# How long will your storage retain usable heat?



## dogwood (Feb 26, 2012)

If you had your storage fully heated, say to 180 degrees or more, and were away for a few days, say four, what temp would you anticipate finding your storage water at upon your return. Assuming you were heating your home in your absence with your back-up furnace/boiler, your tank is reasonably well insulated, and not outside in the cold, or even if it is in an unheated space.  Conditions vary, what what would you expect in your situation with your storage tank size? 

I guess I am wondering how quickly a fully heated, reasonably insulated tank will cool off to below 140 degress , if unused a few days. Don't know if there's a difference between how fast a 300, 500, or 1000 gallon tank might cool. 

Mike


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## Onfoot (Feb 26, 2012)

This is an impossible question to answer, Dogwood, without more information.  A BTU is defined as the amount of energy required to raise the temperature of one pound of water by one degree F.  Conversely, if you are drawing energy (in the form of heat) from a storage tank, you will be losing one degree F per pound of water per BTU that is being drawn to heat your home.

So, for example, my heat storage tank holds 850 gallons, which equals 7,094 pounds (water weighs 8.3454 lbs. per US gallon).  It therefore takes 7,094 BTUs to raise the temp of my tank from, say, 150F to 151F.  (Of course that presumes that a perfect transfer of heat from the boiler to the heat storage which is never the case.  There will always be heat losses along the way.  But for the sake of the illustration...)

In my system a while back I monitored the heat loss of my tank over two hours.  Outside temp was about 25F (as I recall--cannot find my notes) and I noted that the tank dropped 10 degrees F over the two hours--a loss of 70,940 BTUs or 35,470 BTUs per hour.  At that temperature (quite mild for here), if the effective useful temperature range of my tank was between 112F and 175F, then the tank has 446,922 BTUs available which at 35,470 per hour equals 12.6 hours of useful heat.

However, if the outside temp was, say, -45F (a not untypical cold snap temp), then those 446,922 BTUs are going to be used up much, much more quickly.

So sizing a tank will relate to how many BTUs you predict will be needed to provide heat to your system and etc.

Sorry if I have gone on in too much detail-but helps me as I think about my own tank sizing needs.

Barrett


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## ewdudley (Feb 27, 2012)

Depends on surface area of the box, R-value of the insulation, thickness of the insulation, temperature difference, and the amount of water inside the box.

These are pretty rough figures, but assuming a 5 ft x 8 ft x 10 ft box of 8 inch expanded polystyrene enclosing two 500 gallon tanks of water starting out at 180 degF sitting in a 32 degF space, here's the temperature at the start of each day:


```
-
 0 180.0
 1 175.6
 2 171.3
 3 167.2
 4 163.2
 5 159.3
 6 155.5
 7 151.8
 8 148.3
 9 144.8
10 141.5
11 138.2
12 135.1
13 132.0
14 129.0
15 126.1
```

Of course the bottom of the enclosure isn't going to see 32 degF, and the bottom of the tank won't be 180 degF for long, and if the enclosure is inside somewhere then the other walls won't see 32 degF, and your R-value may be better than 8 inches of polystyrene, and you may have some interstitial insulation around the tanks, so this should be a rather pessimistic estimate.


```
use strict;

my $lambda = 0.035;
my $d = 0.2032;
my $m2K_per_W = $d / $lambda;
my $m2 = 31.587034;
my $W_per_K = (1.0 / $m2K_per_W) * $m2;
my $t0 = 82.222;
my $tA = 0.0;
my $t = $t0;
my $h;
my $liter = 3785.0;
my $hour = 24.0;
my $btu_per_hour_per_W =  3.4121416;
my $W_hour_per_K_liter = 1.1613131;
my @t = ();
for ($h = 0; $h < (30 * $hour); $h += $hour) {
   my $W = $W_per_K * ($t - $tA);
   my $dT = 
    (1.0 / $W_hour_per_K_liter) * 
    (1.0 / $liter) *
    ($hour) *
    ($W)
   ;
   push(@t, $t);
   $t -= $dT;
   printf(
    "W_per_K=%.3f W=%.3f btu/h=%.3f K=%.3f dT_degF=%.3f t=%.3f
"
    ,$W_per_K
    ,$W
    ,$W * $btu_per_hour_per_W
    ,$dT
    ,$dT * 1.8
    ,$t
   );
}
my $i = 0;
foreach (@t) {
   printf(
    " %d %5.1f
"
    ,$i
    ,32.0 + ($_ * 1.8)
   );
   $i++;
}
```


