removed)

What do you cover the outside with? The pictures with foam on the outside, should you not worry about it being flammable?

gg

 

[maple1]

I still haven't finished the outside of my enclosure either - I haven't been able to decide on what to finish it with. Seems to be taking the longest to decide of any decision I had to make during all this. One day I think just throw some plywood on it, next day it'll be thinking to get some steel roofing leftovers from the guy I got my roofing from, next day it'll be another layer of shiney-sided foam board with shiney side out - round it goes...