Pressure switch to help summer outfires.

Pressure switch to help summer outfires.

PostBy: plumber On: Sat Jan 12, 2013 7:51 pm

As I'm still on the fence of running year round. (I want to shut down, wife wants me to keep it going.)
I'm thinking about those hot humid days last summer when I'd get into a cold shower and have to re light the boiler because I lost draft.
While farting around on the net, I was looking at some hvac controls and thought of this.
If I cut in a tee on the line that goes to my manometer and hook it up to a pressure switch then splice in the wireing to TT. I would set the switch to -.01 or -.02 WC. Then if my draft fell below that point, the pressure switch would make the stoker run making fire, heating up the chimney, restoring my draft.

This is the switch. http://www.comfortgurus.com/product_inf ... ts_id/9265

Any thoughts?
plumber
 
Stoker Coal Boiler: EFM 350

Re: Pressure switch to help summer outfires.

PostBy: Dennis On: Sat Jan 12, 2013 7:56 pm

What happens when boiler is up to temp and your pressure switch activates the boiler to turn on,you will eventually be over firing and dumping.As long as you have some sort of load to lower the boiler temps it bound to happen
Dennis
 
Hand Fed Coal Boiler: AHS/WOC55-multi-fuel/wood,oil,coal
Coal Size/Type: Anthracite/stove size

Re: Pressure switch to help summer outfires.

PostBy: Lightning On: Sat Jan 12, 2013 9:03 pm

plumber wrote:If I cut in a tee on the line that goes to my manometer and hook it up to a pressure switch then splice in the wireing to TT. I would set the switch to -.01 or -.02 WC. Then if my draft fell below that point, the pressure switch would make the stoker run making fire, heating up the chimney, restoring my draft.


Yeah... Thats awesome :) I would like that kind of insurance too.. I would have it turn my draft inducer on if it fell below .01" WC I wonder if its really that reliable and accurate....
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut Size / White Ash


Re: Pressure switch to help summer outfires.

PostBy: plumber On: Sat Jan 12, 2013 9:04 pm

Dennis wrote:What happens when boiler is up to temp and your pressure switch activates the boiler to turn on,you will eventually be over firing and dumping.As long as you have some sort of load to lower the boiler temps it bound to happen


I could wire it to call for my DHW.
plumber
 
Stoker Coal Boiler: EFM 350

Re: Pressure switch to help summer outfires.

PostBy: Lightning On: Sat Jan 12, 2013 9:05 pm

Trouble is.... What happens when it senses draft is restored.. It would immediately shut off?? So it would constantly toggle on and off, wouldn't it??
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut Size / White Ash

Re: Pressure switch to help summer outfires.

PostBy: Rigar On: Sat Jan 12, 2013 9:06 pm

interesting idea... but would handle your stack temps? ..
... or is that why you're going into the manometer with a TEE...?
... just a thought.... but I monitor my stack temps constantly..
you could probably utilize what I have... but in reverse
a simple snap switch...( mine is open on rise) prevents hi stack temperatures.
so what this does it shuts dowwn the stoker feed... until the exhaust gases cool... Then the switch closes.. allowing the stoker to run again

you need 1 that closed on temperature drop
... I'm just thinking out loud
Rigar
 
Hot Air Coal Stoker Furnace: Keystoker A 150
Coal Size/Type: anthracite rice
Stove/Furnace Make: Keystoker
Stove/Furnace Model: A 150 warm air furnace

Re: Pressure switch to help summer outfires.

PostBy: Rigar On: Sat Jan 12, 2013 9:20 pm

Cont....
wouldn't that be a thermostat ??!....lol :D
... sometimes I need to think to myself. BEFORE I think out loud!

maybe you could use a dual or triple acting boiler control( limit switch)
Rigar
 
Hot Air Coal Stoker Furnace: Keystoker A 150
Coal Size/Type: anthracite rice
Stove/Furnace Make: Keystoker
Stove/Furnace Model: A 150 warm air furnace

Re: Pressure switch to help summer outfires.

