Econoburn 150 - Ramp down fan speed for the night.

[eriesigtau]

Need some input here. I have a Econoburn 150 with 500gal pressurized storage. My routine is to start the boiler at 4PM when I get home from work and keep loading until I go to bed around 10PM. Most of the time, the system is up to temp and starts idling about the time I go to bed. The way I figure it, my wood is probably exhausted by midnight and then the fan blows on high speed for the next several hours until I leave for work and shut it off. Seems like a lot of wasted electricity and wear out on my fan. Does anyone have a proven solution? Is there anything built into the control that can do this? What would be really awesome is to reduce the fan speed to low for the entire night so the fire would last longer.

 

[ewdudley]

One improvement would be to add a thermal switch draft fan shutdown control. Guys have used mechanical snap-discs and electronic flue gas sensors in parallel with a keep-alive timer to shut the draft fan after the fire goes out:

https://www.hearth.com/talk/threads/end-of-burn-draft-fan-shutdown-control.73405/

To regulate the burn process to give a constant burn over a longer period of time look into electronic draft inlet regulation:

https://www.hearth.com/talk/threads/gassifier-draft-control.63286/page-3

http://www.allchinas.com/probe/

 

[NCFord]

I have a timer that I plan on using when I get my storage up. I can set the timer to be on all the time or anything up to 12 hours. My plan is to just
set it so that It goes off well after the fire goes out. With the timer I don't have to install anything else...very simple. I can get the timer specs if you
would like.

 

[eriesigtau]

ok, the way I see it, if you install a simple $5 timer from Walmart and install it in series with the fan power, I can have the fan shutoff at midnight and stay off until 4PM. Because only the fan power is cut, the circulator pump is still running, thus the boiler would not overheat. Once the circ temp drops below 150, it shuts off and the storage takes over. It would also be possible to snuff out the fire and maintain a coal bed for the next days fire. Right?

 

[ewdudley]

It would also be possible to snuff out the fire and maintain a coal bed for the next days fire. Right?

You can experiment with trying to set the timer to shut down before the fuel is all gone. It doesn't have to be very close, a little charcoal or a lot both work quite well for restarting the fire when you get home.

However, depending on the boiler and the strength of your natural draft you may find that the coals get enough air to turn to ash even with the draft fan turns off. Because of this problem I ended up with the draft control pictured above that shuts the draft inlet off completely when the draft fan shuts off.

 

[eriesigtau]

Ill give that a try. I'm a little surprised Econoburn has not built these functions into their controls. At least give me a button I can push when I want low fire for the remainder of the burn.

 

[eriesigtau]

Wow... my system works 10x better. I can now start the boiler at 4PM, run it till 10, turn the new blower switch off, and the circulator continues to pump until the boiler temp drop below the setpoint which is 150deg. The fire gets completely snuffed out and is ready for the next days fire up. Because I already have charcoalized wood, I can be gassifying within 10min! In the old days, that would take an hours or more! I'm still playing, but I'm think my wood consumption will drop off substantially. maybe 20-30% less? Awesome.

 

[goosegunner]

Wow... my system works 10x better. I can now start the boiler at 4PM, run it till 10, turn the new blower switch off, and the circulator continues to pump until the boiler temp drop below the setpoint which is 150deg. The fire gets completely snuffed out and is ready for the next days fire up. Because I already have charcoalized wood, I can be gassifying within 10min! In the old days, that would take an hours or more! I'm still playing, but I'm think my wood consumption will drop off substantially. maybe 20-30% less? Awesome.

I have been using a simple spring wound count down timer, it works well. With use I know how long it will run and leave charcoal.

Even without charcoal I can gasify in less than 10 minutes. If it was taking you hours or more I would guess that your wood is either too big, not dry enough or both.

With storage the other issue is having the pump run until temp drops to 150. It will mix your tank until the bottom reaches 150. I bumped my launch temp to 160 but it still circulates too long when the tank is charged to 185 on the bottom.

gg

 

[eriesigtau]

I installed one of those countdown timers in parallel with the toggle switch. That way I have a choice on which one Id like to use. Does come in handy on very cold nights when you would like the system to idle a little longer before the tank takes over. Not sure what you mean about the circ pump. Maybe Im not having that issue since I only store 500gal? From fire start to the time my 600gal system is up to 175 takes about 3 hours. Then it idles for 4-5 more hours, then the tank is on til the next day. Firewood wise, you are probably right.I usually just split a 8" log in 4's. Smaller logs get split in half, etc. I cut in the spring, and store in a dry location under roof. Half my firewood supply is slab wood as well. Theres a place here that cut it to length. It drys very quickly and burns hot. Cuts out a lot of work too. I cant justify cutting a year ahead because I dont have a place to store it all where i wouldnt have to relocate half of it for the next season. My wood is probably wetter than it should be but its not wet enough to creosote up the turbulators. Mixing it with dry slab is probably helping me.

 

[goosegunner]

I don't idle mine at all. It runs flat out until wood is gone leaving a little charcoal. Timer stops the fan. When the tank is hot it returns water to the boiler until the temp falls below the pump start temp, which is 160 on mine. The pump will circulate water from storage to boiler and back until it drops the boiler below 160 and stops the pump.

Controls aren't the best for running with storage. There really should be to set ups, idling or storage use.

gg