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## dogwood (Feb 27, 2012)

Eliot and Onfoot, what I am trying to do is get a ballpark figure on how long it would take for my thousand gallon (propane-type) tank to cool off on its own, if was heated to 180-190 degrees and there was no load placed on it. I haven't determined if it will be spray foamed or I will use blown in insulation. It's in a heated boiler room, room temperature equivalent to what you might find in a basement. I think Piker a while back said his sprayed tank could maintain its own temperature for a considerable period of time. I was wondering how long that might be. I guess three and a half to four days is too much to hope for.

My issue is that I am away from home from 5:00 AM Monday to 9:00 PM Thursday. If I ran the boiler and heated the tank before I left, what temp would I see in the tank when I got home to fire it up for my three day weekends? From your chart Eliot, it looks like I could expect the tank to be back to room temperature by the time I got home. My alternative may be to heat the tank up to temp Sunday night. Then my wife would heat the house off storage until the tank is down to 140 degress. The tank would cool to room temperature from there, while the home is heated by our propane furnace until I get back Thursday. 

I'm thinking it would take a while to get the tank back up to 180 degrees if I started out from room temperature each Thursday evening. I hoped I could let the heated tank lay dormant until I got home, and maybe it would have some of its some of its btu's left. Then I would not have to reheat it from such a low temp. My Solo Innova 50 puts out 171,000 btu's so maybe it wouldn't take all that long to reheat it anyway.

As you can see I am thinking this through. Just ordered $600.00 of plumbing fittings and hope to get some of the plumbing done during my vacation this March. That is, when I can get away from preparing our vegetable garden for spring planting. I am trying to figure out how to get some use out of the system even though I'm away too much. Eventually, as I figure out how to operate the system, I hope I can get my wife confident in operating it while I'm away. In the meantime..... Thanks.

Mike


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## ewdudley (Feb 27, 2012)

> ... what I am trying to do is get a ballpark figure on how long it would take for my thousand gallon (propane -type) tank to cool off on its own, if was heated to 180-190 degrees and there was no load placed on it.


From the chart I'm guessing a reasonably pessimistic estimate would be something like 20 degF loss after four full days.  The chart is day number on the left, degF on the right.



> My alternative may be to heat the tank up to temp Sunday night, have my wife heat the house off storage until the tank is down to 140 degress, and heat the home with the propane furnace until I get back.


I think this would be the correct strategy.  Instead of letting the heat leak away, have your wife use it up and then go to backup heat.  The sooner you lower the storage temperature, the less heat is lost to leakage because the temperature delta is lower sooner. 



> I'm thinking it would take a while to get the tank back up to 180 degrees if I started out from room temperature each Thursday.



In nearly every implementation the wood boiler heats top of storage and then load is drawn from top of storage.  No matter what temperature the storage tanks are down to when you get home you should have enough hot water at the top of storage to start heating inside of a half hour from when you light the boiler, more or less.


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## hobbyheater (Feb 27, 2012)

[quote author="dogwood" date="1330314860"]If you had your storage fully heated, say to 180 degrees or more, and were away for a few days, say four, what temp would you anticipate finding your storage water at upon your return. Assuming you were heating your home in your absence with your back-up furnace/boiler, your tank is reasonably well insulated, and not outside in the cold, or even if it is in an unheated space.  Conditions vary, what what would you expect in your situation with your storage tank size? 

I guess I am wondering how quickly a fully heated, reasonably insulated tank will cool off to below 140 degress , if unused a few days. Don't know if there's a difference between how fast a 300, 500, or 1000 gallon tank might cool. 

Mike[/quote 

Our storage is 1,000 gallons with a working range of 150F  to 195 F.  Drawing 15,000 BTU'S per hour brings the tank down to 159 F in 24 hours, not enough for two days between firings.  For the area that I live in, it would represent an average amount of BTU'S being taken from the tank. For your area, your BTU draw is going to be a lot higher.

