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Great Fire, No Heat!
Posted: Tue. Feb. 12, 2008 9:28 pm
by coalmark
I think I need someone familiar with both coal and HVAC for some advice. I finally seem to have a good fire going, nice orange glow and abundant blue flame. My house is still cold. I have a Newmac combination furnace. It burns oil, wood or coal. I have it set up for coal, shaker grates and cast iron liner plates. It has a thermostatically controlled fan whose flow can be restricted with a sliding gate, as well as a manual damper in the ash door for use in case of power failure. Currently I am running it with the fan partially (about 50%) open and the manual damper fully closed. The stove pipe going to the chimney is very hot to the touch, the plenum is not, very warm at best. I am experimenting with different combinations of opening for the fan and manual damper in the ash door. Any suggestions or advice would be greatly appreciated.
I am not experiencing these problems when burning oil.
Re: Great Fire, No Heat!
Posted: Tue. Feb. 12, 2008 9:34 pm
by Flyer5
coalmark wrote:I think I need someone familiar with both coal and HVAC for some advice. I finally seem to have a good fire going, nice orange glow and abundant blue flame. My house is still cold. I have a Newmac combination furnace. It burns oil, wood or coal. I have it set up for coal, shaker grates and cast iron liner plates. It has a thermostatically controlled fan whose flow can be restricted with a sliding gate, as well as a manual damper in the ash door for use in case of power failure. Currently I am running it with the fan partially (about 50%) open and the manual damper fully closed. The stove pipe going to the chimney is very hot to the touch, the plenum is not, very warm at best. I am experimenting with different combinations of opening for the fan and manual damper in the ash door. Any suggestions or advice would be greatly appreciated.
I am not experiencing these problems when burning oil.
Do you have a barometric damper installed . With the oil the flame shooting into the end of the furnace causes a better transfer of heat . Where as the coal heat is just being carried out the pipe ,
Re: Great Fire, No Heat!
Posted: Tue. Feb. 12, 2008 9:55 pm
by coaledsweat
Your going to need a baro, your heat is going up the chimney. Another thing is to make sure your firebox is completely full of coal, right to the top.
Re: Great Fire, No Heat!
Posted: Tue. Feb. 12, 2008 9:57 pm
by coalmark
Baro?
Re: Great Fire, No Heat!
Posted: Tue. Feb. 12, 2008 10:01 pm
by coaledsweat
coalmark wrote:Baro?
http://www.fieldcontrols.com/draftcontrol.php#draftwork
Poke around there, it will describe how it works and why. Most of us here run an R/C model from Field Controls. A barometric damper is pretty much required on most installs.
Re: Great Fire, No Heat!
Posted: Tue. Feb. 12, 2008 10:05 pm
by coalmark
Got one
Re: Great Fire, No Heat!
Posted: Tue. Feb. 12, 2008 10:35 pm
by coaledsweat
Was it tuned with a manometer? Does it move freely? Crack the baro flapper about half way with a chunk of coal, within a few minutes, does the stovepipe cool and the heat exchanger warm up?
Have you burned wood? The back of the baro could be coated with creosote and not in proper tune (out of balance).
Firebox full?
Re: Great Fire, No Heat!
Posted: Tue. Feb. 12, 2008 10:43 pm
by GreenAcres
Coal stoves are pretty simple, but they've been engineered and tested for efficient operation. Different fuels behave differently and furnaces are designed with specific chamber size and shape to get the most out of the a specific fuel it's burning. I'm skeptical of multi fuel units. They may work fine with one fuel and less efficiently with another's. It's a trade off for versatility. My coal stoves surface will boil water, but you can rest your hand on the vent pipe. The one reply I read may have something about having enough coal on the grates. Oil and wood burns fast and the hot gases expand so quickly that it can't escape through the vent easily as slow burning goal. Adding more coal could increase the hot gases and slow down the escape through the vent.
If you're thinking about restricting the vent, be sure your CO alarm is operational.
Re: Great Fire, No Heat!
Posted: Tue. Feb. 12, 2008 11:29 pm
by coalmark
coaledsweat wrote:Was it tuned with a manometer? Does it move freely? Crack the baro flapper about half way with a chunk of coal, within a few minutes, does the stovepipe cool and the heat exchanger warm up?
Have you burned wood? The back of the baro could be coated with creosote and not in proper tune (out of balance).
Firebox full?
Yes it has been tuned, the damper door moves freely, no creosote. By heat exchanger, you mean in the furnace itself? I will check the plenum. The coal box has been fairly full for the last three days. Thanks for all the input I will look into these and post soon
Re: Great Fire, No Heat!
Posted: Wed. Feb. 13, 2008 4:48 pm
by beatle78
coalmark wrote:coaledsweat wrote:Was it tuned with a manometer? Does it move freely? Crack the baro flapper about half way with a chunk of coal, within a few minutes, does the stovepipe cool and the heat exchanger warm up?
Have you burned wood? The back of the baro could be coated with creosote and not in proper tune (out of balance).
Firebox full?
Yes it has been tuned, the damper door moves freely, no creosote. By heat exchanger, you mean in the furnace itself? I will check the plenum. The coal box has been fairly full for the last three days. Thanks for all the input I will look into these and post soon
correct me if I'm wrong, but with a properly tuned baro, the stove pipe after the baro should be cool enough to put your hand on for a second or 2 (the not so scientific expression). Not sure was the actual stack temp should be.
Re: Great Fire, No Heat!
Posted: Wed. Feb. 13, 2008 6:05 pm
by WNY
It depends on how hot the stove is running, the baro will cool the downstrem part of the pipe quite a bit, maybe 50-150 degrees. My exhaust temp just before going into the chimney about 6 feet of pipe after the baro runs 160-250 degrees depends on how hot the fire is burning. It averages around 200 degrees most of the time. That is measuring INSIDE the pipe with a digital thermometer and probe.
Re: Great Fire, No Heat!
Posted: Wed. Feb. 13, 2008 8:06 pm
by coalstoves
beatle78 wrote:
correct me if I'm wrong, but with a properly tuned baro, the stove pipe after the baro should be cool enough to put your hand on for a second or 2 (the not so scientific expression)
I like it like that before the Baro and even a little cooler after it, remember the baro does not just cool the exhaust gas but rather the big hole in the chimney reduces draft overall to slow the draw
. Not sure was the actual stack temp should be.
Re: Great Fire, No Heat!
Posted: Wed. Feb. 13, 2008 8:21 pm
by North Candlewood
Question is was the baro setup for the oil end of this unit or coal. Most oil setups are not done as accurate as we coal burners need.
Re: Great Fire, No Heat!
Posted: Wed. Feb. 13, 2008 9:27 pm
by coalmark
Damper is tuned for oil. My heating guy told me the fire was not high enough. I loaded the stove to just shy of the very top of the firebox. House is 70 degrees, fire is burning great and the wife is warm and happy. So far so good.
Re: Great Fire, No Heat!
Posted: Wed. Feb. 13, 2008 10:27 pm
by coalstoves
North Candlewood wrote:Most oil setups are not done as accurate as we coal burners need.
Okay
