Using Cold Air for Combustion

Post Reply
 
User avatar
traderfjp
Member
Posts: 1801
Joined: Wed. Apr. 19, 2006 10:32 pm
Location: New York

Post by traderfjp » Sat. Oct. 04, 2008 12:22 am

I'm just curious if anyone has seen a loss in effeciency after installing a cold air line for the combustion blower?

Thanks

 
User avatar
Freddy
Member
Posts: 7293
Joined: Fri. Apr. 11, 2008 2:54 pm
Location: Orrington, Maine
Stoker Coal Boiler: Axeman Anderson 130 (pea)
Coal Size/Type: Pea size, Superior, deep mined

Post by Freddy » Sat. Oct. 04, 2008 5:33 am

With an oil boiler they claim it's more efficient.... the cold air is more dense and helps the burn and, you are no longer using air from inside the house.

 
User avatar
coalkirk
Member
Posts: 5185
Joined: Wed. May. 17, 2006 8:12 pm
Location: Forest Hill MD
Stoker Coal Boiler: 1981 EFM DF520 retired
Hand Fed Coal Stove: Jotul 507 on standby
Coal Size/Type: Lehigh anthracite/rice coal

Post by coalkirk » Sat. Oct. 04, 2008 7:46 am

traderfjp wrote:I'm just curious if anyone has seen a loss in effeciency after installing a cold air line for the combustion blower?

Thanks
Should be just the opposite. Your house doesn't like a vacuum. If you use conditioned air from your home to burn coal (or oil, gas, wood) that air has to be replaced. Air gets sucked in around windows, doors, exhaust fans, anywhere it can find a pathway from outside. Then that cold air has to be reheated. Outside combustion air is the way to go. That's how 90% gas condensing furnaces get their 90% efficiency rating. They use outside air.


 
User avatar
gambler
Member
Posts: 1611
Joined: Mon. Jan. 29, 2007 12:02 pm
Location: western Pa

Post by gambler » Sat. Oct. 04, 2008 9:23 am

I have been running outside air for years with my pellet/corn stove and now my coal stove. I have a fairly tight house and never wanted any issues with not having enough combustion air.

 
User avatar
orvis
Member
Posts: 64
Joined: Thu. Sep. 04, 2008 8:40 am

Post by orvis » Sat. Oct. 04, 2008 7:31 pm

Well your temperature *rise* would be the same when you tune for best combustion. Your inlet air is colder, so your stack/combustion temp is lower. In an oil burner application, you need to retune with a combustion tester so you do not have excess air which will waste energy.

Pluses would be you will never have to worry about a too tight house. Minuses would be that in an oil burner application you might get less atomization and thus more soot (smoke). In a coal application there is probably no down side, you want to keep the grates cold.

Post Reply

Return to “Stoker Coal Furnaces & Stoves Using Anthracite (Hot Air)”