Water Storage tank, Add-on to Boiler

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dtd64

New Member
Hearth Supporter
Mar 2, 2009
5
Central MN
I have a Central Boiler. Classic, CL-5036. It holds roughly 200 gallons of water. And has 250,000 BTU's and from what it claims, replaces up to 250 gallons of Fuel oil per month. When I purchased the Boiler. Oct. 2008. I knew it was right at the limit, of what I needed. But really could not afford the next model up.

I have two options, for tanks available, here, that I can use to add on. One is a used, oil barrel, that holds 240-250 gallons, the other is a stainless steel mixer, to mix the milk for cream, or something like that. It has a small paddle in the bottom. So it was used for mixing. It would hole around 100. "JUST A GUESS" It has only a cover. It is not a sealed tank. My thought for this one, was to make sure it is high enough of the slab, in my garage, so that it is equal to the high level of the water in the boiler. This way I would not have to weld, and seal the top cover. just insulate the thing real good.

I have a friend who works a Polar tank. They build tanks for semi trucks. I could have him take it to work, to weld in the fittings to attach the water pipes to.

I'm afraid if I were to add the oil tank, the extra 250 gallons would be to much, for the size fire box. (50"x36"x30") What are your thoughts? The fire box for the next size model. CL-6048 at 400 gallons, is (60"x48"x36") At 500,000 BTU's.

Of which would be perfect for my needs. If I would of had the $$$$, that is. I'm the kinda guy who buys with CASH. I do not like paying interest on anything. "PERIOD"

The main reason why my boiler is maxed out. I have two heat exchangers.

22X22: 269,000 btu, House Sq. Ft. 3,500 w/9' ceiling, 80 years old.
20X20:185,000 btu, garage. Sq. Ft. 1000. Insulated well. But I rarely use this one.

I have one pump now on the boiler. "OUT" It is a BELL & GOSSETT PL36. Do you think it would be best, to add another pump, to the system? The exact same pump. I would assume it would almost be necessary.

All of the PEX pipe is 1" inside. No T's, or elbows. YET!!! Total, around 230'. 160 underground. The rest, in house, between the side arm, and the two exchangers. I have it plumbed, from boiler, to the side arm, then to the house exchanger, to the garage exchanger then back to the boiler.

My change idea. Boiler, to add-on tank, side arm, house, garage, "add the 2nd. pump here", then back to the boiler.



Any info. from the group, to help me with this add-on would be greatly appreciated.

Thanks,

Doug
 
Well Doug I am no expert but I have a eko 60 and have 150' of 1" pex and there is no way I can get my units rated btu to transfer thru 1" pex no mater how big of pump you put on it. Here is a quote from heaterman from this site..... I hope this helps


"That’s probably the most common mistake I see on installations using any type of remotely located boiler. The OWB hacks have settled on 1” pex as the maximum size needed for any and all applications and have done a masterful job of perpetuating that myth. I’ve have stood face to face with that type of installer and heard them say “If you need more heat just use a bigger pump”. At which point I am left nearly speechless at the utter stupidity of that statement. It’s hard to explain things like head and how many GPM are required to effectively carry XX,xxx BTU’s to someone with absolutely no knowledge of hydronic piping or any inclination to learn.

So here’s the rough rule of thumb again.

3/4 “ tube = 4GPM = 40,000BTU
1” tube = 8GPM = 80,000 BTU
1.25” tube = 14 GPM = 140,000 BTU
1.5” tube = 22 GPM = 220,000 BTU

Once you try to go much above those flow rates in a given size tube you will find that about all you are doing is wasting electricity generating head instead of flow

NOTE: these are rough rules of thumb and flow rates will decrease drastically when tubing lengths exceed 150-200 ft.

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I am still considering on adding a add-on tank, to increase the size basically. Anyone that has done this, and has any thing that I should know would be appreciated. I was just looking at Craig's list. There is a guy about 50 miles down the road who has a 80 gallon hot water heater for FREE. It's a older model. With no leaks. Is this something that would be a good add-on, or not. It being used of so many years, am I a looking at problems with Rust, and should just stay away from it.

I have the 250 gallon fuel barrel, probably to big. Then the stainless steel cream mixer, out of a creamery, which is about 100 gallons.

Those who have added onto their boilers, with a add-on tank. Please help in your findings as to what is working best for you.

Thanks again,

Doug
 
I am not a pro, but from anything I've learned so far, the main advantage of storage is being able to take a boiler that is capable of attaining highest efficiency when run "full tilt" and using the storage to allow the boiler to be used for periodic, high-efficiency fires (and then go out or just have a few coals in-between fires) rather than a more continuous, low-efficiency, slow burn.

To do that, you need big storage relative to the volume of the boiler, and also a boiler that will really leap in efficiency when run full tilt.

I am not sure that your CB OWB will realize a big gain in efficiency when run full tilt, and all of your storage options mentioned are barely as big as your boiler, so would not necessarily offer much "between fire" time.

Storage can be great- but I tend to think that with the technology you've got with your OWB, it may not be worth the cost/ complexity/ effort.

I'm not trying to disrespect what you've got or what you're trying to do- just not sure that your situation is the most beneficial situation in which to put the effort into storage.
 
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