Storage for Attack 45

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HD08Rocker

Member
Nov 8, 2012
29
Moira NY
So I am definitely going to need some storage for my attack. I have been just firing when my water temp gets down. Without any storage this has become quite a juggling act. Especially this morning at 4 am when I heard my oil furnace come on because the water temp had dropped below 100 and my thermostat was cranked up to get that heat from my wood.

So my question becomes. How much pressure do you need. I am seeing there r people building tanks out of wood. Others are using old propane What I am thinking... My system runs about 10 to 12 psi. I am a pretty decent DIYer(except for the attack that is giving me a run for my money) I have access to a couple 250 gal fuel drums. What do you guys think about rigging those tanks for storage?
 
air compressor tanks seem like a good option, if you are not buying new, specific designed tanks. I believe you need to make sure what the inside looks like (flakeing rust) seems like the worst thing to deal with. Air compessor tanks seem to be for sale because the pump lost compression and let oil into them. Oil could be cleaned out much easier than a rusted (flaking) tank interior. I believe that you need to install some kind of filter, that will trap any and all sediment that is left in a tank that was not purchased new. If you purchase used tanks that need to be cleaned inside, that will be a lot of extra work. Just by your previous posts, this newbe thinks you have enough room in your boiler room for a few hundred gallons of storage. Insulate the storage after you can assure their are no leaks. Just a newbe opinion. You do need to decide on a pressurized or a none pressurized storage system. There is a big difference.
 
NO, on the fuel tanks. Look around on the forums.. the idea always comes up. The tanks aren't built to hold pressure.

The deciding factor in storage seems to be if you can get it INTO the area you are going to put it.

I believe those propane tanks are 38" wide for a 500 gal model. Many great ways to stack them have been shown on these threads. I had space vertical in my boiler room.. so mine were built to stand up straight.

All things being equal... pressurized storage linked directly to your system will be less "issues"

Not saying non pressurized can't be done well. But seems like many on here with issues from pump and heat exchanger sizing.

JP
 
For storage considerations It would be good to know the lowest temp you can deliver to your baseboards and still be able to heat your space at the coldest time of the year. Obviously the lower the better as this would give you more usable btu's in storage. There is a decent chance your heating system was over sized if it was installed in the era of cheap energy.

Keep in mind when you add storage you will need to add more expansion capacity. It gets expensive, brace yourself.

Noah
 
As said, big NO on the fuel tanks.

In a closed system they won't hold pressure, in an open system they'll rust.

It will likely come down to what you have room for & can get into your space, and what you can find. Propane tanks come in various sizes, as do compressor tanks. Start looking & asking at salvage yards - if they don't have some they might know where some are.
 
All things being equal... pressurized storage linked directly to your system will be less "issues"

Not saying non pressurized can't be done well. But seems like many on here with issues from pump and heat exchanger sizing.

Why do I keep hearing this. I read this forum as much as anyone and I don't see people having issues with unpressurized storage. Also, unpressurized storage does not mean an unpressurized system. The storage water isn't under pressure, but the water in the exchanger still is. That means I need very little expansion volume plus I don't have a 1000 gallon missile in my basement.

Both have positive and negative aspects. Sorry, I don't mean to pick on you JP but it seems like every time the subject comes up everyone is very quick to dismiss unpressurized storage, for what I can tell, no really good reason.

K
 
Not saying non pressurized can't be done well. But seems like many on here with issues from pump and heat exchanger sizing.

I have unpressurized storage and have never had the issues you speak of. Nice 500 gallon stainless tank with coils that supply my radiant floor and my DHW with no sidearm, etc. It is also the heat sink for my overheat loop.
 
The only thing I can think of is people associate unpressurized storage with a Garn/OWB style setup where you heated water is not under pressure but is circulated and transfers the heat via a flat plate exchanger. There circulator sizing, exchanger sizing and water chemistry are all vital.

What Fred61 and I have are completely different. The plumbing in the end is more or less the same as it would be with an LP tank.

K
 
I think it's the internal heat exchangers (copper, flat plate with SS pumps, etc) that are a potential for undersizing where more people run into trouble and give un-pressureized a bad name. Also as you said, the water chemicals need to be correct or else tank/exchangers can deteriorate. There are different issues with the "ol propane tank trick" with expansive expansion tanks, or open expansion tanks up in the attic with rust inhibitor chemicals.

TS
 
I have unpressurized storage and have never had the issues you speak of. Nice 500 gallon stainless tank with coils that supply my radiant floor and my DHW with no sidearm, etc. It is also the heat sink for my overheat loop.

I was referring to a properly sized and designed system. The addition of a FPHX is just more math that needs to be right. Not unsurmountable.. but also something that can leave many on this site head scratching for a while.
 
10-4 good sir! It's not by chance that most systems work the way that they do, it's by design, planned or not.

