Mission Accomplished

[Tennman]

I was gone for almost 3 weeks. While gone my wife was sick. The Windhager operated perfectly. Didn't burn a drop of propane. She would not have been physically able to keep the BioMass going. Seeing signs of Spring here. Best wishes to all.

 

[velvetfoot]

Eggzellent! I forget...what is your bulk storage setup?

 

[Tennman]

1000 gals in 2 vertical tanks. Fed by either the Windhager or BioMass isolated by check valves. The Windhager is controlled via the external demand terminals using a A419. I'll be adding either a Tekmar or Honeywell T775 controller with outside temp reset. Like the backlit T775.

 

[velvetfoot]

I'm sorry, I meant the pellet bulk storage. Even with warmish winter weather, I don't think you could go three weeks with just the onboard hopper.

I have the $129 T775 that does two proportional outputs, as yet uninstalled. Once you add the reset, it comes to more money, but I imagine, less than the Tekmar, who seem to get a lot for all their products.

 

[JohnDolz]

1000 gals in 2 vertical tanks. Fed by either the Windhager or BioMass isolated by check valves. The Windhager is controlled via the external demand terminals using a A419. I'll be adding either a Tekmar or Honeywell T775 controller with outside temp reset. Like the backlit T775.

Will you be using the T775 to control water temp being delivered to your emitters?

 

[Tennman]

Ahhh... VF, I'm using a plastic chemical hopper that's about 4'x4'x4' which I added sheet metal sloping sides to form a trough to the suction pickup. The boiler hopper is automatically refilled from the hopper. Because of our latitude the rather smallish hopper actually is working fine. It's about the same volume as a one ton pallet of pellets. My original plan was to fill 6-8 chemical hoppers from the pellet manufacturer and rotate hoppers. But really loading the one hopper as needed is not burdensome at all. Only during the worst of Jan were we using as many as 160-200 lbs of pellets/day (4-5 bags). I'm able to place a pallet of pellets right beside the hopper for easy refilling. I must confess to now being spoiled vs the time demands of feeding the BioMass.

John, our system has one emitter.... The WTA HX in our ductwork. Our home is a very old two story and adding radiant for our relatively short heating season is impractical. The A419 or its T775 replacement only manages storage temp. At the moment the 419's TC controlling the mid-tank temp between 130-150F resulting in about 175F top to 140F bottom storage temps. It's really nice because we essentially only heat the downstairs with heat rising to keep the upstairs a comfortable 5-6F degrees cooler for sleeping.

My goal with the 775 is to reduce storage temps as a function of outside temps to reduce pellet consumption. When outside temps are warmer (50-60F days are common even in Jan) we can get by with reduced temp water to the HX. Not so when it gets in the 20-30's.

 

[JohnDolz]

Ahhh... VF, I'm using a plastic chemical hopper that's about 4'x4'x4' which I added sheet metal sloping sides to form a trough to the suction pickup. The boiler hopper is automatically refilled from the hopper. Because of our latitude the rather smallish hopper actually is working fine. It's about the same volume as a one ton pallet of pellets. My original plan was to fill 6-8 chemical hoppers from the pellet manufacturer and rotate hoppers. But really loading the one hopper as needed is not burdensome at all. Only during the worst of Jan were we using as many as 160-200 lbs of pellets/day (4-5 bags). I'm able to place a pallet of pellets right beside the hopper for easy refilling. I must confess to now being spoiled vs the time demands of feeding the BioMass.

John, our system has one emitter.... The WTA HX in our ductwork. Our home is a very old two story and adding radiant for our relatively short heating season is impractical. The A419 or its T775 replacement only manages storage temp. At the moment the 419's TC controlling the mid-tank temp between 130-150F resulting in about 175F top to 140F bottom storage temps. It's really nice because we essentially only heat the downstairs with heat rising to keep the upstairs a comfortable 5-6F degrees cooler for sleeping.

My goal with the 775 is to reduce storage temps as a function of outside temps to reduce pellet consumption. When outside temps are warmer (50-60F days are common even in Jan) we can get by with reduced temp water to the HX. Not so when it gets in the 20-30's.

