Starting my "storage and replumb" project

I don't have a whole lot of experience with plate HXs, but I do have one. That's a big difference in DTs between sides - 80 on the boiler side, and 30 on the load side. Which I'm thinking says there's a flow imbalance between sides. I think they should theoretically be the same on each side. The 30 sounds not bad, the 80 is a lot. So I think there should be more flow through it on the boiler side - but that is compounded by the low startup temps, and the boiler bypass bypassing most of your flow to maintain decent boiler return temps.

I think I would run it like this until you get your storage temps closer to where they are normally going to be when heating, then see how the HX temps level out at. As storage rises, your bypass should bypass less, then your flow should improve through the boiler side of the HX. Assuming a 'typical' DT of 20° through the boiler, and a protected return temp of 140, I would say your boiler is doing OK at present and wouldn't expect to see much more than 160 on it until your storage return gets hotter. I see right at 160 on boiler supply & storage top on my first lap through storage - and if storage is fully cold, that first lap can take a long time since most of the boiler flow is going around the bypass to maintain 140 return.

Not sure what to say about the fan - I don't even have one so even less experience there. Can you tell if heat is creeping/conducting back through the fan piping, from the boiler inlet to the fan? If so, some kind of gasketing for a thermal break might help. But also thinking the heat sink should be on the top side of the fan, otherwise the heat it is shedding will rise right into the fan again. Is the sink very hot?

Haven't followed this install thread because I had been traveling and doing my chores at home. Just did a bulk read and am very impressed. The one thing I noticed that may be a problem in the future is not isolating the air eliminator from the air scoop with a ball valve. Like your circulators, these are prone to failure and need to be changed out in the furure. Having to drain down the system just to change that little devil can be frustrating. Ask me how I know.

Adding home-made turbulators to my Tarm Solo reduced the outgoing flue temp very nearly 100F.

And I don't think you can take any conclusions from your system until you have the storage tank temps up to at least 90F (or more) top-to-bottom.

Could you insulate your flue pipe? With rockwool stuff or the like?

warno said:

How long does it take to heat this much water in general?

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You can calculate this quite easily, subject to the variable of the efficiency of your boiler and efficiency in transferring hot water from the boiler to storage or to your system. Seasoned wood (20% MC), has 6050 btu/lb of available heat energy at 400F flue temperature. One btu raises one pound of water 1F, and one gallon of water weighs 8.34 lbs. Assume about 80% efficiency in boiler/system transfer of heat to water in a 1000 gallon storage tank.

1000 gallons of water in storage weighs 8340 lbs. Therefore, it takes 8340/6050/0.82 = about 17 lbs of wood to raise the entire 1000 gallons of water 1F.

To answer your question, the length of time is the time it takes to burn wood of known weight and doing the calculation.

As you have noticed, your boiler shed becomes quite warm. Those are btus not being transferred to the water. Depending on the location of the boiler and storage, total system efficiency can be quite a bit better than 80% if that "lost" heat becomes usable in some way. My boiler and 1000 gallon storage tank are located in my shop, my flue temp roughly ranges between 350-450F during a burn cycle, but all the heat thrown off by the boiler and the flue, as well as piping between the boiler and storage and any heat lost by storage through the insulation also heats the shop. Total system efficiency in heating my shop may approach 90%,

Are you using that for boiler return temp protection?

I have no experience with diverter valves - but this is more like what others are using for boiler return temp protection:

http://www.supplyhouse.com/Caleffi-280166A-1-Male-NPT-ThermoMix-Thermostatic-Mixing-Valve-140F

Ah OK, I thought I was seeing it on the back of your boiler.

CV=7.5, it might be throttling things some. Curious what others would say - over my head a bit with it. But thinking it would flow like a zone valve, and I don't think I would want something flowing like that, on my boiler loop. (Seat of the pants thing only....). The Thermomix I randomly clicked on had CV=10, I think.

warno said:

Just alittle update on things. I have been trying to heat the tanks I have gotten to about 130 so far. I think I'm losing to much heat through radiant off the tank surface so I'm thinking about doing the spray foam kit from ebay to get some insulation on them. anybody had any luck with those kits?

Also I noticed my pressure at the top gauge is reading next to nothing and the bottom is reading almost 20. should I be seeing this much pressure difference?

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U would think u could get it above 130?

I didn't use the kits.. I had a spray foam contractor come in... he had a groan of a time spraying anything that he couldn't get the wand a couple ft away..

Save your money and buy 4 rolls of the 6 inch by 18 inch batts of roll insulation without the moisture barrier or aluminum facing and just throw it over the top and pull it down and tape the batt ends and sides together and do the same thing on the ends of the tanks. The duct tape wont care where its used and the fiberglass insulation will not be affected by the heat.

People insulate tanks with household insulation all the time and use chicken wire to hold it in place.

The 180°F will not hurt the foam. I used foam to maximize the R value and minimize the overall final tank diameter. The tanks were sprayed with an average of 2.5" of foam for an R value of just over 15. The tanks in the picture were sprayed in the basement, cladded then piped. When at temperature the tanks lose about 0.75% per hour initially.