My geeked-out stove setup (so far)

I usually just ask questions, so now I'm posting the way I have my stove set up to share my ideas and maybe get a few back. The stove is a basement installed air tight Englander that takes side loaded 30" splits. No glass. In the top of the stove lies a manifold made of pipe. On the side there's a blower that forces air through the pipes and out the front. I've attached a metal duct to the blower to supply outside air. I installed thermocouples in the elbow nearest the thimble. One TC goes to a temperature controller that actuates the blower fan when the stove gets up to temp. The result is that I get hot air blowing while also creating a more positive pressure in the house. A second TC goes to a controller upstairs next to the TV. The controller displays my flue temps and illuminates a light if the temp rises above 900f and sounds an alarm if they rise over 1100F. A 3rd controller has two TCs wired in series, one upstairs and one in the basement. This controller turns on a fan to force hot air to the upstairs area (and cold air down) when the basement gets more than 20F hotter than the upstairs temp. I'm in the process of installing thermocouples in my flue next to the SS liner at the bottom, middle and top. These will allow me to see the temp gradient and also alarm if there's a fire. I have plans to install a differential pressure meter that will change things when the clothes dryer, kitchen vent etc. create a negative air pressure. Maybe some of these ideas will be useful to someone. I'm open to any critiques.

mellow said:

What are you using for your controller?

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Most any el cheapo temp controller will work if it has a cooling option. You want cooling because when the temp reaches a certain point the controller closes it's relay contacts thinking it turning on a cooler. They will stay closed until the temp is below whatever you tell it you want. I've played around with Yokogawa, Honeywell, Omron Eurotherm etc. and all were in the $200 range. Now I use $20 fleaBay controllers that are most often used by home beer brewers. My current fan controller is a MyPin TA4. For upstairs I use an Omega display because of the large digits. I can read it from across the room. I've been testing the Autonics controllers with good results. They're in the $60 range.

For those who are interested (and/or don't know) I'll try to explain how a temperature controller works. Sorry if I over simplify or leave out details. A temperature controller is a lot like a thermostat in that It tries to either increase or decrease temperature based on what it thinks the temperature is. It gets the temperature feedback from a thermocouple, RTD or other temperature sensor in order to make a decision. A simple controller will have a built in relay that, when in heating control, is actuated to turn on heating elements when the furnace is too cool. When the furnace reaches the temperature you tell it you want it opens the contacts. In cooling control it actuates the relay when it thinks the femp is too hot. Most controllers have a second "alarm" relay. You set the alarm temp separate from the target temp ("process variable" or "set point" in controller speak). I.e. For my blower control I have the set point at 200 degrees and the controller in cooling control. When the stove pipe thermocouple hits 200 the controller turns on the blower to "cool" the furnace. When the stove cools off it turns off the blower and pats itself on the back for a job well done. This keeps me from blowing cold outside air into the house at 5a.m. For my light and alarm I have the SP at 900 and the alarm value at 1200. At 900 it actuates the cooling relay which turns on a light upstairs. At 1200 it actuates the alarm relay to turn on a piezo buzzer. You can also program a controller's hysteresis. I.e. if the hysteresis is 5 and the setpoint is 900, the relay is on at 900 and off at 895. This prevents rapid cycling of the load. All this for $29.95 and free shipping! Some really cheap ($20) controllers only display in celsius. I have one of those controlling an attic fan for summer and another controlling a heat lamp for the dogs in winter. Anyway, I can get into more depth about controllers, data acquisition, automation etc. if anyone has nothing better to do than read feeble attempt at a tutorial. Don't even get me started on my BBQ smoker setup

WES999 said:

That IS pretty geeked-out, maybe post some pics or a vid.
My stove is geeked-out as well:

Wireless temp data logger, logs stove top temp and ambient room temp.
Auto air control, closes air when flue temp reaches 875
Auto blower control, turns on blower when stove top reaches 675
Sec air control.

View attachment 137078 View attachment 137079

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My stove has knobs for inlet air that I was going to replace with gears and a linear actuator. It would regulate the draft and also shut off the air if the stove over fired or the chimney started blazing. Your solution is MUCH nicer (sniff). Nice work. Most of my setup is torn apart while I line my flue. I'll post a few pics from last year when it was together. My stove is also in the basement, so aesthetics were/are not much of a concern. That's my excuse for sloppy wiring and I'm sticking to it.

begreen said:

1200 seems quite high. Have you tried lower settings?

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I hit 1000 a few times last year when it was record cold and the stove was cranking on coal. I set 1200 as the "get out of bed and do something right now" temp. It may very well be too high. I'm open to suggestions since my knowledge is limited.

The stove I was using when I hit those temps was an old circulator similar to US Stove BCAC. It was pretty much worn out and leaked air around the ash door. It was in the house when I moved in, so I used it for a couple of months then ditched it. Piping was 24ga. Rusted so also gone now.

Hmm... The house was built around 1960, but I just gutted it down to the studs and remodeled. New windows, insulation in all walls, etc. My thinking was that the outside air was not proportionally that much colder than the inside air as compared to the heated air from the stove, so I used outside air to aid the draft. I thought the positive air pressure would counter bathroom, kitchen and laundry vents. I was also fighting an oversize flue, which is now being corrected. Even with outside air the air temp from the stove is too hot to hold your hand in front of. Guess I need to rethink this... I also thought the duct work looked cool, so there's that...

I'm not arguing your point, but this is interesting. For the sake of debate I'll counter the logic. Based on the post above, the house exchanges all of it's air a few times an hour. I presume this exchange would involve cold outside air. Would forcing preheated air into the house, which in theory would reduce or eliminate cold air drafting, not tip the scale in the other direction? I'm genuinely interested in how this works.

BTW, I need to search OAK and ERV. That may answer my questions. I checked out the links. There goes my million dollar idea