Heat Storage....Finally...!!!

[Marshy]

I agree it would be technically more efficient, but only if it would have enough flow. I would think it would take a long time for the boiler protection to open if it had 1000 gal of 120f water behind it. I think it would open a little, close and repeat for a long time. I don't really know for sure, it would be great to hear what jpelizza does and how it works for him.

He doesn't have any return protection.

 

[maple1]

I agree it would be technically more efficient, but only if it would have enough flow. I would think it would take a long time for the boiler protection to open if it had 1000 gal of 120f water behind it. I think it would open a little, close and repeat for a long time. I don't really know for sure, it would be great to hear what jpelizza does and how it works for him.

Mine opens a bit & stays there, no off/on effect.

If you knew what your boiler circ was pumping, you could figure it out. If you had 120 cold from storage, mixed 140 to boiler return, and 160 boiler supply, that would roughly correlate to 1/2 of boiler output going around the bypass and 1/2 going to storage. So if your boiler circ was pumping say 5gpm, that would be 2.5 gpm to storage - 400 minutes for one full lap, at which point your boiler return would go from mixed 140, to 160 not mixed. Which is quite a while. But that number is likely on the low side, maybe. Second lap would be half as long. Depends also if any of your heat is going to loads or not.

 

[Marshy]

It's not worth the mental aggravation to figure thst out because all the while the boiler outlet temp would be increasing as the fire rages inside it. It would be a dynamic change and before long your boiler jacket is 200F and the more heat is being sent to the tank.

 

[maple1]

I didn't find much at all worthwhile actually figuring out when I was doing my setup. I just winged most of it, seat of pants like, and ended up kinda lucky in some thing I did the way I did. Maybe not the recommended approach.

But I have found that boiler temp stays pretty constant thru the burn, by lap. First lap (2/3 of burn time?), it's 160-165 out, second lap maybe 185 out. dT stays pretty steady at either. Also my fire is burning out part way thru lap 2. It's good to have a 3 speed boiler pump, you can get the dT you want pretty easy, then it's set & forget.

 

[Fred61]

It's not worth the mental aggravation to figure thst out because all the while the boiler outlet temp would be increasing as the fire rages inside it. It would be a dynamic change and before long your boiler jacket is 200F and the more heat is being sent to the tank.

That's right and meanwhile the Danfoss is tempering the flow allowing more system water through as the temperature rises. Efficiency rises as the boiler heats up which allows the fire to burn hotter.