Determine your hourly BTU draw, then if you are going the way of a boiler and storage size, your boiler should take your storage to its maximum temperature on one firing and your storage the 24 hours to your next  firing.

Below is the section from the EKO manual on sizing your storage  to your boiler. It's a starting point.

Hot Water Storage
For the best results, the use of a heat storage tank is recommended. A properly sized storage tank
can cut wood consumption by as much as 40%. Hot water storage allows the boiler to run at optimum
capacity regardless of the demand for heat from the building being heated. The stored heat can be
recovered later, both stretching the time between boiler re-fuelings, and as an additional source of
heat on very cold days. Generally, the bigger the storage tank the better, as the boiler is most efficient
when running at full capacity. The rule of thumb on tank sizing is that 13 gallons of water can store
about 1KW of boiler heat. Using the EKO 25 as an example: 13 gal/1KW x 31KW = 421 gallons, 421
gallons x 91% efficiency = 383 gallon minimum size water tank. A hot water storage tank connected to
an EKO boiler can also be used to store hot water from a solar water heater.


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## dogwood (Feb 27, 2012)

Well Eliot, I misread your chart, mistaking hours for days. I am more encouraged now.

Here's another question for you about heating off the top of the tank since you mentioned it. The plumbing schematic I am using from Tarm Biomass has a bypass plumbed in so you can circulate directly from the boiler to the load. In my case the load is w/a hx and a flat plate hx servicing the DHW. The remainder of the boiler's output goes directly to storage, or entirely to storage when there is no call for heat or hot DHW. I was looking at HR's recent Iodronic's post and the article it linked to had a schematic as you describe with all boiler output going directly to storage, and from there is circulated to the loads when there is a call for heat. This is certainly a simpler plumbing arrangement. Do you think it would be okay to go that route (and leave our the bypass)?

Mike


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## hobbyheater (Feb 27, 2012)

dogwood said:
			
		

> Well Eliot, I misread your chart, mistaking hours for days. I am more encouraged now.
> 
> I was looking at HR's recent Iodronic's post and it had a schematic as you describe with all boiler output going directly to storage, and from there recirculated to the loads. This is certainly a simpler arrangement. Do you think it would be advantageous?
> 
> Mike



In our system the boiler charges the storage. There are two heat exchangers in the storage tank - one for heat and the other for DHW. If your storage has ample reserve, it works well.
If our storage goes much below 120 F that's the bottom end for a comfortable shower!


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## ewdudley (Feb 27, 2012)

> Here's another question for you about heating off the top of the tank. The plumbing schematic I am using from Tarm Biomass has a bypass plumbed in so you can circulate directly from the boiler to the load.


I didn't know that any of the Tarm reference designs for pressurized storage had a provision to isolate storage from the wood boiler.  Are you sure you're not looking at an unpressurized 'heat battery' system?



> I was looking at HR's recent Iodronic's post and it had a schematic as you describe with all boiler output going directly to storage, and from there is circulated to the loads when there is a call for heat. This is certainly a simpler plumbing arrangement. Do you think it would be okay to go that route (and leave our the bypass)?



Whether you go from boiler to storage with one set of tank fittings and then from storage to load with another set of tank fittings, or with a pair of lines with tees going off to storage as in the 'Simplest', it doesn't make a whole lot of difference hydraulically.  Whichever works out best for your situation is fine.  If you want to have the most hot water a litter faster after firing the boiler then the 'Simplest' would work a little better because you're not heating a layer of hot water across the top of the tank, but again, it would be just be somewhat faster, no big deal.


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## dogwood (Feb 27, 2012)

Eliot, my current Tarm schematic is their PT3 diagram on page 21 of: http://www.woodboilers.com/admin/uploads/public/WoodBoilerPlumbingSchematic0111Web.pdf
HRâ€™s schematic is Figure 6-21 on page 35 of:  http://www.caleffi.us/en_US/caleffi/Details/Magazines/pdf/idronics_10_us.pdf

The PT3 has a bypass to the storage going directly to the load. Maybe that is too much trouble for what its worth. Would you bother with it?

