STORAGE FOR THE TARM

Jim my boiler is in the back of the garage and my unpressurized storage is in the basement ........Actual thermosiphon probably would be better from the basement then the garage , Also any heat loss is in your home . Since you have more room ease of installment I would go for the basement , Use the extra room you saved for a little extra wood storage . I like my set up , Boiler is in a walled off section back of the garage , I can get to the room from the outside , from the garage or I have a door directly from my bathroom to the boiler room . I have room enough to store a full cord of wood with it in the same room .
Webie
I take it the install is going to be in the garage , I don't think once you have it in you will regret installing it there . Sure is nice when its below zero and you are in your shorts fireing up ......LOL

You will NOT get thermosiphon activity going from a boiler in the garage to a tank in the basement - the boiler is the hot spot, and also the high point, so there is no gravity / density difference potential to drive circulation.... To get thermosiphoning, you have to have the "hot spot" be significantly lower than the cold area so that the heated water will rise out of the hot spot and drive the circulation.

That said, there is no reason the storage tanks have to be next to the boiler, so putting them in the basement would be fine, and offer the potential advantage that any heat loss from the tanks will go into the heating envelope of the house. You would just need to provide a different dump loop of some sort.

The only big issues of concern are the same red flag that goes up any time someone talks about putting a wood burner in a garage - it is something with considerable code and insurance issues around it, which I'm not going to go into here; and the potential concern about the risk of freezing if you are not burning in cold weather for whatever reason...

Gooserider

Jim unless you loose power every other week don't worry to much about the thermosiphon , I use to have my boiler set up with a back up UPS . Battery was dead when i needed it and I was on a down cycle when the only real outage hit , couple of blips or a minute out doesn't count . I have a Honda generator for back up here in case , but if you are on a super hot burn you need a lot to dissipate the heat , the worse case you boil over blow the pressure relief till it cools a little and your cold water makes up the difference . Remember once your boiler has no power it will go out !

I would always recommend putting the storage in the heated dwelling if you can. No matter how much you insulate it, you will always get some heat loss. I wish I had the room for this but I didn't so mine is out of the dwelling.

Storage is best inside the heated area if possible to maximize efficiency of the system.

A gravity feed loop should be installed ABOVE the boiler large enough to radiate 10% of the boilers rated output as stated in your Tarm manual. Better to not blow the prv than to release hot steam and water into the garage and then bring 50* water out of your well into your hot boiler vessel from the pressure reducing valve.

A properly installed gravity loop is a relatively small investment to protect yourself and your boiler.

cheers

Piker said:

Storage is best inside the heated area if possible to maximize efficiency of the system.

A gravity feed loop should be installed ABOVE the boiler large enough to radiate 10% of the boilers rated output as stated in your Tarm manual. Better to not blow the prv than to release hot steam and water into the garage and then bring 50* water out of your well into your hot boiler vessel from the pressure reducing valve.

A properly installed gravity loop is a relatively small investment to protect yourself and your boiler.

cheers

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Agreed with all the above, and in addition to the temperature shock, you don't really want a situation where you _expect_ to be introducing new water when it can be avoided -- from all that I've gathered about hydronic systems, the main way that corrosion of ferrous metals is prevented is by way of the fact that oxygen is driven out of the heated water-- when new water enters, oxygen comes with it, leading to more/faster internal corrosion than if you had a sealed system. When you've got multi-kilo-bucks in a boiler, might as well take the rest of the steps (pretty minor compared to the main installation) to protect the longevity of the investment.

Old cast iron radiator works perfectly for this. When you take one that is room temperature (cool) water in it and use it as a heat dump it will adsorb a tremendous amount of BTU's.
Rob

RobC said:

Old cast iron radiator works perfectly for this. When you take one that is room temperature (cool) water in it and use it as a heat dump it will adsorb a tremendous amount of BTU's.
Rob

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http://duluth.craigslist.org/mat/1517039453.html

webie said:

RobC said:

Old cast iron radiator works perfectly for this. When you take one that is room temperature (cool) water in it and use it as a heat dump it will adsorb a tremendous amount of BTU's.
Rob

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http://duluth.craigslist.org/mat/1517039453.html

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here is another
http://duluth.craigslist.org/mat/1565075513.html

I have pressurized storage in the basement and the Tarm in an attached boiler room on the 1st floor. Having the tanks in the basement has been great in that any heat that is lost is heating the flooring of the 1st floor. The basement is warmer than it ever was before and a place that one might go to accomplish something if they had some time. I vote for the basement option.

