Automation is an awesome thing

[jebatty]

I have used two approaches to measure efficiency involving weighed wood burns, using the figure of 6050 (or 6040) of available btu's per pound of wood at 20% MC and 400F stack temperature. I have calculated the total available btu's by weighing the wood in a burn and then by measuring the increase of temperature in a known quantity of water.

Alternatively, where I have been able to determine flow rate by differential pressure, and logging output and return temp delta-T, I also have calculated btu's to the system divided by btu's available in a known weight of wood to determine efficiency.

As to ewd's critiques, at times I have bristled a bit under my breath at his comments on some of my posts, but in the end I take them as learning opportunities to expand or challenge my understanding. It doesn't mean we will agree in the end, although we usually do, and I respect the comments of all who do their best to share knowledge so that we all come out ahead.

Today I traveled to Lamppa Manufacturing in Tower, MN, 150 miles from my home, and visited with Daryl Lamppa. Lamppa is the maker of the Kuma Vapor-Fire wood furnace. I will be posting soon regarding my visit, and I suspect some info from my visit may offer more perspective on efficiency.

 

[TCaldwell]

If I understand correctly, you have tuned your boiler and storage hydronics to maximize heat transfer, resulting in a greater delta and reduced flue temps. All important for comfort and effiency , made possible by the logging, interpretation and resultant action through nofo's control system. This is a great start, but to get a total system effiency, combustion needs to be looked at also, the water doesn't heat itself ! Using jim's wood weighing calculation is a good start to determine how good your wood is, average btu output and total btu output for a burn. Basically it all starts with the wood, if your boiler's combustion effiency is 60% the delta t is of lesser importance. But congratulations on the good work, there is something to be learned by all.

 

[PassionForFire&Water]

Interesting topic but way to much to read ... .
I am gone pass on this one

 

[George Webster]

George you may have said this, but I'm still not getting it. Your house demand is being managed and pretty constant via flow control, the controls manage the dT in storage so that energy also demand is nearly constant. So to keep everything in balance I'm presuming the controller is managing boiler output also so there isn't excess energy that needs a place to go. If the Vesta is also managing boiler output to keep everything in balance then I get it. This is assuming you like everyone else bought a boiler with reserve capacity. If the Vesta is optimizing boiler output to keep your dT goals and house demands then I get the wood saving. Good discussion and I still may not have it.

Vizsla, thanks for your comments. Bottom line is all I'm aiming for is more of the heat I generate going where I bought the boiler to put it. Tenman, Not to worry. I think I need to get my system diagram out there so we can talk in specifics, but yes, the Vesta is managing a lot of stuff, so I don't have to. I did buy a boiler with excess capacity which turns out to be part of the reason I went with a more sophisticated control system, since I could not run the boiler at an efficient burn rate and also absorb all the energy it was putting out. I sized my FPX to the tank to ensure that it could handle way more than the full output of the boiler, even when there is no other demand. Turns out, this was the right direction to head. For one thing, there wasn't a huge cost differential, so I opted on the side of caution. It's a lot easier to have to throttle things back, as is my case, than it is to compensate for an inability to transfer heat. Typically, under full boiler output, I'm only running my circulator at 35% until storage comes within 10% of being saturated (full charge). That gives me a lot of flexibility. None of this is simple when you get to the tuning phase. Let's keep this going, I think we can learn a lot from each other.

 

[maple1]

I think I can sum up my thinkings - keep boiler return temp as cool as possible (140 to avoid condensation issues) for as long as possible.

I do that by fully depleting storage, not trying to charge it to the max, and keeping my loading unit on low speed. Not quite the wiz-bang appeal as the full-gadget approach, but it works for me.

 

[Tennman]

Huh, didn't realize Nofo's product had made this big step into commercialization. Big congrats Nofo, no small feat starting a business, selling products, and keeping customers happy. So I take from your last post George that the Vesta DOES control the boiler fan or something about the boiler to regulate boiler output. Then it all makes sense and the universe is in balance since the Vesta matches btu output to balance demand and storage dT once you achieve your saturation goal. Fascinating system and big high five to Nofo.

 

[Nofossil]

Huh, didn't realize Nofo's product had made this big step into commercialization. Big congrats Nofo, no small feat starting a business, selling products, and keeping customers happy. So I take from your last post George that the Vesta DOES control the boiler fan or something about the boiler to regulate boiler output. Then it all makes sense and the universe is in balance since the Vesta matches btu output to balance demand and storage dT once you achieve your saturation goal. Fascinating system and big high five to Nofo.

Thanks. We have in fact gone commercial, but with a big emphasis on putting our customers in control of their own destiny. Our first big trade show is next week - 'Better Buildings By Design' in Burlington Vermont. I've been controlling boiler fan and circulators for quite a while now.

I think George is just managing the heat load on the boiler to match the boiler's output so that it stays in the sweet spot and doesn't idle, as well as maximizing storage stratification.

Huff here is another early adopter, and we have a few more customers who are forum related. This place has been a great resource for me - I've learned a lot, and just making sure I understand well enough to comment keeps me honest in a healthy way.

Check the live link in my sig - it should be working now.