Low pressure weather system and out fires?

Low pressure weather system and out fires?

PostBy: Kungur On: Mon Sep 02, 2013 7:45 am

This past month I have had more out fires than the past 2 Summers combined. It seems that we are having some long spells of humid weather, low pressure system. And this is when I have a out fire.
My guess is the low pressure "kills" the draft.
Anyone else experiencing this?
Kungur
 
Stove/Furnace Make: Keystoker
Stove/Furnace Model: K-2

Re: Low pressure weather system and out fires?

PostBy: Wiz On: Mon Sep 02, 2013 8:17 am

Only time I was having issues with out fires is during several days of high humid days. Had to add pins to timer and open secondary blower wide open. Getting more unburnt coal during humid days too. Cooler weather is coming ;)
Wiz
 
Stoker Coal Boiler: Keystoker Ka 6
Coal Size/Type: Casey Junk Coal :(

Re: Low pressure weather system and out fires?

PostBy: Lightning On: Mon Sep 02, 2013 11:08 am

Kungur wrote:This past month I have had more out fires than the past 2 Summers combined. It seems that we are having some long spells of humid weather, low pressure system. And this is when I have a out fire.
My guess is the low pressure "kills" the draft.
Anyone else experiencing this?


Low and high pressure systems influence draft, not because of their "pressure" per say but because of other factors such as temperature and humidity. Probably more temperature than the other variables.

Chimney draft is a natural occurrence based on differences between the air temperature outside and the temperature of the flue gases. As temperature rises outside the gap closes between these two variables and draft decreases. But I'm sure you know this part :D

It would make sense that atmospheric pressure influences IF pressure in the house remained constant. But we know this can't be the case since opening doors and windows would keep inside and outside pressure equal.

Hypothetically speaking though if you could keep pressure in the house constant, a low pressure weather system would actually increase draft since there would be a higher pressure in the house. And we know high pressure always flows towards a low pressure.
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix


Re: Low pressure weather system and out fires?

PostBy: Rob R. On: Mon Sep 02, 2013 12:19 pm

Kungur wrote:My guess is the low pressure "kills" the draft.


Yes. Hot & humid days are draft killers. Worse yet is when you have a cool night and it quickly gets hot in the morning...the chimney may be cooler than the outside temperature and it will sometimes reverse.

You may have to increase the timer duration on your Ka-2.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: Low pressure weather system and out fires?

PostBy: Lightning On: Mon Sep 02, 2013 1:34 pm

Pardon my confusion partner but you answered his question with yes but then went on to demonstrate that temp and humidity influence drafting. Are you saying that low pressure areas are associated with warmth and humidity? I would agree with that :D
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Low pressure weather system and out fires?

PostBy: Rob R. On: Mon Sep 02, 2013 1:51 pm

Low pressure, heat, and humidity...any combination of those will reduce draft or at least make the boiler operator uncomfortable. :P
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: Low pressure weather system and out fires?

PostBy: steveyrock On: Mon Sep 16, 2013 7:27 am

I was having the same draft issues on very hot still days until I introduced outside air directly into the combustion fan.The house was closed up tight with the air conditioning running and that would reduce my draft and I could see it on the manometer.

I ran two inch PVC to the outside of the basement with a 90 elbow turned down at the outside end to keep rain out.There is a mesh screen in front to keep bugs ect out.I then put a 4inch to 2inch PVC reducer right up against the squirrel cage intake of the combustion fan.I didn't glue any of the fittings so it easily comes apart when needed.This completely stopped any hot day draft issues and I haven't had a CO alarm go off since.I run the outside piped air all year long because that combustion fan is going to pull air in any crack avialable and exuast it out the chimney.
steveyrock
 

Re: Low pressure weather system and out fires?

PostBy: Lightning On: Mon Sep 16, 2013 7:41 am

Well done partner :)
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Low pressure weather system and out fires?

PostBy: Rob R. On: Mon Sep 16, 2013 9:09 am

I did something similar with 4" PVC, but I just ran a "drop" down to about 12" off the floor in a far corner of the basement. It is amazing how much air gets pulled through it when the chimney is pulling hard.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: Low pressure weather system and out fires?

PostBy: steveyrock On: Mon Sep 16, 2013 11:44 am

Yes Rob, when I put my hand over my pipe outside and can feel the suction that little fan produces. I wonder how many times a day it would exchange the entire house air if it was not able to get it directly from the pipe. Imagine all the cold air it would be pulling in to the house in dead winter,such as under exterior doors,along sides of window ect. I believe direct and deliberate cold air introduction saves heat and cuts down on drafts in the living area of the home.
steveyrock
 

Re: Low pressure weather system and out fires?

PostBy: Sting On: Tue Sep 17, 2013 7:15 pm

steveyrock wrote:I was having the same draft issues on very hot still days until I introduced outside air directly into the combustion fan.The house was closed up tight with the air conditioning running and that would reduce my draft and I could see it on the manometer.

I ran two inch PVC to the outside of the basement with a 90 elbow turned down at the outside end to keep rain out.There is a mesh screen in front to keep bugs ect out.I then put a 4inch to 2inch PVC reducer right up against the squirrel cage intake of the combustion fan.I didn't glue any of the fittings so it easily comes apart when needed.This completely stopped any hot day draft issues and I haven't had a CO alarm go off since.I run the outside piped air all year long because that combustion fan is going to pull air in any crack avialable and exuast it out the chimney.


Make up air like this should be on all appliances
Sting
 
Other Heating: BurnHAM=NG-gas