Mike


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## ewdudley (Feb 27, 2012)

dogwood said:
			
		

> Eliot, my current Tarm schematic is their PT3 diagram on page 21 of: http://www.woodboilers.com/admin/uploads/public/WoodBoilerPlumbingSchematic0111Web.pdf
> HRâ€™s schematic is Figure 6-21 on page 35 of:  http://www.caleffi.us/en_US/caleffi/Details/Magazines/pdf/idronics_10_us.pdf
> 
> The PT3 has a bypass to the storage going directly to the load. Maybe that is too much trouble for what it worth. What do you think?
> ...



If I'm looking at the right drawing, PT3 from version 12-10 dated 2010-12-07 has no bypass.  For some reason there's ZV-1, but it serves no purpose, so I'm assuming it is a pasting error by the draftsman.

Hydraulically the PT3 and Figure 6-21 are nearly identical.  But neither has a fossil fuel boiler integrated, so you still have to deal with that.

--ewd


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## dogwood (Feb 27, 2012)

Eliot, The line with the ZV-1 is the line I'm referring to. My use of the term bypass might be in error. But it seems you can heat from the boiler directly to the load and back again in the PT-3 arrangement. And I give you credit for spotting that misbegotten ZV-1 valve. I had a longish post regarding that valve some time back before discovering it was extraneous, and even talked with the then BioHeat USA about it. Unfortunately I had already spent a small fortune, ($158.45) on a 1.5 inch motorized ball valve to use as that ZV-1, since I am using 1.5 inch black pipe, and couldn't find a 1.5 inch zone valve. You know, I might put in that extra pipe line just to use that part.

I don't have a fossil fuel boiler, just a forced hot air furnace with a newly installed w/a hx in the plenum above it, so one less thing to deal with. Hobbyheater sounds like you have a straightforward system. I like that and have tried to keep mine as straight forward as possible. I hadn't thought of running the storage supply to DHW to a 120-130 degree mark, which is lower than the 140 the W/A hx needs at minimum. I'll see if I can work that in and get a little more bang out of my storage. I'd eventually like to get panel radiators to utilize lower storage temps.

Mike


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## ewdudley (Feb 27, 2012)

dogwood said:
			
		

> it seems you can heat from the boiler directly to the load and back again in the PT-3 arrangement.



I'm just saying that the hot water will float across the top of the tank nicely in the Figure 6-21 design, in effect 'bypassing' the tank.   True, the PT-3 system will bypass somewhat more effectively, and it's the way I did mine, but either way is fine.  Again, in PT3 ZV-1 doesn't do anything and it doesn't help-- or make possible--storage tank bypass.


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## dogwood (Feb 27, 2012)

The ZV-1 does make your wallet lighter, if nothing else. I'm no plumber or hydronics expert, but was even less tutored when I bought that unnecessary thing. Live and learn.  Thanks again.

Mike


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## flyingcow (Feb 27, 2012)

FWIW- my first fire in the Innova-30, i brought 820 gals/unpressurized storage from 52 degrees to 180 in about 12 hours. This was on a night where the house got down to about 50f. We had taken the house offline to hook up system. It was -10 outside with a stiff breeze. The boiler heated the tank and brought the house up to temp in no time. The house was first in line for the heat. Then heated tank and house together. The house is a pretty big load. I don't think you're Innova-50 will be long bringing your tank back up to temp. 

Also, i couldn't load the Tarm schematics, so bear with me. If your layout has a Termovar valve to divert heat to the house, if the house is calling for heat(while your wood boiler is running) I would use it. On my unpressurized storage system layout, it works great. Within 45 minutes of throwing match I have 165 degree water running thru my baseboard. In 60 minutes it's 190ish and climbing. And there is heat going to storage. This is a nice plus if house is cool and tank is down below it being useful.


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## peakbagger (Feb 27, 2012)

I have 550 gallons of pressurized storage supplied by American Solartechnics. I believe they sell at least a porion of the output to the Tarm folks in NH. When I was setting up the controls, I charged up the tank a couple of times with no way to remove the heat. I came up with a rough estimate of about 3 degrees loss per day but you would have to do some calculus to figure it out exactly as the amout of heat transfer is directly realted to the temperature difference bewteen the inside of the tank and the outside of the tank. Think of its this way, if the suroundings are at the same temp as the tank it will not cool down. If the tank is at the maximum difference between the  inside and the outside it will cool down the quickest. To further confuse the issue the tank top will give up more heat per amount of surface area than the walls due to convective air flow and the tank bottom will give off substantially less heat than the top as it most likely is sitting on the floor. Now add in that the temperature of the inside of the tank is not the same due to stratification with warmer water sitting on top and it get more complicated. 