Thanks, if you are motivated I would love a bit of an education. I am not very familiar with pellet boilers or what 429 TC's do, how would you leverage the Outdoor reset? Would it change the target temp of the boiler causing it to modulate, burn a lower flame and therefore save pellets? My propane condensing/modulating boiler functions pretty much that way but right now it is not tied to storage (I may actually do that since I could reduce the "firing cycle" to 1x day or maybe less.

I am no expert on heat exchangers for a whole house but I do have a Modine Hydronic heater in my basement and a 350 sqft addition over an unheated garage with almost 4 exposed walls (basically lots of heat loss) which is heated with a toe/kick heater (WAY underpowered for the need). Bottom line is that those are heat exchangers and I am running extremely low temp water through them and they get the job done. Of course they need to run a lot more than if you had higher temp water running through them and the additional electrical cost may offset any heating savings but I am guessing you can go much lower that you think. Right now it is 32 degrees outside and my flow temp is 104F. I keep my house at 72 +/- (slant fin baseboard) but my basement I keep at 65, honestly don't like the noise of the Modine heater running so much. I would guess you would need somewhat hotter water than this but if you are OK with letting the blower go I think you will be surprised how low you can go.

 

[Tennman]

John, My first disclaimer is that I'm not a controls guy. But I do understand if you store water that is much hotter than is necessary for the current demand the rate of wasted btus is higher than necessary. By wasted I mean losses due to not having perfect insulation everywhere because stored btus like to sneak away. At the moment our A419 controller manages mid-tank temp between 130-150F which for 30F days gives reasonable fan on-times in the house. When we send 130-140F water to our HX on a cold day, obviously the fan on-time gets long. So an indirect way of monitoring/controlling more optimum storage temps is by making our fan on-time more consistent better matching the outside air temp. Rather than having 165F top tank temp for a 45-50F day, we could easily get by with 140-150F top tank temp. This should extend the times for the pellet boiler to recharge storage on those days we have shoulder season weather, which for us is often (like today). The Tekmar 256 or Honeywell T775 will allow me to experiment with a shifting mid-tank control range as a function of outside air. Apparently this is routinely done with sophisticated radiant systems, so why not a forced air system to reduce fan and boiler on-time.

We're rapidly approaching the end of our heating season so probably won't make this change until Sept or Oct. No idea if that answers your question but at least it allows folks to throw darts at my logic.

 

[JohnDolz]

John, My first disclaimer is that I'm not a controls guy. But I do understand if you store water that is much hotter than is necessary for the current demand the rate of wasted btus is higher than necessary. By wasted I mean losses due to not having perfect insulation everywhere because stored btus like to sneak away. At the moment our A419 controller manages mid-tank temp between 130-150F which for 30F days gives reasonable fan on-times in the house. When we send 130-140F water to our HX on a cold day, obviously the fan on-time gets long. So an indirect way of monitoring/controlling more optimum storage temps is by making our fan on-time more consistent better matching the outside air temp. Rather than having 165F top tank temp for a 45-50F day, we could easily get by with 140-150F top tank temp. This should extend the times for the pellet boiler to recharge storage on those days we have shoulder season weather, which for us is often (like today). The Tekmar 256 or Honeywell T775 will allow me to experiment with a shifting mid-tank control range as a function of outside air. Apparently this is routinely done with sophisticated radiant systems, so why not a forced air system to reduce fan and boiler on-time.

We're rapidly approaching the end of our heating season so probably won't make this change until Sept or Oct. No idea if that answers your question but at least it allows folks to throw darts at my logic.

Thanks for the info, I think I made my own disclaimer somewhere - I barely know what I know. As I mentioned I am not very familiar with pellet boilers, only that the approach is different from a gasifier. Can you tell me how the controller controls mid-tank temps and are you pulling supply from mid-tank? In my world of gasification I run the boiler all out (most efficient) and bring the tanks up as high in temp as possible. I don't worry about the lost BTU's as they are being lost into the house and boiler efficiency makes up for it (I hope). Then I pull hot water from the top of the tank tank and mix it with return water to get the ideal flow temperature based on the outdoor reset. I get the sense that this is what you are doing with your midtank controller but I am not quite sure how it is done. In my world, by using minimal amounts of hot water from the top of the tank I get better "gas mileage" out of the stored BTU's. I understand that in the pellet world this benefit may be more than offset by the efficiency gained heating to lower water temps. Not sure if any of that makes sense or if I have now confused the 2 of us.