RobC said:

Old cast iron radiator works perfectly for this. When you take one that is room temperature (cool) water in it and use it as a heat dump it will adsorb a tremendous amount of BTU's.
Rob

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cast iron rads are probably the least expensive option your going to get for a gravity overheat loop.

My installer put in a blower with a pump for overheat and I never got around to doing a gravity loop for power outage. I did however get the dhw coil in my Tarm Solo 30 and running the dhw through it cools an overheating boiler off pretty quick. We are on city water and it has a generator, so it is always on even when the electiricty is out in town. I actually had to use it once in an outage to cool the boiler... worked well. I don't burn when no one is home so I have not needed a gravity loop...

I agree with everyone else that the storage in the basement sounds like a great location... good luck!

jimde said:

Thanks for the reply fellas, It sounds like the basement is the way to go. Webie, I thank you for the extra work on finding the rads. I will give him a shout. Can the gravity loop be useful in a power loss and as a overheat due to other component failure or would they have to be two seperate loops? WNO ,what do you mean by saying you have the DHW coil in your solo 30?

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Jim you should not have to worry about an overheat as you are running with storage . But just incase you could use that as a combo dump zone also , I use my basement zone as my dump . Not sure anymore but you could buy a DHW coil to fit in the solos water jacket , FYI you could get that and use that for heating your DHW instead of useing a sidearm .
Jim if you got a bunch of time yet just run a wanted in craigs list for a cast iron radiator , Or maybe even the WI farmer .
Might be able to find one close to home .
I was trying to find an ad for a guy that ripped out his hot water heat and had a bunch of slantfin cheap that would work too.

jimde said:

Thanks for the reply fellas, It sounds like the basement is the way to go. Webie, I thank you for the extra work on finding the rads. I will give him a shout. Can the gravity loop be useful in a power loss and as a overheat due to other component failure or would they have to be two seperate loops? WNO ,what do you mean by saying you have the DHW coil in your solo 30?

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Bioheat (TarmUSA when I bought my unit) sold a coil that is mounted inside the upper chamber of the boiler. The coil sits in the boiler water and allows you to heat domestic hot water. I run my dhw mostly through storage now so that there is always some available even when there is no fire, but in an over heat situation I can direct the dhw through that coil and bring down the temp.

One of the other boiler companies (I think it is Eko) offers an "overheat coil" for their boilers which is basically the same thing and it gave me the idea to use mine as one in this situation.

To answer your other question, yes the rads could be used as both a powered and unpowered dump zone. You would need an automag zone valve (or something like it) to open automatically on power outage and also a circ hooked to the overheat aquastat for when there is power and it overheats.

Ok I will try to explain this as best I can . Your tarm has basically 2 shut offs for your combustion blower Your main control the knob and then under a small cap near the main fuse is a resettable maximum high temperature breaker ( Do not know actual max , but lets say its like 210 ). I am guessing that you will be set up about like the rest of us with storage and that is a main loop that Goes from boiler to storage and back unless there is a call for heat then a zone valve or valves open and your zone pump kicks in supply water to the house for heat then back . OK lets say for instance your boiler combustion fan doesn't shut off and it keeps burning past your normal 190 limit , and it keeps cranking and cranking , your boiler is now over 200 and still going up . Think about this as logical You have or will have 740 gals of pressurized storage plus another say 60 for the boiler . First there is no way that ever your storage will be fully the same complete temp as the output of your boiler , its not possible there is always heat loss , may not be alot but always some. OK now your boiler hits that max of 210 and pops that relay at that point you stop heating up the water anymore and your pump is cycleing 210 water to your storage and lets just say your return is 205 .Between your 800 gals of storage you have you wont gain more than a couple of degrees if any because of heat loss and no more heat input . If you didn't have the storage that would be a different story but since you do It takes alot to keep raising that temp higher and higher , That mountain gets steeper as you go . Besides you would need one heck of cast iron radiator to be able to dissipate a continual 200,000 Btu out put of your tarm . Oh and by the way I have popped mine .. we all do bad things . Here is another worry saver I do believe in your book it says something like if this high temp ever does blow you need to fix the problem This is your nearly last safety . The relay has to be reset manually for your combustion blower to work again so if this happens in the middle of a burn cycle no worries your boiler wont fire again till you reset it .

Craigs list link, It states register, but then says they don't leak. With the sizes given it should say CI radiator. I would check before driving on what he actually has.
Mine is set up with a EBV and even though it's not above the stove it works well enough for no power dump.
If you go to pick up CI radiators be prepared they are really heavy. There has been many past posts on pressure testing them, cleaning and repainting.