I did notice that the copper piping used to charge the tank are very effective at thermosyphoning heat. On the connection to my side wall coils, I ran the pipe down with a couple of elbows before heading up to the ceiling. This should stop the thermosyphoning.


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## Rory (Feb 27, 2012)

There seems to be a couple of different questions here - how much standby loss do we get, and how long can the tank heat the house.   The answer to the first is not much, if you're well insulated.  I have the passive "heat battery", a 4x4x8 rubber lined plywood box, insulated with 2 2" layers of foil faced foam.   The tank hugs an outside cellar wall on one of the long sides, an interior wooden uninsulated wall on a short side, and it sits on the concrete cellar floor.  We've had some stretches in the summer when we were away for a few days, and the tank leaks very little heat when it's just sitting there.   In my climate, the buffer is enough to get through most of the coldest winter days with two fires and no restoking.


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## dogwood (Feb 27, 2012)

Thanks Rory, Flyingcow and Peakbagger. I appreciate the information. Flyingcow, I just tried the link to the Tarm Plumbing schematics pdf and it worked. If you're  can't pull it up, it's on the Tarm Biomasss site under Products, Woodboilers then under Solo Innova.

Mike


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## Chris Hoskin (Feb 27, 2012)

lots going on here.  First, ZV1 is closed only when there is no call for heat from the zones.  This assures that all flow goes through storage and no ghost flow through the zones.  Given the hydraulics of drawing PT3, probably not strictly necessary, but can't hurt.  If you are incorporating a back-up boiler, please see drawings PT1 or PT2.

The OP asked about standby loss under no load, if I understand correctly.  Mostly a theoretical exercise, right?  Can't imagine a real-world situation where you would need this info?  If you are looking to know how long your thermal storage will last between firings, you need to determine the load and then use the math around BTU that others have already shared to show how many BTU you have stored and how long that will last.

In our experience, and purely anecdotally, systems that allow for 24 hours of coast on the coldest days of the year between boiler firings have been intentionally over-sized.  For example, something like a 50,000BTU load with a 170,000BTU boiler and 1000 gallons of storage (just an example, don't bother doing the math).  We have had people take three days of continuous boiler firing to charge/re-charge 5000 gallons of thermal storage, but that is very unusual, of course.

hope that helps shed some light, good luck with the project and don't hesitate to give us a call with questions.

Chris


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## in hot water (Feb 27, 2012)

Any time you have "pumped" flows in a tank there will be temperature blending.  The water doesn't always do what the color in the drawing shows, hot top, cooler bottom.

With a hydraulic separator or separator tank you can define that temperature blending.  It changes depending on how many GPM both sides of the tank are flowing.

If the boiler is flowing 8 gpm, and the distribution is 8 gpm, then the temperature on in and out ports will be about the same.  If either side gpm flow changes, so does the mixed temperature.  this graphic shows what goes on inside the tank. Also the formula to calculate the mixed temperature.

I think an open, unpressurized tank, with coils inside probably stratifies better as long as the water in the tank is not pumped, hot water rises, cooler water drops to the bottom.

The same concept with your home water heater, hotter water on top.  Unless you add a recirc DHW pump, then the tank temperature blends, depending on where the pump ties into the tank.

hr


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## dogwood (Feb 27, 2012)

Chris, I wish this was a theoretical exercise for me. I am away from home from early Monday morning to late Thursday night. I am trying to figure out how approximately how fast an insulated 1000 gallon tank might drop off in temp if I put no load on it for those four days. This would be the case if I used the back-up forced hot air furnace only to keep the house warm in my absence. With a rough idea of how cold the tank might be on my return, it might be easier to figure out how long it might take to get the 1000 gallons back up to temp. 

What you say about the ZV-1 preventing ghost flow makes sense and is what Gooserider pointed out to me when I posted on this subject a ways back, if I correctly recall. I already own the valve so in it goes. You might want to label that part as optional on the diagram to save future PT-3 users some dollars Thanks for your reply. 

