Sizing Impacts on WoodCombustion PerformanceNovember 8, 2012Nathan Russell, Buildings R&DNew York State Energy Research and Development AuthorityBiomass R&DActivities and Objectives:• Evaluate energy-efficiency and emissions and compare to oilfired systems• Develop advanced commercial and residential technologies• Demonstrate advanced technologies in representativeapplications• Evaluate feedstocks (energy, ash, moisture, trace elements)• Evaluate the net effect of emissions on local airquality• Evaluate emission control technologies• Provide updated information for the NEI• Provide objective scientific information for the development ofhigh-efficiency and low-emission biomass heating initiatives inNYSNYSERDA BackgroundBoilersDetermine the Heat LoadMethod Details AccuracyManual J, Energy 10,DOE 2 etcInsulation, solar gain, internal gains,temperature, infiltration, weather dataetcHighSquare footage How big is the house? LowPrevious system What was the output of the previoussystem?Low-Over sizing is very common-NYSERDA programs require a Manual J (or equivalent) calculation todetermine proper HVAC equipment sizing.Daily heat load profileHeat Load Analysis12.5.4 Heat Output Capacity Validation. The first test run mustproduce a heat output rate that is within 10% of themanufacturer’s rated heat output capacity (CategoryIV)throughout the test run and an average heat outputrate within5% of the manufacturer’s rated heat output capacity. If theappliance is not capable of producing a heat outputwithin theselimits, the manufacturer’s rated heat output capacity isconsidered not validated and testing is to be terminated. In suchcases, the tests may be restarted using a lower heat outputcapacity if requested by the manufacturer.Nominal OutputHeat LoadsVery Cold Cold ModerateDesign Day (DD)Heat Load65 kBtu/hr 40 kBtu/hr 20 kBtu/hrBoiler output DD 42% 26% 13%70% DD 46 kBtu/hr 28 kBtu/hr 13 kBtu/hrBoiler output 70%DD29% 18% 9%•White Tag 8 hour average: 116 kBtu/hr•8 hour average, weighted average of outputs at Cat IIand III or IIIand IV• Assume 8 hour average is 75% of max output of 155 kBtu/hrWeighting FactorsEmissions vsOutputEmissions per Syracuse Day

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Total PM Emitted per Daily Syracuse Heat Load deman d (lbs)Hydronic Heater Unit and Fuel Type•Responding to same heatload with no thermal storageexcept for US downdraftOWB – 10-14 lbPellet – 0.08 lbMade-in-NY 2-stage – 1.37 lbULSHO – 0.00004 lbEmissions0.0000440.0000680.00130.00360.023 0.0230.0440.320.0190.0290.561.69.99.9191400224365861081290.000.050.100.150.200.250.300.35Natural Gas Ultra Low Sulfur#2Low Sulfur #2 #2 Home HeatingOil#6* ResidualHeating Oil2-StageEuropean^ Pellet2-StageEuropean^ SplitWoodUS EPA White Tag **mg/MJ**

**lb/mmBtu Fuel** **Fine Particulate Emissions (Output) for Residential Boilers by Fuel Type** ULS #2 home heating oil, 11 ppm sulfur, 85% efficiencyLS #2 home heating oil, 322 ppm sulfur, 85% efficiency#2 home heating oil, 1520 ppm sulfur, 85% efficiency* Commercial Boiler, 70% efficiency (estimated)^Average of Top 25% Performers1x100x1,000x10,000x• Peak performance at steady state and full output• Mandates the use of thermal storage• Guidelines vary:– 6 gallons per 1,000 Btu/hr nominal output– Enough to take full charge of wood– ~ 300 gallons for 100 kBtu/hrThermal StoragePellet Boiler Efficiency vsOutput01020304050607080900 20000 40000 60000 80000 100000 120000 140000 160000 180000Output (Btu/hr)

Efficiency (%)• Sizing a problem for all boilersespecially challenging for solid fuels• More challenging with larger fuel charge• Auxiliary thermal storage serves as amajor efficiency measure for stagedcombustion units resulting in loweremissions• Pellet boilers also benefit from smallerbuffer tanksTake homeThankYou!PON 2652• Air quality and health effect studies• Product development• Energy efficient retrofits• Wood chip drying• Pellet trucks• Pellet demonstrations• Grass combustion$2.5 Million Biomass R&D