I'm sorry, I meant the pellet bulk storage. Even with warmish winter weather, I don't think you could go three weeks with just the onboard hopper.

I have the $129 T775 that does two proportional outputs, as yet uninstalled. Once you add the reset, it comes to more money, but I imagine, less than the Tekmar, who seem to get a lot for all their products.

Karl - see I need a trip up your way to get my pellet boiler fundamentals!

 

[Tennman]

John, The Windhager was just added to our existing gasification boiler/storage system. Our BioMass is essentially hooked up just like your Effecta. In fact I bought the Laddomat 21-100 and many other components to get storage working before Brian passed away. So we have either the BioMass wood gasser OR the pellet boiler charging storage. So charging storage and pulling for demand is just like yours. What I don't need to do is dump all the energy from a load of wood somewhere. The BioMass has to run until the wood is expended. Not so with the pellet. It just stops burning pellets when the A419 controller says its satisfied. Which in our case is when the middle of storage reaches 150F. The pellet provides 178F water to storage, but since it can be turned on and of (unlike wood) I'm choosing to charge our storage to about half energy capacity. The BioMass can go into idle is there's no place to put the btus, but that causes LOTS of other problems. Really, I'm operating the pellet boiler as if it was an oil, propane, or whatever boiler. Just that we happen to have 1000 gal of storage which allows us to control the frequency and duration of the Windhager's burns. Not a great picture, but you can see the side of the BioMass 60 on the left side of our system. What you can't see is a large pellet hopper on the right of the Windhager where the bulk pellets are stored. The Windhager automatically refills the boiler's hopper from the bulk storage hopper. Now we can burn the blow down from our land or be lazy and burn pellets (which i love). Hope that helps.

 

[JohnDolz]

John, The Windhager was just added to our existing gasification boiler/storage system. Our BioMass is essentially hooked up just like your Effecta. In fact I bought the Laddomat 21-100 and many other components to get storage working before Brian passed away. So we have either the BioMass wood gasser OR the pellet boiler charging storage. So charging storage and pulling for demand is just like yours. What I don't need to do is dump all the energy from a load of wood somewhere. The BioMass has to run until the wood is expended. Not so with the pellet. It just stops burning pellets when the A419 controller says its satisfied. Which in our case is when the middle of storage reaches 150F. The pellet provides 178F water to storage, but since it can be turned on and of (unlike wood) I'm choosing to charge our storage to about half energy capacity. The BioMass can go into idle is there's no place to put the btus, but that causes LOTS of other problems. Really, I'm operating the pellet boiler as if it was an oil, propane, or whatever boiler. Just that we happen to have 1000 gal of storage which allows us to control the frequency and duration of the Windhager's burns. Not a great picture, but you can see the side of the BioMass 60 on the left side of our system. What you can't see is a large pellet hopper on the right of the Windhager where the bulk pellets are stored. The Windhager automatically refills the boiler's hopper from the bulk storage hopper. Now we can burn the blow down from our land or be lazy and burn pellets (which i love). Hope that helps.

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Thanks for the education, I think I got it now. I was reading about the T775 and I believe it also allows you to use it to target flow (Design_ temp. I know Brian did not really believe in the value of using low flow temperature water but I certainly do. The maximum value seems to come in the 30 - 50 degree days, where my storage last MUCH longer than it used to. Not sure if you want to undertake this project but it would allow you to get better "gas mileage" out of your storage no matter if you use wood or pellet. The question I can't answer is how low you can go with a heat exchanger, how noisy/annoying it is to have the blower going much more often and what impact that will have an your electric bill.

 

[velvetfoot]

Again, beautiful install!

 

[Tennman]

Thanks VF