PostBy: plumber On: Sat Jan 12, 2013 9:36 pm

I've watched my boiler for a good time in the summer. On the 90+ days I completely lose draft. If I jump something out and run the stoker 4-5 minutes the draft goes up to .03-.04. It stays above .02 for a few hours. So I don't think it would cycle. As far as the switch handling stack temps that's exactly why I want to tie in to the manometer line.
plumber
 
Stoker Coal Boiler: EFM 350

Re: Pressure switch to help summer outfires.

PostBy: Rigar On: Sat Jan 12, 2013 10:08 pm

Plumber
... I thought stack temp might be more indicative...especially in summer...just sayin.
Rigar
 
Hot Air Coal Stoker Furnace: Keystoker A 150
Coal Size/Type: anthracite rice
Stove/Furnace Make: Keystoker
Stove/Furnace Model: A 150 warm air furnace

Re: Pressure switch to help summer outfires.

PostBy: Lightning On: Sun Jan 13, 2013 6:26 am

Rigar wrote:Plumber
... I thought stack temp might be more indicative...especially in summer...just sayin.

When my pipe falls below 130 degrees (as measured 12 inches from the outlet, top side of the pipe) my BBQ alarm lets me know. Its at that temperature, that I've seen the draft fail.. Strange thing is, sometimes I can choke it down hard for a low and slow burn and when the pipe gets to 130 degrees, it can still have a healthy draft. So as far as draft failure is concerned, pipe temp doesn't always justify it. One of these pressure switches would be a great solution provided it didn't oscillate on and off as it noticed draft was good or not. It would need to trip a timer for a combustion blower or draft inducer to come on for a specific time period, say 15 minutes or so. Right? or am I missing something?
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut Size / White Ash

Re: Pressure switch to help summer outfires.

PostBy: Rob R. On: Sun Jan 13, 2013 8:43 am

I think a draft inducer would be a more reliable solution.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: Pressure switch to help summer outfires.

PostBy: plumber On: Sun Jan 13, 2013 9:04 am

Rob R. wrote:I think a draft inducer would be a more reliable solution.


It would, but I don't have the room to make it work. As well, It's not legal to put positive pressure into a chimney.
plumber
 
Stoker Coal Boiler: EFM 350

Re: Pressure switch to help summer outfires.

PostBy: Rigar On: Sun Jan 13, 2013 9:37 am

Lightning wrote:
Rigar wrote:Plumber
... I thought stack temp might be more indicative...especially in summer...just sayin.

When my pipe falls below 130 degrees (as measured 12 inches from the outlet, top side of the pipe) my BBQ alarm lets me know. Its at that temperature, that I've seen the draft fail.. Strange thing is, sometimes I can choke it down hard for a low and slow burn and when the pipe gets to 130 degrees, it can still have a healthy draft. So as far as draft failure is concerned, pipe temp doesn't always justify it. One of these pressure switches would be a great solution provided it didn't oscillate on and off as it noticed draft was good or not. It would need to trip a timer for a combustion blower or draft inducer to come on for a specific time period, say 15 minutes or so. Right? or am I missing something?


....in the summer ?
Rigar
 
Hot Air Coal Stoker Furnace: Keystoker A 150
Coal Size/Type: anthracite rice
Stove/Furnace Make: Keystoker
Stove/Furnace Model: A 150 warm air furnace

Re: Pressure switch to help summer outfires.

PostBy: Rigar On: Sun Jan 13, 2013 9:39 am

plumber wrote:
Rob R. wrote:I think a draft inducer would be a more reliable solution.


It would, but I don't have the room to make it work. As well, It's not legal to put positive pressure into a chimney.



... I've got a dumb question... :o :?:

....do you have a baro installed ?
Rigar
 
Hot Air Coal Stoker Furnace: Keystoker A 150
Coal Size/Type: anthracite rice
Stove/Furnace Make: Keystoker
Stove/Furnace Model: A 150 warm air furnace

Re: Pressure switch to help summer outfires.

PostBy: plumber On: Sun Jan 13, 2013 9:47 am

Yes I do have a baro installed.
plumber
 
Stoker Coal Boiler: EFM 350