Outdoor Reset Control

Outdoor Reset Control

PostBy: kstills On: Sun Jan 15, 2012 9:00 am

These will be of limited use in a system where the boiler can produce condensate, right? Unless you use a secondary water supply?
kstills
 
Stoker Coal Boiler: WL 110
Stove/Furnace Make: Leisure Line

Re: Outdoor Reset Control

PostBy: homecomfort On: Sun Jan 15, 2012 10:43 am

all boilers will produce condensation if stack temp is too low. some can handle, some not,(steel) outdoor resets work great on oil and gas, you would need a primary -secondary loop system to use coal boiler. may not save alot of fuel, but will allow for more even heating.
homecomfort
 
Stove/Furnace Make: Franco-Belge,+ Penn Stove
Stove/Furnace Model: Normandie, + Chubby

Re: Outdoor Reset Control

PostBy: Sting On: Sun Jan 15, 2012 11:02 am

any ODR worth its salt has a min set/run potential
Sting
 
Other Heating: OBSO Lennox Pulse "Air Scorcher" burning NG


Re: Outdoor Reset Control

PostBy: vermontash On: Sun Jan 15, 2012 11:40 am

Take a look at the features on a Tekmar 256.I use this outdoor reset control on 4 of our stokers and I believe they dropped our coal consumption by 18-20%. You can program it to provide custom temperature algorythms based upon the actual building design parameters ( insulation, solar orientation, windows, etc,) vs outdoor temp. Right now its boiler target temp is 180 (outdoor temp now @ 12 degrees) but the target will drop as low as 135 degrees as the outdoor temp increases during the day. We have not experienced condensation in any of our applications as a result of the reset control.
vermontash
 
Stove/Furnace Make: efm 520 X2
Stove/Furnace Model: (3) AA 260

Re: Outdoor Reset Control

PostBy: kstills On: Sun Jan 15, 2012 12:41 pm

vermontash wrote:Take a look at the features on a Tekmar 256.I use this outdoor reset control on 4 of our stokers and I believe they dropped our coal consumption by 18-20%. You can program it to provide custom temperature algorythms based upon the actual building design parameters ( insulation, solar orientation, windows, etc,) vs outdoor temp. Right now its boiler target temp is 180 (outdoor temp now @ 12 degrees) but the target will drop as low as 135 degrees as the outdoor temp increases during the day. We have not experienced condensation in any of our applications as a result of the reset control.


I guess this is what I don't understand about these things. You're running a low of 135f on the boiler temp? That would kill me right now, because a call for heat would drop me way below 130f.

I can mitigate that somewhat by using a larger water mass, but that gets back to a primary-secondary loop setup, I think.
kstills
 
Stoker Coal Boiler: WL 110
Stove/Furnace Make: Leisure Line

Re: Outdoor Reset Control

PostBy: kstills On: Sun Jan 15, 2012 12:42 pm

Sting wrote:any ODR worth its salt has a min set/run potential


Careful, I bought those books by Holohan.

You start answering now, you may never get a chance to stop. :)
kstills
 
Stoker Coal Boiler: WL 110
Stove/Furnace Make: Leisure Line

Re: Outdoor Reset Control

PostBy: Rob R. On: Sun Jan 15, 2012 12:47 pm

kstills wrote:You're running a low of 135f on the boiler temp? That would kill me right now, because a call for heat would drop me way below 130f.


That is because of the way your system is setup. 4 way mixing valves, primary/secondary, injection pumping...lots of ways to avoid condensing boiler temperatures. It can be as simple as a simple aquastat to shutoff the circualtor at a set temperature.

kstills wrote:Careful, I bought those books by Holohan.


Excellent. Do your homework. :)
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Coal Size/Type: Lehigh Rice
Other Heating: Dad's 1953 EFM Highboy

Re: Outdoor Reset Control

PostBy: kstills On: Sun Jan 15, 2012 3:01 pm

Rob R. wrote:
kstills wrote:You're running a low of 135f on the boiler temp? That would kill me right now, because a call for heat would drop me way below 130f.


