AEE&36 WoodBurning and Unhrcrsityof Kentrcky College of Agrlcuhue Coopentiw Edension Service CreosoteBuildup Depafinent of Agricultuml Engineedng S. S. Holhnd, L R. Plercy,D. G. Colliverand E. S. Holmes

Formany years, wood was the primesource wherethe temperaturedrops below 250oF. of heatingthe houseand continues to be so in Between150o and 250oF, this condensed creosote someparts of the world.In thiscountry, we are depositis quitefluid. lt canoften be seenas dark beginningto seemany individuals returning to streaksthat haveflowed down outside of the woodburning-using it as an alternateheat chimney. sourceand even occasionally as a primaryheat Controllingthe amount of inletcombustion air source.Heating with wood, however, is not for will holdthe volatilegases in the combustion everyone.lt is not as simpleas heatingwith gas, chamberuntil the chambertemperature is around oil or electricity.lt is not as convenientto use 1100'F.This will causethe creosoteto burn,more becauseit requiresa considerableamount of energywill be realized,and stove efficiencies can labor,a largestorage area for the wood,more go as highas 65 percent.This compares to about cleaningof the home,many more safety 10percent efficiency with a standardfireplace. precautions,and acceptance of fluctuatingroom Suchtypes of stovesare often referredto as temperatures. airtightand havea manualor temperature-sensing Withthe developmentof etficientwood stoves dampercontrol. andfurnaces, creosote buildup in the chimney becamemore of a problembecause the fluegas temperatureswero lower due to moreof the heat ContrclllngCrcosote Problems beingput in the roomrather than going up the Managementof a woodburner is very chimney.Greosote clings firmly to the pipeand importantfor safeand successful operation. This chimneywalls, causing buildup of a very includesinspecting the chimneyand/or pipes at flammablematerial. When creosote deposits catch the startof the heatingseason for leaksor fire,the heatis veryintense and can resultin roof creosotebuildup. You can do this by gradually and housefires. Even if the burningcreosote does loweringa flashlightor batterylantern down the not causea fire fromflying sparks or cracksin the chimney.Gorrect any problemsbefore using the chimney,it tendsto weakenthe chimneymasonry woodburner again. To removecreosote, you'll or warpmetal chimneys. needa wirebrush which is availablein various sizesand configurations to fit differentpipes and WhyCrcosote Forms chimneys.Make sure to repeatthese inspections everytwo monthsduring heavy use. In the burningprocess, wood starts to Manyfamilies using airtight stoves have chemicallybreak down at 500oF,producing controlledcreosote by dailystocking the stove volatilegases including creosote. These gases with dry kindlingand allowing it to burnintensely burnat about1100'F; if thattemperature is not for 10to 15minutes before burning the woodin roached,the gaseswill escapeup the chimney, the regularmanner. This tends to burnotf anythin resultingin the lossof muchof the wood'senergy. coatof creosotethat mighthave formed from the In additionto losingenergy, the creosotein the previousday. One word of cautionis thatyou gasesremains unburned. shouldnot beginthis technique until after the Creosotecan be seenas a dark brownor chimneyhas been thoroughly cleaned. Even with blackmaterial and hasan unpleasantodor. dailykindling burning, you still need to inspect Combinedwith droplets of watervapor, it comes yourchimney for creosoteformation. out the chimneyas smoke. The creosote will Whenstarting a fire withthe regularwood, condenseat any pointin the pipeor chimney leavethe primaryair inletat leasthalfway open htb/Jshed bg the Coopmthse fuenslon &ruice ln copmtion wlth the tkrxuckg Deprrnent of Eneryg as a paft of the lkntuckg Eneryg Conxnntionhqmm, untilthe fire is well-established. This gives the levelafter a goodburn is established contributes fireboxtime to reachthe desiredtemperature of no moreto creosoteformation than does dry 1100oFneeded to ignitethe volatilegases. lf the wood.The greenwood contributes less to total woodis dry andof goodquality, you canthen set heatoutprit since heat is beingused to removethe the inletat the desiredheat demand position. excesswater. It is oftendifficult to judgehow well wood is Thereis considerable controversy as to how burning.You can fasten an oventhermometer effectivechemicals are in preventingcreosote about20 inchesabove the stoveconnection on formation.A varietyof chemicalchimney cleaners the flue pipeto estimatethe fireboxtemperature. havebeen tested and found to be substantially As longas the oventhermometer reads between ineffectivein reducingthe accumulationof 200'Fto 400oF,the firebox temperature should be creosoteor in eliminatingexisting deposits.l Many around1 100'F. of thechemical cleaners also contained sodium Overloadingthe firebox with wood increases chloride(table salt) as a majoringredient which creosotebuildup by reducingcomplete can be corrosiveto bothmetal and masonry combustionand causing more of the unburned materials. gasesto escapeup thechimney. A gooddaytime managementpractice is to feedthe fireboxmore ChimneyFires often,each time neverexceeding one-third of a full load.Freshly fed woodneeds to be well- Whenfaced with a chimneyfire, follow these exposedto the livecoals of the previousloading. steps: Usingtoo manylarge logs also willcontribute 1) Callthefire department immediately. to creosoteformation. These large pieces of wood 2) lf you havean airtightstove, cut off the willproduce more wasted combustible gases than oxygensupply by closingall openings. With smallerpieces in directcontact with the live stovesthat are not airtight,close the fluedamper. fireboxcoals. Smaller pieces of wood alsotend to 3) Alerteveryone in the house. makeit easierto controlthe temperature 4) lf thestove fire is still burning, use an fluctuations. approvedfire extinguisher or throwbaking soda Hardwoodwith a 20 percentor lessmoisture ontothe burning fire. Commercial chimney fire contentis the best wood to burn.For many years, extinguishingflares are also available for this highmoisture wood was associated with creosote purpose. formationbut this has beenproven untrue. fncreasing the amount of primary air as green tsheltonJ.w., and C. Barczgs.1981. Teding chemicat Chimneg wood is added and then reducing it to the normal Cleaners.Mother tufth Na.us,No. 71, kpL/OcL p. 11&120.

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Otlice, College ol Agriculture, Univarsity ot Kentucky, Room S-105,Agticultural Science Building-North, L6xington, Kentucky 40s46. lssued in lurtheranceof CooperativeExtension work, Acts ot May 8 and June 30, 1914,in cooperationwith the U.S. Departmentot Agriculture.Charles E. Barnhart,Director of CooperativeExt€nsion Service, University ol KentuckyCollege ot Agriculture,Lexington, and KentuckyState University, Frankfort. 10M-6-84