Coal Stove Heat Duct Temps

Coal Stove Heat Duct Temps

PostBy: tmbm50 On: Thu Nov 08, 2007 7:51 pm

I'm getting my HyFire II very shortly. I have a 10" pipe that will feed into some existing duct work to feed the house. But I'm worried about the temps of the hot air and the fact that after about 5 feet of pipe duct work, the "duct" is nothing more than a sealed wall cavity. I guess with the normal heat pump this was ok becuase the temps for the air are never greater than 100. But with the coal stove I suspect the air temps to be far greater.

Does this pose a fire risk?

An engineer friend told me wood can ignite as low as 300 degrees. But I'm just not sure how hot the exhaust air will be.
tmbm50
 

Re: Coal Stove Heat Duct Temps

PostBy: coaledsweat On: Thu Nov 08, 2007 8:56 pm

If you can get you air temperature up to 300*, you won't have to worry about the house catching on fire. :)
Wood that is exposed to very high temps for long periods can ignite at much lower temps, perhaps 220*. I would place a thermometer at the opening and see what the actual air temp is flowing into the duct. If it is less than 200* there should be no problem. If it exceeds that, insulate the duct.
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Re: Coal Stove Heat Duct Temps

PostBy: WNY On: Fri Nov 09, 2007 8:40 am

Depending on the blower setup, I am using the stock blowers on the stove.
I have Temp probe in the 8" duct going upstairs which about 4 feet from the stove, it doesn't get much over 120 degrees so far.
WNY
 
Hot Air Coal Stoker Stove: Keystoker 90K, Leisure Line Hyfire I
Coal Size/Type: Rice
Stove/Furnace Make: Keystoker, LL & CoalTrol
Stove/Furnace Model: 90K, Hyfire I, VF3000 Soon


Re: Coal Stove Heat Duct Temps

PostBy: e.alleg On: Fri Nov 16, 2007 11:34 am

coaledsweat wrote:If you can get you air temperature up to 300*, you won't have to worry about the house catching on fire. :)


Why? because the house is already on fire if the duct is 300 degrees? :lol:
e.alleg
 
Stove/Furnace Make: EFM
Stove/Furnace Model: 520

Re: Coal Stove Heat Duct Temps

PostBy: WNY On: Fri Nov 16, 2007 12:21 pm

Actually not a bad Idea, we had the rehostat fail that controlled the fans and the duct temps going upstairs got up around 200 degrees.....luckily we were home when I smelled something getting HOT and I unplugged the rehostat/fans and plugged into an outlet. :)
WNY
 
Hot Air Coal Stoker Stove: Keystoker 90K, Leisure Line Hyfire I
Coal Size/Type: Rice
Stove/Furnace Make: Keystoker, LL & CoalTrol
Stove/Furnace Model: 90K, Hyfire I, VF3000 Soon

Re: Coal Stove Heat Duct Temps

PostBy: Matthaus On: Fri Nov 16, 2007 7:46 pm

Installing a bimetallic type "snap switch" rated to open at whatever temp you think is reasonable is a cheap way to ensure that an overtemp will not occur.

If you wire the stove power through the switch it will shut things down till the lower limit is reached. :)
Matthaus
 
Stoker Coal Boiler: Leisure Line WL110 Dual Fuel
Hot Air Coal Stoker Stove: Leisure Line Lil' Heater (rental house)
Coal Size/Type: Rice and Buckwheat Anthracite