HR, thanks for your input too. I will have to study what you said about the hydraulic separator and study the math too.

Mike


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## ewdudley (Feb 27, 2012)

dogwood said:
			
		

> I wish this was a theoretical exercise for me. I am away from home from early Monday morning to late Thursday night. I am trying to figure out how approximately how fast an insulated 1000 gallon tank might drop off in temp if I put no load on it for those four days.



I believe the point is that figuring out how fast the no-load tank would lose temperature is a theoretical exercise because there is no scenario where it could offer any advantage.

To minimize the amount of load on the propane system just go ahead and draw down storage for as long as it is available, then switch to propane, then light a fire as soon as you get home.  Within a half or three quarters of an hour you'll have heat from the wood boiler and the propane system can be shut down.

For as long as you do 'double duty' heating the house and charging storage after you get back home, the heat going in to storage will be heat that would have come from propane had you switched to propane when you left, and over and above that will be the heat you didn't lose to leakage due to leaving storage setting idle.  Kind of a use it or lose it situation.

--ewd


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## dogwood (Feb 28, 2012)

That does make perfect sense Eliot, and is exactly what I will do. 

Not knowing what to expect, I had speculated the tank might lose so much heat it would take forever to recharge the 1000 gallon tank, and I'd be tied to the house while the wood boiler is firing. I don't know how long it takes a 170,000 btu wood boiler to reheat a tank from room temp. I suppose that wouldn't be too difficult to calculate. Flyingcow provided some insight with his initial firing example. But looking at your example the tank wouldn't lose nearly that much heat anyway, maybe twenty degrees in four days. And, it seems, looses heat less quickly as it cools. I was, for one, trying to get a general idea of how long that reheat might take. I thought people with real life experience in this matter could provide some guidance, as they have. If the tank temp isn't dropping too precipitously after it gets to 140 and only got down to 120, it might not take too long to reheat it back to 180-190 degrees. I'll have to calculate how long that might be. I can live with those numbers.

By the way Peakbagger, thats a good idea to pipe in a U shaped heat trap to stop thermosiphoning from storage. I was planning to do this on my DHW tank when I reconfigure that to plumb in the Flat plate W/A hx for the DHW zone. Good idea to do that for the storage tank too.
Thanks all.

Mike


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## Rory (Feb 28, 2012)

dogwood, your last post reminds me of one of the plumbers involved in hooking up my system.  With the DHW heat coil in my tank, I had the plumbers remove my boiler-mate from my furnace.  One of the plumbers thought I was nuts, and he went on about all the oil it would take to heat the storage if I ever got hurt and couldn't build my fires.  He couldn't seem to grasp the point that all the heat going into the tank was going to end up heating my house or DHW anyways, so it wasn't really an issue.


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## jebatty (Feb 28, 2012)

Standby loss on a pressurized, insulated tank in a heated space is very low at moderate temperatures. My system is setup to operate as follows on a fully charged tank, Tarm has burned out: draw down storage to radiant floor to maintain shop heat at 61F floor temperature. When storage has dropped to 80F, shut down radiant draw from storage. Shop will continue to be heated at 50F air temp from an electric space heater. Storage tank will remain 60F+ for at least 2-3 weeks. If I take a winter vacation, that is the scenario.


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## woodsmaster (Feb 28, 2012)

In the summer I can go 4 to 5 days just heating DHW so If I wasn't heating anything and was fully charged I would think there would be usable heat for at least a couple weeks.


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## goosegunner (Feb 28, 2012)

I have coil in my forced air furnace. Right at the coil supply I have a auqa-stat that senses water temp. I have it set at 130 degrees, it is connected to a time delay. If the water is not 130 after 3 minutes it opens the circuit to the pump which stops power. It then closes the circuit to the gas furnace and the lp kicks in.

My pumps are controlled by a Taco zone control panel.  I have it wired with a switch so if I am going to be gone for a while I just shut off the power to the Taco panel. That way there is no pumping and the lp just kicks in after 3 minutes.