That is because of the way your system is setup. 4 way mixing valves, primary/secondary, injection pumping...lots of ways to avoid condensing boiler temperatures. It can be as simple as a simple aquastat to shutoff the circualtor at a set temperature.

kstills wrote:Careful, I bought those books by Holohan.


Excellent. Do your homework. :)


This is the 'homework' part. I'm getting some ideas, just running them by folks here to see how practical they'll end up being. :)
kstills
 
Stoker Coal Boiler: WL 110
Stove/Furnace Make: Leisure Line

Re: Outdoor Reset Control

PostBy: Scottscoaled On: Sun Jan 15, 2012 7:07 pm

kstills wrote:
vermontash wrote:Take a look at the features on a Tekmar 256.I use this outdoor reset control on 4 of our stokers and I believe they dropped our coal consumption by 18-20%. You can program it to provide custom temperature algorythms based upon the actual building design parameters ( insulation, solar orientation, windows, etc,) vs outdoor temp. Right now its boiler target temp is 180 (outdoor temp now @ 12 degrees) but the target will drop as low as 135 degrees as the outdoor temp increases during the day. We have not experienced condensation in any of our applications as a result of the reset control.


I guess this is what I don't understand about these things. You're running a low of 135f on the boiler temp? That would kill me right now, because a call for heat would drop me way below 130f.

I can mitigate that somewhat by using a larger water mass, but that gets back to a primary-secondary loop setup, I think.



I run a Tekmar also. My minimun is set for 140. That is the boiler temperature minimum when the outside temperature is at 70. I just had to adjust the reset curve to a lower setting because the boiler temp was getting too high for my pex. This morning when the outside temp was around zero, the boiler temp was going over 190, since I turned down the curve, the temp is down to 180. After reading your post, it seems like you are under the impression that the boiler temp starts at 135 on a cold day like this. The fact is that the outdoor reset module adjusts the minimum temperature of the boiler to colder when it's warm outside and hotter when it's colder outside. :)
Scottscoaled
 
Stoker Coal Boiler: EFM 520x3, 700 Van Wert 800
Hot Air Coal Stoker Furnace: EFM 150, Keystoker 150
Coal Size/Type: Lots of buck

Re: Outdoor Reset Control

PostBy: kstills On: Sun Jan 15, 2012 7:37 pm

Scottscoaled wrote:
kstills wrote:
vermontash wrote:Take a look at the features on a Tekmar 256.I use this outdoor reset control on 4 of our stokers and I believe they dropped our coal consumption by 18-20%. You can program it to provide custom temperature algorythms based upon the actual building design parameters ( insulation, solar orientation, windows, etc,) vs outdoor temp. Right now its boiler target temp is 180 (outdoor temp now @ 12 degrees) but the target will drop as low as 135 degrees as the outdoor temp increases during the day. We have not experienced condensation in any of our applications as a result of the reset control.


I guess this is what I don't understand about these things. You're running a low of 135f on the boiler temp? That would kill me right now, because a call for heat would drop me way below 130f.

I can mitigate that somewhat by using a larger water mass, but that gets back to a primary-secondary loop setup, I think.



I run a Tekmar also. My minimun is set for 140. That is the boiler temperature minimum when the outside temperature is at 70. I just had to adjust the reset curve to a lower setting because the boiler temp was getting too high for my pex. This morning when the outside temp was around zero, the boiler temp was going over 190, since I turned down the curve, the temp is down to 180. After reading your post, it seems like you are under the impression that the boiler temp starts at 135 on a cold day like this. The fact is that the outdoor reset module adjusts the minimum temperature of the boiler to colder when it's warm outside and hotter when it's colder outside. :)



My main concern with a coal boiler was that the lower temps on warm days would result in condensation inside the boiler. However, it appears coal boilers have a very low probability of having water condense inside when they are running, regardless of temp (given that it's actually burning :)). I asked that question in another thread, so a reset actually makes sense to me now.
kstills
 
Stoker Coal Boiler: WL 110
Stove/Furnace Make: Leisure Line

Re: Outdoor Reset Control

PostBy: Sting On: Sun Jan 15, 2012 9:30 pm

Good

now who said anything about stopping???

For that matter who said anything about starting
Sting
 
Other Heating: OBSO Lennox Pulse "Air Scorcher" burning NG