My geeked-out stove setup (so far)

[AtomicDog]

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]

What are you using for your controller?

 

[Chuck the Canuck]

That sounds freakin awesome! I've played around a bit with a few thermocouples and a datalogger, but you have most definitely taken it to the next level. I love it!

Cheers,
Keith

 

[Treacherous]

Subscribing to this thread...

 

[WES999]

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.

 

[AtomicDog]

What are you using for your controller?

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.

 

[AtomicDog]

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

 

[begreen]

1200 seems quite high. Have you tried lower settings?

 

[AtomicDog]

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

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.

 

[AtomicDog]

1200 seems quite high. Have you tried lower settings?

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.

 

[KindredSpiritzz]

I been thinking about hooking up a security camera on the roof pointed at my chimney so i can monitor whats going on without having to go outside. I see Menards has an infrared set on sale for $150. Be nice to monitor the smoke output and watch for chimney fires without having to stand in the snow.

 

[begreen]

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.

Is the piping heavy duty? Continuous service at 1000F is pushing the limit. That seems like a huge amount of waste heat going up the chimney. The stove sounds very inefficient as a coal burner.

 

[AtomicDog]

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.

 

[begreen]

Good that it is all gone now. Got the details in the other thread.

 

[Treacherous]

Not suggesting it is a good thing...but you can probably get away with continuous 1000°F with ICC.

(broken link removed to http://www.icc-rsf.com/en/technical-information-ultrablack-chimney)

"Max Continuous 650°C (1200°F)"

 

[jharkin]

Why the outside air for your blower manifold? Unless your house is super new its probably changing all the inside air a few times an hour through natural leakage already.... Adding that blower is just making the stove work harder and burn more fuel to keep the house warm.

If the place is tight and you need the combustion air use an OAK to the stoves air inlet.

 

[Bluezx636]

I been thinking about hooking up a security camera on the roof pointed at my chimney so i can monitor whats going on without having to go outside. I see Menards has an infrared set on sale for $150. Be nice to monitor the smoke output and watch for chimney fires without having to stand in the snow.

Ha, I have been wanting to do the same... Been looking to monitor whole outside of house and would be a good way to see how clean I'm burning.

 

[AtomicDog]

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...

 

[jharkin]

Well, if you know the CFM of that blower and have a rough idea of the heat load of the house we could do the math.

I looked it up and it takes 0.172 BTU to heat one cubic foot of air 1F.

So lets say that blower is only as strong as a bath fan (say 120CFM) and its 32F outside and you want to get 70F inside

120 x (70-32) x 0.172 = 784 BTU/hr

Doesn't sound like much, but consider that this is over and above the natural heat loss of the building, since you are forcing this ventilation. That hourly rate adds up to about 19k BTU per day. The figure Ive seen used is that very dry wood makes 8300 BTU/lb but unless you have a super efficient stove consider half of that goes up the flue. So divide 19k by 4000 or so, you are burning an extra 5lb of wood per day to make up losses from bringing in cold air.

5lb per day over a 6 month heating season is an extra 900 lb of wood you had to haul inside. Approximately one extra face cord. If you have a strong blower like 200 or 500 CFM you are talking even more.


I can see the fun of geeking this out... but if its ultimate efficiency you are going for I'd do an OAK right to the stoves combustion air inlet and install an ERV to get the makup air the house needs and compensate for all those exhausts.

 

[AtomicDog]

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.

 

[mellow]

If we have any newbies looking at this thread and don't want all the hassle but want an alarm check this out, it works great, I am on my 3rd season with it: http://www.auberins.com/index.php?main_page=product_info&cPath=17&products_id=292

I just noticed Auber now has wireless sensors if you wanted to place one in a different spot: http://www.auberins.com/index.php?main_page=product_info&cPath=17&products_id=441

Also another option is if you want the control but want a package setup for your stove check out: (broken link removed to http://inveninc.com/faq/)

 

[AtomicDog]

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

 

[BrotherBart]

If we have any newbies looking at this thread and don't want all the hassle but want an alarm check this out, it works great, I am on my 3rd season with it: http://www.auberins.com/index.php?main_page=product_info&cPath=17&products_id=292

Thanks mellow. I ordered one with the magnetic tc today for the 30-NC. Been thinking about cobbling one together but this looks like what I want.

 

[mellow]

You will love it BB, set the Max at say 900 and the alarm goes off, it will wake me up from a dead sleep upstairs from just the base unit which is downstairs, I did not get the external buzzer. It has saved my butt a few times in the middle of the night when the stove decides to go nuclear due to wind or some other reason (air leak in ashpan).

Not to mention being able to see the temp from across the room as an added bonus.

 

[mellow]

forum freaked out and posted twice