You could run it down to a chosen temp and then have your wife shut off power to the panel. That would stop flow from the tank and minimize heat loss.

gg


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## flyingcow (Feb 28, 2012)

Again my is unpressurized storage, but if my tank is down to 100/110 it will take about 4 hours? to bring up to 180. thats with no load from the house. With your Innova-50 i would think that would be quicker?


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## hiker88 (Feb 28, 2012)

FlyingCow,  sent you a PM.  Thanks.


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## goosegunner (Feb 28, 2012)

flyingcow said:
			
		

> Again my is unpressurized storage, but if my tank is down to 100/110 it will take about 4 hours? to bring up to 180. thats with no load from the house. With your Innova-50 i would think that would be quicker?



You must really have it dialed in. That is averaging 136612 btus/hr for just the 820 gallons. 

I have a hard time getting that to storage with my Econoburn 200 but I am always feeding my load for the duration of the burn. I have never tried it with the load off.

gg


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## flyingcow (Feb 28, 2012)

goosegunner said:
			
		

> flyingcow said:
> 
> 
> 
> ...




Yeah , does sound a little off, now that i really think of it. I can push it to 165/170. Probably closer to 5 1/2 hours to push it to 180, and my bottom would be about 165? Thanks for picking that up gg.


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## dogwood (Feb 28, 2012)

Onfoot, I did some calculations today following your lead, and figured it would take only six hours to reheat the 1000 gallons to 180 degrees, even if it dropped in the worst case scenario, to room temp of 70 degrees, assuming no load from the home or DHW. This seems very unlikely to be the case based on all your input. If my wife runs it down to 140 and then it drops another 20 degrees, per Eliot's estimates on standby losses, it should take only about three or so hours to get it back to temp, and probably some more with the load of the home added in. This seems to be in keeping with Flyingcow's experience with his Solo Innova 30, and doesn't seem unreasonable, or too much to deal with. Thanks all.

Jebatty, Woodmaster, and Rory, thanks also. Looks like I may be able to get some good use and value from the boiler even though I'm gone half the week or more. This whole problem will resolve upon retirement five-six years hence when I'll be home seven days a week and happily burning every day of the heating season. 

Mike


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## goosegunner (Feb 28, 2012)

flyingcow said:
			
		

> goosegunner said:
> 
> 
> 
> ...



I wasn't doubting you. I have heard those Tarm Innova boilers are pretty nice, induced draft and lots of fire tube transfer area.

gg


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## flyingcow (Feb 29, 2012)

goosegunner said:
			
		

> flyingcow said:
> 
> 
> 
> ...



You didn't bother me, it was a good observation. Yeah I'm pretty impressed with the unit, if it had Lambda controls on it....make me very happy. But then I'd have a Froling'.     Or the new Effecta w/lambda. 

I might be able to get this unit to run a little better, but once i get it set i usually don't goof with the settings.  i run by stack temps mainly. If i hit 400-450  when the unit has clean tubes, I'm happy. Also i burn 90% rockmaple. Whats not rock is beech....It's the good stuff.


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## dogwood (Feb 29, 2012)

Flyingcow, you probably already knew this, but in Europe you can get the Solo Innova with a Lambda control. I wonder if they could be retrofitted if you could somehow obtain one. They also have a DHW coil as an add-on. I tried to find out about their Lambda control a while back but was unable to get a response from the email address on the European site. 

Mike


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## Pat53 (Feb 29, 2012)

My 500 gallon tank will keep usable heat for 3 weeks....  in July


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## flyingcow (Feb 29, 2012)

dogwood said:
			
		

> Flyingcow, you probably already knew this, but in Europe you can get the Solo Innova with a Lambda control. I wonder if they could be retrofitted if you could somehow obtain one. They also have a DHW coil as an add-on. I tried to find out about their Lambda control a while back but was unable to get a response from the email address on the European site.
> 
> Mike



Chances are i chased the same website.


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## dogwood (Mar 1, 2012)

If anyone's interested here is a link to the brochure on the Tarm Solo Innova LC (with Lambda Control), available in Europe. http://eshop.fbcstore.co.uk/WebRoot...0C6/4053/5C2F/35E1/0A0A/33E8/2751/SI20001.pdf


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## dogwood (Mar 2, 2012)

Thanks Pat53. We'll be burning in July too for DHW use.

Mike


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