TS
 
I was referring to a properly sized and designed system. The addition of a FPHX is just more math that needs to be right. Not unsurmountable.. but also something that can leave many on this site head scratching for a while.

And there's where the confusion is. The Attack is designed to run pressurized, you are comparing it to boilers that are not (OWB, Garns, Empyre). Those are what Taylor was talking about in his post above.

I guess you could run the Attack unpressurized but then you are just making things more complicated on your self.

Apples and Oranges. Sorry to hjack but this is one of those things that bugs me. There are two very different types of unpressurized storage, they simply can't be lumped together.

K
 
Why do I keep hearing this. I read this forum as much as anyone and I don't see people having issues with unpressurized storage. Also, unpressurized storage does not mean an unpressurized system. The storage water isn't under pressure, but the water in the exchanger still is. That means I need very little expansion volume plus I don't have a 1000 gallon missile in my basement.

Both have positive and negative aspects. Sorry, I don't mean to pick on you JP but it seems like every time the subject comes up everyone is very quick to dismiss unpressurized storage, for what I can tell, no really good reason.

K

There have been countless threads on this site debating the merits of both. The bottom line is this: You will get higher performance and efficiencey from a pressurized system as well as a "more simple" plumbing arrangement. However, many many people go the non-pressurized route to accomodate space constraints, code constraints (ASME) and cost constraints (expansion tanks are pricey, new pressure vessels are very pricey for those of us using non-scrap units). Non-pressurized also enables easier DHW pre-heat but I would argue this particular process requires an HX with either type of storage so should really be a net zero advantage for either type.

I've not heard many people on this site "dismiss" non-pressurized storage. It's a fact that for many users there is no other option. And it's still a great option. I couldn't even throw a guess at the efficiency/performance difference but I can tell you that there are very few non-pressurized guys out there running their tanks up to 190 every day, top to bottom. Lined tanks don't like the uber high temps for too long. And there are losses associated with plate and/or coil heat exchangers that also come in to play. Does this amount to 1% less efficiency or 10%? No guess. And if you're boiler is inside the only "real" loss is what goes up the chimney and the electricity you pay for to run your pumps.

Pressurized storage is plug-and-play. No heat exchangers (storage side), no tank liners to worry about, very little relative water maintainence. If you have the space, money and can meet code it is indeed hard to beat pressurized storage. There are plenty of good reasons for this common "belief". Read on....read on....
 
There have been countless threads on this site debating the merits of both. The bottom line is this: You will get higher performance and efficiencey from a pressurized system as well as a "more simple" plumbing arrangement. However, many many people go the non-pressurized route to accomodate space constraints, code constraints (ASME) and cost constraints (expansion tanks are pricey, new pressure vessels are very pricey for those of us using non-scrap units). Non-pressurized also enables easier DHW pre-heat but I would argue this particular process requires an HX with either type of storage so should really be a net zero advantage for either type.

I've not heard many people on this site "dismiss" non-pressurized storage. It's a fact that for many users there is no other option. And it's still a great option. I couldn't even throw a guess at the efficiency/performance difference but I can tell you that there are very few non-pressurized guys out there running their tanks up to 190 every day, top to bottom. Lined tanks don't like the uber high temps for too long. And there are losses associated with plate and/or coil heat exchangers that also come in to play. Does this amount to 1% less efficiency or 10%? No guess. And if you're boiler is inside the only "real" loss is what goes up the chimney and the electricity you pay for to run your pumps.

Pressurized storage is plug-and-play. No heat exchangers (storage side), no tank liners to worry about, very little relative water maintainence. If you have the space, money and can meet code it is indeed hard to beat pressurized storage. There are plenty of good reasons for this common "belief". Read on....read on....

I don't see how it can get much more plug and play then my setup. Pipe up either side of the exchanger, exactly like you would with an LP tank. It took me a day to put my tank together and install the liner and plop the exchanger in. That's no longer, and probably faster then it would take to prep an LP tank.

Liner to deal with or faulty welds to deal with, flip of the coin IMHO.

It seems the complete DIY crowd likes the LP tanks, and that's fine. I honestly just ran out of gas to find a tank, buy it, clean it, have it welded up and then get the blasted thing into my basement. When I added up all the costs it was pretty much a wash between buying the setup I have now (American Solartechnics) and dealing with a 1000 gallon LP tank. If you buy a premade one then the cost is the same.

I'm not saying they don't work, they do work very well but I don't agree with you that folks here don't dismiss unpressurized storage, I've seen it plenty of times. The thing that burns me is most dismiss it because they simply don't understand it (ie comparing it with a completely open system).

This is coming from someone who had to deal with a faulty liner out of the gate. That stunk but I've seen plenty of folks have get the welder back to fix a fitting as well.

Both work, it's not a competition, I just don't like misinformation.

K
 
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